WorldWideScience

Sample records for hybrid pollen fertility

  1. Allelic interaction of F1 pollen sterility loci and abnormal chromosome behaviour caused pollen sterility in intersubspecific autotetraploid rice hybrids.

    Science.gov (United States)

    He, J H; Shahid, M Q; Li, Y J; Guo, H B; Cheng, X A; Liu, X D; Lu, Y G

    2011-08-01

    The intersubspecific hybrids of autotetraploid rice has many features that increase rice yield, but lower seed set is a major hindrance in its utilization. Pollen sterility is one of the most important factors which cause intersubspecific hybrid sterility. The hybrids with greater variation in seed set were used to study how the F(1) pollen sterile loci (S-a, S-b, and S-c) interact with each other and how abnormal chromosome behaviour and allelic interaction of F(1) sterility loci affect pollen fertility and seed set of intersubspecific autotetraploid rice hybrids. The results showed that interaction between pollen sterility loci have significant effects on the pollen fertility of autotetraploid hybrids, and pollen fertility further decreased with an increase in the allelic interaction of F(1) pollen sterility loci. Abnormal ultra-structure and microtubule distribution patterns during pollen mother cell (PMC) meiosis were found in the hybrids with low pollen fertility in interphase and leptotene, suggesting that the effect-time of pollen sterility loci interaction was very early. There were highly significant differences in the number of quadrivalents and bivalents, and in chromosome configuration among all the hybrids, and quadrivalents decreased with an increase in the seed set of autotetraploid hybrids. Many different kinds of chromosomal abnormalities, such as chromosome straggling, chromosome lagging, asynchrony of chromosome disjunction, and tri-fission were found during the various developmental stages of PMC meiosis. All these abnormalities were significantly higher in sterile hybrids than in fertile hybrids, suggesting that pollen sterility gene interactions tend to increase the chromosomal abnormalities which cause the partial abortion of male gametes and leads to the decline in the seed set of the autotetraploid rice hybrids. © 2011 The Author(s).

  2. Pollen Morphology and Viability Relates to Seed Production in Hybrid Roses

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    Nadeem Muhammad

    2014-10-01

    Full Text Available Fertility of hybrid tea roses is often reduced due to their interspesific origin but also to intensive inbreeding. New genotypes used as pollen donors represent an economic risk for a breeding program, as their influence on seed production is unknown. In this study 9 garden rose genotypes were selected from a company database as high fertile or low fertile male parents, according to the number of seeds per hybridization. Pollen morphology and in vitro germination of the selected genotypes were characterized. Pollen was either small (mean diameter = 30 urn, shrunken, and irregular (abnormal, or large (mean diameter = 30 urn, elliptical and crossed by furrows (normal. High correlations were found between the number of seeds produced per hybridization and the pollen diameter (r = 0.94 or the percentage of normal pollen (r = 0.96. In order to evaluate the predictive power of the models, we conducted regression analyses and performed a validation experiment on genotypes not present in the database and without background information on fertility. Pollen diameter and percentage of normal pollen were characterized and fitted in the regression models for seed set predictions. Validation with an independent dataset gave a good prediction for 83.3% of the data. This indicates that using either the mean pollen diameter or the percentage of normal pollen resulted in effective fertility prediction. Moreover cluster analysis of the data classified all the cultivars into various groups with varying fertility. This tool could enhance the genetic variability in crossings between hybrid tea roses, thus creating possibilities for less economically risky exploitation of new tetraploid genotypes as male parents.

  3. Induced sterility in petunia correlation between pollen and ovule fertilities

    International Nuclear Information System (INIS)

    Singh, I.S.

    1976-01-01

    An estimation of ovular fertility in petunia was carried out in order to show an eventual correlation between pollen and ovule fertilities. Two lines, TL-h 1 and Sf-1a, their F 1 hybrid and some pollen sterile plants isolated in M 1 after mutagenic treatments were vegetatively maintained in greenhouse. Data pollen fertility, number of ovules per ovary and number of seeds per capsule were obtained from each genotype. The ovule fertility was calculated as follows: mean number of seeds per capsule/mean number of ovules per ovary x 100. The analysis of variance detected: a highly significance variance component among genotypes, a highly significant differences between the sexes, and, a highly significant genotypes x sexes interaction. A highly significant positive correlation coefficient was found between pollen and ovule fertilities. Thus, it can be concluded that pollen and ovule fertilities may be affected in the same direction in the different mutant clones studied, but in a different manner from genotype to genotype [fr

  4. Effect of gamma irradiation on pollen and seed fertility in pigeon pea

    International Nuclear Information System (INIS)

    Ahmed John, S.

    1997-01-01

    A study was undertaken in pigeon pea parents and their F 1 hybrid to analyse the pollen and seed fertility following gamma irradiation. It is found that the reduction of pollen and seed fertility in pigeon pea was lesser over those of black gram and cowpea. 5 refs., 1 tab

  5. Ploidia e fertilidade de pólen em progênies de citros Ploidy and pollen fertility in citrus hybrids

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    Eduardo Cesar Brugnara

    2008-01-01

    Full Text Available Este trabalho foi desenvolvido para estimar a fertilidade do pólen e determinar o nível de ploidia em progênies dos cruzamentos da tangerineira 'Montenegrina' (C. deliciosa Ten. com a tangerineira 'King' (C. nobilis Lour. e com a laranjeira 'Caipira' (C. sinensis (L. Osb.. As plantas, de pés-francos e com idade entre 11 e 12 anos, são mantidas na Estação Experimental Agronômica da Universidade Federal do Rio Grande do Sul, em Eldorado do Sul. Avaliaram-se o nível de ploidia, através da contagem dos cromossomos em células em meiose, e a fertilidade do pólen, por coloração do pólen com carmim propiônico, em 2005 e 2006. Todos os híbridos avaliados são diplóides e a fertilidade de pólen variou de zero a 98%. C27 - híbrido de 'Montenegrina' x 'Caipira' - revelou-se praticamente estéril, e a fertilidade de C21, do mesmo cruzamento, é de 10%. A menor fertilidade observada no cruzamento da 'Montenegrina' x 'King' foi de 42%.This work was performed to estimate pollen fertility and determinate the ploidy level of 11 to 12 years old progenies of crosses of 'Montenegrina' mandarin (Citrus deliciosa Ten. with 'King' mandarin (C. nobilis Lour. and with 'Caipira' sweet orange (C. sinensis (L. Osb. maintained at Estação Experimental Agronômica of UFRGS, in Eldorado do Sul, Brazil. The ploidy level was determined by chromosome countings in meiosis cells and pollen fertility evaluated by staining pollen grains with propionic carmine. All evaluated hybrids are diploid and pollen fertility varied from zero to 98%. C27, a hybrid 'Montenegrina' x 'Caipira', was found is sterile, and C21, from the same cross, showed 10 % fertility. The lowest observed fertility in the progeny 'Montenegrina' x 'King' was 42 %.

  6. Peptide signalling during the pollen tube journey and double fertilization.

    Science.gov (United States)

    Qu, Li-Jia; Li, Ling; Lan, Zijun; Dresselhaus, Thomas

    2015-08-01

    Flowering seed plants (angiosperms) have evolved unique ways to protect their gametes from pathogen attack and from drying out. The female gametes (egg and central cell) are deeply embedded in the maternal tissues of the ovule inside the ovary, while the male gametes (sperm cells) are enclosed in the vegetative pollen tube cell. After germination of the pollen tube at the surface of papilla cells of the stigma the two immobile sperm cells are transported deep inside the sporophytic maternal tissues to be released inside the ovule for double fertilization. Angiosperms have evolved a number of hurdles along the pollen tube journey to prevent inbreeding and fertilization by alien sperm cells, and to maximize reproductive success. These pre-zygotic hybridization barriers require intensive communication between the male and female reproductive cells and the necessity to distinguish self from non-self interaction partners. General molecules such as nitric oxide (NO) or gamma-aminobutyric acid (GABA) therefore appear to play only a minor role in these species-specific communication events. The past 20 years have shown that highly polymorphic peptides play a leading role in all communication steps along the pollen tube pathway and fertilization. Here we review our current understanding of the role of peptides during reproduction with a focus on peptide signalling during self-incompatibility, pollen tube growth and guidance as well as sperm reception and gamete activation. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  7. Flowering and the Pollen Fertility in Iranian Garlic Clones

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    A. R. Abbasifar

    2015-06-01

    Full Text Available Garlic (Allium sativum L. cannot produce seed because it is a sterile plant. For studying bolting and determination of pollen fertility, 68 Iranian garlic clones were gathered from different parts of Iran and evaluated in Research Field of Horticultural Department, Faculty of Agriculture, Bu-Ali Sina University in 2010-2011 and 2011-2012. For determining the pollen fertility, some tests including specific RAPD marker, pollen germination, pollen viability detection using acetocarmine and in vitro culture of ovules and fruits were used. Results showed that 37 of Iranian garlic clones could produce scape and inflorescence. The percentage range of pollen stained with acetocarmine was from 0.5 up to 20 percent showing infertility of pollens. Lack of two markers (OPJ121300 and OPJ121700 and pollen tube growth proved the infertility of garlic clones pollen. Fruits and embryo sac were alive for more than two months, showing their potential for producing seeds following pollination with fertile pollens.

  8. DETERMINATION OF FERTILITY AND POLLEN VIABILITY OF BREEDING LINE OF PATTYUPAN SQUASH WITH MALE STERILITY OF FUNCTIONAL TYPE

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    A. M. Shantasov

    2014-01-01

    Full Text Available This article describes the features of the development of male sterility trait of functional type in patty"pan squash. The viability of pollen grains in different periods of vegetation was studied. The determined fertility ability of pollen can be used for hybrid seed production of different varieties of pumpkin.

  9. Fertility and fertilizing ability of cotton pollen following γ-radiation (Co60)

    International Nuclear Information System (INIS)

    Filatov, P.S.

    1976-01-01

    The effect of Co 60 gamma radiation on the fertility and fertilizing ability of ripe cotton (Tashkent-2 variety) pollen was studied. Radiation doses were 0.5, 1, 1.5, 2, 3, 4, 5, and 10kR. The generally accepted cross-pollination method was used. The viability of the pollen after irradiation was determined by the Shardakov and aceto-carmine dye method. Determination of the peroxidase activity, which in this case was used as an index of the pollen viability, made it possible to assess its physiological state. Non-irradiated flowers were used as controls. It was shown that the pollen viability depended on the radiation dose. Doses from 0.5 to 2 kR had no effect on the peroxidase activity. Irradiation decreased the percentage of viable pollen somewhat (compared to controls). A similar relation to irradiation was observed in the pollen color in the aceto-carmine test for fertility. Doses of 5-10 kR decreased the percentage of fertility of the pollen. An important factor in evaluating the radiation sensitivity of cotton pollen is the number and type of bound bolls and seeds. Studies showed that the number of bound bolls depends on the radiation dose. With doses of 0.5 and 1.5 kR an average of 78.6% bound bolls formed, compared to 80.0% in the controls. With 1 kR the number of bound rolls formed, compared to 80.0% in the controls. With these doses the shape and size of the bolls did not differ from those in the controls; the average weight was 4.3 g. Doses of 2.3 and 4kR gave an average of 66% bound bolls, i.e., 14% different from the controls. With increase in the radiation dose, the size and shape of the bolls changed significantly. Doses of 5 and 10 kR had a lethal action on formation of filled-out seed; not one filled seed was found. Thus, pollen treated with different gamma radiation doses retains its viability, depending on the radiation dose

  10. The proteome and phosphoproteome of maize pollen uncovers fertility candidate proteins.

    Science.gov (United States)

    Chao, Qing; Gao, Zhi-Fang; Wang, Yue-Feng; Li, Zhe; Huang, Xia-He; Wang, Ying-Chun; Mei, Ying-Chang; Zhao, Biligen-Gaowa; Li, Liang; Jiang, Yu-Bo; Wang, Bai-Chen

    2016-06-01

    Maize is unique since it is both monoecious and diclinous (separate male and female flowers on the same plant). We investigated the proteome and phosphoproteome of maize pollen containing modified proteins and here we provide a comprehensive pollen proteome and phosphoproteome which contain 100,990 peptides from 6750 proteins and 5292 phosphorylated sites corresponding to 2257 maize phosphoproteins, respectively. Interestingly, among the total 27 overrepresented phosphosite motifs we identified here, 11 were novel motifs, which suggested different modification mechanisms in plants compared to those of animals. Enrichment analysis of pollen phosphoproteins showed that pathways including DNA synthesis/chromatin structure, regulation of RNA transcription, protein modification, cell organization, signal transduction, cell cycle, vesicle transport, transport of ions and metabolisms, which were involved in pollen development, the following germination and pollen tube growth, were regulated by phosphorylation. In this study, we also found 430 kinases and 105 phosphatases in the maize pollen phosphoproteome, among which calcium dependent protein kinases (CDPKs), leucine rich repeat kinase, SNF1 related protein kinases and MAPK family proteins were heavily enriched and further analyzed. From our research, we also uncovered hundreds of male sterility-associated proteins and phosphoproteins that might influence maize productivity and serve as targets for hybrid maize seed production. At last, a putative complex signaling pathway involving CDPKs, MAPKs, ubiquitin ligases and multiple fertility proteins was constructed. Overall, our data provides new insight for further investigation of protein phosphorylation status in mature maize pollen and construction of maize male sterile mutants in the future.

  11. The dose effect of irradiated rice pollen on double fertilization

    International Nuclear Information System (INIS)

    Wang Houcong; Chen Zhengming; Chen Ruming; Qiu Simi; Yang Juemin; Yang Huijie

    1995-01-01

    The mature panicles of rice were treated with 60 Co γ-rays in the range of 0∼0.372 kGy. The male sterile line used as the female plants were fertilized with γ-irradiated pollen manually. The dose effect of the irradiated pollen on double fertilization was investigated. It was found that double fertilization of the irradiated pollen was suppressed to different degrees as compared with the control. The effect was noticeable as that the fusion time of the male nucleolus with the female one was delayed with the increasing of γ-radiation dose. The delayed time was less than 13 hours when the dose was below 0.186 kGy and it was more than 15 hours when the dose was above 0.279 kGy. Furthermore, several types of deformed embryonic cells and endosperm nuclei were observed

  12. Evolvement of transgenic male-sterility and fertility-restoration system in rice for production of hybrid varieties.

    Science.gov (United States)

    Rao, Gundra Sivakrishna; Deveshwar, Priyanka; Sharma, Malini; Kapoor, Sanjay; Rao, Khareedu Venkateswara

    2018-01-01

    We have developed a unique male-sterility and fertility-restoration system in rice by combining Brassica napus cysteine-protease gene (BnCysP1) with anther-specific P12 promoter of rice for facilitating production of hybrid varieties. In diverse crop plants, male-sterility has been exploited as a useful approach for production of hybrid varieties to harness the benefits of hybrid vigour. The promoter region of Os12bglu38 gene of rice has been isolated from the developing panicles and was designated as P12. The promoter was fused with gusA reporter gene and was expressed in Arabidopsis and rice systems. Transgenic plants exhibited GUS activity in tapetal cells and pollen of the developing anthers indicating anther/pollen-specific expression of the promoter. For engineering nuclear male sterility, the coding region of Brassica napus cysteine protease1 (BnCysP1) was isolated from developing seeds and fused to P12 promoter. Transgenic rice plants obtained with P12-BnCysP1 failed to produce functional pollen grains. The F 1 seeds obtained from BnCysP1 male-sterile plants and untransformed controls showed 1:1 (tolerant:sensitive) ratio when germinated on the MS medium supplemented with phosphinothricin (5 mg/l), confirming that the male sterility has been successfully engineered in rice. For male fertility restoration, transgenic rice plants carrying BnCysP1Si silencing system were developed. The pollination of BnCysP1 male-sterile (female-fertile) plants with BnCysP1Si pollen resulted in normal grain filling. The F 1 seeds of BnCysP1 × BnCysP1Si when germinated on the MS basal medium containing PPT (5 mg/l) and hygromycin (70 mg/l) exhibited 1:1 (tolerant:sensitive) ratio and the tolerant plants invariably showed normal grain filling. The overall results clearly suggest that the customized male-sterility & fertility-restoration system can be exploited for quality hybrid seed production in various crops.

  13. Effects of CO₂ on Acer negundo pollen fertility, protein content, allergenic properties, and carbohydrates.

    Science.gov (United States)

    Silva, M; Ribeiro, H; Abreu, I; Cruz, A; Esteves da Silva, J C G

    2015-05-01

    Atmospheric gaseous pollutants can induce qualitative and quantitative changes in airborne pollen characteristics. In this work, it was investigated the effects of carbon dioxide (CO2) on Acer negundo pollen fertility, protein content, allergenic properties, and carbohydrates. Pollen was collected directly from the anthers and in vitro exposed to three CO2 levels (500, 1000, and 3000 ppm) for 6 and 24 h in an environmental chamber. Pollen fertility was determined using viability and germination assays, total soluble protein was determined with Coomassie Protein Assay Reagent, and the antigenic and allergenic properties were investigated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunological techniques using patients' sera. Also, pollen fructose, sucrose, and glucose values were determined. Carbon dioxide exposure affected negatively pollen fertility, total soluble protein content, and fructose content. The patient sera revealed increased IgE reactivity to proteins of A. negundo pollen exposed to increasing levels of the pollutant. No changes were detected in the SDS-PAGE protein profiles and in sucrose and glucose levels. Our results indicate that increase in atmospheric CO2 concentrations can have a negative influence of some features of A. negundo airborne pollen that can influence the reproductive processes as well as respiratory pollen allergies in the future.

  14. Microsatellite-Aided Screening for Fertility Restoration Genes (Rf Facilitates Hybrid Improvement

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    Raafat El-Namaky

    2016-05-01

    Full Text Available DNA markers enabled to determine the chromosomal locations of the two Rf genes (Rf3 and Rf4 in the wild-abortive cytoplasmic male sterility (WA-CMS system. Four simple sequence repeats (SSRs RM171, RM258, RM315 and RM443 were used to detect the allelic status with respect to the fertility restoration genes (Rf3 and Rf4 in 300 rice cultivars or breeding lines. The results revealed that out of 300 lines, 90 lines screened had Rf3, 65 lines had Rf4, and 45 lines had Rf3 and Rf4 alleles. Furthermore, 45 lines selected using SSR markers were mated with a CMS line (IR58025A to analyze their restoring ability. Offspring of all the test lines except HHZ8-SAL9DT1-Y1, HHZ5-SAL9-Y3-1 and IDSA77 exhibited higher pollen and spikelet fertility (> 80%, thus confirming they bear the Rf alleles. The hybrid offspring of ARH12-6-1-1-B-3-1, IR32307-10-3-2-1 and Sahel 329 had the highest pollen fertility (97.39%, 98.30% and 97.10%, respectively and spikelet fertility (95.10%, 97.07% and 96.10%, respectively.

  15. Effect of radiation on fruit pollen germination and distant hybridization compatibility

    International Nuclear Information System (INIS)

    Li Jing; Shang Xiaoli

    2006-01-01

    Pollens of Zhouxingshantao peach trees, apricot cultivar Katy and plum cultivar Friar were irradiated by different doses of 60 Co γ-rays and ultraviolet to study the radiation effect on the pollen germination and distant hybridization settings. The germination percentages of the pollen irradiated by 60 Co γ-rays and ultraviolet were lower than those of the controls. The pollens of the tested fruits have different sensitivities of 60 Co γ-rays and ultraviolet: the Friar pollen was the most sensitive to the radiation, and the Katy was the least. With the germinate percentages of the irradiated pollen dropping, the distant hybridization fruit setting percentage also lowered. (authors)

  16. Interspecific Hybridization within Ornamental Plants

    DEFF Research Database (Denmark)

    Kuligowska, Katarzyna

    commercially important genera of ornamental plants: Kalanchoë and Hibiscus. The nature of hybridization barriers hampering hybrid production was investigated during pre- and post-fertilization stages. For each genus the interspecific crosses of Kalanchoë species and Hibiscus species, abnormal germination...... and growth of pollen tubes, as well as lower frequencies of pollen tubes were observed in specific cross-combinations. Post-fertilization barriers related to endosperm development and hybrid incompatibility were also observed in Kalanchoë and Hibiscus genus, respectively. Qualitative and quantitative...

  17. [Effects of exogenous silicon on the pollination and fertility characteristics of hybrid rice under heat stress during anthesis].

    Science.gov (United States)

    Wu, Chen-Yang; Chen, Dan; Luo, Hai-Wei; Yao, Yi-min; Wang, Zhi-Wei; Tsutomu, Matsui; Tian, Xiao-Hai

    2013-11-01

    Taking two medium-maturing indica rice hybrids Jinyou 63 and Shanyou 63 as test materials, this paper studied the effects of applying silicon fertilizer on the flag leaf chlorophyll content, photosynthetic properties, antioxidant enzyme activities, malondialdehyde (MDA) content, pollen vigor, anther acid invertase activity, pollination, and seed-setting of hybrid rice under the heat stress during anthesis. This study was conducted in pots and under growth chamber. Soluble solution of silicon fertilizer applied as Na2SiO3 x 9H2O was sprayed on the growing plants after early jointing stage, with three times successively and at an interval of one week. The pots were then moved into growth chamber to subject to normal temperature vs. high temperature (termed as heat stress) for five days. In treatment normal temperature, the average daily temperature was set at 26.6 degrees C, and the maximum daily temperature was set at 29.4 degres C; in treatment high temperature, the average and the maximum daily temperature were set at 33.2 degrees C and 40.1 degrees C, respectively. As compared with the control, applying silicon increased the flag leaf chlorophyll content significantly, improved the net photosynthetic rate and stomatal conductance, decreased the accumulative inter- cellular CO2 concentration, improved the leaf photosynthesis, reduced the MDA content, and improved the activities of SOD, POD and CAT under heat stress. In addition, applying silicon improved the anther acid invertase activity and the pollen vigor, increased the anther basal dehiscence width, total number of pollination per stigma, germinated number, germination rate of pollen, and percentage of florets with more than 10 germinated pollen grains, decreased the percentage of florets with fewer than 20 germinated pollen grains, and thus, alleviated the fertility loss of Jinyou 63 and Shanyou 63 under heat stress by 13.4% and 14.1%, respectively. It was suggested that spraying exogenous silicon in the

  18. Male-female crosstalk during pollen germination, tube growth and guidance, and double fertilization.

    Science.gov (United States)

    Dresselhaus, Thomas; Franklin-Tong, Noni

    2013-07-01

    Sperm cells of flowering plants are non-motile and thus require transportation to the egg apparatus via the pollen tube to execute double fertilization. During its journey, the pollen tube interacts with various sporophytic cell types that support its growth and guide it towards the surface of the ovule. The final steps of tube guidance and sperm delivery are controlled by the cells of the female gametophyte. During fertilization, cell-cell communication events take place to achieve and maximize reproductive success. Additional layers of crosstalk exist, including self-recognition and specialized processes to prevent self-fertilization and consequent inbreeding. In this review, we focus on intercellular communication between the pollen grain/pollen tube including the sperm cells with the various sporophytic maternal tissues and the cells of the female gametophyte. Polymorphic-secreted peptides and small proteins, especially those belonging to various subclasses of small cysteine-rich proteins (CRPs), reactive oxygen species (ROS)/NO signaling, and the second messenger Ca(2+), play center stage in most of these processes.

  19. Incompatible pollen tubes in the plum style and their impact on fertilization success

    Directory of Open Access Journals (Sweden)

    Đorđević Milena

    2014-01-01

    Full Text Available The pistils of plum (Prunus domestica L. cv. ‘Čačanska Lepotica’ were self- and cross-pollinated in order to investigate occurrence of incompatible pollen tubes in the style, and their impact on fertilization success. The investigation also included open pollination variant. The highest percentage of these stopped the growth in the upper third of the style. Under cross-pollination variant, 15.4% and 12.1% of pollen tubes observed in the upper part of the style in the first and the second years of study, respectively, were found incompatible. In view of the above parameters, in the self- pollination variant, 15.0% and 17.0% of pollen tubes were found incompatible by years. As for the open pollination, percentages of incompatible pollen tubes in the upper part of the style by years were 14.0% and 14.4%, respectively. The occurrence of incompatible pollen tubes did not influence the fertilization success in these pollination variants. [Projekat Ministarstva nauke Republike Srbije, br. TR31064-Development and preservation of genetic potential of temperate zone fruits

  20. A plant plasma membrane Ca2+ pump is required for normal pollen tube growth and fertilization

    DEFF Research Database (Denmark)

    Schiøtt, Morten; Romanowsky, Shawn M; Bækgaard, Lone

    2004-01-01

    Ca(2+) signals are thought to play important roles in plant growth and development, including key aspects of pollen tube growth and fertilization. The dynamics of a Ca(2+) signal are largely controlled by influx (through channels) and efflux (through pumps and antiporters). The Arabidopsis genome...... and a high frequency of aborted fertilization, resulting in a >80% reduction in seed set. These findings identify a plasma membrane Ca(2+) transporter as a key regulator of pollen development and fertilization in flowering plants.......Ca(2+) signals are thought to play important roles in plant growth and development, including key aspects of pollen tube growth and fertilization. The dynamics of a Ca(2+) signal are largely controlled by influx (through channels) and efflux (through pumps and antiporters). The Arabidopsis genome......-inducing) plasmid that is transferred to plant cells] gene disruptions of ACA9 were found to result in partial male sterility. Complementation was observed by using a ACA9-yellow fluorescence protein (YFP) fusion that displayed plasma membrane localization. Mutant aca9 pollen displayed a reduced growth potential...

  1. Cytological effects of pollen irradiation on wheat x leymus angustus hybrids

    International Nuclear Information System (INIS)

    Li Guiying; Wang Linqing; Shi Jinguo

    2000-01-01

    Cytological effects of pollen irradiation on wheat x Leymus angustus hybrids were studied using callus clones and their derived plants of hybrid embryos as experimental materials. The results showed that variation range of chromosome number (VRCN) of hybrid callus clone became wider after pollination with irradiated paternal pollen. VRCN of the control clone was 43-64, and 26-66 was found in 9 Gy treatment clone. The average chromosome number per cell decreased by 4.9. Pollen irradiation enhanced chromosomal structural aberration (CSA). The CSA frequency was 45.35% in the control clone, and 77.31% in 9 Gy treatment clone. The main CSA in the control clone was telo-centric chromosome. Except for telo-centric chromosomes, there were also minichromosomes in 9 Gy treatment clone with the similar frequency to telo-centric chromosomes. The higher frequency of dicentric and ring chromosomes and fragments in 9 Gy treatment showed that pollen irradiation enhanced chromosomal translocation and recombination

  2. Studies on the abnormality of embryo sac and pollen fertility in aurotetraploid rice during different growing seasons

    International Nuclear Information System (INIS)

    Shahid, M.; Jilanfan, S.; Changmin, W.; Peng, Z.; Xiang-dong, X.

    2010-01-01

    Auto tetraploid rice has a great genetic potential but low seed setting rate is the major encumbrance in its use. Embryo sac fertility and pollen fertility are the most important factors which affect the seed setting rate in auto tetraploid rice. Whole mount eosin B-staining confocal laser scanning microscopy (WE-CLSM) was used to study the fertility and abnormalities in embryo sacs of diploid and auto tetraploid rice during different seasons. The results indicated that the embryo sac fertility (64.5%) was much low in auto tetraploid than that in diploid rice (86%), and five main types of abnormal embryo sac were found in all 10 auto tetraploid rice. Moreover, some other type abnormal embryo sacs were also observed in auto tetraploid rice. Embryo sac without female germ unit and embryo sac degeneration were the most frequent types of abnormalities in auto tetraploid rice. Embryo sac fertility ranged from 49.3% to 79.3%, pollen fertility ranged from 56.2 to 85.9%, and seed setting rate varied from 12.5 to 69.01% in various genotypes of auto tetraploid rice. Embryo sac and pollen fertility were found to have a significant correlation with seed setting rate. Seasons have significant effect on pollen and embryo sac fertility in both type of rice. All the auto tetraploid lines exhibited different types of embryo sac abnormalities which indicated that these might be related to different genotypes. (author)

  3. An orange fluorescent protein tagging system for real-time pollen tracking.

    Science.gov (United States)

    Rice, J Hollis; Millwood, Reginald J; Mundell, Richard E; Chambers, Orlando D; Abercrombie, Laura L; Davies, H Maelor; Stewart, C Neal

    2013-09-27

    Monitoring gene flow could be important for future transgenic crops, such as those producing plant-made-pharmaceuticals (PMPs) in open field production. A Nicotiana hybrid (Nicotiana. tabacum × Nicotiana glauca) shows limited male fertility and could be used as a bioconfined PMP platform. Effective assessment of gene flow from these plants is augmented with methods that utilize fluorescent proteins for transgenic pollen identification. We report the generation of a pollen tagging system utilizing an orange fluorescent protein to monitor pollen flow and as a visual assessment of transgene zygosity of the parent plant. This system was created to generate a tagged Nicotiana hybrid that could be used for the incidence of gene flow. Nicotiana tabacum 'TN 90' and Nicotiana glauca were successfully transformed via Agrobacterium tumefaciens to express the orange fluorescent protein gene, tdTomato-ER, in pollen and a green fluorescent protein gene, mgfp5-er, was expressed in vegetative structures of the plant. Hybrids were created that utilized the fluorescent proteins as a research tool for monitoring pollen movement and gene flow. Manual greenhouse crosses were used to assess hybrid sexual compatibility with N. tabacum, resulting in seed formation from hybrid pollination in 2% of crosses, which yielded non-viable seed. Pollen transfer to the hybrid formed seed in 19% of crosses and 10 out of 12 viable progeny showed GFP expression. The orange fluorescent protein is visible when expressed in the pollen of N. glauca, N. tabacum, and the Nicotiana hybrid, although hybrid pollen did not appear as bright as the parent lines. The hybrid plants, which show limited ability to outcross, could provide bioconfinement with the benefit of detectable pollen using this system. Fluorescent protein-tagging could be a valuable tool for breeding and in vivo ecological monitoring.

  4. Abnormal pollen mitoses (PM I and PM II) in an interspecific hybrid ...

    Indian Academy of Sciences (India)

    Unknown

    sporocytes and pollen grains were prepared by squashing and stained with 0.5% propionic carmine. All meiotic phases and stages of pollen development were evaluated. More than 6000 microspores and pollen grains were care- fully analysed. Keywords. Brachiaria decumbens; Brachiaria ruziziensis; interspecific hybrid; ...

  5. Post-pollination mechanisms in Nicotiana longiflora and N. plumbaginifolia: pollen tube growth rate, offspring paternity and hybridization.

    Science.gov (United States)

    Figueroa-Castro, Dulce M; Holtsford, Timothy P

    2009-09-01

    In natural populations where interfertile species coexist, conspecific and heterospecific pollen can be delivered to the stigmas. Post-pollination mechanisms might determine the seed siring success of different pollen donors within species as well as the chances for hybridization between species. Nicotiana longiflora and N. plumbaginifolia occur in sympatry in Northwest Argentina, where they have overlapping flowering seasons and share floral visitors. We explored (1) pollen tube growth rates for outcross versus self pollen in single-donor pollinations; (2) siring success of self versus outcross pollen donors in competitive pollinations, and (3) possibilities for hybridization by performing two- (outcross conspecific vs. heterospecific) and three-pollen donor (self vs. outcross vs. heterospecific) crosses. In N. longiflora, both pollen tube growth rate and siring success favored outcross pollen over self pollen and strong rejection of heterospecific pollen. In N. plumbaginifolia, pollen tube growth rate was similar for self and outcross pollen, self pollen sired similar numbers of offspring than outcross pollen and heterospecific pollen sired roughly the same number of progeny than self pollen. Results suggest that in natural sympatric populations, interspecific crosses would likely lead to unidirectional hybridization with N. plumbaginifolia as the seed parent.

  6. Overcoming interspecific incompatibility in the cross Brassica campestris ssp. japonica x Brassica oleracea var. botrytis using irradiated mentor pollen page

    International Nuclear Information System (INIS)

    Sarla, N.

    1988-01-01

    The cross B. campestris ssp. japonica x B. oleracea var. botrytis fails due to incompatibility barrier at the stigma. To realize this cross, irradiated compatible pollen (mentor pollen) was used before the incompatible pollination. The presence of mentor pollen stimulated the incompatible pollen to germinate and effect fertilization and seed set. One hybrid was thus obtained. Most of the seeds were inviable. Of the 5 plants raised one was a hybrid and 4 resembled the female parent. 1 tab., 7 refs

  7. Effects of silicon on seed setting rate of rice intersubspecific hybrids.

    Science.gov (United States)

    Li, W-C; Zhang, L; Wang, J; Wang, D; Wang, T-X; Duan, C-X

    2015-09-01

    The present study found semi-sterility in rice intersubspecific hybrids of 'Taichung 65' x 'Guangluai 4' and 'Ludao' x 'Qiuguang'. Embryo sac fertility was evaluated using the overall staining transparent method. The results showed that the embryo sac contained a normal egg cell, normal synergid cells, polar nuclei cells, and antipodal cells, indicating that semi-sterility was caused mainly by pollen semi-sterility. In the pot experiment, the effects of silicon on the seed-setting rate of the two intersubspecific hybrids were examined. The results showed that the rate of anther dehiscence, number of pollen per stigma of Fl plants, potential of pollen grain germination, and fertility of the spikelet were significantly improved by the utilization of silicon fertilizer.

  8. Assessing hybrid sterility in Oryza glaberrima x O. sativa hybrid progenies by PCR marker analysis and crossing with wide compatibility varieties.

    Science.gov (United States)

    Heuer, Sigrid; Miézan, Kouamé M

    2003-09-01

    Interspecific crossing of the African indigenous rice Oryza glaberrima with Oryza sativa cultivars is hindered by crossing barriers causing 100% spikelet sterility in F(1) hybrids. Since hybrids are partially female fertile, fertility can be restored by back crossing (BC) to a recurrent male parent. Distinct genetic models on spikelet sterility have been developed predicting, e.g., the existence of a gamete eliminator and/or a pollen killer. Linkage of sterility to the waxy starch synthase gene and the chromogen gene C, both located on chromosome 6, have been demonstrated. We selected a segregating BC(2)F(3) population of semi-sterile O. glaberrima x O. sativa indica hybrid progenies for analyses with PCR markers located at the respective chromosome-6 region. These analyses revealed that semi-sterile plants were heterozygous for a marker (OSR25) located in the waxy promoter, whereas fertile progenies were homozygous for the O. glaberrima allele. Adjacent markers showed no linkage to spikelet sterility. Semi-sterility of hybrid progenies was maintained at least until the F(4) progeny generation, suggesting the existence of a pollen killer in this plant material. Monitoring of reproductive plant development showed that spikelet sterility was at least partially due to an arrest of pollen development at the microspore stage. In order to address the question whether genes responsible for F(1) sterility in intraspecific hybrids ( O. sativa indica x japonica) also cause spikelet sterility in interspecific hybrids, crossings with wide compatibility varieties (WCV) were performed. WCV accessions possess "neutral" S-loci ( S(n)) improving fertility in intraspecific hybrids. This experiment showed that the tested S(n)-loci had no fertility restoring effect in F(1) interspecific hybrids. Pollen development was completely arrested at the microspore stage and grains were never obtained after selfing. This suggests that distinct or additional S-loci are responsible for sterility

  9. Meiotic behavior and pollen fertility of five species in the genus ...

    African Journals Online (AJOL)

    Meiotic behavior and pollen fertility were analysed in five Epimedium species: Epimedium chlorandrum, Epimedium acuminatum, Epimedium davidii, Epimedium ecalcaratum and Epimedium pubescens. Chromosome numbers for five species were 2n = 2x = 12. All examined species displayed stable meiotic process and ...

  10. Meiotic behavior and pollen fertility of five species in the genus ...

    African Journals Online (AJOL)

    fe

    2011-11-16

    Nov 16, 2011 ... Meiotic behavior and pollen fertility were analysed in five Epimedium species: Epimedium chlorandrum,. Epimedium acuminatum, Epimedium davidii, Epimedium ecalcaratum and Epimedium pubescens. Chromosome numbers for five species were 2n = 2x = 12. All examined species displayed stable ...

  11. Reproductive characterization of interspecific hybrids among Capsicum species

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo da Silva Monteiro

    2011-01-01

    Full Text Available The objective of this study was the reproductive characterization of Capsicum accessions as well as of interspecifichybrids, based on pollen viability. Hybrids were obtained between Capsicum species. Pollen viability was high in most accessions,indicating that meiosis is normal, resulting in viable pollen grains. The pollen viability of species C. pubescens was the lowest (27%. The interspecific hybrids had varying degrees of pollen viability, from fertile combinations (C. chinense x C. frutescens and C.annuum x C. baccatum to male sterile combinations. Pollen viability also varied within the hybrid combination according toaccessions used in the cross. Results indicate that male sterility is one of the incompatibility barriers among Capsicum species sincehybrids can be established, but may be male sterile.

  12. Polyploidy Enhances F1 Pollen Sterility Loci Interactions That Increase Meiosis Abnormalities and Pollen Sterility in Autotetraploid Rice1[OPEN

    Science.gov (United States)

    Wu, Jinwen; Chen, Lin; Chen, Zhixiong; Wang, Lan; Lu, Yonggen

    2015-01-01

    Intersubspecific autotetraploid rice (Oryza sativa ssp. indica × japonica) hybrids have greater biological and yield potentials than diploid rice. However, the low fertility of intersubspecific autotetraploid hybrids, which is largely caused by high pollen abortion rates, limits their commercial utility. To decipher the cytological and molecular mechanisms underlying allelic interactions in autotetraploid rice, we developed an autotetraploid rice hybrid that was heterozygous (SiSj) at F1 pollen sterility loci (Sa, Sb, and Sc) using near-isogenic lines. Cytological studies showed that the autotetraploid had higher percentages (>30%) of abnormal chromosome behavior and aberrant meiocytes (>50%) during meiosis than did the diploid rice hybrid control. Analysis of gene expression profiles revealed 1,888 genes that were differentially expressed between the autotetraploid and diploid hybrid lines at the meiotic stage, among which 889 and 999 were up- and down-regulated, respectively. Of the 999 down-regulated genes, 940 were associated with the combined effect of polyploidy and pollen sterility loci interactions (IPE). Gene Ontology enrichment analysis identified a prominent functional gene class consisting of seven genes related to photosystem I (Gene Ontology 0009522). Moreover, 55 meiosis-related or meiosis stage-specific genes were associated with IPE in autotetraploid rice, including Os02g0497500, which encodes a DNA repair-recombination protein, and Os02g0490000, which encodes a component of the ubiquitin-proteasome pathway. These results suggest that polyploidy enhances epistatic interactions between alleles of pollen sterility loci, thereby altering the expression profiles of important meiosis-related or meiosis stage-specific genes and resulting in high pollen sterility. PMID:26511913

  13. Polyploidy Enhances F1 Pollen Sterility Loci Interactions That Increase Meiosis Abnormalities and Pollen Sterility in Autotetraploid Rice.

    Science.gov (United States)

    Wu, Jinwen; Shahid, Muhammad Qasim; Chen, Lin; Chen, Zhixiong; Wang, Lan; Liu, Xiangdong; Lu, Yonggen

    2015-12-01

    Intersubspecific autotetraploid rice (Oryza sativa ssp. indica × japonica) hybrids have greater biological and yield potentials than diploid rice. However, the low fertility of intersubspecific autotetraploid hybrids, which is largely caused by high pollen abortion rates, limits their commercial utility. To decipher the cytological and molecular mechanisms underlying allelic interactions in autotetraploid rice, we developed an autotetraploid rice hybrid that was heterozygous (S(i)S(j)) at F1 pollen sterility loci (Sa, Sb, and Sc) using near-isogenic lines. Cytological studies showed that the autotetraploid had higher percentages (>30%) of abnormal chromosome behavior and aberrant meiocytes (>50%) during meiosis than did the diploid rice hybrid control. Analysis of gene expression profiles revealed 1,888 genes that were differentially expressed between the autotetraploid and diploid hybrid lines at the meiotic stage, among which 889 and 999 were up- and down-regulated, respectively. Of the 999 down-regulated genes, 940 were associated with the combined effect of polyploidy and pollen sterility loci interactions (IPE). Gene Ontology enrichment analysis identified a prominent functional gene class consisting of seven genes related to photosystem I (Gene Ontology 0009522). Moreover, 55 meiosis-related or meiosis stage-specific genes were associated with IPE in autotetraploid rice, including Os02g0497500, which encodes a DNA repair-recombination protein, and Os02g0490000, which encodes a component of the ubiquitin-proteasome pathway. These results suggest that polyploidy enhances epistatic interactions between alleles of pollen sterility loci, thereby altering the expression profiles of important meiosis-related or meiosis stage-specific genes and resulting in high pollen sterility. © 2015 American Society of Plant Biologists. All Rights Reserved.

  14. Evaluation of reproductive barriers contributes to the development of novel interspecific hybrids in the Kalanchoë genus

    DEFF Research Database (Denmark)

    Kuligowska, Katarzyna; Lütken, Henrik Vlk; Christensen, Brian

    2015-01-01

    BackgroundInterspecific hybridization is a useful tool in ornamental breeding to increase genetic variability and introduce new valuable traits into existing cultivars. The successful formation of interspecific hybrids is frequently limited by the presence of pre- and post-fertilization barriers....... In the present study, we investigated the nature of hybridization barriers occurring in crosses between Kalancho? species and evaluated possibilities of obtaining interspecific hybrids.ResultsThe qualitative and quantitative analyses of pollen tube growth in situ were performed following intra- and interspecific...... pollinations. They revealed occurrence of pre-fertilization barriers associated with inhibition of pollen germination on the stigma and abnormal growth of pollen tubes. Unilateral incongruity related to differences in pistil length was also observed. The pollen quality was identified as a strong factor...

  15. An RNA-seq transcriptome analysis of floral buds of an interspecific Brassica hybrid between B. carinata and B. napus.

    Science.gov (United States)

    Chu, Pu; Liu, Huijuan; Yang, Qing; Wang, Yankun; Yan, Guixia; Guan, Rongzhan

    2014-12-01

    Interspecific hybridizations promote gene transfer between species and play an important role in plant speciation and crop improvement. However, hybrid sterility that commonly found in the first generation of hybrids hinders the utilization of interspecific hybridization. The combination of divergent parental genomes can create extensive transcriptome variations, and to determine these gene expression alterations and their effects on hybrids, an interspecific Brassica hybrid of B. carinata × B. napus was generated. Scanning electron microscopy analysis indicated that some of the hybrid pollen grains were irregular in shape and exhibited abnormal exine patterns compared with those from the parents. Using the Illumina HiSeq 2000 platform, 39,598, 32,403 and 42,208 genes were identified in flower buds of B. carinata cv. W29, B. napus cv. Zhongshuang 11 and their hybrids, respectively. The differentially expressed genes were significantly enriched in pollen wall assembly, pollen exine formation, pollen development, pollen tube growth, pollination, gene transcription, macromolecule methylation and translation, which might be associated with impaired fertility in the F1 hybrid. These results will shed light on the mechanisms underlying the low fertility of the interspecific hybrids and expand our knowledge of interspecific hybridization.

  16. [Inheritance of reversions to male fertility in male-sterile sorghum hybrids with 9E cytoplasm male sterility induced by environmental conditions].

    Science.gov (United States)

    Elkonin, L A; Gerashchenkov, G A; Domanina, I V; Rozhnova, N A

    2015-03-01

    Heritable phenotypic alterations occurring during plant ontogenesis under the influence of environmental factors are among the most intriguing genetic phenomena. It was found that male-sterile sorghum hybrids in the 9E cytoplasm from the F1 and F2 generations, which were obtained by crossing CMS lines with different fertile lines grown in field conditions, were transferred to greenhouse produce fertile tillers. Lines created by the self-pollination of revertant tillers exhibit complete male fertility upon cultivation under various environments (in the field, Tdry plot,(y) Tirrigated plot(y)). In a number of test-crosses of revertants to CMS lines in the 9E cytoplasm, restoration of male fertility in F1 hybrids was found, indicating that revertants possess functional fertility-restoring genes. A high positive correlation was found between the fertility level of the test-cross hybrids and the hydrothermal coefficient (the ratio of the sum of precipitation to the sum of temperatures) during the booting stage and pollen maturation (r = 0.75...0.91; Pmale fertility are due to up-regulation of fertility-restoring genes by a high level of water availability. Comparative MSAP-analysis of DNA of male-sterile and male-fertile test-cross hybrids using HpaII/MspI restrictases and primers to polygalacturonase gene ADPG2, which is required for cell separation during reproductive development, and gene MYB46, the transcription factor regulating secondary wall biosynthesis, revealed differences in the number and the length of amplified fragments. Changes in the methylation of these genes in conditions of drought stress are apparently the reason for male sterility of sorghum hybrids in the 9E cytoplasm. These data demonstrate that methylation of nuclear genes in sterility-inducing cytoplasm may be one of mechanisms causing the CMS phenomenon.

  17. Genetic analysis of a hybrid sterility gene that causes both pollen and embryo sac sterility in hybrids between Oryza sativa L. and Oryza longistaminata.

    Science.gov (United States)

    Chen, H; Zhao, Z; Liu, L; Kong, W; Lin, Y; You, S; Bai, W; Xiao, Y; Zheng, H; Jiang, L; Li, J; Zhou, J; Tao, D; Wan, J

    2017-09-01

    Oryza longistaminata originates from African wild rice and contains valuable traits conferring tolerance to biotic and abiotic stress. However, interspecific crosses between O. longistaminata and Oryza sativa cultivars are hindered by reproductive barriers. To dissect the mechanism of interspecific hybrid sterility, we developed a near-isogenic line (NIL) using indica variety RD23 as the recipient parent and O. longistaminata as the donor parent. Both pollen and embryo sac semi-sterility were observed in F 1 hybrids between RD23 and NIL. Cytological analysis demonstrated that pollen abortion in F 1 hybrids occurred at the early bi-nucleate stage due to a failure of the first mitosis in microspores. Partial embryo sacs in the F 1 hybrids were defective during the functional megaspore formation stage. Most notably, nearly half of the male or female gametes were aborted in heterozygotes S40 i S40 l , regardless of their genotypes. Thus, S40 was indicated as a one-locus sporophytic sterility gene controlling both male and female fertility in hybrids between RD23 and O. longistaminata. A population of 16 802 plants derived from the hybrid RD23/NIL-S40 was developed to fine-map S40. Finally, the S40 locus was delimited to an 80-kb region on the short arm of chromosome 1 in terms with reference sequences of cv. 93-11. Eight open reading frames (ORFs) were localized in this region. On the basis of gene expression and genomic sequence analysis, ORF5 and ORF8 were identified as candidate genes for the S40 locus. These results are helpful in cloning the S40 gene and marker-assisted transferring of the corresponding neutral allele in rice breeding programs.

  18. Overcoming hybridization barriers by the secretion of the maize pollen tube attractant ZmEA1 from Arabidopsis ovules.

    Science.gov (United States)

    Márton, Mihaela L; Fastner, Astrid; Uebler, Susanne; Dresselhaus, Thomas

    2012-07-10

    A major goal of plant reproduction research is to understand and overcome hybridization barriers so that the gene pool of crop plants can be increased and improved upon. After successful pollen germination on a receptive stigma, the nonmotile sperm cells of flowering plants are transported via the pollen tube (PT) to the egg apparatus for the achievement of double fertilization. The PT path is controlled by various hybridization mechanisms probably involving a larger number of species-specific molecular interactions. The egg-apparatus-secreted polymorphic peptides ZmEA1 in maize and LURE1 and LURE2 in Torenia fournieri as well as TcCRP1 in T. concolor were shown to be required for micropylar PT guidance, the last step of the PT journey. We report here that ZmEA1 attracts maize PTs in vitro and arrests their growth at higher concentrations. Furthermore, it binds to the subapical region of maize PT tips in a species-preferential manner. To overcome hybridization barriers at the level of gametophytic PT guidance, we expressed ZmEA1 in Arabidopsis synergid cells. Secreted ZmEA1 enabled Arabidopsis ovules to guide maize PT in vitro in a species-preferential manner to the micropylar opening of the ovule. These results demonstrate that the egg-apparatus-controlled reproductive-isolation barrier of PT guidance can be overcome even between unrelated plant families. Copyright © 2012 Elsevier Ltd. All rights reserved.

  19. MS26/CYP704B is required for anther and pollen wall development in bread wheat (Triticum aestivum L. and combining mutations in all three homeologs causes male sterility.

    Directory of Open Access Journals (Sweden)

    Manjit Singh

    Full Text Available Development of anthers and pollen represents an important aspect of the life cycle in flowering plants. Genes contributing to anther and pollen development have been widely studied in many plant species. Ms26/CYP704B genes play an important role in pollen development through biosynthesis of sporopollenin for pollen exine formation. To investigate the role of Ms26/CYP704B genes in anther and pollen development of bread wheat, mutations in the A-, B-, and D-homeologs of the putative Ms26/CYP704B gene were analyzed. Single and double homozygous mutants in any of the homeologs did not affect pollen development and male fertility. Triple homozygous mutants resulted in completely male sterile plants that were defective in pollen and anther development. Additionally, double homozygous-single heterozygous mutants were also male sterile although with varying levels of residual fertility. The fertility of these triple mutants was dependent upon the homeolog contributing the wild-type allele. Two heterologous Ms26/CYP704B genes, when transformed into a triple homozygous mutant background, completely restored male fertility, whereas a single gene was unable to restore fertility. Functional analysis of Ms26/CYP704B furthers the understanding of male fertility genes which can be utilized for the development of novel hybrid seed production systems in wheat.

  20. Natural hybridization between Phlomis lycia D. Don x P. bourgaei Boiss., (Lamiaceae) revealed by RAPD markers.

    Science.gov (United States)

    Yüzbaşioğlu, Ertuğrul; Dadandi, Mehmet Yaşar; Ozcan, Sebahattin

    2008-05-01

    Randomly Amplified Polymorphic DNA markers (RAPD) were used to assess the hybrid identity of individuals sampled as Phlomis x termessi Davis. Out of 95 primers screened, 11 primers produced reproducible amplification patterns used for discrimination of P. x termessi and their parents. Eleven primers produced 81 bands. Forty two percent of the RAPD bands existed in parents. Of the 54 bands found in P. lycia, 19 were found only in this species and 7 of these were monomorphic. Similarly, of 57 RAPD bands observed in P. bourgaei, 18 were found only in P. bourgaei and 6 of these were monomorphic. Among hybrid individuals, 35 of the 73 markers were monomorphic. Fifteen of these existed in individual parents showing that parents were homozygous for these markers. Of the 35 monomorphic bands observed among hybrid individuals, 5 were present in the samples of one of the parents and completely absent from the samples of the other; therefore, additive inheritance is indicated. Of the 5 additive bands, 1 was inherited from P. bourgaei and 4 were inherited from P. lycia. Among 38 polymorhic markers observed in hybrid individuals, 9 were new and hybrid-specific. Pollen fertility was also investigated. Mean pollen fertility for P. lycia and P. bourgaei was 93% and 97% respectively. However, mean pollen fertility for hybrids was 65% (+/-10.5).

  1. Hybridizing pines with diluted pollen

    Science.gov (United States)

    Robert Z. Callaham

    1967-01-01

    Diluted pollens would have many uses by the tree breeder. Dilutions would be particularly advantageous in making many controlled pollinations with a limited amount of pollen. They also would be useful in artificial mass pollinations of orchards or single trees. Diluted pollens might help overcome troublesome genetic barriers to crossing. Feasibility o,f using diluted...

  2. 7 CFR 201.78 - Pollen control for hybrids.

    Science.gov (United States)

    2010-01-01

    ... line used to pollinate an A Line and to restore fertility in the resulting hybrid seed.) (b) Corn. When 5 percent or more of the seed parent plants have receptive silks, shedding tassels in the seed...

  3. Hybrid breeding in wheat: technologies to improve hybrid wheat seed production.

    Science.gov (United States)

    Whitford, Ryan; Fleury, Delphine; Reif, Jochen C; Garcia, Melissa; Okada, Takashi; Korzun, Viktor; Langridge, Peter

    2013-12-01

    Global food security demands the development and delivery of new technologies to increase and secure cereal production on finite arable land without increasing water and fertilizer use. There are several options for boosting wheat yields, but most offer only small yield increases. Wheat is an inbred plant, and hybrids hold the potential to deliver a major lift in yield and will open a wide range of new breeding opportunities. A series of technological advances are needed as a base for hybrid wheat programmes. These start with major changes in floral development and architecture to separate the sexes and force outcrossing. Male sterility provides the best method to block self-fertilization, and modifying the flower structure will enhance pollen access. The recent explosion in genomic resources and technologies provides new opportunities to overcome these limitations. This review outlines the problems with existing hybrid wheat breeding systems and explores molecular-based technologies that could improve the hybrid production system to reduce hybrid seed production costs, a prerequisite for a commercial hybrid wheat system.

  4. Interrelationship of pollination conditions, fertilization and sunflower seed yield

    Directory of Open Access Journals (Sweden)

    Joksimović Jovan

    2005-01-01

    Full Text Available Four commercially important sunflower hybrids (NS-H-45, NS-H-l 11, NS-H-702 and Velja and their parental components (Ha-74B, Ha-98B, CMS-3-8B, Ha-26B, RHA-583, RHA-R-PI-2/1 and RHA-113N were used over a period of two years to study the following traits: disk flower corolla length, nectar content, pollen viability, bee visitation, fertilization percentage and seed yield. Relations among the traits were determined by path coefficient analysis. The simple correlation coefficients showed that fertilization percentage and bee visitation had a highly significant influence on seed yield. The corolla length had a positive effect on nectar content, while nectar content had a significant negative influence on pollen viability. The highest significant direct influence on seed yield was that of fertilization percentage, while the effect on nectar content on seed yield was negative but not significant. The coefficient of determination was 0.8071.

  5. Genomic structural variation-mediated allelic suppression causes hybrid male sterility in rice.

    Science.gov (United States)

    Shen, Rongxin; Wang, Lan; Liu, Xupeng; Wu, Jiang; Jin, Weiwei; Zhao, Xiucai; Xie, Xianrong; Zhu, Qinlong; Tang, Huiwu; Li, Qing; Chen, Letian; Liu, Yao-Guang

    2017-11-03

    Hybrids between divergent populations commonly show hybrid sterility; this reproductive barrier hinders hybrid breeding of the japonica and indica rice (Oryza sativa L.) subspecies. Here we show that structural changes and copy number variation at the Sc locus confer japonica-indica hybrid male sterility. The japonica allele, Sc-j, contains a pollen-essential gene encoding a DUF1618-domain protein; the indica allele, Sc-i, contains two or three tandem-duplicated ~ 28-kb segments, each carrying an Sc-j-homolog with a distinct promoter. In Sc-j/Sc-i hybrids, the high-expression of Sc-i in sporophytic cells causes suppression of Sc-j expression in pollen and selective abortion of Sc-j-pollen, leading to transmission ratio distortion. Knocking out one or two of the three Sc-i copies by CRISPR/Cas9 rescues Sc-j expression and male fertility. Our results reveal the gene dosage-dependent allelic suppression as a mechanism of hybrid incompatibility, and provide an effective approach to overcome the reproductive barrier for hybrid breeding.

  6. Effects of fluorides and sulphur dioxide on pollen germination and growth of the pollen tube

    Directory of Open Access Journals (Sweden)

    Leon Mejnartowicz

    2014-01-01

    Full Text Available The action of fluorides and sulphur dioxides from emissions from a phosphate fertilizer factory significantly reduced the germination of Scots pine pollen grains. The pollen tube length indicated that its growth is uninhibited even though the pollen was collected under conditions of air-pollution. There are statistically significant differences showing longer tubes in the sensitive trees pollen grains. l he ageing of pollen from the sensitive trees occurs probably more rapidly than in the tolerant trees.

  7. In vivo fertilization of banana

    Directory of Open Access Journals (Sweden)

    Taliane Leila Soares

    2014-01-01

    Full Text Available The aim of this research was to study the in vivo fertilization process of banana cultivars. The diploid hybrid (AA 091087-01 was the male progenitor. Flower samples were checked for fertilization from the first to the twentieth day after pollination. The size of the diploid ovules increased gradually at the beginning of the seed formation process. On the other hand, in the AAA triploids (Cavendish subgroup, the not fertilized ovules were aborted. In the AAB triploids (Prata subgroup some ovules were fertilized. The flowers of Grand Naine, Nanicão and 'Pacovan' cultivars presented necrosis in the distal part of the ovary on the first day after pollination. Necrosis can hinder pollen tube growth towards the ovule, which might be related to the low seed yield in 'Pacovan' cultivars and to the absence of seeds in the Cavendish subgroup cultivars.

  8. Induced pollen sterility in petunia. Mode of inheritance and tapetal behavior

    International Nuclear Information System (INIS)

    Singh, I.S.

    1975-01-01

    A study was undertaken to investigate the characteristics of different mutants for induced pollen sterility in Petunia hybrida Hort. The F 1 hybrid zygotes (TL-h 1 #female# x Sf-la #male#) were exposed to a 0.2% solution of ethyl methane sulfonate and to 0.75kR of 60 Co gamma rays. Their seeds were sown and pollen sterile plants were observed in the M 1 . The pattern of inheritance in the F 2 and the backcrosses of some selected pollen sterile M 1 mutants showed that sterility mutations had been induced. Whether the mutations are recessive or dominant is not yet known, but it has been shown that they act through the sporophytic tissues. Morphological and cytological observations on four highly sterile M 1 plants showed a similar abnormal behavior of the tapetum. The tapetum of the pollen sterile anthers was thicker, more vacuolated and did persist until a later stage than those in fertile anthers. It is suggested that the persistence of the tapetum after a certain stage blocks the trophic process required for the development of the microspore into viable pollen, and the cause of pollen abortion is sporophytic even when no inheritance of the sterility is observed [fr

  9. Cytogenetical investigations on fertilization, embriogenesis and fruit formation by irradiated pollen

    International Nuclear Information System (INIS)

    Dryanovska, O.

    1981-01-01

    The mechanism of fertilization pollination with gamma-irradiated pollen (1-500 kR) in plants of various double fertilization: Crepis (Nicotiana tabacum, Lycopersicum esculentum, Solanum melongena, Ornithogalum gramminifolium, Melandrium rubrum) type, Lilium (Lilium speciosum) type, and Trandescantia (Tradescantia paludosa) type was studied, along with the opportunity of its modification, embryogenesis and fruit and seed formation. In the Crepis type, depending on the disturbances of male chromatin, fertilization manifested itself as: 1) normal karyogamy with decondensation of male chromatin and the formation of supplementary nucleoli and further development of embryo and endosperm (1-500 kR); 2) karyogamy without decondensation and functioning of the male chromatin (1-500 kR); 3) karyogamy or sticking the male chromatin to the nuclei of the female sex cells, stimulating the development of the ovule, embryo, and endosperm (50-500 kR); 4) sticking the highly pycnotized male chromatin to the nuclei of the female sex cells without evidence of zygote and endosperm function and further development (50-500 kR). In the Lilium type modification of fertilization was manifested by: 1) normal karyogamy with developing diploid embryos and pentaploid endosperm with aberrations (1-20 kK); 2) sticking the male chromatin to the nuclei of the female sex cells and stimulation of their development (50-500 kR). In the Trandescantia type the irradiated male chromatin modified fertilization as: 1) karyogamy with spermia having fragments, two spermia connected by a bridge or with a generative nucleus with aberrations (1-50 kR); 2) karyogamy without developing the female sex nuclei (10-500kR); 3) karyogamy or sticking the male chromatin to the female sex cell nuclei and stimulation of their development (10-500 kR); 4) sticking the male chromatin with no stimulating effect (10-500 kR). (author)

  10. Speciation and reduced hybrid female fertility in house mice.

    Science.gov (United States)

    Suzuki, Taichi A; Nachman, Michael W

    2015-09-01

    In mammals, intrinsic postzygotic isolation has been well studied in males but has been less studied in females, despite the fact that female gametogenesis and pregnancy provide arenas for hybrid sterility or inviability that are absent in males. Here, we asked whether inviability or sterility is observed in female hybrids of Mus musculus domesticus and M. m. musculus, taxa which hybridize in nature and for which male sterility has been well characterized. We looked for parent-of-origin growth phenotypes by measuring adult body weights in F1 hybrids. We evaluated hybrid female fertility by crossing F1 females to a tester male and comparing multiple reproductive parameters between intrasubspecific controls and intersubspecific hybrids. Hybrid females showed no evidence of parent-of-origin overgrowth or undergrowth, providing no evidence for reduced viability. However, hybrid females had smaller litter sizes, reduced embryo survival, fewer ovulations, and fewer small follicles relative to controls. Significant variation in reproductive parameters was seen among different hybrid genotypes, suggesting that hybrid incompatibilities are polymorphic within subspecies. Differences in reproductive phenotypes in reciprocal genotypes were observed and are consistent with cyto-nuclear incompatibilities or incompatibilities involving genomic imprinting. These findings highlight the potential importance of reduced hybrid female fertility in the early stages of speciation. © 2015 The Author(s). Evolution © 2015 The Society for the Study of Evolution.

  11. Development of a novel recessive genetic male sterility system for hybrid seed production in maize and other cross-pollinating crops.

    Science.gov (United States)

    Wu, Yongzhong; Fox, Tim W; Trimnell, Mary R; Wang, Lijuan; Xu, Rui-Ji; Cigan, A Mark; Huffman, Gary A; Garnaat, Carl W; Hershey, Howard; Albertsen, Marc C

    2016-03-01

    We have developed a novel hybridization platform that utilizes nuclear male sterility to produce hybrids in maize and other cross-pollinating crops. A key component of this platform is a process termed Seed Production Technology (SPT). This process incorporates a transgenic SPT maintainer line capable of propagating nontransgenic nuclear male-sterile lines for use as female parents in hybrid production. The maize SPT maintainer line is a homozygous recessive male sterile transformed with a SPT construct containing (i) a complementary wild-type male fertility gene to restore fertility, (ii) an α-amylase gene to disrupt pollination and (iii) a seed colour marker gene. The sporophytic wild-type allele complements the recessive mutation, enabling the development of pollen grains, all of which carry the recessive allele but with only half carrying the SPT transgenes. Pollen grains with the SPT transgenes exhibit starch depletion resulting from expression of α-amylase and are unable to germinate. Pollen grains that do not carry the SPT transgenes are nontransgenic and are able to fertilize homozygous mutant plants, resulting in nontransgenic male-sterile progeny for use as female parents. Because transgenic SPT maintainer seeds express a red fluorescent protein, they can be detected and efficiently separated from seeds that do not contain the SPT transgenes by mechanical colour sorting. The SPT process has the potential to replace current approaches to pollen control in commercial maize hybrid seed production. It also has important applications for other cross-pollinating crops where it can unlock the potential for greater hybrid productivity through expanding the parental germplasm pool. © 2015 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  12. Storage and irradiation of Cucumis pollen and their influence on pollen vitality

    International Nuclear Information System (INIS)

    Oost, E.H.; Nijs, A.P.M. den

    1979-01-01

    In connection with an interspecific hybridization programme and a mentor pollen experiment in Cucumis, the optimal storage conditions and in vitro germination medium for both fresh and irradiated pollen of the cultivated cucumber and two wild African Cucumis species have been searched for. (Auth.)

  13. Effect of space flight on meiosis of pollen mother cells and its derived pollens in impatiens balsamina

    International Nuclear Information System (INIS)

    Tang Zesheng; Yang Jun; Yuan Haiyun; Zhao Yan

    2005-01-01

    Effects of space flight on meiosis of pollen mother cells and meiosis of microspores in Impatiens balsamina were investigated. It was found that meiosis showed abnormal in most plants germinated from seeds after space flight, and chromosome fragment, chromosomal bridge and lagging chromosome were observed in the process of meiosis in these plants. Disproportional segregation of chromosome, multipolar division and multinucleus were also observed in most plants, which developed into paraspores with different chromosome number. Mitosis of microspores was found to be abnormal in most plants, and the number of chromosome in microspore unequal. The fertility of the pollens was tested with iodic solution; it was found that the fertility of pollens varied in different plants. (authors)

  14. Genetical and ultrastructural aspects of self and cross incompatibility in interspecific hybrids between self-compatible Lycopersicum esculentum and self-incompatible L. peruvianum.

    Science.gov (United States)

    De Nettancourt, D; Devreux, M; Laneri, U; Cresti, M; Pacini, E; Sarfatti, G

    1974-01-01

    Cytological and genetical analyses were made of the breeding system of embryo-cultured interspecific tomato hybrids between L. esculentum and L. peruvianum. It was found that fluorescence techniques and electron microscopy allowed a distinction to be made between pollen tubes inhibited by a unilateral incompatibility reaction and pollen tubes inhibited by a self-incompatibility reaction, after self-pollination of the hybrids or after reciprocal crossing between the hybrid and the parental species. The observed differences, if real and reliable, demonstrate that unilateral incompatibility in esculentum pollen tubes is governed by a single gametophytic factor which is either linked or allelic to the S-locus. This finding is discussed with reference to recent reports that unilateral incompatibility is controlled, in peruvianum styles, by a number of different dominant genes and it is concluded that these dominant genes, the S-locus of self-incompatibility and the gametophytic factor regulating the unilateral reaction in esculentum pollen belong to the same linkage group. The strong sterility barriers which prevent practically all backcrosses between the hybrid and the parental species were shown to be independent of the factors regulating stylar incompatibility. L. peruvianum is heterozygous for the sterility genes which prevent fertilization or embryo formation when the interspecific hybrid is crossed, as pistillate parent, to different accessions of L. peruvianum. One peruvianum stock was found which, as a pollinator, was highly cross-fertile with the hybrids.The presence of a concentric endoplasmic reticulum in inhibited pollen tubes was observed to be a constant feature of both the self- and the unilateral incompatibility reactions and was interpreted as an indication that incompatibility might lead to a general cessation of protein synthesis. Although incompatible tubes very much resemble, in this respect, the pollen tubes cultured in vitro, it seems probable, on

  15. Genetic incompatibility dampens hybrid fertility more than hybrid viability: yeast as a case study.

    Directory of Open Access Journals (Sweden)

    Meibo Xu

    Full Text Available Genetic incompatibility is believed to be the major cause of postzygotic reproductive isolation. Despite huge efforts seeking for speciation-related incompatibilities in the past several decades, a general understanding of how genetic incompatibility evolves in affecting hybrid fitness is not available, primarily due to the fact that the number of known incompatibilities is small. Instead of further mapping specific incompatible genes, in this paper we aimed to know the overall effects of incompatibility on fertility and viability, the two aspects of fitness, by examining 89 gametes produced by yeast S. cerevisiae-S. paradoxus F1 hybrids. Homozygous F2 hybrids formed by autodiploidization of F1 gametes were subject to tests for growth rate and sporulation efficiency. We observed much stronger defects in sporulation than in clonal growth for every single F2 hybrid strain, indicating that genetic incompatibility affects hybrid fertility more than hybrid viability in yeast. We related this finding in part to the fast-evolving nature of meiosis-related genes, and proposed that the generally low expression levels of these genes might be a cause of the observation.

  16. Genetic analysis of fertility restoration genes for WAtype cytoplasmic ...

    African Journals Online (AJOL)

    Pollen staining test with 1% I2KI solution showed segregation ratio of 15:1 (fertile: sterile), representing two nuclear independent dominant genes controlling the trait carried by fertile parent DN-33-18. Segregation for spikelet fertility in F2 confirmed the results of pollen fertility test. Molecular tagging of fertility restorer genes ...

  17. Characterization of F1 interspecific hybrids between wild Helianthus annuus L. populations and cultivated sunflower

    Directory of Open Access Journals (Sweden)

    Terzić Sreten

    2006-01-01

    Full Text Available Phenotype, chromosomes pairing and pollen vitality were compared between parental populations and F1 hybrids of interspecific cross between Helianthus annuus L. and cultivated sunflower. The investigation of the simple sequence repeats (SSR polymorphism was also used to test the hybrid nature of F1 populations. The phenotypic traits of F1 hybrid plants were either closer to the wild species or intermediate. Irregular chromosome pairing was found in only 0 to 10% of meiocytes in the meiosis of F1 hybrid plants. Interspecific crosses were confirmed with SSR markers in all hybrid combinations. Alleles that were not present in parental DNA were frequently observed in F1 hybrids. That is additional evidence that those hybrid combinations were not produced by self-fertilization. The results suggest that SSR markers can be efficiently used for the F1 hybrid characterization in crosses between closely related species, in which, the changes of phenotype, meiosis and pollen vitality are not always significant.

  18. Premature Tapetum Degeneration: a Major Cause of Abortive Pollen Development in Photoperiod Sensitive Genic Male Sterility in Rice

    Institute of Scientific and Technical Information of China (English)

    Yinlian Shi; Sha Zhao; Jialing Yao

    2009-01-01

    Photoperiod-sensitive genic male-sterile (PSGMS) rice (Oryza sativa L.), a natural mutant found in the rice cultivar Nongken 58, is very useful for the development of hybrid rice cultivars. Despite its widespread use in breeding programs, the initial stage of the abortive development of PSGMS rice and the possible cytological mechanisms of pollen abortion have not been determined. In the present study, a systematic cytological comparison of the anther development of PSGMS rice with its normal fertile counterpart is conducted. The results show that pollen abortion in PSGMS rice first occurs before the pollen mother cell (PMC) stage, and continues during the entire process of pollen development until pollen degradation. The abortive process was closely associated with the abnormal behavior of the tapetum. Although tapetum degeneration in PSGMS rice initiates already at the PMC stage, it proceeds slowly and does not complete until the breakdown of the pollen. Such cytological observations were supported by the results of the TUNEL (TdT-mediated dUTP Nick End Labeling) assay, which detects DNA fragmentation resulting from programmed cell death (PCD), indicating that the premature tapetum degeneration is in the process of PCD.

  19. Fine mapping of S37, a locus responsible for pollen and embryo sac sterility in hybrids between Oryza sativa L. and O. glaberrima Steud.

    Science.gov (United States)

    Shen, Yumin; Zhao, Zhigang; Ma, Hongyang; Bian, Xiaofeng; Yu, Yang; Yu, Xiaowen; Chen, Haiyuan; Liu, Linglong; Zhang, Wenwei; Jiang, Ling; Zhou, Jiawu; Tao, Dayun; Wan, Jianmin

    2015-11-01

    Hybrid sterility locus S37 between Oryza glaberrima and Oryza sativa results in both pollen and embryo sac sterility. Interspecific crossing between African cultivated rice Oryza glaberrima and Oryza sativa cultivars is hindered by hybrid sterility. To dissect the mechanism of interspecific hybrid sterility, we developed a near-isogenic line (NIL)-S37 using Dianjingyou1 (DJY1) as the recipient parent and an African cultivated rice variety as the donor parent. Empty pollen and embryo sac sterility were observed in F1 hybrids between DJY1 and NIL-S37. Cytological analyses showed that pollen abortion in the F1 hybrids occurred at the late binucleate stage due to a failure of starch accumulation in pollen grains. In addition, partial abortion of the embryo sac in the F1 hybrid was observed during function megaspore developing into mature embryo sac. Molecular analysis revealed that the semi-sterility was largely caused by the abortion of male and female gametophytes carrying the S37 allele from DJY1. A population of 25,600 plants derived from the hybrid DJY1/NIL-S37 was developed to fine map S37. Based on the physical location of molecular markers, S37 locus was finally delimited to a region of 205 kb on the short arm of chromosome 1 in terms of reference sequences of cv. Nipponbare. Interestingly, an about 97-kb DNA segment was deleted in the NIL-S37 based on BAC clone information of O. glaberrima. Fifty-four open reading frames (ORF) were predicted in this 205-kb region of DJY1, whereas only 31 ORFs were in that of NIL-S37. These results are valuable for cloning of S37 gene and further breaking reproductive isolation between Oryza glaberrima and Oryza sativa cultivars, as well as marker-assisted transferring of the corresponding neutral allele in rice breeding programs.

  20. iTRAQ-Based Proteomics Analyses of Sterile/Fertile Anthers from a Thermo-Sensitive Cytoplasmic Male-Sterile Wheat with Aegilops kotschyi Cytoplasm

    Directory of Open Access Journals (Sweden)

    Gaoming Zhang

    2018-05-01

    Full Text Available A “two-line hybrid system” was developed, previously based on thermo-sensitive cytoplasmic male sterility in Aegilops kotschyi (K-TCMS, which can be used in wheat breeding. The K-TCMS line exhibits complete male sterility and it can be used to produce hybrid wheat seeds during the normal wheat-growing season; it propagates via self-pollination at high temperatures. Isobaric tags for relative and absolute quantification-based quantitative proteome and bioinformatics analyses of the TCMS line KTM3315A were conducted under different fertility conditions to understand the mechanisms of fertility conversion in the pollen development stages. In total, 4639 proteins were identified, the differentially abundant proteins that increased/decreased in plants with differences in fertility were mainly involved with energy metabolism, starch and sucrose metabolism, phenylpropanoid biosynthesis, protein synthesis, translation, folding, and degradation. Compared with the sterile condition, many of the proteins that related to energy and phenylpropanoid metabolism increased during the anther development stage. Thus, we suggest that energy and phenylpropanoid metabolism pathways are important for fertility conversion in K-TCMS wheat. These findings provide valuable insights into the proteins involved with anther and pollen development, thereby, helping to further understand the mechanism of TCMS in wheat.

  1. Studies on increasing fertility of distant hybrid by irradiation of androgametes of wheat

    International Nuclear Information System (INIS)

    Chen Yichun; Sun Guangzu; Zhang Yuexue

    1994-01-01

    Distant hybridization was carried out by using hexaploid triticale, Heizha 266, as female parent and 2 varieties of spring wheat, Longfumai 3 and Longfumai 5, as male parent which were irradiated by slow irradiation of living bodies with 60 Co gamma rays from 600 to 2400 rad before distant hybridization. Through the observation of pollen mother cells of first generation of distant hybrilization (M 1 ), it was found that the amount of bivalents at meiosis metaphase was 13.65 on average, and was 14.55 on maximum, which were close to theoretical value, but the corresponding amount of bivalents at the same stage produced by unirradiated pollen mother cells were 12.80, which were lower than theorectical value. Chromosome pairing was improved by irradiation. Average setting ratio of M 1 generation affected by irradiation was 52.85%, but the corresponding figure for F 1 generation affected by un-irradiation was 6.49%. It is obvious that irradiation treatment increases setting rate of M 1 hybrid generation. The optimum doses for irradiating androgametes are 1600 and 2400 rad, respectively. However, there are significant differences of irradiation sensibility between different varieties of wheat

  2. Cytogenetical investigations on fertilization, embriogenesis and fruit formation by irradiated pollen. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Dryanovska, O.

    1981-01-01

    The mechanism of fertilization pollination with gamma-irradiated pollen (1-500 kR) in plants of various double fertilization: Crepis (Nicotiana tabacum, Lycopersicum esculentum, Solanum melongena, Ornithogalum gramminifolium, Melandrium rubrum) type, Lilium (Lilium speciosum) type, and Trandescantia (Tradescantia paludosa) type was studied, along with the opportunity of its modification, embryogenesis and fruit and seed formation. In the Crepis type, depending on the disturbances of male chromatin, fertilization manifested itself as: 1) normal karyogamy with decondensation of male chromatin and the formation of supplementary nucleoli and further development of embryo and endosperm (1-500 kR); 2) karyogamy without decondensation and functioning of the male chromatin (1-500 kR); 3) karyogamy or sticking the male chromatin to the nuclei of the female sex cells, stimulating the development of the ovule, embryo, and endosperm (50-500 kR); 4) sticking the highly pycnotized male chromatin to the nuclei of the female sex cells without evidence of zygote and endosperm function and further development (50-500 kR). In the Lilium type modification of fertilization was manifested by: 1) normal karyogamy with developing diploid embryos and pentaploid endosperm with aberrations (1-20 kK); 2) sticking the male chromatin to the nuclei of the female sex cells and stimulation of their development (50-500 kR). In the Trandescantia type the irradiated male chromatin modified fertilization as: 1) karyogamy with spermia having fragments, two spermia connected by a bridge or with a generative nucleus with aberrations (1-50 kR); 2) karyogamy without developing the female sex nuclei (10-500kR); 3) karyogamy or sticking the male chromatin to the female sex cell nuclei and stimulation of their development (10-500 kR); 4) sticking the male chromatin with no stimulating effect (10-500 kR).

  3. Impact of common cytostatic drugs on pollen fertility in higher plants.

    Science.gov (United States)

    Mišík, Miroslav; Kundi, Michael; Pichler, Clemens; Filipic, Metka; Rainer, Bernhard; Mišíková, Katarina; Nersesyan, Armen; Knasmueller, Siegfried

    2016-08-01

    Cytostatic drugs are among the most toxic chemicals which are produced. Many of them cause damage of the genetic material which may affect the fertility of higher organisms. To study the impact of the widely used anticancer drugs [cisplatin (CisPt), etoposide (Et), and 5-fluorouracil (5-FU)] on the reproduction of higher plants, pollen abortion experiments were conducted with species which belong to major plant families, namely with Tradescantia paludosa (Commelinaceae), Arabidopsis thaliana (Brassicaceae), Chelidonium majus (Papaveraceae), and Alisma plantago-aquatica (Alismataceae). All compounds increased the frequencies of abortive grains. The lowest effective doses were in general in a narrow range (i.e., 1 and 10 mg/kg of dry soil). The effects of the individual drugs were similar in T. paludosa, A. plantago-aquatica, and Ch. majus, while A. thaliana was consistently less sensitive. The highest abortion rate was obtained in most experiments with CisPt, followed by 5-FU and Et. Comparisons of the doses which caused effects in the present experiments in the different species with the predicted environment concentrations and with the levels of the cytostatics which were detected in hospital wastewaters show that the realistic environmental concentrations of the drugs are 4-6 orders of magnitude lower. Therefore, it is unlikely that these drugs affect the fertility of higher plants in aquatic and terrestrial ecosystems.

  4. Silencing of the pollen-specific gene NTP303 and its family members in tobacco affects in vivo pollen tube growth and results in male sterile plants

    NARCIS (Netherlands)

    Groot, de P.; Weterings, K.; Been, de M.; Wittink, F.; Hulzink, R.; Custers, J.B.M.; Herpen, van T.W.J.M.; Wullems, G.

    2004-01-01

    In seed plants, successful fertilization requires correct regulation of pollen tube growth. At germination and during growth, the pollen tube interacts with tissues from the pistil while the pollen tube extends via tip growth. Despite the fact that much research has been devoted to the mechanisms

  5. Suppression or knockout of SaF/SaM overcomes the Sa-mediated hybrid male sterility in rice

    Institute of Scientific and Technical Information of China (English)

    Yongyao Xie; Baixiao Niu; Yunming Long; Gousi Li; Jintao Tang; Yaling Zhang; Ding Ren; Yao-Guang Liu; Letian Chen

    2017-01-01

    Hybrids between the indica and japonica subspecies of rice (Oryza sativa) are usually sterile, which hinders utilization of heterosis in the inter-subspecific hybrid breeding. The complex locus Sa comprises two adjacently located genes, SaF and SaM, which interact to cause abortion of pollen grains carrying the japonica allele in japonica-indica hybrids. Here we showed that silencing of SaF or SaM by RNA interference restored male fertility in indica-japonica hybrids with heterozygous Sa. We further used clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-based genome editing to knockout the SaF and SaM alleles, respectively, of an indica rice line to create hybrid-compatible lines. The resultant artificial neutral alleles did not affect pollen viability and other agricultural traits, but did break down the reproductive barrier in the hybrids. We found that some rice lines have natural neutral allele Sa-n, which was compatible with the typical japonica or indica Sa alleles in hybrids. Our results demonstrate that SaF and SaM are required for hybrid male sterility, but are not essential for pollen development. This study provides effective approaches for the generation of hybrid-compatible lines by knocking out the Sa locus or using the natural Sa-n allele to overcome hybrid male sterility in rice breeding.

  6. Pollen Killer Gene S35 Function Requires Interaction with an Activator That Maps Close to S24, Another Pollen Killer Gene in Rice

    Directory of Open Access Journals (Sweden)

    Takahiko Kubo

    2016-05-01

    Full Text Available Pollen killer genes disable noncarrier pollens, and are responsible for male sterility and segregation distortion in hybrid populations of distantly related plant species. The genetic networks and the molecular mechanisms underlying the pollen killer system remain largely unknown. Two pollen killer genes, S24 and S35, have been found in an intersubspecific cross of Oryza sativa ssp. indica and japonica. The effect of S24 is counteracted by an unlinked locus EFS. Additionally, S35 has been proposed to interact with S24 to induce pollen sterility. These genetic interactions are suggestive of a single S24-centric genetic pathway (EFS–S24–S35 for the pollen killer system. To examine this hypothetical genetic pathway, the S35 and the S24 regions were further characterized and genetically dissected in this study. Our results indicated that S35 causes pollen sterility independently of both the EFS and S24 genes, but is dependent on a novel gene close to the S24 locus, named incentive for killing pollen (INK. We confirmed the phenotypic effect of the INK gene separately from the S24 gene, and identified the INK locus within an interval of less than 0.6 Mb on rice chromosome 5. This study characterized the genetic effect of the two independent genetic pathways of INK–S35 and EFS–S24 in indica–japonica hybrid progeny. Our results provide clear evidence that hybrid male sterility in rice is caused by several pollen killer networks with multiple factors positively and negatively regulating pollen killer genes.

  7. Pollen Killer Gene S35 Function Requires Interaction with an Activator That Maps Close to S24, Another Pollen Killer Gene in Rice.

    Science.gov (United States)

    Kubo, Takahiko; Yoshimura, Atsushi; Kurata, Nori

    2016-05-03

    Pollen killer genes disable noncarrier pollens, and are responsible for male sterility and segregation distortion in hybrid populations of distantly related plant species. The genetic networks and the molecular mechanisms underlying the pollen killer system remain largely unknown. Two pollen killer genes, S24 and S35, have been found in an intersubspecific cross of Oryza sativa ssp. indica and japonica The effect of S24 is counteracted by an unlinked locus EFS Additionally, S35 has been proposed to interact with S24 to induce pollen sterility. These genetic interactions are suggestive of a single S24-centric genetic pathway (EFS-S24-S35) for the pollen killer system. To examine this hypothetical genetic pathway, the S35 and the S24 regions were further characterized and genetically dissected in this study. Our results indicated that S35 causes pollen sterility independently of both the EFS and S24 genes, but is dependent on a novel gene close to the S24 locus, named incentive for killing pollen (INK). We confirmed the phenotypic effect of the INK gene separately from the S24 gene, and identified the INK locus within an interval of less than 0.6 Mb on rice chromosome 5. This study characterized the genetic effect of the two independent genetic pathways of INK-S35 and EFS-S24 in indica-japonica hybrid progeny. Our results provide clear evidence that hybrid male sterility in rice is caused by several pollen killer networks with multiple factors positively and negatively regulating pollen killer genes. Copyright © 2016 Kubo et al.

  8. Grass Pollen Pollution from Biofuels Farming

    Czech Academy of Sciences Publication Activity Database

    Ratajová, A.; Tříska, Jan; Vrchotová, Naděžda; Kolář, L.; Kužel, S.

    2013-01-01

    Roč. 26, č. 4 (2013), s. 199-203 ISSN 2151-321X R&D Projects: GA MŠk(CZ) ED1.1.00/02.0073 Institutional support: RVO:67179843 Keywords : grass pollen pollution * biofuels farming * temperate climate * PK-fertilization * N-fertilization * phenolic Subject RIV: EH - Ecology, Behaviour Impact factor: 0.556, year: 2013

  9. Effect of gamma-radiation on grapevine pollen

    International Nuclear Information System (INIS)

    Bozhinova-Boneva, I.

    1974-01-01

    A test was performed in 1968-1971. Pollen of the Bolgar and Muscat of Hamburg varieties was irradiated with doses of 0.5, 1.0, 1.5, 10, 20, 30, 40 and 60 kR. Variously treated pollen was used for pollinating 10-20 catkins of Chaoush variety. The viability of treated pollen was checked on 1% agarmedium at 25 0 C. Low doses of 0.5 and 1.0 kR have exerted a stimulant effect on the pollen sprouting. A dose of 60 kR did not bring about full loss of pollen viability. As the dose increased the number of hybrid seeds produced declined. The Chaoush x Bolgar cross as a control yielded 459 seeds; 580 from 0.5 kR-treated pollen; 530 from 1.0 kR-treated pollen; 324 from 1.5 kR-; 287 from 7 kR-; 202 from 10 kR-; 96 from 20 kR-; 46 from 30 kR-; 19 from 40 kR- and no seeds from 60 kR-treated pollen were obtained. A similar picture was obtained for the other cross. The Chaoush x Bolgar cross produced the following number of hybrid seeds: control - 13; 0.5 kR - 16; 1.0kR - 14; 5 kR - 14; 7 kR - 10; 10 kR - 6 seeds and from over 20 kR - nil

  10. Pollen irradiation and possible gene transfer in Nicotiana species

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen

    1985-01-01

    , and Petunia parodii with irradiated pollen from N. alata and Petunia hybrida showed no evidence of gene transfer, nor did experiments with irradiated mentor pollen. This indicates that gene transfer with irradiated pollen between non-crossing species or between species giving sterile hybrids is probably...

  11. Fertilization Mechanisms in Flowering Plants.

    Science.gov (United States)

    Dresselhaus, Thomas; Sprunck, Stefanie; Wessel, Gary M

    2016-02-08

    Compared with the animal kingdom, fertilization is particularly complex in flowering plants (angiosperms). Sperm cells of angiosperms have lost their motility and require transportation as a passive cargo by the pollen tube cell to the egg apparatus (egg cell and accessory synergid cells). Sperm cell release from the pollen tube occurs after intensive communication between the pollen tube cell and the receptive synergid, culminating in the lysis of both interaction partners. Following release of the two sperm cells, they interact and fuse with two dimorphic female gametes (the egg and the central cell) forming the major seed components embryo and endosperm, respectively. This process is known as double fertilization. Here, we review the current understanding of the processes of sperm cell reception, gamete interaction, their pre-fertilization activation and fusion, as well as the mechanisms plants use to prevent the fusion of egg cells with multiple sperm cells. The role of Ca(2+) is highlighted in these various processes and comparisons are drawn between fertilization mechanisms in flowering plants and other eukaryotes, including mammals. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Using maize as a model to study pollen tube growth and guidance, cross-incompatibility and sperm delivery in grasses.

    Science.gov (United States)

    Dresselhaus, Thomas; Lausser, Andreas; Márton, Mihaela L

    2011-09-01

    In contrast to animals and lower plants such as mosses and ferns, sperm cells of flowering plants (angiosperms) are immobile and require transportation to the female gametes via the vegetative pollen tube cell to achieve double fertilization. The path of the pollen tube towards the female gametophyte (embryo sac) has been intensively studied in many intra- and interspecific crossing experiments with the aim of increasing the gene pool of crop plants for greater yield, improved biotic and abiotic stress resistance, and for introducing new agronomic traits. Many attempts to hybridize different species or genotypes failed due to the difficulty for the pollen tubes in reaching the female gametophyte. Detailed studies showed that these processes are controlled by various self-incompatible (intraspecific) and cross-incompatible (interspecific) hybridization mechanisms. Understanding the molecular mechanisms of crossing barriers is therefore of great interest in plant reproduction, evolution and breeding research. In particular, pre-zygotic hybridization barriers related to pollen tube germination, growth, guidance and sperm delivery, which are considered the major hybridization controls in nature and thus also contribute to species isolation and speciation, have been intensively investigated. Despite this general interest, surprisingly little is known about these processes in the most important agronomic plant family, the Gramineae, Poaceae or grasses. Small polymorphic proteins and their receptors, degradation of sterility locus proteins and general compounds such as calcium, γ-aminobutyric acid or nitric oxide have been shown to be involved in progamic pollen germination, adhesion, tube growth and guidance, as well as sperm release. Most advances have been made in the Brassicaceae, Papaveraceae, Linderniaceae and Solanaceae families including their well-understood self-incompatibility (SI) systems. Grass species evolved similar mechanisms to control the penetration

  13. Exogenous selection rather than cytonuclear incompatibilities shapes asymmetrical fitness of reciprocal Arabidopsis hybrids.

    Science.gov (United States)

    Muir, Graham; Ruiz-Duarte, Paola; Hohmann, Nora; Mable, Barbara K; Novikova, Polina; Schmickl, Roswitha; Guggisberg, Alessia; Koch, Marcus A

    2015-04-01

    Reciprocal crosses between species often display an asymmetry in the fitness of F1 hybrids. This pattern, referred to as isolation asymmetry or Darwin's corollary to Haldane's rule, is a general feature of reproductive isolation in plants, yet factors determining its magnitude and direction remain unclear. We evaluated reciprocal species crosses between two naturally hybridizing diploid species of Arabidopsis to assess the degree of isolation asymmetry at different postmating life stages. We found that pollen from Arabidopsis arenosa will usually fertilize ovules from Arabidopsis lyrata; the reverse receptivity being less complete. Maternal A. lyrata parents set more F1 hybrid seed, but germinate at lower frequency, reversing the asymmetry. As predicted by theory, A. lyrata (the maternal parent with lower seed viability in crosses) exhibited accelerated chloroplast evolution, indicating that cytonuclear incompatibilities may play a role in reproductive isolation. However, this direction of asymmetrical reproductive isolation is not replicated in natural suture zones, where delayed hybrid breakdown of fertility at later developmental stages, or later-acting selection against A. arenosa maternal hybrids (unrelated to hybrid fertility, e.g., substrate adaptation) may be responsible for an excess of A. lyrata maternal hybrids. Exogenous selection rather than cytonuclear incompatibilities thus shapes the asymmetrical postmating isolation in nature.

  14. Environmental and economic impacts of fertilizer drawn forward osmosis and nanofiltration hybrid system

    KAUST Repository

    Kim, Jung Eun; Phuntsho, Sherub; Chekli, Laura; Hong, Seungkwan; Ghaffour, NorEddine; Leiknes, TorOve; Choi, Joon Yong; Shon, Ho Kyong

    2017-01-01

    Environmental and economic impacts of the fertilizer drawn forward osmosis (FDFO) and nanofiltration (NF) hybrid system were conducted and compared with conventional reverse osmosis (RO) hybrid scenarios using microfiltration (MF) or ultrafiltration

  15. Gibberellin regulates pollen viability and pollen tube growth in rice.

    Science.gov (United States)

    Chhun, Tory; Aya, Koichiro; Asano, Kenji; Yamamoto, Eiji; Morinaka, Yoichi; Watanabe, Masao; Kitano, Hidemi; Ashikari, Motoyuki; Matsuoka, Makoto; Ueguchi-Tanaka, Miyako

    2007-12-01

    Gibberellins (GAs) play many biological roles in higher plants. We collected and performed genetic analysis on rice (Oryza sativa) GA-related mutants, including GA-deficient and GA-insensitive mutants. Genetic analysis of the mutants revealed that rice GA-deficient mutations are not transmitted as Mendelian traits to the next generation following self-pollination of F1 heterozygous plants, although GA-insensitive mutations are transmitted normally. To understand these differences in transmission, we examined the effect of GA on microsporogenesis and pollen tube elongation in rice using new GA-deficient and GA-insensitive mutants that produce semifertile flowers. Phenotypic analysis revealed that the GA-deficient mutant reduced pollen elongation1 is defective in pollen tube elongation, resulting in a low fertilization frequency, whereas the GA-insensitive semidominant mutant Slr1-d3 is mainly defective in viable pollen production. Quantitative RT-PCR revealed that GA biosynthesis genes tested whose mutations are transmitted to the next generation at a lower frequency are preferentially expressed after meiosis during pollen development, but expression is absent or very low before the meiosis stage, whereas GA signal-related genes are actively expressed before meiosis. Based on these observations, we predict that the transmission of GA-signaling genes occurs in a sporophytic manner, since the protein products and/or mRNA transcripts of these genes may be introduced into pollen-carrying mutant alleles, whereas GA synthesis genes are transmitted in a gametophytic manner, since these genes are preferentially expressed after meiosis.

  16. Suppression or knockout of SaF/SaM overcomes the Sa-mediated hybrid male sterility in rice.

    Science.gov (United States)

    Xie, Yongyao; Niu, Baixiao; Long, Yunming; Li, Gousi; Tang, Jintao; Zhang, Yaling; Ren, Ding; Liu, Yao-Guang; Chen, Letian

    2017-09-01

    Hybrids between the indica and japonica subspecies of rice (Oryza sativa) are usually sterile, which hinders utilization of heterosis in the inter-subspecific hybrid breeding. The complex locus Sa comprises two adjacently located genes, SaF and SaM, which interact to cause abortion of pollen grains carrying the japonica allele in japonica-indica hybrids. Here we showed that silencing of SaF or SaM by RNA interference restored male fertility in indica-japonica hybrids with heterozygous Sa. We further used clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-based genome editing to knockout the SaF and SaM alleles, respectively, of an indica rice line to create hybrid-compatible lines. The resultant artificial neutral alleles did not affect pollen viability and other agricultural traits, but did break down the reproductive barrier in the hybrids. We found that some rice lines have natural neutral allele Sa-n, which was compatible with the typical japonica or indica Sa alleles in hybrids. Our results demonstrate that SaF and SaM are required for hybrid male sterility, but are not essential for pollen development. This study provides effective approaches for the generation of hybrid-compatible lines by knocking out the Sa locus or using the natural Sa-n allele to overcome hybrid male sterility in rice breeding. © 2017 The Authors. Bioelectromagnetics published by Wiley Periodicals, Inc. © 2017 Institute of Botany, Chinese Academy of Sciences.

  17. Physiology, phenology and yield of sunflower (autumn) as affected by NPK fertilizer and hybrids

    International Nuclear Information System (INIS)

    Bakht, J.; Shah, S.U.

    2010-01-01

    The present field studies investigate the effect of NPK fertilizer on the physiology, phenology and yield response of sunflower hybrids at National Agricultural Research Centre (NARC), Islamabad, Pakistan during autumn, 2000 and 2001. The response of sunflower hybrids (SF-187 and Parsun-1) were studied using low medium and high rate of NPK (0, 50, 100,150 kg ha/sup -1/) in factorial design with split plot arrangements. Days to R1 (button stage), R4 (inflorescence begins to open), R5.8 (80% anthesis) and R9 (physiological maturity) stages significantly (P<0.05) increased with an increase in fertilizer levels. Among the hybrids, Parsun-1 matured 4-5 days later than SF-187. Similarly, leaf area index (LAI), crop growth rate (CGR), and dry matter accumulation (DMA) also significantly (P<0.05) increased with an increase in fertilizer levels. Maximum LAI, CGR, DMA and seed yield was produced by fertilizer treatments of 150:100:100 kg ha/sup -1/ during both the seasons. Oil content also varied with different combinations of NPK fertilizers which ranged from 37 to 39% during both the seasons. (author)

  18. Effect of pollen irradiation on hybridization of wheat and Eltrigia intermedia and their embryo development

    International Nuclear Information System (INIS)

    Li Guiying; Wang Linqing; Shi Jinguo

    2005-01-01

    Spikes of Eltrigia intermedia were radiated with 5-100 Gy γ-ray during anthesis, and then their pollens were collected to pollinate to the common wheat 'J-11' and 'Chinese Spring'. The effects of pollen irradiation on the seed setting, embryo development, embryo culture and plantlet rate were studied. The results showed that low dose (5-9 Gy) of irradiation enhanced the seed setting for Chinese spring x E. intermedia, but no such effect for J-11xE. intermedia. Irradiation with all doses damaged embryo development, percentage of seeds with embryos; rate of immature hybrid embryos developing into plantlets decreases with the increased doses. Percentage of seeds with abnormal embryos increased significantly with the doses. 12.9%-14.5% of embryos could develop into plants in 30 Gy treatment, which seldom occur to wheat. Embryos in 50 Gy-100 Gy treatment were affected so serious that even none of them could develop into plants in vitro culture. It may be an effective approach to obtaining more mutants and enhancing induced mutation breeding by using combination of pollen irradiation, immature embryo rescue and anther culture of the resultant progenies. (authors)

  19. Construction of a male sterility system for hybrid rice breeding and seed production using a nuclear male sterility gene.

    Science.gov (United States)

    Chang, Zhenyi; Chen, Zhufeng; Wang, Na; Xie, Gang; Lu, Jiawei; Yan, Wei; Zhou, Junli; Tang, Xiaoyan; Deng, Xing Wang

    2016-12-06

    The breeding and large-scale adoption of hybrid seeds is an important achievement in agriculture. Rice hybrid seed production uses cytoplasmic male sterile lines or photoperiod/thermo-sensitive genic male sterile lines (PTGMS) as female parent. Cytoplasmic male sterile lines are propagated via cross-pollination by corresponding maintainer lines, whereas PTGMS lines are propagated via self-pollination under environmental conditions restoring male fertility. Despite huge successes, both systems have their intrinsic drawbacks. Here, we constructed a rice male sterility system using a nuclear gene named Oryza sativa No Pollen 1 (OsNP1). OsNP1 encodes a putative glucose-methanol-choline oxidoreductase regulating tapetum degeneration and pollen exine formation; it is specifically expressed in the tapetum and miscrospores. The osnp1 mutant plant displays normal vegetative growth but complete male sterility insensitive to environmental conditions. OsNP1 was coupled with an α-amylase gene to devitalize transgenic pollen and the red fluorescence protein (DsRed) gene to mark transgenic seed and transformed into the osnp1 mutant. Self-pollination of the transgenic plant carrying a single hemizygous transgene produced nontransgenic male sterile and transgenic fertile seeds in 1:1 ratio that can be sorted out based on the red fluorescence coded by DsRed Cross-pollination of the fertile transgenic plants to the nontransgenic male sterile plants propagated the male sterile seeds of high purity. The male sterile line was crossed with ∼1,200 individual rice germplasms available. Approximately 85% of the F1s outperformed their parents in per plant yield, and 10% out-yielded the best local cultivars, indicating that the technology is promising in hybrid rice breeding and production.

  20. Two-peaked dose curves for irradiated pollen growth

    International Nuclear Information System (INIS)

    Andrejchenko, S.V.; Grodzinskij, D.M.

    1992-01-01

    The effect of γ-radiation on growth activity of bicellular pollen of hybrid petunia has been investigated. Irradiation of pollen with doses of 5 to 70 Gy increases the pollen tube growth in an artificial culture medium. As the radiation dose increases the germination ability of pollen gradually decreases and the mean pollen tube length shortens, which is accompanied by the suppression of the generative cell division into spermia and inhibition of the unscheduled incorporation of labelled thymidine into DNA. With radiation doses of 1200 to 1700 Gy some pollen tubes grow intensively. It is suggested that the phenomenon observed lays the basis for the gametic transformation

  1. Effect of pollen load size and source (self, outcross) on seed and fruit production in highbush blueberry cv. 'Bluecrop' (VACCINIUM CORYMBOSUM; Ericaceae).

    Science.gov (United States)

    Dogterom, M H; Winston, M L; Mukai, A

    2000-11-01

    Reproductive fitness of a plant is ultimately determined by both number and quality of seed offspring. This is determined by sexual selection of pollen microspores and ovules during pollination and fertilization. These processes may include pollen competition and seed abortion, which reduce the number of microspores and ovules available for final seed production. Thus, even an excess of pollen microspores to ovules does not result in fertile seeds equal to ovule number. We investigated pollen requirements of highbush blueberry (Vaccinium corymbosum cultivar 'Bluecrop') for maximal seed production and how fertile seed number translates into fruit quality, since fruit quality would ultimately determine the dispersal of its offspring. We demonstrate that individual blueberry flowers with a mean of 106 ovules reach their maximum fruit set and mass and minimum time to ripen when 125 outcross pollen tetrads pollinate a flower, compared to 10 or 25. Three hundred tetrads resulted in the increase of fertile seeds, but did not result in a further increase of fruit mass or fruit set, or decrease in time to ripen. We also examined the effect of pure and mixed loads of self and outcross pollen (25 and 125 tetrads), and found no differences in fertile seed number, fruit mass, or percentage fruit set when pollen loads were either 25 self or outcross pollen tetrads, although number of days to ripen was significantly shorter by 8 d with 25 outcross tetrads. When the pollen load of 125 tetrads consisted of self or a 50:50 mixture of self and outcross pollen, fruit mass, days to ripen, and percentage fruit set were not different from loads of 125 outcross pollen. In addition, a pollen load of 25 outcross tetrads resulted in fertile seed number and fruit quality in between that of 25 self, and 125 self, 125 mixed, or 125 outcross tetrads. Large, small, and flat seed types were identified, and only large seeds (length = 1.7 mm) were fertile. These results improve our understanding of

  2. Silencing of the pollen-specific gene NTP303 and its family members in tobacco affects in vivo pollen tube growth and results in male sterile plants.

    Science.gov (United States)

    de Groot, Peter; Weterings, Koen; de Been, Mark; Wittink, Floyd; Hulzink, Raymond; Custers, Jan; van Herpen, Marinus; Wullems, George

    2004-07-01

    In seed plants, successful fertilization requires correct regulation of pollen tube growth. At germination and during growth, the pollen tube interacts with tissues from the pistil while the pollen tube extends via tip growth. Despite the fact that much research has been devoted to the mechanisms regulating pollen tube growth, many aspects are currently unknown. Previously, we have isolated a pollen-specific gene from tobacco--NTP303--that probably functions during pollen tube growth. NTP303 is part of a family of five members. Its expression is regulated both at the transcriptional and at the translational level. While NTP303 transcripts accumulate to high levels between early bi-cellular and mature pollen stages, NTP303 protein is hardly detectable until germination and pollen tube growth. In order to elucidate the role and function of NTP303 in the pollen tube, we studied the effect of NTP303 gene silencing on pollen function. Therefore, we have transformed tobacco plants with NTP303 co-suppression and anti-sense gene constructs. In these plants, the kanamycin resistance trait--which was linked to the NTP303-silencing gene--was not transmitted through the male gametophyte. This indicated that lowering the transcript level of NTP303 and/or its family members interferes with pollen function. Because we could not find a readily distinguishable phenotype in pollen from the hemizygous anti-sense and co-suppression plants, we rescued the defective pollen to produce doubled haploid plants that were homozygous for the NTP303 anti-sense gene. We found that in pollen from these plants the transcript levels of all NTP303 family members were reduced. Although pollen and pollen tubes from these plants appeared completely normal in vitro, the pollen tubes showed slower growth rates in vivo and arrested in the style before they reached the ovary, so that fertilization failed. These data demonstrate that NTP303 and its family members are essential for normal pollen tube growth

  3. Pollen morphology of Rhizophora L. in Peninsular Malaysia

    Energy Technology Data Exchange (ETDEWEB)

    Mohd-Arrabe' , A. B.; Noraini, Talip Noraini [School of Environmental and Natural Resource Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2013-11-27

    Rhizophora L. are common mangrove genus in Peninsular Malaysia, it contains 3 species and 1 hybrid (R. apiculata Blume, R. mucronata Lam., R. stylosa Griff., R. x lamarckii Montrouz). This genus has some unique adaptation towards extreme environment. Rhizophora has looping aerial stilt-root and uniformly viviparous. The aim of this study is to investigate the variation in the pollen morphology of Rhizophora that can be related to their habitat. Methods include in this study is pollen observation under light and acetolysis method under scanning electron microscope. Pollen type of Rhizophora species studied except hybrid species is classified tricolporate, shape spheroidal based on ratio of length polar axis/ length of equatorial axis (1.03 - 1.09). The exine ornamentation is perforate-reticulate for R. apiculata and R. mucronata, while R. stylosa is perforate. For the only hybrid in Peninsular Malaysia, R. x lamarckii (R. apiculata x R. stylosa) differs from others, tricolpate with the absence of porate, shape is subprolate and exine ornamentation is reticulate and striate in equatorial region. Pollenkitt is present due to the salty and extreme environment. This may enhance the volume of pollenkitt present surrounding the pollen grains in Rhizophora for protection and adaptation purposes. Based on these findings, it is evident that pollen morphology is somehow related to its natural habitat.

  4. Pollen morphology of Rhizophora L. in Peninsular Malaysia

    International Nuclear Information System (INIS)

    Mohd-Arrabe', A. B.; Noraini, Talip Noraini

    2013-01-01

    Rhizophora L. are common mangrove genus in Peninsular Malaysia, it contains 3 species and 1 hybrid (R. apiculata Blume, R. mucronata Lam., R. stylosa Griff., R. x lamarckii Montrouz). This genus has some unique adaptation towards extreme environment. Rhizophora has looping aerial stilt-root and uniformly viviparous. The aim of this study is to investigate the variation in the pollen morphology of Rhizophora that can be related to their habitat. Methods include in this study is pollen observation under light and acetolysis method under scanning electron microscope. Pollen type of Rhizophora species studied except hybrid species is classified tricolporate, shape spheroidal based on ratio of length polar axis/ length of equatorial axis (1.03 - 1.09). The exine ornamentation is perforate-reticulate for R. apiculata and R. mucronata, while R. stylosa is perforate. For the only hybrid in Peninsular Malaysia, R. x lamarckii (R. apiculata x R. stylosa) differs from others, tricolpate with the absence of porate, shape is subprolate and exine ornamentation is reticulate and striate in equatorial region. Pollenkitt is present due to the salty and extreme environment. This may enhance the volume of pollenkitt present surrounding the pollen grains in Rhizophora for protection and adaptation purposes. Based on these findings, it is evident that pollen morphology is somehow related to its natural habitat

  5. A small asparagine-rich protein required for S-allele-specific pollen rejection in Nicotiana.

    Science.gov (United States)

    McClure, B; Mou, B; Canevascini, S; Bernatzky, R

    1999-11-09

    Although S-locus RNases (S-RNases) determine the specificity of pollen rejection in self-incompatible (SI) solanaceous plants, they alone are not sufficient to cause S-allele-specific pollen rejection. To identify non-S-RNase sequences that are required for pollen rejection, a Nicotiana alata cDNA library was screened by differential hybridization. One clone, designated HT, hybridized strongly to RNA from N. alata styles but not to RNA from Nicotiana plumbaginifolia, a species known to lack one or more factors necessary for S-allele-specific pollen rejection. Sequence analysis revealed a 101-residue ORF including a putative secretion signal and an asparagine-rich domain near the C terminus. RNA blot analysis showed that the HT-transcript accumulates in the stigma and style before anthesis. The timing of HT-expression lags slightly behind S(C10)-RNase in SI N. alata S(C10)S(C10) and is well correlated with the onset of S-allele-specific pollen rejection in the style. An antisense-HT construct was prepared to test for a role in pollen rejection. Transformed (N. plumbaginifolia x SI N. alata S(C10)S(C10)) hybrids with reduced levels of HT-protein continued to express S(C10)-RNase but failed to reject S(C10)-pollen. Control hybrids expressing both S(C10)-RNase and HT-protein showed a normal S-allele-specific pollen rejection response. We conclude that HT-protein is directly implicated in pollen rejection.

  6. Some results of applied interspecific hybridization in sunflower breeding

    International Nuclear Information System (INIS)

    Tsvetkova, F.

    1976-01-01

    Investigations on the interspecific hybridization in sunflower, aimed at developing a diversified initial selection material, were carried out Wild species of the diploid, tetraploid and hexaploid groups, varieties, hybrids, and selfed-lines of cultivated sunflower were used for crossings. To overcome incrossability between the species and sterility in the hybrids the method of f;cilitating of crossability by mutual gra'fting and gamma-rays treatment of seeds and pollen were applied. Results showed that: 1. By the method of interspecific hybridization forms might be produced resistant to more important diseases. 2. Interspecific hybridization in combination with other methods of selection might produce varieties and hybrids with a complex of valuable qualities. 3. Crossings between wild species and cultivated sunflower gave progenies with gene rale sterility. 4. The species H.tuberosus, H.scaberimus, H.arωphylus and H.lenticularis possess genes of full fertility restoration. (author)

  7. Defensin-like ZmES4 mediates pollen tube burst in maize via opening of the potassium channel KZM1.

    Directory of Open Access Journals (Sweden)

    Suseno Amien

    2010-06-01

    Full Text Available In contrast to animals and lower plant species, sperm cells of flowering plants are non-motile and are transported to the female gametes via the pollen tube, i.e. the male gametophyte. Upon arrival at the female gametophyte two sperm cells are discharged into the receptive synergid cell to execute double fertilization. The first players involved in inter-gametophyte signaling to attract pollen tubes and to arrest their growth have been recently identified. In contrast the physiological mechanisms leading to pollen tube burst and thus sperm discharge remained elusive. Here, we describe the role of polymorphic defensin-like cysteine-rich proteins ZmES1-4 (Zea mays embryo sac from maize, leading to pollen tube growth arrest, burst, and explosive sperm release. ZmES1-4 genes are exclusively expressed in the cells of the female gametophyte. ZmES4-GFP fusion proteins accumulate in vesicles at the secretory zone of mature synergid cells and are released during the fertilization process. Using RNAi knock-down and synthetic ZmES4 proteins, we found that ZmES4 induces pollen tube burst in a species-preferential manner. Pollen tube plasma membrane depolarization, which occurs immediately after ZmES4 application, as well as channel blocker experiments point to a role of K(+-influx in the pollen tube rupture mechanism. Finally, we discovered the intrinsic rectifying K(+ channel KZM1 as a direct target of ZmES4. Following ZmES4 application, KZM1 opens at physiological membrane potentials and closes after wash-out. In conclusion, we suggest that vesicles containing ZmES4 are released from the synergid cells upon male-female gametophyte signaling. Subsequent interaction between ZmES4 and KZM1 results in channel opening and K(+ influx. We further suggest that K(+ influx leads to water uptake and culminates in osmotic tube burst. The species-preferential activity of polymorphic ZmES4 indicates that the mechanism described represents a pre-zygotic hybridization

  8. Defensin-Like ZmES4 Mediates Pollen Tube Burst in Maize via Opening of the Potassium Channel KZM1

    Science.gov (United States)

    Márton, Mihaela L.; Debener, Thomas; Geiger, Dietmar; Becker, Dirk; Dresselhaus, Thomas

    2010-01-01

    In contrast to animals and lower plant species, sperm cells of flowering plants are non-motile and are transported to the female gametes via the pollen tube, i.e. the male gametophyte. Upon arrival at the female gametophyte two sperm cells are discharged into the receptive synergid cell to execute double fertilization. The first players involved in inter-gametophyte signaling to attract pollen tubes and to arrest their growth have been recently identified. In contrast the physiological mechanisms leading to pollen tube burst and thus sperm discharge remained elusive. Here, we describe the role of polymorphic defensin-like cysteine-rich proteins ZmES1-4 (Zea mays embryo sac) from maize, leading to pollen tube growth arrest, burst, and explosive sperm release. ZmES1-4 genes are exclusively expressed in the cells of the female gametophyte. ZmES4-GFP fusion proteins accumulate in vesicles at the secretory zone of mature synergid cells and are released during the fertilization process. Using RNAi knock-down and synthetic ZmES4 proteins, we found that ZmES4 induces pollen tube burst in a species-preferential manner. Pollen tube plasma membrane depolarization, which occurs immediately after ZmES4 application, as well as channel blocker experiments point to a role of K+-influx in the pollen tube rupture mechanism. Finally, we discovered the intrinsic rectifying K+ channel KZM1 as a direct target of ZmES4. Following ZmES4 application, KZM1 opens at physiological membrane potentials and closes after wash-out. In conclusion, we suggest that vesicles containing ZmES4 are released from the synergid cells upon male-female gametophyte signaling. Subsequent interaction between ZmES4 and KZM1 results in channel opening and K+ influx. We further suggest that K+ influx leads to water uptake and culminates in osmotic tube burst. The species-preferential activity of polymorphic ZmES4 indicates that the mechanism described represents a pre-zygotic hybridization barrier and may be a

  9. Genomic Conflicts that Cause Pollen Mortality and Raise Reproductive Barriers in Arabidopsis thaliana.

    Science.gov (United States)

    Simon, Matthieu; Durand, Stéphanie; Pluta, Natacha; Gobron, Nicolas; Botran, Lucy; Ricou, Anthony; Camilleri, Christine; Budar, Françoise

    2016-07-01

    Species differentiation and the underlying genetics of reproductive isolation are central topics in evolutionary biology. Hybrid sterility is one kind of reproductive barrier that can lead to differentiation between species. Here, we analyze the complex genetic basis of the intraspecific hybrid male sterility that occurs in the offspring of two distant natural strains of Arabidopsis thaliana, Shahdara and Mr-0, with Shahdara as the female parent. Using both classical and quantitative genetic approaches as well as cytological observation of pollen viability, we demonstrate that this particular hybrid sterility results from two causes of pollen mortality. First, the Shahdara cytoplasm induces gametophytic cytoplasmic male sterility (CMS) controlled by several nuclear loci. Second, several segregation distorters leading to allele-specific pollen abortion (pollen killers) operate in hybrids with either cytoplasm. The complete sterility of the hybrid with the Shahdara cytoplasm results from the genetic linkage of the two causes of pollen mortality, i.e., CMS nuclear determinants and pollen killers. Furthermore, natural variation at these loci in A. thaliana is associated with different male-sterility phenotypes in intraspecific hybrids. Our results suggest that the genomic conflicts that underlie segregation distorters and CMS can concurrently lead to reproductive barriers between distant strains within a species. This study provides a new framework for identifying molecular mechanisms and the evolutionary history of loci that contribute to reproductive isolation, and possibly to speciation. It also suggests that two types of genomic conflicts, CMS and segregation distorters, may coevolve in natural populations. Copyright © 2016 by the Genetics Society of America.

  10. Spawning and fertility of F1 hybrids of the coral genus Acropora in the Indo-Pacific

    Science.gov (United States)

    Isomura, Naoko; Iwao, Kenji; Morita, Masaya; Fukami, Hironobu

    2016-09-01

    The role of hybridization through multi-specific synchronous spawning in the evolution of reef-building corals has been discussed since the 1990s, particularly for the genus Acropora. However, F1 hybrids have been reported as common in only one case in the Caribbean, with no evidence of mechanisms that would allow continuous reproduction of the hybrids. In this study, we report for the first time the fecundity of two F1 hybrid colonies produced experimentally from two Indo-Pacific species, A. intermedia and A. florida. These F1 hybrids spawned at the same time as the parental corals. Backcrossing and F1 hybrid crossing were successful in both directions. Furthermore, more than 90% self-fertilization was achieved in an F1 hybrid, although it was negligible in the parental corals. While it is possible that the F1 hybrid was a chimera, these results suggest that some products of interspecific hybridization may persist as the offspring of self-fertilizing F1 hybrids.

  11. Involvement of CAT in the detoxification of HT-induced ROS burst in rice anther and its relation to pollen fertility.

    Science.gov (United States)

    Zhao, Qian; Zhou, Lujian; Liu, Jianchao; Cao, Zhenzhen; Du, Xiaoxia; Huang, Fudeng; Pan, Gang; Cheng, Fangmin

    2018-05-01

    HT-induced ROS burst in developing anther is closely related to the lowered CAT activity as the result of the markedly suppressed OsCATB transcript, thereby causing severe fertility injury for rice plants exposed to HT at meiosis stage. The reproductive stage of rice plants is highly sensitive to heat stress. In this paper, different rice cultivars were used to investigate the relationship of HT-induced floret sterility with reactive oxygen species (ROS) detoxification in rice anthers under well-controlled climatic conditions. Results showed that high temperature (HT) exposure significantly enhanced the ROS level and malondialdehyde (MDA) content in developing anther, and the increase in ROS amount in rice anther under HT exposure was closely associated with HT-induced decline in the activities of several antioxidant enzymes. For various antioxidant enzymes, SOD and CAT were more susceptible to the ROS burst in rice anther induced by HT exposure than APX and POD, in which SOD and CAT activity in developing anther decreased significantly by HT exposure, whereas APX activity was relatively stable among different temperature regimes. HT-induced decrease in CAT activity was attributable to the suppressed transcript of OsCATB. This occurrence was strongly responsible for HT-induced increase in ROS level and oxidative-damage in rice anther, thereby it finally caused significant reduction in pollen viability and floret fertility for the rice plants exposed to HT during meiosis. Exogenous application of 1000 µM salicylic acid (SA) may alleviate HT-induced reduction in pollen viability and floret fertility, concomitantly with the increased CAT activity and reduced ROS level in rice anther.

  12. Nutritional characteristics of two pigeon pea hybrids – Liming and phosphated fertilization

    Directory of Open Access Journals (Sweden)

    Marcia Atauri Cardelli de Lucena

    2012-12-01

    Full Text Available The use of legumes in animal production systems can be a sustainable alternative as a protein source in rotational grazing system and/or as a protein bank. Pigeon pea (Cajanus cajan (L. Millsp. figure as an example of success of this use on animal nutrition. The development of this species can be limited by the high acidity and low soil phosphorus content. There is a lack of scientific information on the effects of liming and phosphorus fertilization on some nutritional variables of two pigeon pea new hybrids. This study was conducted in pots containing 5 kg of soil in a greenhouse at the Instituto de Zootecnia, Nova Odessa, São Paulo State. There were studied two pigeon pea hybrids, H1 and H2, and the treatments involved agronomic practices: 1 No liming and without phosphorus (control, 2 Liming (L, 3 Phosphorus fertilization (P and 4 Liming plus phosphorus. Liming was proposed to increase soil base saturation to 50%, it was used dolomite lime PRNT = 90%, in an amount corresponding to 4.5 t/ha. Phosphorus fertilization (as superphosphate rate was 60 kg/ha of PO25. The experimental units were allocated according to a complete randomised block design, with five replications. We analyzed the levels of crude protein (CP, neutral detergent fiber (NDF, acid detergent fiber (ADF, in pigeon pea shoot at 45 days of age. Statistical analyzes were performed using the software SISVAR, averages were compared using test for multiple comparisons Student Newman-Keuls - SNK test (P < 0.05. The H1 hybrid had the highest content of CP, by applying P, lime plus P and the control treatment compared to H2 hybrid. The association lime plus P resulted in higher content of CP mainly due to the increased availability of P for plants. Smaller values were observed for NDF in H2 with P application. Lower values of ADF were observed in H1 in both control treatment and P application. The ADF values were lower for the hybrid H2 only for the treatment lime plus P. The two

  13. Evaluation of pollen viability, stigma receptivity and fertilization ...

    African Journals Online (AJOL)

    AJL

    2013-11-13

    Nov 13, 2013 ... by field artificial pollination were analyzed in this study. The maximum pollen viability .... the day before anthesis to avoid self-pollination. Subsequently, between ..... The Lagerstroemia handbook/checklist. Ameri. Association ...

  14. Prdm9 incompatibility controls oligospermia and delayed fertility but no selfish transmission in mouse intersubspecific hybrids.

    Science.gov (United States)

    Flachs, Petr; Bhattacharyya, Tanmoy; Mihola, Ondřej; Piálek, Jaroslav; Forejt, Jiří; Trachtulec, Zdenek

    2014-01-01

    PR-domain 9 (Prdm9) is the first hybrid sterility gene identified in mammals. The incompatibility between Prdm9 from Mus musculus domesticus (Mmd; the B6 strain) and the Hstx2 region of chromosome (Chr) X from M. m. musculus (Mmm; the PWD strain) participates in the complete meiotic arrest of mouse intersubspecific (PWD×B6)F1 hybrid males. Other studies suggest that also semisterile intersubspecific hybrids are relevant for mouse speciation, but the genes responsible remain unknown. To investigate the causes of this semisterility, we analyzed the role of Prdm9 and Chr X in hybrids resulting from the crosses of PWK, another Mmm-derived inbred strain. We demonstrate that Prdm9 and Chr X control the partial meiotic arrest and reduced sperm count in (PWK×B6)F1 males. Asynapsis of heterosubspecific chromosomes and semisterility were partially suppressed by removal of the B6 allele of Prdm9. Polymorphisms between PWK and PWD on Chr X but not in the Prdm9 region were responsible for the modification of the outcome of Prdm9-Chr X F1 hybrid incompatibility. Furthermore, (PWK×B6)F1 hybrid males displayed delayed fertility dependent on the Prdm9 incompatibility. While the Drosophila hybrid sterility gene Overdrive causes both delayed fertility and increased transmission of its own chromosome to the offspring, the segregation of Chr X and the Prdm9 region from the mouse (PWK×B6)F1 males was normal. Our results indicate extended functional consequences of Prdm9-Chr X intersubspecific incompatibility on the fertility of hybrids and should influence the design of fertility analyses in hybrid zones and of laboratory crosses between Mmm and Mmd strains.

  15. Prdm9 incompatibility controls oligospermia and delayed fertility but no selfish transmission in mouse intersubspecific hybrids.

    Directory of Open Access Journals (Sweden)

    Petr Flachs

    Full Text Available PR-domain 9 (Prdm9 is the first hybrid sterility gene identified in mammals. The incompatibility between Prdm9 from Mus musculus domesticus (Mmd; the B6 strain and the Hstx2 region of chromosome (Chr X from M. m. musculus (Mmm; the PWD strain participates in the complete meiotic arrest of mouse intersubspecific (PWD×B6F1 hybrid males. Other studies suggest that also semisterile intersubspecific hybrids are relevant for mouse speciation, but the genes responsible remain unknown. To investigate the causes of this semisterility, we analyzed the role of Prdm9 and Chr X in hybrids resulting from the crosses of PWK, another Mmm-derived inbred strain. We demonstrate that Prdm9 and Chr X control the partial meiotic arrest and reduced sperm count in (PWK×B6F1 males. Asynapsis of heterosubspecific chromosomes and semisterility were partially suppressed by removal of the B6 allele of Prdm9. Polymorphisms between PWK and PWD on Chr X but not in the Prdm9 region were responsible for the modification of the outcome of Prdm9-Chr X F1 hybrid incompatibility. Furthermore, (PWK×B6F1 hybrid males displayed delayed fertility dependent on the Prdm9 incompatibility. While the Drosophila hybrid sterility gene Overdrive causes both delayed fertility and increased transmission of its own chromosome to the offspring, the segregation of Chr X and the Prdm9 region from the mouse (PWK×B6F1 males was normal. Our results indicate extended functional consequences of Prdm9-Chr X intersubspecific incompatibility on the fertility of hybrids and should influence the design of fertility analyses in hybrid zones and of laboratory crosses between Mmm and Mmd strains.

  16. Standardization of different media for in vitro pollen germination of ...

    African Journals Online (AJOL)

    Almond is an important nut crop which, mostly for fruit set, needs the pollination of flowers followed by fertilization. Therefore, pollen viability and its germination capability are essential. To optimize the pollen culture medium of almond and standardization of the best medium, the present study was carried out with 48 different ...

  17. Viable suspensions of maize (Zea mays L.) pollen with exogenous DNA

    Energy Technology Data Exchange (ETDEWEB)

    Broglia, M. [ENEA, Centro Ricerche Casaccia, Rome (Italy). Dip. Innovazione

    1996-12-01

    A viable suspension of maize pollen in aqueous medium containing exogenous DNA would be a suitable tool in attempting maize genetic transformation via pollen grains by different techniques. In this work the effects of addition of DNA to hypertonic aqueous media able to preserve maize pollen viability were investigated. An almost total loss of viability was found when pollen was incubated with native DNA in water or sucrose medium due to the immediate sticking of DNA on the pollen wall. Calcium in the incubation medium avoided DNA sticking preserving pollen fertilization ability. Pre-washing of pollen in hypertonic sucrose solution was proved to remove DNA binding components from the pollen wall. PEG 20%, that is known to inhibit pollen, and silk nucleases, was also used instead of sucrose, without any reduction in the seed-set yields.

  18. Pollen mitochondria in cytoplasmically male sterile tobacco zygotic and embryonic cells

    International Nuclear Information System (INIS)

    Symillides, Y.

    1985-09-01

    An attempt is being made to establish cytoplasmic organelles transmission during the process of fertilization, by using tobacco grain pollen labelled with leucine 14 C and tritiated thymidine. Through autoradiography the fate of pollen germination and its entry into the embryo sac has been studied. A few days after fertilization, labelled cytoplasmic organelles - mainly mitochondria - were detected in the embryo sac. However, labelling was not observed in cytoplasmic organelles by using tritiated thymidine. For more conclusive results labelled DNA incorporated in cytoplasmic organelles have to be traced during the embryo and endosperm development

  19. Pollinators, geitonogamy and a model of pollen transfer

    International Nuclear Information System (INIS)

    Di Pasquale, C.

    1995-12-01

    A model of pollination that considers the amount of geitonogamous pollen transfer in different flowers and plants is presented. We assumed in this work self-incompatible plant species and we studied how pollination is affected by different round trips described by pollinator from its nest, taking into account the fraction geitonogamy and the fraction pollen export. A deterministic model and a stochastic model of pollen transfer were developed from which we found that when pollinators describe a uniform sequence (visit the same number of flowers in each plant), individuals receive the maximum outcross pollen or minimum self pollen. That is, from the point of view of fertilization, the optimal number of flowers visited in each plant depends on the number of flowers of the plant, the length of the visit and the number of individuals. (author). 18 refs, 1 fig

  20. Coconut (Cocos nucifera l.) pollen cryopreservation.

    Science.gov (United States)

    Karun, A; Sjini, K K; Niral, V; Amarnth, C H; Remya, P; Rajesh, M K; Samsudeen, K; Jerard, B A; Engelmann, F

    2014-01-01

    Coconut genetic resources are threatened by pests and pathogens, natural hazards and human activities. Cryopreservation is the only method allowing the safe and cost-effective long-term conservation of recalcitrant seed species such as coconut. The objective of this work was to test the effect of cryopreservation and of cryostorage duration on coconut pollen germination and fertility. Pollen of two coconut varieties (West Coast Tall WWCTW and Chowghat Orange Dwarf CODC) was collected in March-May over three successive years, desiccated to 7.5 % moisture content (FW) and cryopreserved by direct immersion in liquid nitrogen. Germination and pollen tube length (PTL) of desiccated and cryopreserved pollen were not significantly different for both WCT and COD over the three harvest months of the three consecutive years of study. Pollen germination ranged from 24 to 32 % in desiccated pollen whereas it was between 26 and 29 % in cryopreserved COD pollen. In the case of WCT, germination ranged from 30 to 31 % in desiccated pollen, while it was between 28 and 32 % in cryopreserved pollen. PTL of cryopreserved pollen ranged between 224-390 nm and 226-396 mm for COD and WCT, respectively. Germination of COD pollen varied between 29.0 and 44.1 % after 4 years and 1.0/1.5 years cryostorage, respectively. Germination of WCT pollen did not change significantly between 0 and 6 years cryostorage, being comprised between 32 (24 h) and 40 % (1.5 years). Germination and vigour of cryopreserved pollen were generally higher compared to that of pollen dried in oven and non-cryopreserved. Normal seed set was observed in COD and WCT palms using pollen cryostored for 6 months and 4 years. Cryopreserved pollen of five Tall and five Dwarf accessions displayed 24-31 % and 25-49 % germination, respectively. These results show that it is now possible to establish pollen cryobanks to contribute to coconut germplasm long-term conservation.

  1. Pollen tube branching in the ovary of five species of Oenothera

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    Renata Śnieżko

    2014-01-01

    Full Text Available Flowers of Oenothera hookeri Torr. et Gray, Oe. brevistylis and Oe. lamarkiana de Vries were pollinated after anthesis by insects. Oe. biennis L., Oe. suaveolens Desf and sulfurea were selfpollinated in the buds. Pollen morphology was slightly different: Oe. hookeri have regular, triporated pollen, often germinating through two pores; in Oe. suaveolens many pollen grains had callose patches on the intine; in Oe. brevistylis tetraporated pollen were more often than in other species; in Oe. lamarckiana many pollen grains were empty; in Oe. biennis and Oe. suaveolens pollen grain size and viability varied. The pollen tube growth and fertilization were similar in 5 species and can be considered as typical for Oenothera. In the ovary pollen tubes branched and changed their growth direction. Near micropyle they formed short branches to the inner integument. In the nucellus the pollen tube became swollen.

  2. Assortative mating and differential male mating success in an ash hybrid zone population

    Directory of Open Access Journals (Sweden)

    Frascaria-Lacoste Nathalie

    2006-11-01

    Full Text Available Abstract Background The structure and evolution of hybrid zones depend mainly on the relative importance of dispersal and local adaptation, and on the strength of assortative mating. Here, we study the influence of dispersal, temporal isolation, variability in phenotypic traits and parasite attacks on the male mating success of two parental species and hybrids by real-time pollen flow analysis. We focus on a hybrid zone population between the two closely related ash species Fraxinus excelsior L. (common ash and F. angustifolia Vahl (narrow-leaved ash, which is composed of individuals of the two species and several hybrid types. This population is structured by flowering time: the F. excelsior individuals flower later than the F. angustifolia individuals, and the hybrid types flower in-between. Hybrids are scattered throughout the population, suggesting favorable conditions for their local adaptation. We estimate jointly the best-fitting dispersal kernel, the differences in male fecundity due to variation in phenotypic traits and level of parasite attack, and the strength of assortative mating due to differences in flowering phenology. In addition, we assess the effect of accounting for genotyping error on these estimations. Results We detected a very high pollen immigration rate and a fat-tailed dispersal kernel, counter-balanced by slight phenological assortative mating and short-distance pollen dispersal. Early intermediate flowering hybrids, which had the highest male mating success, showed optimal sex allocation and increased selfing rates. We detected asymmetry of gene flow, with early flowering trees participating more as pollen donors than late flowering trees. Conclusion This study provides striking evidence that long-distance gene flow alone is not sufficient to counter-act the effects of assortative mating and selfing. Phenological assortative mating and short-distance dispersal can create temporal and spatial structuring that appears

  3. PECTATE LYASE-LIKE10 is associated with pollen wall development in Brassica campestris.

    Science.gov (United States)

    Jiang, Jingjing; Yao, Lina; Yu, Youjian; Lv, Meiling; Miao, Ying; Cao, Jiashu

    2014-11-01

    PECTATE LYASE-LIKE10 (PLL10) was previously identified as one of the differentially expressed genes both in microspores during the late pollen developmental stages and in pistils during the fertilization process in Chinese cabbage (Brassica campestris ssp. chinensis). Here, antisense-RNA was used to study the functions of BcPLL10 in Chinese cabbage. Abnormal pollen was identified in the transgenic lines (bcpll10-4, -5, and -6). In fertilization experiments, fewer seeds were harvested when the antisense-RNA lines were used as pollen donor. In vivo and in vitro pollen germination assays less germinated pollen tubes were observed in bcpll10 lines. Scanning electron microscopy observation verified that the tryphine materials were over accumulated around the pollen surface and sticked them together in bcpll10. Moreover, transmission electron microscopy observation revealed that the internal endintine was overdeveloped and predominantly occupied the intine, and disturbed the normal proportional distribution of the two layers in the non-germinal furrow region; and no obvious demarcation existed between them in the germinal furrow region in the bcpll10 pollen. Collectively, this study presented a novel PLL gene that played an important role during the pollen wall development in B. campestris, which may also possess potential importance for male sterility usage in agriculture. © 2014 Institute of Botany, Chinese Academy of Sciences.

  4. The beginning of a seed: regulatory mechanisms of double fertilization.

    Science.gov (United States)

    Bleckmann, Andrea; Alter, Svenja; Dresselhaus, Thomas

    2014-01-01

    THE LAUNCH OF SEED DEVELOPMENT IN FLOWERING PLANTS (ANGIOSPERMS) IS INITIATED BY THE PROCESS OF DOUBLE FERTILIZATION: two male gametes (sperm cells) fuse with two female gametes (egg and central cell) to form the precursor cells of the two major seed components, the embryo and endosperm, respectively. The immobile sperm cells are delivered by the pollen tube toward the ovule harboring the female gametophyte by species-specific pollen tube guidance and attraction mechanisms. After pollen tube burst inside the female gametophyte, the two sperm cells fuse with the egg and central cell initiating seed development. The fertilized central cell forms the endosperm while the fertilized egg cell, the zygote, will form the actual embryo and suspensor. The latter structure connects the embryo with the sporophytic maternal tissues of the developing seed. The underlying mechanisms of double fertilization are tightly regulated to ensure delivery of functional sperm cells and the formation of both, a functional zygote and endosperm. In this review we will discuss the current state of knowledge about the processes of directed pollen tube growth and its communication with the synergid cells resulting in pollen tube burst, the interaction of the four gametes leading to cell fusion and finally discuss mechanisms how flowering plants prevent multiple sperm cell entry (polyspermy) to maximize their reproductive success.

  5. A novel male sterility-fertility restoration system in plants for hybrid seed production.

    Science.gov (United States)

    Singh, Surendra Pratap; Singh, Sudhir P; Pandey, Tripti; Singh, Ram Rakshpal; Sawant, Samir V

    2015-06-15

    Hybrid seeds are used for stimulated crop production, as they harness heterosis. The achievement of complete male-sterility in the female-parent and the restored-fertility in F1-hybrids are the major bottlenecks in the commercial hybrid seed production. Here, we report a male sterility-fertility restoration system by engineering the in most nutritive anther wall layer tapetum of female and male parents. In the female parent, high-level, and stringent expression of Arabidopsis autophagy-related gene BECLIN1 was achieved in the tapetum, which altered the tapetal degeneration program, leading to male sterility. This works on our previously demonstrated expression cassette based on functional complementation of TATA-box mutant (TGTA) promoter and TATA-binding protein mutant3 (TBPm3), with modification by conjugating Long Hypocotyle in Far-Red1 fragment (HFR1(NT131)) with TBPm3 (HFR1(NT131)-TBPm3) to exercise regulatory control over it. In the male parent, tapetum-specific Constitutive photo-morphogenesis1 (COP1) was expressed. The F1 obtained by crossing these engineered parents showed decreased BECLIN1 expression, which was further completely abolished when COP1-mutant (COP1(L105A)) was used as a male parent, leading to normal tapetal development and restored fertility. The system works on COP1-HFR1 interaction and COP1-mediated degradation of TBPm3 pool (HFR1(NT131)-TBPm3). The system can be deployed for hybrid seed production in agricultural crops.

  6. Exposure to environmentally-relevant levels of ozone negatively influence pollen and fruit development.

    Science.gov (United States)

    Gillespie, Colin; Stabler, Daniel; Tallentire, Eva; Goumenaki, Eleni; Barnes, Jeremy

    2015-11-01

    A combination of in vitro and in vivo studies on tomato (Lycopersicon esculentum Mill. cv. Triton) revealed that environmentally-relevant levels of ozone (O3) pollution adversely affected pollen germination, germ tube growth and pollen-stigma interactions - pollen originating from plants raised in charcoal-Purafil(®) filtered air (CFA) exhibited reduced germ tube development on the stigma of plants exposed to environmentally-relevant levels of O3. The O3-induced decline in in vivo pollen viability was reflected in increased numbers of non-fertilized and fertilized non-viable ovules in immature fruit. Negative effects of O3 on fertilization occurred regardless of the timing of exposure, with reductions in ovule viability evident in O3 × CFA and CFA × O3 crossed plants. This suggests O3-induced reductions in fertilization were associated with reduced pollen viability and/or ovule development. Fruit born on trusses independently exposed to 100 nmol mol(-1) O3 (10 h d(-1)) from flowering exhibited a decline in seed number and this was reflected in a marked decline in the weight and size of individual fruit - a clear demonstration of the direct consequence of the effects of the pollutant on reproductive processes. Ozone exposure also resulted in shifts in the starch and ascorbic acid (Vitamin C) content of fruit that were consistent with accelerated ripening. The findings of this study draw attention to the need for greater consideration of, and possibly the adoption of weightings for the direct impacts of O3, and potentially other gaseous pollutants, on reproductive biology during 'risk assessment' exercises. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Low level of pollen-mediated gene flow from cultivated to wild grapevine: consequences for the evolution of the endangered subspecies Vitis vinifera L. subsp. silvestris.

    Science.gov (United States)

    Di Vecchi-Staraz, Manuel; Laucou, Valérie; Bruno, Gérard; Lacombe, Thierry; Gerber, Sophie; Bourse, Thibaut; Boselli, Maurizio; This, Patrice

    2009-01-01

    A parentage and a paternity-based approach were tested for estimation of pollen-mediated gene flow in wild grapevine (Vitis vinifera L. subsp. silvestris), a wind-pollinated species occurring in Mediterranean Europe and southwestern Asia. For this purpose, 305 seedlings collected in 2 years at 2 locations in France from 4 wild female individuals and 417 wild individuals prospected from France and Italy were analyzed using 20 highly polymorphic microsatellite loci. Their profiles were compared with a database consisting of 3203 accessions from the Institut National de la Recherche Agronomique Vassal collection including cultivars, rootstocks, interspecific hybrids, and other wild individuals. Paternity was assigned for 202 (66.2%) of the 305 seedlings, confirming the feasibility of the method. Most of the fertilizing pollen could be assigned to wild males growing nearby. Estimates of pollen immigration from the cultivated compartment (i.e., the totality of cultivars) ranged from 4.2% to 26% from nearby vineyards and from hidden pollinators such as cultivars and rootstocks that had escaped from farms. In an open landscape, the pollen flow was correlated to the distance between individuals, the main pollinator being the closest wild male (accounting for 51.4-86.2% of the pollen flow). In a closed landscape, more complex pollination occurred. Analysis of the parentage of the 417 wild individuals also revealed relationships between nearby wild individuals, but in the case of 12 individuals (3%), analysis revealed pollen immigration from vineyards, confirming the fitness of the hybrid seedlings. These pollen fluxes may have a significant effect on the evolution of wild populations: on the one hand, the low level of pollen-mediated gene flow from cultivated to wild grapevine could contribute to a risk of extinction of the wild compartment (i.e., the totality of the wild individuals). On the other hand, pollen dispersal within the wild populations may induce inbreeding

  8. Heritable effect of plant water availability conditions on restoration of male fertility in the ‘9E’ CMS-inducing cytoplasm of sorghum

    Directory of Open Access Journals (Sweden)

    Lev Aleksandrovich Elkonin

    2012-05-01

    Full Text Available Heritable changes of phenotype arising in plant ontogenesis by the influence of environmental factors belong to the most intriguing genetic phenomena. Studying restoration of male fertility in the ‘9E’ type of CMS-inducing cytoplasm of sorghum and related CMS-inducing cytoplasms, A4 and M35-1A, in some hybrid combinations, we found an unusual inheritance pattern: the Rf-genes functioned in the self-pollinated progenies of F1 hybrids (up to F10 but did not or poorly expressed in backcrosses of these hybrids to CMS-lines with the same cytoplasm type. In experiments on parallel growing of the same F1 hybrid combinations in the ‘dry plot’ and in the ‘irrigated plot’, it was found that high level of plant water availability during panicle and pollen developmental stages significantly increased male fertility of F1 and testcross hybrid populations, in which fertility-restoring genes were in heterozygote state, whereas in F2 populations the influences of water availability conditions cause less pronounce effects. Similarly, male-sterile F1 plants, being transferred from the ‘dry plot’ to greenhouse, produced male-fertile panicles. In addition, male-sterile plants from F2 families, which segregated-out as recessives, being transferred to greenhouse also produced male-fertile panicles. In the progenies of these revertants that were grown in field conditions and in the ‘dry plot’, stable inheritance of male fertility for 3 cycles of self-pollination was observed, and a number of stable fertile lines in the ‘9E’ cytoplasm were obtained. However, in test-crosses of these fertile lines to CMS-lines with the ‘9E’ cytoplasm restoration of male fertility was not observed, except the progeny of one revertant that behaved as fertility-restorer line. These data suggest that the functional state of fertility-restoring genes for the ‘9E’ sorghum cytoplasm is epigenetically-regulated trait established by the influence of environmental

  9. The existence of fertile hybrids of closely related model earthworm species, Eisenia andrei and E. fetida.

    Directory of Open Access Journals (Sweden)

    Barbara Plytycz

    Full Text Available Lumbricid earthworms Eisenia andrei (Ea and E. fetida (Ef are simultaneous hermaphrodites with reciprocal insemination capable of self-fertilization while the existence of hybridization of these two species was still debatable. During the present investigation fertile hybrids of Ea and Ef were detected. Virgin specimens of Ea and Ef were laboratory crossed (Ea+Ef and their progeny was doubly identified. 1 -identified by species-specific maternally derived haploid mitochondrial DNA sequences of the COI gene being either 'a' for worms hatched from Ea ova or 'f' for worms hatched from Ef ova. 2 -identified by the diploid maternal/paternal nuclear DNA sequences of 28s rRNA gene being either 'AA' for Ea, 'FF' for Ef, or AF/FA for their hybrids derived either from the 'aA' or 'fF' ova, respectively. Among offspring of Ea+Ef pairs in F1 generation there were mainly aAA and fFF earthworms resulted from the facilitated self-fertilization and some aAF hybrids from aA ova but none fFA hybrids from fF ova. In F2 generation resulting from aAF hybrids mated with aAA a new generations of aAA and aAF hybrids were noticed, while aAF hybrids mated with fFF gave fFF and both aAF and fFA hybrids. Hybrids intercrossed together produced plenty of cocoons but no hatchlings independently whether aAF+aAF or aAF+fFA were mated. These results indicated that Ea and Ef species, easy to maintain in laboratory and commonly used as convenient models in biomedicine and ecotoxicology, may also serve in studies on molecular basis of interspecific barriers and mechanisms of introgression and speciation. Hypothetically, their asymmetrical hybridization can be modified by some external factors.

  10. Cell Wall Composition, Biosynthesis and Remodeling during Pollen Tube Growth

    Directory of Open Access Journals (Sweden)

    Jean-Claude Mollet

    2013-03-01

    Full Text Available The pollen tube is a fast tip-growing cell carrying the two sperm cells to the ovule allowing the double fertilization process and seed setting. To succeed in this process, the spatial and temporal controls of pollen tube growth within the female organ are critical. It requires a massive cell wall deposition to promote fast pollen tube elongation and a tight control of the cell wall remodeling to modify the mechanical properties. In addition, during its journey, the pollen tube interacts with the pistil, which plays key roles in pollen tube nutrition, guidance and in the rejection of the self-incompatible pollen. This review focuses on our current knowledge in the biochemistry and localization of the main cell wall polymers including pectin, hemicellulose, cellulose and callose from several pollen tube species. Moreover, based on transcriptomic data and functional genomic studies, the possible enzymes involved in the cell wall remodeling during pollen tube growth and their impact on the cell wall mechanics are also described. Finally, mutant analyses have permitted to gain insight in the function of several genes involved in the pollen tube cell wall biosynthesis and their roles in pollen tube growth are further discussed.

  11. Three Cell Fusions during Double Fertilization.

    Science.gov (United States)

    Sprunck, Stefanie; Dresselhaus, Thomas

    2015-05-07

    Fertilization of both egg and central cell is a major distinguishing feature of flowering plants. Now, Maruyama et al. report a third cell fusion event between the persistent synergid and the fertilized central cell shortly after double fertilization in Arabidopsis. This causes rapid dilution of pollen tube attractant(s), preventing polytubey. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Starch Biosynthesis during Pollen Maturation Is Associated with Altered Patterns of Gene Expression in Maize1

    Science.gov (United States)

    Datta, Rupali; Chamusco, Karen C.; Chourey, Prem S.

    2002-01-01

    Starch biosynthesis during pollen maturation is not well understood in terms of genes/proteins and intracellular controls that regulate it in developing pollen. We have studied two specific developmental stages: “early,” characterized by the lack of starch, before or during pollen mitosis I; and “late,” an actively starch-filling post-pollen mitosis I phase in S-type cytoplasmic male-sterile (S-CMS) and two related male-fertile genotypes. The male-fertile starch-positive, but not the CMS starch-deficient, genotypes showed changes in the expression patterns of a large number of genes during this metabolic transition. In addition to a battery of housekeeping genes of carbohydrate metabolism, we observed changes in hexose transporter, plasma membrane H+-ATPase, ZmMADS1, and 14-3-3 proteins. Reduction or deficiency in 14-3-3 protein levels in all three major cellular sites (amyloplasts [starch], mitochondria, and cytosol) in male-sterile relative to male-fertile genotypes are of potential interest because of interorganellar communication in this CMS system. Further, the levels of hexose sugars were significantly reduced in male-sterile as compared with male-fertile tissues, not only at “early” and “late” stages but also at an earlier point during meiosis. Collectively, these data suggest that combined effects of both reduced sugars and their reduced flux in starch biosynthesis along with a strong possibility for altered redox passage may lead to the observed temporal changes in gene expressions, and ultimately pollen sterility. PMID:12481048

  13. Mitochondrial ORF79 levels determine pollen abortion in cytoplasmic male sterile rice.

    Science.gov (United States)

    Kazama, Tomohiko; Itabashi, Etsuko; Fujii, Shinya; Nakamura, Takahiro; Toriyama, Kinya

    2016-03-01

    Cytoplasmic male sterility (CMS) is an important agricultural trait characterized by lack of functional pollen, and caused by ectopic and defective mitochondrial gene expression. The pollen function in CMS plants is restored by the presence of nuclear-encoded restorer of fertility (Rf) genes. Previously, we cloned Rf2, which restores the fertility of Lead Rice (LD)-type CMS rice. However, neither the function of Rf2 nor the identity of the mitochondrial gene causing CMS has been determined in LD-CMS rice. Here, we show that the mitochondrial gene orf79 acts as a CMS-associated gene in LD-CMS rice, similar to its role in BT-CMS rice originating from Chinsurah Boro II, and Rf2 weakly restores fertility in BT-CMS rice. We also show that RF2 promotes degradation of atp6-orf79 RNA in a different manner from that of RF1, which is the Rf gene product in BT-CMS rice. The amount of ORF79 protein in LD-CMS rice was one-twentieth of the amount in BT-CMS rice. The difference in ORF79 protein levels probably accounts for the mild and severe pollen defects in LD-CMS and BT-CMS rice, respectively. In the presence of Rf2, accumulation of ORF79 was reduced to almost zero and 25% in LD-CMS and BT-CMS rice, respectively, which probably accounts for the complete and weak fertility restoration abilities of Rf2 in LD-CMS and BT-CMS rice, respectively. These observations indicate that the amount of ORF79 influences the pollen fertility in two strains of rice in which CMS is induced by orf79. © 2016 The Authors The Plant Journal © 2016 John Wiley & Sons Ltd.

  14. Exposure to environmentally-relevant levels of ozone negatively influence pollen and fruit development

    International Nuclear Information System (INIS)

    Gillespie, Colin; Stabler, Daniel; Tallentire, Eva; Goumenaki, Eleni; Barnes, Jeremy

    2015-01-01

    A combination of in vitro and in vivo studies on tomato (Lycopersicon esculentum Mill. cv. Triton) revealed that environmentally-relevant levels of ozone (O_3) pollution adversely affected pollen germination, germ tube growth and pollen-stigma interactions – pollen originating from plants raised in charcoal-Purafil"® filtered air (CFA) exhibited reduced germ tube development on the stigma of plants exposed to environmentally-relevant levels of O_3. The O_3-induced decline in in vivo pollen viability was reflected in increased numbers of non-fertilized and fertilized non-viable ovules in immature fruit. Negative effects of O_3 on fertilization occurred regardless of the timing of exposure, with reductions in ovule viability evident in O_3 × CFA and CFA × O_3 crossed plants. This suggests O_3-induced reductions in fertilization were associated with reduced pollen viability and/or ovule development. Fruit born on trusses independently exposed to 100 nmol mol"−"1 O_3 (10 h d"−"1) from flowering exhibited a decline in seed number and this was reflected in a marked decline in the weight and size of individual fruit – a clear demonstration of the direct consequence of the effects of the pollutant on reproductive processes. Ozone exposure also resulted in shifts in the starch and ascorbic acid (Vitamin C) content of fruit that were consistent with accelerated ripening. The findings of this study draw attention to the need for greater consideration of, and possibly the adoption of weightings for the direct impacts of O_3, and potentially other gaseous pollutants, on reproductive biology during ‘risk assessment’ exercises. - Highlights: • Environmentally-relevant levels of ozone exert negative effects on pollen viability that translate into direct impacts on fruit yield. • Negative impacts of O_3 pollution on reproductive processes were evident regardless of the stage of plant development. • Exposure to environmentally-relevant levels of O_3

  15. In Vitro Pollen Germination of Eichhornia crassipes (Mart. Solms: An Insight into its Preferred Mode of Clonal Reproduction

    Directory of Open Access Journals (Sweden)

    Somnath BHOWMIK

    2012-05-01

    Full Text Available Eichhornia crassipes (Mart. Solms is an aquatic invasive weed throughout the tropical and subtropical regions of the world. The plant rarely produces any fruit under natural condition In order to understand the causes of failure of seed set in this plant various aspect of pollen biology were studied. Pollen fertility and pollen viability was assessed using Muntzing� s mixture and in acetic orcein and TTZ, while pollen germination was assessed with different concentrations of sucrose supplemented with boric acid and Ca and Mg salts. The aim of present study was to find out the cause of sexual incompatibility of Eichhornia crassipes (Mart. Solms. In spite of high pollen fertility, pollen viability and pollen germination the species show hardly any fruit set under natural condition. The abnormal pollen germination like curling of pollen tubes, shrinkage of pollen tube tips and bending of pollen tube might be reasons of sexual incompatibility of this species. It is observed that the taxa required comparatively low sucrose concentration (5% for their optimal in vitro pollen germination (54.08%. Boric acid to certain extent also influences the in vitro pollen germination (56.2%. In the present investigation the nature of substrate in association with the effect of Boric acid, CaCO3, MgSO4 on the in vitro pollen germination of Eichhornia crassipes is also worked out. However the tested salts show no significant effect on pollen germination in the present study.

  16. Transcriptome profiling of differentially expressed genes in floral buds and flowers of male sterile and fertile lines in watermelon.

    Science.gov (United States)

    Rhee, Sun-Ju; Seo, Minseok; Jang, Yoon-Jeong; Cho, Seoae; Lee, Gung Pyo

    2015-11-09

    Male sterility is an important mechanism for the production of hybrid seeds in watermelon. Although fruit development has been studied extensively in watermelon, there are no reports on gene expression in floral organs. In this study, RNA-sequencing (RNA-seq) was performed in two near-isogenic watermelon lines (genic male sterile [GMS] line, DAH3615-MS and male fertile line, DAH3615) to identify the differentially expressed genes (DEGs) related to male sterility. DEG analysis showed that 1259 genes were significantly associated with male sterility at a FDR P-value of watermelon. This analysis revealed essential genes responsible for stamen development, including pollen development and pollen tube elongation, and allowed their functional classification. These results provided new information on global mechanisms related to male sterility in watermelon.

  17. The LuWD40-1 gene encoding WD repeat protein regulates growth and pollen viability in flax (Linum Usitatissimum L.).

    Science.gov (United States)

    Kumar, Santosh; Jordan, Mark C; Datla, Raju; Cloutier, Sylvie

    2013-01-01

    As a crop, flax holds significant commercial value for its omega-3 rich oilseeds and stem fibres. Canada is the largest producer of linseed but there exists scope for significant yield improvements. Implementation of mechanisms such as male sterility can permit the development of hybrids to assist in achieving this goal. Temperature sensitive male sterility has been reported in flax but the leakiness of this system in field conditions limits the production of quality hybrid seeds. Here, we characterized a 2,588 bp transcript differentially expressed in male sterile lines of flax. The twelve intron gene predicted to encode a 368 amino acid protein has five WD40 repeats which, in silico, form a propeller structure with putative nucleic acid and histone binding capabilities. The LuWD40-1 protein localized to the nucleus and its expression increased during the transition and continued through the vegetative stages (seed, etiolated seedling, stem) while the transcript levels declined during reproductive development (ovary, anthers) and embryonic morphogenesis of male fertile plants. Knockout lines for LuWD40-1 in flax failed to develop shoots while overexpression lines showed delayed growth phenotype and were male sterile. The non-viable flowers failed to open and the pollen grains from these flowers were empty. Three independent transgenic lines overexpressing the LuWD40-1 gene had ∼80% non-viable pollen, reduced branching, delayed flowering and maturity compared to male fertile genotypes. The present study provides new insights into a male sterility mechanism present in flax.

  18. The LuWD40-1 gene encoding WD repeat protein regulates growth and pollen viability in flax (Linum Usitatissimum L..

    Directory of Open Access Journals (Sweden)

    Santosh Kumar

    Full Text Available As a crop, flax holds significant commercial value for its omega-3 rich oilseeds and stem fibres. Canada is the largest producer of linseed but there exists scope for significant yield improvements. Implementation of mechanisms such as male sterility can permit the development of hybrids to assist in achieving this goal. Temperature sensitive male sterility has been reported in flax but the leakiness of this system in field conditions limits the production of quality hybrid seeds. Here, we characterized a 2,588 bp transcript differentially expressed in male sterile lines of flax. The twelve intron gene predicted to encode a 368 amino acid protein has five WD40 repeats which, in silico, form a propeller structure with putative nucleic acid and histone binding capabilities. The LuWD40-1 protein localized to the nucleus and its expression increased during the transition and continued through the vegetative stages (seed, etiolated seedling, stem while the transcript levels declined during reproductive development (ovary, anthers and embryonic morphogenesis of male fertile plants. Knockout lines for LuWD40-1 in flax failed to develop shoots while overexpression lines showed delayed growth phenotype and were male sterile. The non-viable flowers failed to open and the pollen grains from these flowers were empty. Three independent transgenic lines overexpressing the LuWD40-1 gene had ∼80% non-viable pollen, reduced branching, delayed flowering and maturity compared to male fertile genotypes. The present study provides new insights into a male sterility mechanism present in flax.

  19. Overcoming inter-subspecific hybrid sterility in rice by developing indica-compatible japonica lines.

    Science.gov (United States)

    Guo, Jie; Xu, Xiaomei; Li, Wentao; Zhu, Wenyin; Zhu, Haitao; Liu, Ziqiang; Luan, Xin; Dai, Ziju; Liu, Guifu; Zhang, Zemin; Zeng, Ruizhen; Tang, Guang; Fu, Xuelin; Wang, Shaokui; Zhang, Guiquan

    2016-06-01

    Rice (Oryza sativa L.) is an important staple crop. The exploitation of the great heterosis that exists in the inter-subspecific crosses between the indica and japonica rice has long been considered as a promising way to increase the yield potential. However, the male and female sterility frequently occurred in the inter-subspecific hybrids hampered the utilization of the heterosis. Here we report that the inter-subspecific hybrid sterility in rice is mainly affected by the genes at Sb, Sc, Sd and Se loci for F1 male sterility and the gene at S5 locus for F1 female sterility. The indica-compatible japonica lines (ICJLs) developed by pyramiding the indica allele (S-i) at Sb, Sc, Sd and Se loci and the neutral allele (S-n) at S5 locus in japonica genetic background through marker-assisted selection are compatible with indica rice in pollen fertility and in spikelet fertility. These results showed a great promise of overcoming the inter-subspecific hybrid sterility and exploiting the heterosis by developing ICJLs.

  20. The possible role of honey bees in the spread of pollen from field trials

    NARCIS (Netherlands)

    Kleinjans, H.A.W.; Keulen, van S.J.; Blacquière, T.; Booij, C.J.H.; Hok-A-Hin, C.H.; Cornelissen, A.C.M.; Dooremalen, van C.

    2012-01-01

    Honey bees are important pollinators in agricultural crops, home gardens, orchards and wildlife habitats. As they fly from flower to flower in search of nectar and pollen, they transfer pollen from plant to plant, thus fertilizing the plants and enabling them to bear fruit. In light of this, honey

  1. Sulfinylated Azadecalins act as functional mimics of a pollen germination stimulant in Arabidopsis pistils

    Science.gov (United States)

    Qin, Yuan; Wysocki, Ronald J; Somogyi, Arpad; Feinstein, Yelena; Franco, Jessica Y; Tsukamoto, Tatsuya; Dunatunga, Damayanthi; Levy, Clara; Smith, Steven; Simpson, Robert; Gang, David; Johnson, Mark A; Palanivelu, Ravishankar

    2011-01-01

    SUMMARY Polarized cell elongation is triggered by small molecule cues during development of diverse organisms. During plant reproduction, pollen interactions with the stigma result in the polar outgrowth of a pollen tube, which delivers sperm cells to the female gametophyte to effect double fertilization. In many plants, pistils stimulate pollen germination. However, in Arabidopsis, the effect of pistils on pollen germination and the pistil factors that stimulate pollen germination remain poorly characterized. Here, we demonstrate that stigma, style, and ovules in Arabidopsis pistils stimulate pollen germination. We isolated an Arabidopsis pistil extract fraction that stimulates Arabidopsis pollen germination, and employed ultrahigh resolution ESI FT-ICR and MS/MS techniques to accurately determine the mass (202.126 daltons) of a compound that is specifically present in this pistil extract fraction. Using the molecular formula (C10H19NOS) and tandem mass spectral fragmentation patterns of the m/z (mass to charge ratio) 202.126 ion, we postulated chemical structures, devised protocols, synthesized N-Methanesulfinyl 1- and 2-azadecalins that are close structural mimics of the m/z 202.126 ion, and showed that they are sufficient to stimulate Arabidopsis pollen germination in vitro (30 µM stimulated ~50% germination) and elicit accession-specific response. Although N-Methanesulfinyl 2-azadecalin stimulated pollen germination in three species of Lineage I of Brassicaceae, it did not induce a germination response in Sisymbrium irio (Lineage II of Brassicaceae) and tobacco, indicating that activity of the compound is not random. Our results show that Arabidopsis pistils promote germination by producing azadecalin-like molecules to ensure rapid fertilization by the appropriate pollen. PMID:21801250

  2. Fertilization in Flowering Plants

    Indian Academy of Sciences (India)

    Ecology and the. Environment ... agents (pollinators), the next step before fertilization is to se- .... the embryo sac are referred to as pollen-pistil interaction and play ..... evolutionary success of flowering plants when compared to other groups of ...

  3. Possible natural hybridization of two morphologically distinct species of Acropora (Cnidaria, Scleractinia in the Pacific: fertilization and larval survival rates.

    Directory of Open Access Journals (Sweden)

    Naoko Isomura

    Full Text Available Natural hybridization of corals in the Indo-Pacific has been considered rather rare. However, field studies have observed many corals with intermediate interspecific or unusual morphologies. Given that the existence of F1 hybrids with intermediate interspecific morphologies has been proven in the Caribbean, hybrids may also inhabit the Indo-Pacific and occur more frequently than expected. In this study, we focused on two morphologically different species, Acropora florida and A. intermedia, and performed crossing experiments at Akajima Island, Japan. Results showed that these species could hybridize in both directions via eggs and sperm, but that fertilization rates significantly differed according to which species provided eggs. These results are similar to those reported from the Caribbean. Although all embryos developed normally to the planular larval stage, the developmental processes of some hybrid embryos were delayed by approximately 1 h compared with conspecific embryos, suggesting that fertilization occurred 1 h later in interspecific crosses than in intraspecific crosses. More successful hybridization could occur under conditions with low numbers of conspecific colonies. Additionally, a comparison of survival rates between hybrid and intraspecific larvae revealed that intra- and interspecific larvae produced from eggs of A. florida survived for significantly longer than those produced from eggs of A. intermedia. Considering these data, under specific conditions, hybrids can be expected to be produced and survive in nature in the Pacific. Furthermore, we identified one colony with intermediate morphology between A. florida and A. intermedia in the field. This colony was fertilized only by eggs of A. florida, with high fertilization rates, suggesting that this colony would be a hybrid of these two species and might be backcrossed.

  4. Reduced pollen viability and achene development in Solidago ×niederederi Khek from Poland

    Directory of Open Access Journals (Sweden)

    Grzegorz Migdałek

    2014-09-01

    Full Text Available Pollen and achene characters of natural interspecific hybrid Solidago ×niederederi Khek were analyzed and compared with putative parental species S. virgaurea L. and S. canadensis L. to estimate the level of disturbances in generative reproduction resulting from its hybrid nature. Pollen viability (stainability of Solidago ×niederederi from one newly discovered locality in NE Poland was evidently reduced to ~65% in both viability tests (acetocarmine and Alexander. The diameter of viable pollen (median 21.11 µm fell between S. canadensis (median 19.52 µm and S. virgaurea (median 23.48 µm. Both parental species produced normally developed achenes with high frequency (~90% whereas in the hybrid, the seed set was dramatically low (6%. The results clearly indicated that sexual reproduction of hybridogenous taxon S. ×niederederi is disturbed, and its potential impact as an invasive species depends mainly on vegetative propagation.

  5. Improvised Media for In Vitro Pollen Germination of some Species of Apocynaceae

    Directory of Open Access Journals (Sweden)

    Reshmi Chatterjee

    2014-09-01

    Full Text Available Pollen germination forms one of the most important stage post pollination prior to fertilization. This is essential for proper seed setting and seed development. In vitro pollen germination test is the most reliable way of assessing the pollen viability. In the present study pollen grains of seven genera under Apocynaceae family namely, Allamanda, Alstonia, Catharanthus, Nerium, Plumeria, Thevetia and Tabernaemontana were tested in some basic cultural media, such as Brewbaker’s media, 6% Glucose solution, 4% Calcium Nitrate solution and 3% Boron solution. Alstonia pollen grains exhibited highest percentage of germination rate in all the cultural media. Glucose and Brewbaker’s media is found to be highly suitable for efficient pollen germination in all the genera. Boron solution is effective for germination of pollen grains of tree species. In vitro pollen germination can be easily carried out in laboratories. These results can be utilised in plant breeding programmes to improve cultivar and varieties. DOI: http://dx.doi.org/10.3126/ije.v3i3.11074 International Journal of Environment Vol.3(3 2014: 146-153

  6. Evolutionary restoration of fertility in an interspecies hybrid yeast, by whole-genome duplication after a failed mating-type switch.

    Directory of Open Access Journals (Sweden)

    Raúl A Ortiz-Merino

    2017-05-01

    Full Text Available Many interspecies hybrids have been discovered in yeasts, but most of these hybrids are asexual and can replicate only mitotically. Whole-genome duplication has been proposed as a mechanism by which interspecies hybrids can regain fertility, restoring their ability to perform meiosis and sporulate. Here, we show that this process occurred naturally during the evolution of Zygosaccharomyces parabailii, an interspecies hybrid that was formed by mating between 2 parents that differed by 7% in genome sequence and by many interchromosomal rearrangements. Surprisingly, Z. parabailii has a full sexual cycle and is genetically haploid. It goes through mating-type switching and autodiploidization, followed by immediate sporulation. We identified the key evolutionary event that enabled Z. parabailii to regain fertility, which was breakage of 1 of the 2 homeologous copies of the mating-type (MAT locus in the hybrid, resulting in a chromosomal rearrangement and irreparable damage to 1 MAT locus. This rearrangement was caused by HO endonuclease, which normally functions in mating-type switching. With 1 copy of MAT inactivated, the interspecies hybrid now behaves as a haploid. Our results provide the first demonstration that MAT locus damage is a naturally occurring evolutionary mechanism for whole-genome duplication and restoration of fertility to interspecies hybrids. The events that occurred in Z. parabailii strongly resemble those postulated to have caused ancient whole-genome duplication in an ancestor of Saccharomyces cerevisiae.

  7. [Preliminary study on the effect of climate factors on pollen fertility in Platycodon grandiflorum].

    Science.gov (United States)

    Shi, Feng-hua; Zhang, Lei; Wei, Jian-he

    2011-06-01

    To have a better utilization of male sterile lines in heterozygotic breeding of Platycodon grandiflorum and provide theoretical basis for Platycodon grandiflorum hyboridization. The pollen viability was detected by the means of aceto carmine dyeing, and the correlation analysis between climate factors of each anther development stage and pollen viability was estimated by Pearson coefficients. Pollen viability variation range of male-sterile line GP1BC1-12 was 0% - 27%. That of male-sterile line GP12BC4-10 and chifeng germplasm was respectively 1.3% - 17.9% and 75.9% - 98.5%. Further linear regression analysis between climate factors of each anther development stage and pollen viability indicated that the degree of sensitivity varied with different germplasm of Platycodon grandiflorum. Among three germplasm, male sterile line GP12BC4-10 was the most stable one to the climate factors, and the male-sterile line GP1BC1-12 was the most sensitive one. Temperature and solar irradiation are the most important climate factors to affect pollen viability in Platycodon grandflorum, and microspore mother cells stage (MMC) is its sensetive stage.

  8. Anther response to high-temperature stress during development and pollen thermotolerance heterosis as revealed by pollen tube growth and in vitro pollen vigor analysis in upland cotton.

    Science.gov (United States)

    Song, Guicheng; Wang, Miaomiao; Zeng, Bin; Zhang, Jing; Jiang, Chenliang; Hu, Qirui; Geng, Guangtao; Tang, Canming

    2015-05-01

    Pollen tube growth in styles was strongly inhibited by temperature above 35 °C, and the yield of cotton decreased because of the adverse effect of high temperatures during square development. High-temperature stress during flowering influences the square development of upland cotton (Gossypium hirsutum L.) and cotton yield. Although it is well known that square development is sensitive to high temperature, high-temperature sensitive stages of square development and the effects of high temperature on pollen tube growth in the styles are unknown. The effect of high temperature on anther development corresponding to pollen vigor is unknown during anther development. The objectives of this study were to identify the stages of square development that are sensitive to high temperatures (37/30 and 40/34 °C), to determine whether the abnormal development of squares influenced by high temperature is responsible for the variation in the in vitro germination percent of pollen grains at anthesis, to identify the effect of high temperature on pollen germination in the styles, and to determine pollen thermotolerance heterosis. Our results show that the stages from the sporogenous cell to tetrad stage (square length styles was strongly inhibited by temperature above 35 °C, and the yield of cotton decreased because of the effect of high temperature during square development. The thermotolerance of hybrid F1 pollen showed heterosis, and pollen viability could be used as a criterion for screening for high-temperature tolerance cultivars. These results can be used in breeding to develop new cotton cultivars that can withstand high-temperature conditions, particularly in a future warmer climate.

  9. Paternity analysis of pollen-mediated gene flow for Fraxinus excelsior L. in a chronically fragmented landscape.

    Science.gov (United States)

    Bacles, C F E; Ennos, R A

    2008-10-01

    Paternity analysis based on microsatellite marker genotyping was used to infer contemporary genetic connectivity by pollen of three population remnants of the wind-pollinated, wind-dispersed tree Fraxinus excelsior, in a deforested Scottish landscape. By deterministically accounting for genotyping error and comparing a range of assignment methods, individual-based paternity assignments were used to derive population-level estimates of gene flow. Pollen immigration into a 300 ha landscape represents between 43 and 68% of effective pollination, mostly depending on assignment method. Individual male reproductive success is unequal, with 31 of 48 trees fertilizing one seed or more, but only three trees fertilizing more than ten seeds. Spatial analysis suggests a fat-tailed pollen dispersal curve with 85% of detected pollination occurring within 100 m, and 15% spreading between 300 and 1900 m from the source. Identification of immigrating pollen sourced from two neighbouring remnants indicates further effective dispersal at 2900 m. Pollen exchange among remnants is driven by population size rather than geographic distance, with larger remnants acting predominantly as pollen donors, and smaller remnants as pollen recipients. Enhanced wind dispersal of pollen in a barren landscape ensures that the seed produced within the catchment includes genetic material from a wide geographic area. However, gene flow estimates based on analysis of non-dispersed seeds were shown to underestimate realized gene immigration into the remnants by a factor of two suggesting that predictive landscape conservation requires integrated estimates of post-recruitment gene flow occurring via both pollen and seed.

  10. Characterization of a pollen-specific cDNA clone from Nicotiana tabacum expressed during microgametogenesis and germination.

    Science.gov (United States)

    Weterings, K; Reijnen, W; van Aarssen, R; Kortstee, A; Spijkers, J; van Herpen, M; Schrauwen, J; Wullems, G

    1992-04-01

    This report describes the isolation and characterization of a cDNA clone representing a gene specifically expressed in pollen. A cDNA library was constructed against mRNA from mature pollen of Nicotiana tabacum. It was screened differentially against cDNA from mRNA of leaf and of pollen. One clone, NTPc303, was further characterized. On northern blot this clone hybridizes to a transcript 2100 nucleotides in length. NTPc303 is abundant in pollen. Expression of the corresponding gene is restricted to pollen, because no other generative or vegetative tissue contains transcripts hybridizing to NTPc303. Expression of NTP303 is evolutionarily conserved: homologous transcripts are present in pollen from various plant species. The first NTP303 transcripts are detectable on northern blot at the early bi-nucleate stage and accumulate until the pollen has reached maturity. During germination and pollen tube growth in vitro new NTP303 transcripts appear. This transcription has been proved by northern blots as well as by pulse labelling experiments. Nucleotide sequence analysis revealed that NTPc303 has an open reading frame coding for a predicted protein of 62 kDa. This protein shares homology to ascorbate oxidase and other members of the blue copper oxidase family. A possible function for this clone during pollen germination is discussed.

  11. Hybrid male sterility in rice is due to epistatic interactions with a pollen killer locus.

    Science.gov (United States)

    Kubo, Takahiko; Yoshimura, Atsushi; Kurata, Nori

    2011-11-01

    In intraspecific crosses between cultivated rice (Oryza sativa) subspecies indica and japonica, the hybrid male sterility gene S24 causes the selective abortion of male gametes carrying the japonica allele (S24-j) via an allelic interaction in the heterozygous hybrids. In this study, we first examined whether male sterility is due solely to the single locus S24. An analysis of near-isogenic lines (NIL-F(1)) showed different phenotypes for S24 in different genetic backgrounds. The S24 heterozygote with the japonica genetic background showed male semisterility, but no sterility was found in heterozygotes with the indica background. This result indicates that S24 is regulated epistatically. A QTL analysis of a BC(2)F(1) population revealed a novel sterility locus that interacts with S24 and is found on rice chromosome 2. The locus was named Epistatic Factor for S24 (EFS). Further genetic analyses revealed that S24 causes male sterility when in combination with the homozygous japonica EFS allele (efs-j). The results suggest that efs-j is a recessive sporophytic allele, while the indica allele (EFS-i) can dominantly counteract the pollen sterility caused by S24 heterozygosity. In summary, our results demonstrate that an additional epistatic locus is an essential element in the hybrid sterility caused by allelic interaction at a single locus in rice. This finding provides a significant contribution to our understanding of the complex molecular mechanisms underlying hybrid sterility and microsporogenesis.

  12. Novel CMS lines in pigeonpea [Cajanus cajan (L. Millspaugh] derived from cytoplasmic substitutions, and their effective restoration and deployment in hybrid breeding

    Directory of Open Access Journals (Sweden)

    Abhishek Bohra

    2017-02-01

    Full Text Available The availability of stable cytoplasmic male sterile (CMS or A lines coupled with a robust restoration system (R lines is an essential prerequisite for efficient hybrid breeding. CMS-enabled hybrid technology holds immense potential to enhance the long-stagnant productivity of pigeonpea. In the present investigation, cytoplasmic substitutions were made in the nuclear backgrounds of early-maturing pigeonpea varieties or lines. Three new CMS lines (ICPL 88039A, Pusa 992A, and DPP 3-2A resulted from genetic crosses involving cytoplasmic donors from A2 (GT 288A and A4 (ICPA 2089 categories. In addition to visual inspection of anthers, pollen-staining techniques and scanning electron microscopy (SEM analysis were used to confirm pollen sterility. Further, given the relevance of the plant mitochondrial genome to CMS manifestation, 25 mitochondrion-specific DNA markers were assayed on these newly developed A lines and isogenic maintainer (B lines. DNA polymorphism between Pusa 992A and Pusa 992B as revealed by the nad7a_del marker confirmed the successful combination of sterilizing cytoplasm (A4 and nonrestoring nuclear background (Pusa 992. Such cytoplasm-specific DNA markers are required for A2-CMS as well. Further, to assess restoration ability, potential restorers were crossed with these CMS lines, and as a consequence, promising A × R combinations exhibiting 100% pollen fertility could be identified. In parallel, we also analyzed the inheritance patterns underlying fertility restoration using ICPL 88039A-derived F2 and BC1F1 populations, and established a monogenic dominant model to explain the phenomenon of A2-CMS restoration. In summary, we report the successful development of new CMS lines and describe their effective deployment in hybrid breeding of pigeonpea.

  13. The Metabolic Basis of Pollen Thermo-Tolerance: Perspectives for Breeding

    Directory of Open Access Journals (Sweden)

    Marine J. Paupière

    2014-09-01

    Full Text Available Crop production is highly sensitive to elevated temperatures. A rise of a few degrees above the optimum growing temperature can lead to a dramatic yield loss. A predicted increase of 1–3 degrees in the twenty first century urges breeders to develop thermo-tolerant crops which are tolerant to high temperatures. Breeding for thermo-tolerance is a challenge due to the low heritability of this trait. A better understanding of heat stress tolerance and the development of reliable methods to phenotype thermo-tolerance are key factors for a successful breeding approach. Plant reproduction is the most temperature-sensitive process in the plant life cycle. More precisely, pollen quality is strongly affected by heat stress conditions. High temperature leads to a decrease of pollen viability which is directly correlated with a loss of fruit production. The reduction in pollen viability is associated with changes in the level and composition of several (groups of metabolites, which play an important role in pollen development, for example by contributing to pollen nutrition or by providing protection to environmental stresses. This review aims to underline the importance of maintaining metabolite homeostasis during pollen development, in order to produce mature and fertile pollen under high temperature. The review will give an overview of the current state of the art on the role of various pollen metabolites in pollen homeostasis and thermo-tolerance. Their possible use as metabolic markers to assist breeding programs for plant thermo-tolerance will be discussed.

  14. The metabolic basis of pollen thermo-tolerance: perspectives for breeding.

    Science.gov (United States)

    Paupière, Marine J; van Heusden, Adriaan W; Bovy, Arnaud G

    2014-09-30

    Crop production is highly sensitive to elevated temperatures. A rise of a few degrees above the optimum growing temperature can lead to a dramatic yield loss. A predicted increase of 1-3 degrees in the twenty first century urges breeders to develop thermo-tolerant crops which are tolerant to high temperatures. Breeding for thermo-tolerance is a challenge due to the low heritability of this trait. A better understanding of heat stress tolerance and the development of reliable methods to phenotype thermo-tolerance are key factors for a successful breeding approach. Plant reproduction is the most temperature-sensitive process in the plant life cycle. More precisely, pollen quality is strongly affected by heat stress conditions. High temperature leads to a decrease of pollen viability which is directly correlated with a loss of fruit production. The reduction in pollen viability is associated with changes in the level and composition of several (groups of) metabolites, which play an important role in pollen development, for example by contributing to pollen nutrition or by providing protection to environmental stresses. This review aims to underline the importance of maintaining metabolite homeostasis during pollen development, in order to produce mature and fertile pollen under high temperature. The review will give an overview of the current state of the art on the role of various pollen metabolites in pollen homeostasis and thermo-tolerance. Their possible use as metabolic markers to assist breeding programs for plant thermo-tolerance will be discussed.

  15. RNaseI from Escherichia coli cannot substitute for S-RNase in rejection of Nicotiana plumbaginifolia pollen.

    Science.gov (United States)

    Beecher, B; Murfett, J; McClure, B A

    1998-03-01

    Unilateral incompatibility often occurs between self-incompatible (SI) species and their self-compatible (SC) relatives. For example, SI Nicotiana alata rejects pollen from SC N. plumbaginifolia, but the reciprocal pollination is compatible. This interspecific pollen rejection system closely resembles intraspecific S-allele-specific pollen rejection. However, the two systems differ in degree of specificity. In SI, rejection is S-allele-specific, meaning that only a single S-RNase causes rejection of pollen with a specific S genotype. Rejection of N. plumbaginifolia pollen is less specific, occurring in response to almost any S-RNase. Here, we have tested whether a non-S-RNase can cause rejection of N. plumbaginifolia pollen. The Escherichia coli rna gene encoding RNAseI was engineered for expression in transgenic (N. plumbaginifolia x SC N. alata) hybrids. Expression levels and pollination behavior of hybrids expressing E. coli RNaseI were compared to controls expressing SA2-RNase from N. alata. Immunoblot analysis and RNase activity assays showed that RNaseI and SA2-RNase were expressed at comparable levels. However, expression of SA2-RNase caused rejection of N. plumbaginifolia pollen, whereas expression of RNaseI did not. Thus, in this system, RNase activity alone is not sufficient for rejection of N. plumbaginifolia pollen. The results suggest that S-RNases may be specially adapted to function in pollen rejection.

  16. Fertilizers in cereals crops. Effect of fertilization in grain quality

    International Nuclear Information System (INIS)

    Melaj, Mariana

    1997-01-01

    In the last years the yields of the maize cultivation in the Pampeana production region have constantly increased, foreseeing higher increases of yield in the next years. Such increase is due, between other motives, to the use of hybrids of higher potential yield. There is a direct relation between the yield potential of a genotype and the nutrients demand, fact that constitutes one of the geneticists concerns. Maize hybrids reach its maximum expression when the plant is cultivated in good supplied soils with balanced quantities of nutrients that in several cases are reached with the practice of fertilization. The quantitative and qualitative vegetal response to the use of phosphate fertilizers depend of soils, of the environmental conditions, of fertilizer and the way of its application as well as of the maize hybrid that was used. To direct the practice of fertilization towards the reposition of the soil nutrients extracted by genotypes of high yield without producing excesses that increase costs and put in danger the environment, it is necessary to know the real coefficient used by the plants of the phosphorus available in the soils. The isotopic methodology allows to distinguish the phosphorus coming from two nutrient sources: soil and fertilizer, even in the juvenile phase of vegetal development and to evaluate the efficiency of fertilizers in plant nutrition. The objective of the present work was to evaluate the use of phosphorus coming from one of the phosphorus source available (soil, fertilizer), that should allow to increase and make more specific the knowledge's level of the different maize hybrids. This is obtained by determination of the grade of use of nutrient (of the soil) and of the nutrient of fertilizers, evaluating the qualitative and quantitative responses to fertilization

  17. Molecular and cellular characterization of the tomato pollen profilin, LePro1.

    Directory of Open Access Journals (Sweden)

    Long-Xi Yu

    Full Text Available Profilin is an actin-binding protein involved in the dynamic turnover and restructuring of the actin cytoskeleton in all eukaryotic cells. We previously cloned a profilin gene, designated as LePro1 from tomato pollen. To understand its biological role, in the present study, we investigated the temporal and spatial expression of LePro1 during pollen development and found that the transcript was only detected at late stages during microsporogenesis and pollen maturation. Using antisense RNA, we successfully knocked down the expression of LePro1 in tomato plants using stable transformation, and obtained two antisense lines, A2 and A3 showing significant down-regulation of LePro1 in pollen resulting in poor pollen germination and abnormal pollen tube growth. A disorganized F-actin distribution was observed in the antisense pollen. Down-regulation of LePro1 also appeared to affect hydration of pollen deposited on the stigma and arrested pollen tube elongation in the style, thereby affecting fertilization. Our results suggest that LePro1 in conjunction with perhaps other cytoskeletal proteins, plays a regulatory role in the proper organization of F-actin in tomato pollen tubes through promoting actin assembly. Down-regulation of LePro1 leads to interruption of actin assembly and disorganization of the actin cytoskeleton thus arresting pollen tube growth. Based on the present and previous studies, it is likely that a single transcript of profilin gives rise to multiple forms displaying multifunctionality in tomato pollen.

  18. The cysteine protease CEP1, a key executor involved in tapetal programmed cell death, regulates pollen development in Arabidopsis.

    Science.gov (United States)

    Zhang, Dandan; Liu, Di; Lv, Xiaomeng; Wang, Ying; Xun, Zhili; Liu, Zhixiong; Li, Fenglan; Lu, Hai

    2014-07-01

    Tapetal programmed cell death (PCD) is a prerequisite for pollen grain development in angiosperms, and cysteine proteases are the most ubiquitous hydrolases involved in plant PCD. We identified a papain-like cysteine protease, CEP1, which is involved in tapetal PCD and pollen development in Arabidopsis thaliana. CEP1 is expressed specifically in the tapetum from stages 5 to 11 of anther development. The CEP1 protein first appears as a proenzyme in precursor protease vesicles and is then transported to the vacuole and transformed into the mature enzyme before rupture of the vacuole. cep1 mutants exhibited aborted tapetal PCD and decreased pollen fertility with abnormal pollen exine. A transcriptomic analysis revealed that 872 genes showed significantly altered expression in the cep1 mutants, and most of them are important for tapetal cell wall organization, tapetal secretory structure formation, and pollen development. CEP1 overexpression caused premature tapetal PCD and pollen infertility. ELISA and quantitative RT-PCR analyses confirmed that the CEP1 expression level showed a strong relationship to the degree of tapetal PCD and pollen fertility. Our results reveal that CEP1 is a crucial executor during tapetal PCD and that proper CEP1 expression is necessary for timely degeneration of tapetal cells and functional pollen formation. © 2014 American Society of Plant Biologists. All rights reserved.

  19. Cytological evidences of pollen abortion in Ornithogalum caudatum Ait

    African Journals Online (AJOL)

    Administrator

    2011-10-19

    Oct 19, 2011 ... sterility. INTRODUCTION. Genus Ornithogalum caudatum Ait, with common name ..... chromosome association in F1 hybrids Triticum aestivum × Secale ... nutrient metabolism and pollen abortion of male sterile lines in Lycium.

  20. Nutrient enrichment is associated with altered nectar and pollen chemical composition in Succisa pratensis Moench and increased larval mortality of its pollinator Bombus terrestris L.

    Directory of Open Access Journals (Sweden)

    Tobias Ceulemans

    Full Text Available Pollinators are declining worldwide and possible underlying causes include disease, invasive pest species and large scale land use changes resulting in habitat loss and degradation. One particular cause of habitat degradation is the increased inflow of nutrients due to anthropogenic combustion processes and large scale application of agricultural fertilizers. This nutrient pollution has been shown to affect pollinators through the loss of nectar and pollen-providing plant species. However, it may also affect pollinators through altering the nectar and pollen chemical composition of plant species, hence influencing pollinator food quality. Here, we experimentally investigated the effect of nutrient enrichment on amino acid and sugar composition of nectar and pollen in the grassland plant Sucissa pratensis, and the subsequent colony size and larval mortality of the pollinating bumblebee Bombus terrestris. We found less of the essential amino acids glycine and arginine in the pollen of fertilized plants, and more arginine, ornithine and threonine in the pollen of control plants. Nectar glucose and pollen fructose levels were lower in fertilized plants as compared to control plants. Furthermore, bumblebee colonies visiting fertilized plants showed more dead larvae than colonies visiting control plants. Our results suggest that the fitness of bumblebees can be negatively affected by changes in their food quality following nutrient pollution. If similar patterns hold for other plant and pollinator species, this may have far reaching implications for the maintenance of pollination ecosystem services, as nutrient pollution continues to rise worldwide.

  1. Nutrient enrichment is associated with altered nectar and pollen chemical composition in Succisa pratensis Moench and increased larval mortality of its pollinator Bombus terrestris L.

    Science.gov (United States)

    Ceulemans, Tobias; Hulsmans, Eva; Vanden Ende, Wim; Honnay, Olivier

    2017-01-01

    Pollinators are declining worldwide and possible underlying causes include disease, invasive pest species and large scale land use changes resulting in habitat loss and degradation. One particular cause of habitat degradation is the increased inflow of nutrients due to anthropogenic combustion processes and large scale application of agricultural fertilizers. This nutrient pollution has been shown to affect pollinators through the loss of nectar and pollen-providing plant species. However, it may also affect pollinators through altering the nectar and pollen chemical composition of plant species, hence influencing pollinator food quality. Here, we experimentally investigated the effect of nutrient enrichment on amino acid and sugar composition of nectar and pollen in the grassland plant Sucissa pratensis, and the subsequent colony size and larval mortality of the pollinating bumblebee Bombus terrestris. We found less of the essential amino acids glycine and arginine in the pollen of fertilized plants, and more arginine, ornithine and threonine in the pollen of control plants. Nectar glucose and pollen fructose levels were lower in fertilized plants as compared to control plants. Furthermore, bumblebee colonies visiting fertilized plants showed more dead larvae than colonies visiting control plants. Our results suggest that the fitness of bumblebees can be negatively affected by changes in their food quality following nutrient pollution. If similar patterns hold for other plant and pollinator species, this may have far reaching implications for the maintenance of pollination ecosystem services, as nutrient pollution continues to rise worldwide.

  2. The Cysteine Protease CEP1, a Key Executor Involved in Tapetal Programmed Cell Death, Regulates Pollen Development in Arabidopsis[W][OPEN

    Science.gov (United States)

    Zhang, Dandan; Liu, Di; Lv, Xiaomeng; Wang, Ying; Xun, Zhili; Liu, Zhixiong; Li, Fenglan; Lu, Hai

    2014-01-01

    Tapetal programmed cell death (PCD) is a prerequisite for pollen grain development in angiosperms, and cysteine proteases are the most ubiquitous hydrolases involved in plant PCD. We identified a papain-like cysteine protease, CEP1, which is involved in tapetal PCD and pollen development in Arabidopsis thaliana. CEP1 is expressed specifically in the tapetum from stages 5 to 11 of anther development. The CEP1 protein first appears as a proenzyme in precursor protease vesicles and is then transported to the vacuole and transformed into the mature enzyme before rupture of the vacuole. cep1 mutants exhibited aborted tapetal PCD and decreased pollen fertility with abnormal pollen exine. A transcriptomic analysis revealed that 872 genes showed significantly altered expression in the cep1 mutants, and most of them are important for tapetal cell wall organization, tapetal secretory structure formation, and pollen development. CEP1 overexpression caused premature tapetal PCD and pollen infertility. ELISA and quantitative RT-PCR analyses confirmed that the CEP1 expression level showed a strong relationship to the degree of tapetal PCD and pollen fertility. Our results reveal that CEP1 is a crucial executor during tapetal PCD and that proper CEP1 expression is necessary for timely degeneration of tapetal cells and functional pollen formation. PMID:25035401

  3. Distribution of pectins in the pollen apertures of Oenothera hookeri.velans ster/+ster.

    Science.gov (United States)

    Noher de Halac, I; Cismondi, I A; Rodriguez-Garcia, M I; Famá, G

    2003-04-01

    Cell wall pectins are some of the most complex biopolymers known, and yet their functions remain largely mysterious. The aim of this paper was to deepen the study of the spatial pattern of pectin distribution in the aperture of Oenothera hookeri.velans ster/+ster fertile pollen. We used "in situ" immunocytochemical techniques at electron microscopy, involving monoclonal antibodies JIM5 and JIM7 directed against pectin epitopes in fertile pollen grains of Oenothera hookeri.velans ster/+ster. The same region was also analyzed by classical cytochemistry for polysaccharide detection. Immunogold labelling at the JIM7 epitope showed only in mature pollen labelling mainly located at the intine endo-aperture region. Cytoplasmic structures near the plasma membrane of the vegetative cell showed no labelling gold grains. In the same pollen stge the labelling at the JIM5 epitope was mostly confined to a layer located in the limit between the endexine and the ektexine at the level of the border of the oncus. Some tubuli at the base of the ektexine showed also an accumulation of gold particles. No JIM5 label was demonstrated in the aperture chamber and either in any cytoplasmic structure of the pollen grains. The immunocytochemical technique, when compared with the traditional methods for non-cellulose polysaccharide cytochemistry is fare more sensitive and allows the univocal determination of temporal and spatial location of pectins recognized by the JIM7 and JIM5 MAbs.

  4. Receptor-like kinases as surface regulators for RAC/ROP-mediated pollen tube growth and interaction with the pistil

    Science.gov (United States)

    Zou, Yanjiao; Aggarwal, Mini; Zheng, Wen-Guang; Wu, Hen-Ming; Cheung, Alice Y.

    2011-01-01

    Background RAC/ROPs are RHO-type GTPases and are known to play diverse signalling roles in plants. Cytoplasmic RAC/ROPs are recruited to the cell membrane and activated in response to extracellular signals perceived and mediated by cell surface-located signalling assemblies, transducing the signals to regulate cellular processes. More than any other cell types in plants, pollen tubes depend on continuous interactions with an extracellular environment produced by their surrounding tissues as they grow within the female organ pistil to deliver sperm to the female gametophyte for fertilization. Scope We review studies on pollen tube growth that provide compelling evidence indicating that RAC/ROPs are crucial for regulating the cellular processes that underlie the polarized cell growth process. Efforts to identify cell surface regulators that mediate extracellular signals also point to RAC/ROPs being the molecular switches targeted by growth-regulating female factors for modulation to mediate pollination and fertilization. We discuss a large volume of work spanning more than two decades on a family of pollen-specific receptor kinases and some recent studies on members of the FERONIA family of receptor-like kinases (RLKs). Significance The research described shows the crucial roles that two RLK families play in transducing signals from growth regulatory factors to the RAC/ROP switch at the pollen tube apex to mediate and target pollen tube growth to the female gametophyte and signal its disintegration to achieve fertilization once inside the female chamber. PMID:22476487

  5. Prunus necrotic ringspot virus Early Invasion and Its Effects on Apricot Pollen Grain Performance.

    Science.gov (United States)

    Amari, Khalid; Burgos, Lorenzo; Pallas, Vicente; Sanchez-Pina, María Amelia

    2007-08-01

    ABSTRACT The route of infection and the pattern of distribution of Prunus necrotic ringspot virus (PNRSV) in apricot pollen were studied. PNRSV was detected both within and on the surface of infected pollen grains. The virus invaded pollen during its early developmental stages, being detected in pollen mother cells. It was distributed uniformly within the cytoplasm of uni- and bicellular pollen grains and infected the generative cell. In mature pollen grains, characterized by their triangular shape, the virus was located mainly at the apertures, suggesting that PNRSV distribution follows the same pattern as the cellular components required for pollen tube germination and cell wall tube synthesis. PNRSV also was localized inside pollen tubes, especially in the growth zone. In vitro experiments demonstrated that infection with PNRSV decreases the germination percentage of pollen grains by more than half and delays the growth of pollen tubes by approximately 24 h. However, although PNRSV infection affected apricot pollen grain performance during germination, the presence of the virus did not completely prevent fertilization, because the infected apricot pollen tubes, once germinated, were able to reach the apricot embryo sacs, which, in the climatic conditions of southeastern Spain, mature later than in other climates. Thus, infected pollen still could play an important role in the vertical transmission of PNRSV in apricot.

  6. The influence of pollen γ-irradiation of the growth and development of plants

    International Nuclear Information System (INIS)

    Andrejchenko, S.V.; Grodzinskij, D.M.

    1986-01-01

    A study was made on the influence of pollen gamma irradiation on induction of phenotypic mutation in F 1 hybrid petunia. Some dose regularities characterizing the rate of growth and development of daughter plants were revealed. It was shown that seed formation and embryogenesis depend directly on the degree of pollen gamma irradiation damage

  7. Pollen-Mediated Gene Flow in Maize: Implications for Isolation Requirements and Coexistence in Mexico, the Center of Origin of Maize.

    Science.gov (United States)

    Baltazar, Baltazar M; Castro Espinoza, Luciano; Espinoza Banda, Armando; de la Fuente Martínez, Juan Manuel; Garzón Tiznado, José Antonio; González García, Juvencio; Gutiérrez, Marco Antonio; Guzmán Rodríguez, José Luis; Heredia Díaz, Oscar; Horak, Michael J; Madueño Martínez, Jesús Ignacio; Schapaugh, Adam W; Stojšin, Duška; Uribe Montes, Hugo Raúl; Zavala García, Francisco

    2015-01-01

    Mexico, the center of origin of maize (Zea mays L.), has taken actions to preserve the identity and diversity of maize landraces and wild relatives. Historically, spatial isolation has been used in seed production to maintain seed purity. Spatial isolation can also be a key component for a strategy to minimize pollen-mediated gene flow in Mexico between transgenic maize and sexually compatible plants of maize conventional hybrids, landraces, and wild relatives. The objective of this research was to generate field maize-to-maize outcrossing data to help guide coexistence discussions in Mexico. In this study, outcrossing rates were determined and modeled from eight locations in six northern states, which represent the most economically important areas for the cultivation of hybrid maize in Mexico. At each site, pollen source plots were planted with a yellow-kernel maize hybrid and surrounded by plots with a white-kernel conventional maize hybrid (pollen recipient) of the same maturity. Outcrossing rates were then quantified by assessing the number of yellow kernels harvested from white-kernel hybrid plots. The highest outcrossing values were observed near the pollen source (12.9% at 1 m distance). The outcrossing levels declined sharply to 4.6, 2.7, 1.4, 1.0, 0.9, 0.5, and 0.5% as the distance from the pollen source increased to 2, 4, 8, 12, 16, 20, and 25 m, respectively. At distances beyond 20 m outcrossing values at all locations were below 1%. These trends are consistent with studies conducted in other world regions. The results suggest that coexistence measures that have been implemented in other geographies, such as spatial isolation, would be successful in Mexico to minimize transgenic maize pollen flow to conventional maize hybrids, landraces and wild relatives.

  8. Effects of water suspension and wet-dry cycling on fertility of Douglas-fir pollen.

    Science.gov (United States)

    Donald L. Copes; Nan C. Vance

    2000-01-01

    Studies were made to determine how long Douglas-fir pollen remains viable after suspension in cool water form 0 to 34 days. Linear regression analysis of in vivo and in vitro tests indicated that filled seed efficiency and pollen viability, respectively, decreased about 3 percent per day. The relation may have been nonlinear the first 6 days, as little decrease...

  9. Bio energy production in birch and hybrid aspen after addition of residue based fertilizers - establishment of fertilization trials; Bioenergiproduktion hos bjoerk och hybridasp vid tillfoersel av restproduktbaserade goedselmedel - etablering av goedslingsfoersoek

    Energy Technology Data Exchange (ETDEWEB)

    Thelin, Gunnar (EkoBalans Fenix AB, Malmoe (Sweden))

    2009-03-15

    Sewage sludge and wood ashes could be used as fertilizers in order to increase forest tree production. In southern Sweden forest growth normally increases with approximately 10 % after ash recycling due to increased N and/or P availability. P is added with the ashes and the pH-increasing effect of the wood ash can lead to increased N net mineralization. Other positive effects of wood ash recycling are improved nutrient sustainability and less acid run-off water. Possible negative effects are heavy metal accumulation, if the content of one or more heavy metals of the recycled ash exceeds the heavy metal content of the harvested biomass, and nitrate leaching if the vegetation cannot take up nitrified N. It is important to evaluate the sustainability of fertilization systems based on residues such as sludge and wood ash. Wood ash does not contain N and the P concentration often is too low for the ashes to function as an NP fertilizer. Thus N and sometimes P must be added. Sludge is an interesting alternative. The main purpose of the project is to study sustainable production of forest bio energy in intensively cultivated birch and hybrid aspen stands. Another purpose is to establish experiments that can be used for long term studies and as demonstration objects. In the first few years the goal is to study the short term effects of residue based fertilization compared to conventional NPK fertilization on tree nutrient uptake, nutrient leaching, sustainability and economy. In the long term the goal is to design appropriate fertilization strategies in a residue based fertilization system for the intensive cultivation of birch and hybrid aspen without negative side effects such as large scale nutrient leaching. Four field experiments were established in 2008 and one additional experiment in hybrid aspen will be established in the spring of 2009. Elevated bud N and P concentrations after fertilization with both Ashes+N and NPK means good possibilities for future growth

  10. Anther-preferential expressing gene PMR is essential for the mitosis of pollen development in rice.

    Science.gov (United States)

    Liu, Yaqin; Xu, Ya; Ling, Sheng; Liu, Shasha; Yao, Jialing

    2017-06-01

    Phenotype identification, expression examination, and function prediction declared that the anther-preferential expressing gene PMR may participate in regulation of male gametophyte development in rice. Male germline development in flowering plants produces the pair of sperm cells for double fertilization and the pollen mitosis is a key process of it. Although the structural features of male gametophyte have been defined, the molecular mechanisms regulating the mitotic cell cycle are not well elucidated in rice. Here, we reported an anther-preferential expressing gene in rice, PMR (Pollen Mitosis Relative), playing an essential role in male gametogenesis. When PMR gene was suppressed via RNAi, the mitosis of microspore was severely damaged, and the plants formed unmatured pollens containing only one or two nucleuses at the anthesis, ultimately leading to serious reduction of pollen fertility and seed-setting. The CRISPR mutants, pmr-1 and pmr-2, both showed the similar defects as the PMR-RNAi lines. Further analysis revealed that PMR together with its co-expressing genes were liable to participate in the regulation of DNA metabolism in the nucleus, and affected the activities of some enzymes related to the cell cycle. We finally discussed that unknown protein PMR contained the PHD, SWIB and Plus-3 domains and they might have coordinating functions in regulation pathway of the pollen mitosis in rice.

  11. speciation through asexuality in fish: postzygotic reproductive isolation may be completed in spite of fertility of hybrids

    Directory of Open Access Journals (Sweden)

    Karel Janko

    2015-12-01

    Altogether, it appears that initiation of hybrid asexuality and the completion of speciation process through formation of postRIMs are interconnected phenomena. Both processes are linked to the genetic divergence of hybridizing taxa: initially, hybridization between little diverged species leads to recombinant and fertile hybrids allowing intensive gene flow. As the hybridizing taxa continue to diverge, clonally reproducing hybrid females and sterile males become dominant and the gene flow ceases. The speciation may therefore be completed through asexuality of hybrids The work was supported by grant no. 13-12580S provided by the Czech Science Foundation (www.gacr.cz. Further support was provided by the Academy of Sciences of the Czech Republic (www.cas.cz by the grant no. RVO 67985904

  12. Chromosomal rearrangements in interspecific hybrids between Nicotiana gossei Domin and N. tabacum L., obtained by crossing with pollen exposed to helium ion beams or gamma-rays

    International Nuclear Information System (INIS)

    Kitamura, S.; Inoue, M.; Ohmido, N.; Fukui, K.; Tanaka, A.

    2003-01-01

    It is very difficult to obtain interspecific hybrids between Nicotiana tabacum L. (2n=48) and N. gossei Domin (2n=36), because of strong cross incompatibility. We had already obtained interspecific hybrids between these two species, crossing N. gossei flower with N. tabacum pollen exposed to He ions or gamma-rays. Here, we analyze chromosome constitution of these hybrids by genomic in situ hybridization. In root tip cells of the two hybrids obtained with He ion exposure, most mitotic cells contained 18 chromosomes of N. gossei and 24 chromosomes of N. tabacum. However, in some cells, translocations and insertions between parental genomes were observed. On the other hand, in a hybrid obtained by gamma-ray irradiation, intergenomic rearrangements were not observed, although mitotic cells showed 19 hybridization signals with N. gossei DNA in 41 chromosomes. Such chromosomal changes in structure or constitution may be related to overcoming cross incompatibility between these two species

  13. Isolation and analysis of differentially expressed genes between male fertile and male sterile flower buds of marigold (tagetes erecta L. )

    International Nuclear Information System (INIS)

    Hou, Z.; Tang, N.

    2016-01-01

    Male sterility is an important approach in utilization of heterosis in marigold (Tagetes erecta L.). Study on the mechanism of male sterility is very important, especially in mining of fertility-related genes. Three suppression subtractive hybridization (SSH) cDNA libraries were constructed between male fertile and male sterile flower buds of marigold. Out of 1920 clones, five hundred and six positive clones were verified by dot-blot hybridization. Two hundred and eighty-six non-redundant ESTs were obtained of which, one hundred and ninety-two ESTs corresponding to proteins with known functions. Through GO function annotation, fifteen candidate genes that may have a function in male sterility were identified. These genes involved in hormone pathways and cell cycles as well as encoded transcription factors and protein kinases. Further more, five of them were verified by quantitative real-time PCR, they were CDKB2;1 functioned in cell division, AMS involved in anther wall tapetum development, LAP3 played a role in pollen exine formation, ACOS5 and CYP703A2 involved in sporopollenin biosynthetic process. This is the first study that constructing cDNA libraries containing differentially expressed gene pools associate with male fertility using SSH strategy, and provides a first step to understand the mechanism of male reproductive development in marigold. (author)

  14. Assessing the bioconfinement potential of a Nicotiana hybrid platform for use in plant molecular farming applications.

    Science.gov (United States)

    Rice, J Hollis; Mundell, Richard E; Millwood, Reginald J; Chambers, Orlando D; Stewart, C Neal; Davies, H Maelor

    2013-08-06

    The introduction of pharmaceutical traits in tobacco for commercial production could benefit from the utilization of a transgene bioconfinement system. It has been observed that interspecific F1Nicotiana hybrids (Nicotiana tabacum × Nicotiana glauca) are sterile and thus proposed that hybrids could be suitable bioconfined hosts for biomanufacturing. We genetically tagged hybrids with green fluorescent protein (GFP), which was used as a visual marker to enable gene flow tracking and quantification for field and greenhouse studies. GFP was used as a useful proxy for pharmaceutical transgenes. Analysis of DNA content revealed significant genomic downsizing of the hybrid relative to that of N. tabacum. Hybrid pollen was capable of germination in vitro, albeit with a very low frequency and with significant differences between plants. In two field experiments, one each in Tennessee and Kentucky, we detected outcrossing at only one location (Tennessee) at 1.4%. Additionally, from 50 hybrid plants at each field site, formation of 84 and 16 seed was observed, respectively. Similar conclusions about hybrid fertility were drawn from greenhouse crosses. In terms of above-ground biomass, the hybrid yield was not significantly different than that of N. tabacum in the field. N. tabacum × N. glauca hybrids show potential to contribute to a bioconfinement- and biomanufacturing host system. Hybrids exhibit extremely low fertility with no difference of green biomass yields relative to N. tabacum. In addition, hybrids are morphologically distinguishable from tobacco allowing for identity preservation. This hybrid system for biomanufacturing would optimally be used where N. glauca is not present and in physical isolation of N. tabacum production to provide total bioconfinement.

  15. Environmental and economic impacts of fertilizer drawn forward osmosis and nanofiltration hybrid system

    KAUST Repository

    Kim, Jung Eun; Phuntsho, Sherub; Chekli, Laura; Hong, Seungkwan; Ghaffour, NorEddine; Leiknes, TorOve; Choi, Joon Yong; Shon, Ho Kyong

    2017-01-01

    Environmental and economic impacts of the fertilizer drawn forward osmosis (FDFO) and nanofiltration (NF) hybrid system were conducted and compared with conventional reverse osmosis (RO) hybrid scenarios using microfiltration (MF) or ultrafiltration (UF) as a pre-treatment process. The results showed that the FDFO-NF hybrid system using thin film composite forward osmosis (TFC) FO membrane has less environmental impact than conventional RO hybrid systems due to lower consumption of energy and cleaning chemicals. The energy requirement for the treatment of mine impaired water by the FDFO-NF hybrid system was 1.08 kWh/m, which is 13.6% less energy than an MF-RO and 21% less than UF-RO under similar initial feed solution. In a closed-loop system, the FDFO-NF hybrid system using a TFC FO membrane with an optimum NF recovery rate of 84% had the lowest unit operating expenditure of AUD $0.41/m. Besides, given the current relatively high price and low flux performance of the cellulose triacetate and TFC FO membranes, the FDFO-NF hybrid system still holds opportunities to reduce operating expenditure further. Optimizing NF recovery rates and improving the water flux of the membrane would decrease the unit OPEX costs, although the TFC FO membrane would be less sensitive to this effect.

  16. Environmental and economic impacts of fertilizer drawn forward osmosis and nanofiltration hybrid system

    KAUST Repository

    Kim, Jung Eun

    2017-05-08

    Environmental and economic impacts of the fertilizer drawn forward osmosis (FDFO) and nanofiltration (NF) hybrid system were conducted and compared with conventional reverse osmosis (RO) hybrid scenarios using microfiltration (MF) or ultrafiltration (UF) as a pre-treatment process. The results showed that the FDFO-NF hybrid system using thin film composite forward osmosis (TFC) FO membrane has less environmental impact than conventional RO hybrid systems due to lower consumption of energy and cleaning chemicals. The energy requirement for the treatment of mine impaired water by the FDFO-NF hybrid system was 1.08 kWh/m, which is 13.6% less energy than an MF-RO and 21% less than UF-RO under similar initial feed solution. In a closed-loop system, the FDFO-NF hybrid system using a TFC FO membrane with an optimum NF recovery rate of 84% had the lowest unit operating expenditure of AUD $0.41/m. Besides, given the current relatively high price and low flux performance of the cellulose triacetate and TFC FO membranes, the FDFO-NF hybrid system still holds opportunities to reduce operating expenditure further. Optimizing NF recovery rates and improving the water flux of the membrane would decrease the unit OPEX costs, although the TFC FO membrane would be less sensitive to this effect.

  17. Regulation of fertilization and early seed development.

    Science.gov (United States)

    Dresselhaus, Thomas; Doughty, James

    2014-04-01

    Plant reproduction meetings often deal either with pre-fertilization processes such as flowering and pollen biology or post-fertilization processes such as embryogenesis and seed development. The Biochemical Society Focused Meeting entitled 'Regulation of Fertilization and Early Seed Development' was organized to close this gap and to discuss mechanistic similarities and future research directions in the reproductive processes shortly before, during and after fertilization. As an outcome of the workshop, invited speakers and a few selected oral communication presenters contributed focused reviews and technical articles for this issue of Biochemical Society Transactions. We provide here a short overview of the contents and highlights of the various articles.

  18. Phenology, sterility and inheritance of two environment genic male sterile (EGMS) lines for hybrid rice.

    Science.gov (United States)

    El-Namaky, R; van Oort, P A J

    2017-12-01

    There is still limited quantitative understanding of how environmental factors affect sterility of Environment-conditioned genic male sterility (EGMS) lines. A model was developed for this purpose and tested based on experimental data from Ndiaye (Senegal) in 2013-2015. For the two EGMS lines tested here, it was not clear if one or more recessive gene(s) were causing male sterility. This was tested by studying sterility segregation of the F2 populations. Daylength (photoperiod) and minimum temperatures during the period from panicle initiation to flowering had significant effects on male sterility. Results clearly showed that only one recessive gene was involved in causing male sterility. The model was applied to determine the set of sowing dates of two different EGMS lines such that both would flower at the same time the pollen would be completely sterile. In the same time the local popular variety (Sahel 108, the male pollen donor) being sufficiently fertile to produce the hybrid seeds. The model was applied to investigate the viability of the two line breeding system in the same location with climate change (+2oC) and in two other potential locations: in M'Be in Ivory Coast and in the Nile delta in Egypt. Apart from giving new insights in the relation between environment and EGMS, this study shows that these insights can be used to assess safe sowing windows and assess the suitability of sterility and fertility period of different environments for a two line hybrid rice production system.

  19. Construction of a multicontrol sterility system for a maize male-sterile line and hybrid seed production based on the ZmMs7 gene encoding a PHD-finger transcription factor.

    Science.gov (United States)

    Zhang, Danfeng; Wu, Suowei; An, Xueli; Xie, Ke; Dong, Zhenying; Zhou, Yan; Xu, Liwen; Fang, Wen; Liu, Shensi; Liu, Shuangshuang; Zhu, Taotao; Li, Jinping; Rao, Liqun; Zhao, Jiuran; Wan, Xiangyuan

    2018-02-01

    Although hundreds of genetic male sterility (GMS) mutants have been identified in maize, few are commercially used due to a lack of effective methods to produce large quantities of pure male-sterile seeds. Here, we develop a multicontrol sterility (MCS) system based on the maize male sterility 7 (ms7) mutant and its wild-type Zea mays Male sterility 7 (ZmMs7) gene via a transgenic strategy, leading to the utilization of GMS in hybrid seed production. ZmMs7 is isolated by a map-based cloning approach and encodes a PHD-finger transcription factor orthologous to rice PTC1 and Arabidopsis MS1. The MCS transgenic maintainer lines are developed based on the ms7-6007 mutant transformed with MCS constructs containing the (i) ZmMs7 gene to restore fertility, (ii) α-amylase gene ZmAA and/or (iii) DNA adenine methylase gene Dam to devitalize transgenic pollen, (iv) red fluorescence protein gene DsRed2 or mCherry to mark transgenic seeds and (v) herbicide-resistant gene Bar for transgenic seed selection. Self-pollination of the MCS transgenic maintainer line produces transgenic red fluorescent seeds and nontransgenic normal colour seeds at a 1:1 ratio. Among them, all the fluorescent seeds are male fertile, but the seeds with a normal colour are male sterile. Cross-pollination of the transgenic plants to male-sterile plants propagates male-sterile seeds with high purity. Moreover, the transgene transmission rate through pollen of transgenic plants harbouring two pollen-disrupted genes is lower than that containing one pollen-disrupted gene. The MCS system has great potential to enhance the efficiency of maize male-sterile line propagation and commercial hybrid seed production. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  20. Is there a hybridization barrier between Gentiana lutea color morphs?

    Science.gov (United States)

    Losada, María; Veiga, Tania; Guitián, Javier; Guitián, José; Guitián, Pablo; Sobral, Mar

    2015-01-01

    In Gentiana lutea two varieties are described: G. lutea var. aurantiaca with orange corolla colors and G. lutea var. lutea with yellow corolla colors. Both color varieties co-occur in NW Spain, and pollinators select flower color in this species. It is not known whether a hybridization barrier exists between these G. lutea color varieties. We aim to test the compatibility between flower color varieties in G. lutea and its dependence on pollen vectors. Within a sympatric population containing both flower color morphs, we analyzed differences in reproductive success (number, weight, viability and germinability of seeds) depending on fertilization treatments (autogamy and xenogamy within variety and among varieties). We found a 93% reduction in number of seeds and a 37% reduction in seed weight respectively of autogamy treatments compared to xenogamy crossings. Additionally, reproductive success is higher within color varieties than among varieties, due to a 45% seed viability reduction on hybrids from different varieties. Our results show that G. lutea reproductive success is strongly dependent on pollinators and that a partial hybridization barrier exists between G. lutea varieties.

  1. Is there a hybridization barrier between Gentiana lutea color morphs?

    Science.gov (United States)

    Losada, María; Veiga, Tania; Guitián, Javier; Guitián, José; Guitián, Pablo

    2015-01-01

    In Gentiana lutea two varieties are described: G. lutea var. aurantiaca with orange corolla colors and G. lutea var. lutea with yellow corolla colors. Both color varieties co-occur in NW Spain, and pollinators select flower color in this species. It is not known whether a hybridization barrier exists between these G. lutea color varieties. We aim to test the compatibility between flower color varieties in G. lutea and its dependence on pollen vectors. Within a sympatric population containing both flower color morphs, we analyzed differences in reproductive success (number, weight, viability and germinability of seeds) depending on fertilization treatments (autogamy and xenogamy within variety and among varieties). We found a 93% reduction in number of seeds and a 37% reduction in seed weight respectively of autogamy treatments compared to xenogamy crossings. Additionally, reproductive success is higher within color varieties than among varieties, due to a 45% seed viability reduction on hybrids from different varieties. Our results show that G. lutea reproductive success is strongly dependent on pollinators and that a partial hybridization barrier exists between G. lutea varieties. PMID:26528404

  2. Is there a hybridization barrier between Gentiana lutea color morphs?

    Directory of Open Access Journals (Sweden)

    María Losada

    2015-10-01

    Full Text Available In Gentiana lutea two varieties are described: G. lutea var. aurantiaca with orange corolla colors and G. lutea var. lutea with yellow corolla colors. Both color varieties co-occur in NW Spain, and pollinators select flower color in this species. It is not known whether a hybridization barrier exists between these G. lutea color varieties. We aim to test the compatibility between flower color varieties in G. lutea and its dependence on pollen vectors. Within a sympatric population containing both flower color morphs, we analyzed differences in reproductive success (number, weight, viability and germinability of seeds depending on fertilization treatments (autogamy and xenogamy within variety and among varieties. We found a 93% reduction in number of seeds and a 37% reduction in seed weight respectively of autogamy treatments compared to xenogamy crossings. Additionally, reproductive success is higher within color varieties than among varieties, due to a 45% seed viability reduction on hybrids from different varieties. Our results show that G. lutea reproductive success is strongly dependent on pollinators and that a partial hybridization barrier exists between G. lutea varieties.

  3. Fertilization effects on forest carbon storage and exchange, and net primary production: A new hybrid process model for stand management

    Science.gov (United States)

    D. A. Sampson; R. H. Waring; C. A. Maier; C. M. Gough; M. J. Ducey; K. H. Johnsen

    2006-01-01

    A critical ecological question in plantation management is whether fertilization, which generally increases yield, results in enhanced C sequestration over short rotations. We present a rotation-length hybrid process model (SECRETS-3PG) that was calibrated (using control treatments; CW) and verified (using fertilized treatments; FW) using daily estimates of H

  4. Pollen flow of wheat under natural conditions in the Huanghuai River Wheat Region, China

    Science.gov (United States)

    Sun, Ai-Qing; Zhang, Chun-Qing; Wu, Cheng-Lai; Gao, Qing-Rong

    2015-01-01

    abstract The transgenic pollen spread is the main pathway of transgenic plant gene flow. The maximum distance of pollen dispersal (horizontal), the spatial dynamics of pollen movement (vertical), and the patterns of pollen dispersal are important considerations in biosafety assessments of genetically modified crops. To evaluate wheat (Triticum aestivum) pollen dispersal, we measured the pollen suspension velocity and analyzed pollen dispersal patterns under natural conditions in the Huanghuai River wheat-growing region in 2009. The pollen suspension velocity was 0.3–0.4 m/s. The highest pollen densities were detected in the north, northwest, and south of the pollen source. Pollen was dispersed over distances greater than 245 m in the northwest and northeast directions. At the pollen source center, pollen density decreased with increasing vertical height. In the north of the pollen source, the pollen density from 65 m to 225 m showed a wave-mode decrease with increasing height. The horizontal transport of pollen over longer distances fitted polynomial equations. In the north, the pollen density was highest at 45 m from the pollen source, and decreased with increasing distance. In the northwest, the pollen density showed a double-peak trend. In the northeast, pollen density was highest from 45 m to 125 m from the source. Wind speeds greater than the pollen suspension velocity and the duration of continuous gusts were the main factors affecting pollen dispersal. This information will be useful for determining the spatial isolation distances for hybrid seed production and for the commercial production of transgenic wheat. PMID:25658025

  5. Effect of gamma-ray irradiation on hybridization between Chamaecyparis obtusa S. et Z. and C. pisifera S. et Z

    International Nuclear Information System (INIS)

    Maeta, Takehiko

    1980-01-01

    The effect of gamma irradiation on the interspecific hybridization between Chamaecyparis obtusa and C. pisifera was investigated, and F 1 seedlings were examined cytologically. Acute gamma irradiation and chronic gamma irradiation given throughout annual growing seasons on male flowers were effective in producing hybrids between these two species. The crossing of C. obtusa x C. pisifera was better than the reverse crossing because the pollen of C. obtusa rapidly loses its fertility, and C. pisifera blooms earlier than C. obtusa. Chronic gamma irradiation of male flowers throughout the annual growing season was slightly effective for producing the hybrids, but that of female flowers was not. Acute gamma irradiation of male flowers at the first to second telophase (300 R) was considered to be desirable for hybrid production. However, it was confirmed by cytological observation that all of the hybrids produced were triploid which had two identical genomes originated from either parent. Therefore, the unreduced male gametophytes or unreduced eggs seem to participate in the formation of the hybrids. It seems difficult to produce diploid hybrids between C. obtusa and C. pisifera. (Kaihara, S.)

  6. [Inheritance of bc1 gene in intersubspecific hybrids of rice (Oryza sativa L.)].

    Science.gov (United States)

    Lü, Chuan-Gen; Zong, Shou-Yu; Zhao, Ling; Qi, Qing-Ming; Zou, Jiang-Shi; Ikehashi, Hiroshi

    2004-10-01

    Distorted segregation of the brittle culm-1 gene (bc1) on rice chromosome 3 was found with greatly increased or decreased frequency of bc1 bc1 genotype in inter-subspecific hybrids, although the gene normally transmitted to its offspring following the Mendelian Law in intra-subspecific hybrids. In a combination of Kamairazu//Ketan Nangka/Kamairazu,an increased frequency of bc1 bc1 in F1, normal segregation in F2, and increased and decreased frequency in a few F3 and F4 lines were observed. In a cross of IR36/Kamairazu, decreased frequency in F2, both normal and decreased segregations in F3 and F4, and a few lines of increased ratio in F4 were found. In F2 of Ketan Nangka/IR36//Kamairazu, increased and decreased and normal segregations were all observed. There was no significant correlation between the frequency of bc1 bc1 and pollen fertility. It implied that distorted segregation of bc1 was caused by selective fertilization of male gametes, which were governed by gametophyte genes of ga2, ga3 and ga14 on chromosome 3.

  7. Estimating paternal efficiency in an agamic polyploid complex: pollen stainability and variation in pollen size related to reproduction mode, ploidy level and hybridogenous origin in Pilosella (Asteraceae)

    Czech Academy of Sciences Publication Activity Database

    Rotreklová, O.; Krahulcová, Anna

    2016-01-01

    Roč. 51, č. 2 (2016), s. 175-186 ISSN 1211-9520 Institutional support: RVO:67985939 Keywords : autonomous apomixis * effect of pollen parent * hybridization Subject RIV: EF - Botanics Impact factor: 1.017, year: 2016

  8. Pollen diversity, viability and floral structure of some Musa genotypes

    African Journals Online (AJOL)

    Prof. Ogunji

    This is related to sterility due to triploidy, variation in genome size and structure ... Pollen grains are structures that house the male gametophytes generation of .... the mean value for all the genotypes was recorded for PITA 14, an 11TA hybrid.

  9. Molecular cloning and transcriptional activity of a new Petunia calreticulin gene involved in pistil transmitting tract maturation, progamic phase, and double fertilization.

    Science.gov (United States)

    Lenartowski, Robert; Suwińska, Anna; Prusińska, Justyna; Gumowski, Krzysztof; Lenartowska, Marta

    2014-02-01

    Calreticulin (CRT) is a highly conserved and ubiquitously expressed Ca²⁺-binding protein in multicellular eukaryotes. As an endoplasmic reticulum-resident protein, CRT plays a key role in many cellular processes including Ca²⁺ storage and release, protein synthesis, and molecular chaperoning in both animals and plants. CRT has long been suggested to play a role in plant sexual reproduction. To begin to address this possibility, we cloned and characterized the full-length cDNA of a new CRT gene (PhCRT) from Petunia. The deduced amino acid sequence of PhCRT shares homology with other known plant CRTs, and phylogenetic analysis indicates that the PhCRT cDNA clone belongs to the CRT1/CRT2 subclass. Northern blot analysis and fluorescent in situ hybridization were used to assess PhCRT gene expression in different parts of the pistil before pollination, during subsequent stages of the progamic phase, and at fertilization. The highest level of PhCRT mRNA was detected in the stigma-style part of the unpollinated pistil 1 day before anthesis and during the early stage of the progamic phase, when pollen is germinated and tubes outgrow on the stigma. In the ovary, PhCRT mRNA was most abundant after pollination and reached maximum at the late stage of the progamic phase, when pollen tubes grow into the ovules and fertilization occurs. PhCRT mRNA transcripts were seen to accumulate predominantly in transmitting tract cells of maturing and receptive stigma, in germinated pollen/growing tubes, and at the micropylar region of the ovule, where the female gametophyte is located. From these results, we suggest that PhCRT gene expression is up-regulated during secretory activity of the pistil transmitting tract cells, pollen germination and outgrowth of the tubes, and then during gamete fusion and early embryogenesis.

  10. Erratic Male Meiosis Resulting in 2n Pollen Grain Formation in a 4x Cytotype (2n=28 of Ranunculus laetus Wall. ex Royle

    Directory of Open Access Journals (Sweden)

    Puneet Kumar

    2012-01-01

    Full Text Available Two accessions were studied for male meiosis in Ranunculus laetus from the cold regions of Northwest Himalayas. One accession showed the presence of 14 bivalents at diakinesis and regular segregation of bivalents at anaphase I which lead to normal tetrad formation with four n microspores and consequently n pollen grains and 100% pollen fertility. Second accession from the same locality revealed the erratic meiosis characterized by the presence of all the 28 chromosomes as univalents in meiocytes at metaphase I. Univalent chromosomes failed to segregate during anaphases and produced restitution nuclei at meiosis I and II. These restitution nuclei resulted into dyads and triads which subsequently produced two types of apparently fertile pollen grains. On the basis of size, the two types of pollen grains were categorized as n (normal reduced and 2n (unreduced, 1.5-times larger than the n pollen grains. The estimated frequency of 2n pollen grains from dyads and triads (61.59% was almost the same as that of the observed one (59.90%, which indicated that 2n pollen grains in R. laetus were the result of dyads and triads. The present paper herein may provide an insight into the mechanisms of the formation of various intraspecific polyploids through sexual polyploidization in R. laetus.

  11. Pollen morphology of Amygdalus L. (Rosaceae in Iran

    Directory of Open Access Journals (Sweden)

    Mahnaz Vafadar

    2011-01-01

    Full Text Available Pollen grain of 16 species and three hybrids of the genus Amygdalus L., representing two subgenera and two sections distributed in Iran were examined by light and scanning electron microscopy. All pollen grains are tricolporate. The shape of grains varies from subprolate through prolate. Regarding outline, in polar view, pollen grains are triangular-circular and in equatorial view, elliptic. Regarding sculpturing of exine, the frequent type like many members of family Rosaceae is striate with or without perforations that can be subdivided into three subtypes: type I (A-B, type II (A-B and type V. In three species, A. trichamygdalus, A. spinosissima and A. orientalis, exine sculpture type is completely different. In the first species is rugulate, in the second species is reticulate and in A. orientalis, it is gemmate-perforate. Ornamentation of ridges (muri in the striate sculpture is parallel to ectocolpus. Number of perforations in tectum, diameter of them, striae intervals and the thickness of ridges varies among studied taxa. The striae have different depth and slope. Results showed that among pollen grain characters, shape is useful character solely for separating of taxonomic ranks in Iranian Amygdalus specially in subgeneric or section level.

  12. A study on compatibilities on transgenic herbicide-resistant rice with wild relatives by using autoradiography of 32P labeled pollen

    International Nuclear Information System (INIS)

    Liu Linli; Qiang Sheng; Song Xiaoling

    2004-01-01

    To evaluate the possibility of gene flow through observation of the sexual compatibilities of transgenic herbicide-resistant rice with wild relative by using isotope tracer to label pollen grains, the experiments on radioactivity, tracer mode, autoradiography film and time were conducted. Better procedure was to label pollen grains of transgenic herbicide-resistant rice by culturing the rice in a 1.48 x 10 7 Bq/L 32 P nutrient liquid, to pollinate the labelled pollen grains on the stigmas of barnyard grass (Echinochloa crusgalli var. mitis), Oryza officinalis and weedy rice (Oryza sativa) respectively, and then 3 hour later, to fix these pistils on a piece of glass plate and cover the film of Luck 400 on it for autoradiography. The autoradiographs show that the tube of the transgenic rice's pollens cannot penetrate the stigma of barnyard grass and arrive at embryo sacs to fertilize, so that the possibility of gene flow between them is the lowest; the tube of the labelled pollens can penetrate the stigma of O officinalis and enter the style but can not arrive at embryo sacs to fertilize, so the possibility of gene flow between them is relatively low; and the pollen tube can arrive at the embryo sacs of the weedy rice, so that the possibility of gene flow is relatively high from transgenic herbicide-resistant rice to weedy rice. (authors)

  13. Identification of Genes Potentially Associated with the Fertility Instability of S-Type Cytoplasmic Male Sterility in Maize via Bulked Segregant RNA-Seq.

    Directory of Open Access Journals (Sweden)

    Aiguo Su

    Full Text Available S-type cytoplasmic male sterility (CMS-S is the largest group among the three major types of CMS in maize. CMS-S exhibits fertility instability as a partial fertility restoration in a specific nuclear genetic background, which impedes its commercial application in hybrid breeding programs. The fertility instability phenomenon of CMS-S is controlled by several minor quantitative trait locus (QTLs, but not the major nuclear fertility restorer (Rf3. However, the gene mapping of these minor QTLs and the molecular mechanism of the genetic modifications are still unclear. Using completely sterile and partially rescued plants of fertility instable line (FIL-B, we performed bulk segregant RNA-Seq and identified six potential associated genes in minor effect QTLs contributing to fertility instability. Analyses demonstrate that these potential associated genes may be involved in biological processes, such as floral organ differentiation and development regulation, energy metabolism and carbohydrates biosynthesis, which results in a partial anther exsertion and pollen fertility restoration in the partially rescued plants. The single nucleotide polymorphisms (SNPs identified in two potential associated genes were validated to be related to the fertility restoration phenotype by KASP marker assays. This novel knowledge contributes to the understanding of the molecular mechanism of the partial fertility restoration of CMS-S in maize and thus helps to guide the breeding programs.

  14. Studies on the utility of artificial mutations in plant breeding, 16: Gene analysis of male sterility induced in rice [Oryza sativa

    International Nuclear Information System (INIS)

    Ko, T.; Yamagata, H.

    1987-01-01

    Eleven male-sterile mutants were induced from a rice variety Sasanishiki by ethyleneimine and γ-ray treatments of seeds. Nine of them produced no pollen grains or only abortive ones and the other two showed extremely low pollen fertilities. The eleven mutants were crossed with the original variety. All F 1 hybrids were fertile, i.e., normal in both pollen and seed fertilities. In eight of their F 2 progenies, fertile and male-sterile plants segregated in a ratio of 3 to 1, indicating that the male sterility of the eight mutants was controlled by a single recessive gene. In one of the other three, segregation ratio suggested the participation of two recessive genes, while in the remaining two, the number of the genes responsible for male sterility could not be determined. (author)

  15. A putative hybrid swarm within Oonopsis foliosa (Asteraceae: Astereae)

    Science.gov (United States)

    Hughes, J.F.; Brown, G.K.

    2004-01-01

    Oo??nopsis foliosa var. foliosa and var. monocephala are endemic to short-grass steppe of southeastern Colorado and until recently were considered geographically disjunct. The only known qualitative feature separating these 2 varieties is floral head type; var. foliosa has radiate heads, whereas var. monocephala heads are discoid. Sympatry between these varieties is restricted to a small area in which a range of parental types and intermediate head morphologies is observed. We used distribution mapping, morphometric analyses, chromosome cytology, and pollen stainability to characterize the sympatric zone. Morphometrics confirms that the only discrete difference between var. foliosa and var. monocephala is radiate versus discoid heads, respectively. The outer florets of putative hybrid individuals ranged from conspicuously elongated yet radially symmetric disc-floret corollas, to elongated radially asymmetric bilabiate- or deeply cleft corollas, to stunted ray florets with appendages remnant of corolla lobes. Chromosome cytology of pollen mother cells from both putative parental varieties and a series of intermediate morphological types collected at the sympatric zone reveal evidence of translocation heterozygosity. Pollen stainability shows no significant differences in viability between the parental varieties and putative hybrids. The restricted distribution of putative hybrids to a narrow zone of sympatry between the parental types and the presence of meiotic chromosome-pairing anomalies in these intermediate plants are consistent with a hybrid origin. The high stainability of putative-hybrid pollen adds to a growing body of evidence that hybrids are not universally unfit.

  16. Selection against recombinant hybrids maintains reproductive isolation in hybridizing Populus species despite F1 fertility and recurrent gene flow.

    Science.gov (United States)

    Christe, Camille; Stölting, Kai N; Bresadola, Luisa; Fussi, Barbara; Heinze, Berthold; Wegmann, Daniel; Lexer, Christian

    2016-06-01

    Natural hybrid zones have proven to be precious tools for understanding the origin and maintenance of reproductive isolation (RI) and therefore species. Most available genomic studies of hybrid zones using whole- or partial-genome resequencing approaches have focused on comparisons of the parental source populations involved in genome admixture, rather than exploring fine-scale patterns of chromosomal ancestry across the full admixture gradient present between hybridizing species. We have studied three well-known European 'replicate' hybrid zones of Populus alba and P. tremula, two widespread, ecologically divergent forest trees, using up to 432 505 single-nucleotide polymorphisms (SNPs) from restriction site-associated DNA (RAD) sequencing. Estimates of fine-scale chromosomal ancestry, genomic divergence and differentiation across all 19 poplar chromosomes revealed strikingly contrasting results, including an unexpected preponderance of F1 hybrids in the centre of genomic clines on the one hand, and genomically localized, spatially variable shared variants consistent with ancient introgression between the parental species on the other. Genetic ancestry had a significant effect on survivorship of hybrid seedlings in a common garden trial, pointing to selection against early-generation recombinants. Our results indicate a role for selection against recombinant genotypes in maintaining RI in the face of apparent F1 fertility, consistent with the intragenomic 'coadaptation' model of barriers to introgression upon secondary contact. Whole-genome resequencing of hybridizing populations will clarify the roles of specific genetic pathways in RI between these model forest trees and may reveal which loci are affected most strongly by its cyclic breakdown. © 2016 John Wiley & Sons Ltd.

  17. Identification of Candidate Genes and Biosynthesis Pathways Related to Fertility Conversion by Wheat KTM3315A Transcriptome Profiling

    Directory of Open Access Journals (Sweden)

    Lingli Zhang

    2017-04-01

    Full Text Available The Aegilops kotschyi thermo-sensitive cytoplasmic male sterility (K-TCMS system may facilitate hybrid wheat (Triticum aestivum L. seed multiplication and production. The K-TCMS line is completely male sterile during the normal wheat-growing season, whereas its fertility can be restored in a high-temperature environment. To elucidate the molecular mechanisms responsible for male sterility/fertility conversion and candidate genes involved with pollen development in K-TCMS, we employed RNA-seq to sequence the transcriptomes of anthers from K-TCMS line KTM3315A during development under sterile and fertile conditions. We identified 16840 differentially expressed genes (DEGs in different stages including15157 known genes (15135 nuclear genes and 22 plasmagenes and 1683 novel genes. Bioinformatics analysis identified possible metabolic pathways involved with fertility based on KEGG pathway enrichment of the DEGs expressed in fertile and sterile plants. We found that most of the genes encoding key enzyme in the phenylpropanoid biosynthesis and jasmonate biosynthesis pathways were significant upregulated in uninucleate, binuclate or trinucleate stage, which both interact with MYB transcription factors, and that link between all play essential roles in fertility conversion. The relevant DEGs were verified by quantitative RT-PCR. Thus, we suggested that phenylpropanoid biosynthesis and jasmonate biosynthesis pathways were involved in fertility conversion of K-TCMS wheat. This will provide a new perspective and an effective foundation for the research of molecular mechanisms of fertility conversion of CMS wheat. Fertility conversion mechanism in thermo-sensitive cytoplasmic male sterile/fertile wheat involves the phenylpropanoid biosynthesis pathway, jasmonate biosynthesis pathway, and MYB transcription factors.

  18. Comparative transcript profiling of fertile and sterile flower buds from multiple-allele-inherited male sterility in Chinese cabbage (Brassica campestris L. ssp. pekinensis).

    Science.gov (United States)

    Zhou, Xue; Liu, Zhiyong; Ji, Ruiqin; Feng, Hui

    2017-10-01

    We studied the underlying causes of multiple-allele-inherited male sterility in Chinese cabbage (Brassica campestris L. ssp. pekinensis) by identifying differentially expressed genes (DEGs) related to pollen sterility between fertile and sterile flower buds. In this work, we verified the stages of sterility microscopically and then performed transcriptome analysis of mRNA isolated from fertile and sterile buds using Illumina HiSeq 2000 platform sequencing. Approximately 80% of ~229 million high-quality paired-end reads were uniquely mapped to the reference genome. In sterile buds, 699 genes were significantly up-regulated and 4096 genes were down-regulated. Among the DEGs, 28 pollen cell wall-related genes, 54 transcription factor genes, 45 phytohormone-related genes, 20 anther and pollen-related genes, 212 specifically expressed transcripts, and 417 DEGs located on linkage group A07 were identified. Six transcription factor genes BrAMS, BrMS1, BrbHLH089, BrbHLH091, BrAtMYB103, and BrANAC025 were identified as putative sterility-related genes. The weak auxin signal that is regulated by BrABP1 may be one of the key factors causing pollen sterility observed here. Moreover, several significantly enriched GO terms such as "cell wall organization or biogenesis" (GO:0071554), "intrinsic to membrane" (GO:0031224), "integral to membrane" (GO:0016021), "hydrolase activity, acting on ester bonds" (GO:0016788), and one significantly enriched pathway "starch and sucrose metabolism" (ath00500) were identified in this work. qRT-PCR, PCR, and in situ hybridization experiments validated our RNA-seq transcriptome analysis as accurate and reliable. This study will lay the foundation for elucidating the molecular mechanism(s) that underly sterility and provide valuable information for studying multiple-allele-inherited male sterility in the Chinese cabbage line 'AB01'.

  19. Tightly Controlled Expression of bHLH142 Is Essential for Timely Tapetal Programmed Cell Death and Pollen Development in Rice

    Directory of Open Access Journals (Sweden)

    Swee-Suak Ko

    2017-07-01

    Full Text Available Male sterility is important for hybrid seed production. Pollen development is regulated by a complex network. We previously showed that knockout of bHLH142 in rice (Oryza sativa causes pollen sterility by interrupting tapetal programmed cell death (PCD and bHLH142 coordinates with TDR to modulate the expression of EAT1. In this study, we demonstrated that overexpression of bHLH142 (OE142 under the control of the ubiquitin promoter also leads to male sterility in rice by triggering the premature onset of PCD. Protein of bHLH142 was found to accumulate specifically in the OE142 anthers. Overexpression of bHLH142 induced early expression of several key regulatory transcription factors in pollen development. In particular, the upregulation of EAT1 at the early stage of pollen development promoted premature PCD in the OE142 anthers, while its downregulation at the late stage impaired pollen development by suppressing genes involved in pollen wall biosynthesis, ROS scavenging and PCD. Collectively, these events led to male sterility in OE142. Analyses of related mutants further revealed the hierarchy of the pollen development regulatory gene network. Thus, the findings of this study advance our understanding of the central role played by bHLH142 in the regulatory network leading to pollen development in rice and how overexpression of its expression affects pollen development. Exploitation of this novel functionality of bHLH142 may confer a big advantage to hybrid seed production.

  20. Influence of Electric Fields and Conductivity on Pollen Tube Growth assessed via Electrical Lab-on-Chip

    Science.gov (United States)

    Agudelo, Carlos; Packirisamy, Muthukumaran; Geitmann, Anja

    2016-01-01

    Pollen tubes are polarly growing plant cells that are able to rapidly respond to a combination of chemical, mechanical, and electrical cues. This behavioural feature allows them to invade the flower pistil and deliver the sperm cells in highly targeted manner to receptive ovules in order to accomplish fertilization. How signals are perceived and processed in the pollen tube is still poorly understood. Evidence for electrical guidance in particular is vague and highly contradictory. To generate reproducible experimental conditions for the investigation of the effect of electric fields on pollen tube growth we developed an Electrical Lab-on-Chip (ELoC). Pollen from the species Camellia displayed differential sensitivity to electric fields depending on whether the entire cell or only its growing tip was exposed. The response to DC fields was dramatically higher than that to AC fields of the same strength. However, AC fields were found to restore and even promote pollen growth. Surprisingly, the pollen tube response correlated with the conductivity of the growth medium under different AC frequencies—consistent with the notion that the effect of the field on pollen tube growth may be mediated via its effect on the motion of ions. PMID:26804186

  1. The stylar 120 kDa glycoprotein is required for S-specific pollen rejection in Nicotiana.

    Science.gov (United States)

    Hancock, C Nathan; Kent, Lia; McClure, Bruce A

    2005-09-01

    S-RNase participates in at least three mechanisms of pollen rejection. It functions in S-specific pollen rejection (self-incompatibility) and in at least two distinct interspecific mechanisms of pollen rejection in Nicotiana. S-specific pollen rejection and rejection of pollen from Nicotiana plumbaginifolia also require additional stylar proteins. Transmitting-tract-specific (TTS) protein, 120 kDa glycoprotein (120K) and pistil extensin-like protein III (PELP III) are stylar glycoproteins that bind S-RNase in vitro and are also known to interact with pollen. Here we tested whether these glycoproteins have a direct role in pollen rejection. 120K shows the most polymorphism in size between Nicotiana species. Larger 120K-like proteins are often correlated with S-specific pollen rejection. Sequencing results suggest that the polymorphism primarily reflects differences in glycosylation, although indels also occur in the predicted polypeptides. Using RNA interference (RNAi), we suppressed expression of 120K to determine if it is required for S-specific pollen rejection. Transgenic SC N. plumbaginifolia x SI Nicotiana alata (S105S105 or SC10SC10) hybrids with no detectable 120K were unable to perform S-specific pollen rejection. Thus, 120K has a direct role in S-specific pollen rejection. However, suppression of 120K had no effect on rejection of N. plumbaginifolia pollen. In contrast, suppression of HT-B, a factor previously implicated in S-specific pollen rejection, disrupts rejection of N. plumbaginifolia pollen. Thus, S-specific pollen rejection and rejection of N. plumbaginifolia pollen are mechanistically distinct, because they require different non-S-RNase factors.

  2. PIV Measurements of Atmospheric Turbulence and Pollen Dispersal Above a Corn Canopy

    Science.gov (United States)

    Zhu, W.; van Hout, R.; Luznik, L.; Katz, J.

    2003-12-01

    Dispersal of pollen grains by wind and gravity (Anemophilous) is one of the oldest means of plant fertilization available in nature. Recently, the growth of genetically modified foods has raised questions on the range of pollen dispersal in order to limit cross-fertilization between organically grown and transgenic crops. The distance that a pollen grain can travel once released from the anther is determined, among others, by the aerodynamic parameters of the pollen and the characteristics of turbulence in the atmosphere in which it is released. Turbulence characteristics of the flow above a pollinating corn field were measured using Particle Image Velocimetry (PIV). The measurements were performed on the eastern shore of the Chesapeake Bay, in Maryland, during July 2003. Two PIV systems were used simultaneously, each with an overall sample area of 18x18 cm. The spacing between samples was about equal to the field of view. The PIV instrumentation, including CCD cameras, power supply and laser sheets forming optics were mounted on a measurement platform, consisting of a hydraulic telescopic arm that could be extended up to 10m. The whole system could be rotated in order to align it with the flow. The flow was seeded with smoke generated about 30m upstream of the sample areas. Measurements were carried out at several elevations, from just below canopy height up to 1m above canopy. The local meteorological conditions around the test site were monitored by other sensors including sonic anemometers, Rotorod pollen counters and temperature sensors. Each processed PIV image provides an instantaneous velocity distribution containing 64x64 vectors with a vector spacing of ~3mm. The pollen grains (~100mm) can be clearly distinguished from the smoke particles (~1mm) based on their size difference. The acquired PIV data enables calculation of the mean flow and turbulence characteristics including Reynolds stresses, spectra, turbulent kinetic energy and dissipation rate. Data

  3. Fertilization-independent seed development in Arabidopsis thaliana

    Science.gov (United States)

    Chaudhury, Abdul M.; Ming, Luo; Miller, Celia; Craig, Stuart; Dennis, Elizabeth S.; Peacock, W. James

    1997-01-01

    We report mutants in Arabidopsis thaliana (fertilization-independent seed: fis) in which certain processes of seed development are uncoupled from the double fertilization event that occurs after pollination. These mutants were isolated as ethyl methanesulfonate-induced pseudo-revertants of the pistillata phenotype. Although the pistillata (pi) mutant has short siliques devoid of seed, the fis mutants in the pi background have long siliques containing developing seeds, even though the flowers remain free of pollen. The three fis mutations map to loci on three different chromosomes. In fis1 and fis2 seeds, the autonomous endosperm nuclei are diploid and the endosperm develops to the point of cellularization; the partially developed seeds then atrophy. In these two mutants, proembryos are formed in a low proportion of seeds and do not develop beyond the globular stage. When FIS/fis plants are pollinated by pollen from FIS/FIS plants, ≈50% of the resulting seeds contain fully developed embryos; these seeds germinate and form viable seedlings (FIS/FIS). The other 50% of seeds shrivel and do not germinate; they contain embryos arrested at the torpedo stage (FIS/fis). In normal sexual reproduction, the products of the FIS genes are likely to play important regulatory roles in the development of seed after fertilization. PMID:9108133

  4. Fertilization-independent seed development in Arabidopsis thaliana.

    Science.gov (United States)

    Chaudhury, A M; Ming, L; Miller, C; Craig, S; Dennis, E S; Peacock, W J

    1997-04-15

    We report mutants in Arabidopsis thaliana (fertilization-independent seed:fis) in which certain processes of seed development are uncoupled from the double fertilization event that occurs after pollination. These mutants were isolated as ethyl methanesulfonate-induced pseudo-revertants of the pistillata phenotype. Although the pistillata (pi) mutant has short siliques devoid of seed, the fis mutants in the pi background have long siliques containing developing seeds, even though the flowers remain free of pollen. The three fis mutations map to loci on three different chromosomes. In fis1 and fis2 seeds, the autonomous endosperm nuclei are diploid and the endosperm develops to the point of cellularization; the partially developed seeds then atrophy. In these two mutants, proembryos are formed in a low proportion of seeds and do not develop beyond the globular stage. When FIS/fis plants are pollinated by pollen from FIS/FIS plants, approximately 50% of the resulting seeds contain fully developed embryos; these seeds germinate and form viable seedlings (FIS/FIS). The other 50% of seeds shrivel and do not germinate; they contain embryos arrested at the torpedo stage (FIS/fis). In normal sexual reproduction, the products of the FIS genes are likely to play important regulatory roles in the development of seed after fertilization.

  5. Production of viable male unreduced gametes in Brassica interspecific hybrids is genotype specific and stimulated by cold temperatures

    Directory of Open Access Journals (Sweden)

    Cowling Wallace A

    2011-06-01

    Full Text Available Abstract Background Unreduced gametes (gametes with the somatic chromosome number may provide a pathway for evolutionary speciation via allopolyploid formation. We evaluated the effect of genotype and temperature on male unreduced gamete formation in Brassica allotetraploids and their interspecific hybrids. The frequency of unreduced gametes post-meiosis was estimated in sporads from the frequency of dyads or giant tetrads, and in pollen from the frequency of viable giant pollen compared with viable normal pollen. Giant tetrads were twice the volume of normal tetrads, and presumably resulted from pre-meiotic doubling of chromosome number. Giant pollen was defined as pollen with more than 1.5 × normal diameter, under the assumption that the doubling of DNA content in unreduced gametes would approximately double the pollen cell volume. The effect of genotype was assessed in five B. napus, two B. carinata and one B. juncea parents and in 13 interspecific hybrid combinations. The effect of temperature was assessed in a subset of genotypes in hot (day/night 30°C/20°C, warm (25°C/15°C, cool (18°C/13°C and cold (10°C/5°C treatments. Results Based on estimates at the sporad stage, some interspecific hybrid genotypes produced unreduced gametes (range 0.06 to 3.29% at more than an order of magnitude higher frequency than in the parents (range 0.00% to 0.11%. In nine hybrids that produced viable mature pollen, the frequency of viable giant pollen (range 0.2% to 33.5% was much greater than in the parents (range 0.0% to 0.4%. Giant pollen, most likely formed from unreduced gametes, was more viable than normal pollen in hybrids. Two B. napus × B. carinata hybrids produced 9% and 23% unreduced gametes based on post-meiotic sporad observations in the cold temperature treatment, which was more than two orders of magnitude higher than in the parents. Conclusions These results demonstrate that sources of unreduced gametes, required for the triploid

  6. Loss of the Arabidopsis thaliana P4-ATPases ALA6 and ALA7 Impairs Pollen Fitness and Alters the Pollen Tube Plasma Membrane

    Directory of Open Access Journals (Sweden)

    Stephen C McDowell

    2015-04-01

    Full Text Available Members of the P4 subfamily of P-type ATPases are thought to create and maintain lipid asymmetry in biological membranes by flipping specific lipids between membrane leaflets. In Arabidopsis, 7 of the 12 Aminophospholipid ATPase (ALA family members are expressed in pollen. Here we show that double knockout of ALA6 and ALA7 (ala6/7 results in siliques with a ~2-fold reduction in seed set with a high frequency of empty seed positions near the bottom. Seed set was reduced to near zero when plants were grown under a hot/cold temperature stress. Reciprocal crosses indicate that the ala6/7 reproductive deficiencies are due to a defect related to pollen transmission. In-vitro growth assays provide evidence that that ala6/7 pollen tubes are short and slow, with ~2-fold reductions in both maximal growth rate and overall length relative to wild-type. Outcrosses show that when ala6/7 pollen are in competition with wild-type pollen, they have a near 0% success rate in fertilizing ovules near the bottom of the pistil, consistent with ala6/7 pollen having short and slow growth defects. The ala6/7 phenotypes were rescued by the expression of either an ALA6-YFP or GFP-ALA6 fusion protein, which showed localization to both the plasma membrane and highly-mobile endomembrane structures. A mass spectrometry analysis of mature pollen grains revealed significant differences between ala6/7 and wild-type, both in the relative abundance of lipid classes and in the average number of double bonds present in acyl side chains. A change in the properties of the ala6/7 plasma membrane was also indicated by a ~10-fold reduction of labeling by lipophilic FM-dyes relative to wild-type. Together, these results indicate that ALA6 and ALA7 provide redundant activities that function to directly or indirectly change the distribution and abundance lipids in pollen, and support a model in which ALA6 and ALA7 are critical for pollen fitness under normal and temperature-stress conditions.

  7. Preferential exclusion of hybrids in mixed pollinations between oilseed rape (Brassica napus) and weedy B. campestris (Brassicaceae)

    DEFF Research Database (Denmark)

    Hauser, T.P.; Bagger Jørgensen, Rikke; Østergård, Hanne

    1997-01-01

    amplified polymorphic DNA analysis. Using data on the proportion of fully developed seeds and the proportion of these seeds that were hybrids, a statistical model was constructed to estimate the fitness of conspecific and heterospecific pollen and the survival of conspecific and heterospecific zygotes...... for competition between male gametophytes and/or seeds within pods. To test whether competition influences the success of hybridization, pollen from the two species was mixed in different proportions and applied to stigmas of both species. The resulting seeds were scored for paternity by isozyme and randomly...... to seeds. B. campestris pollen in B. napus styles had a significantly lower fitness than the conspecific pollen, whereas no difference between pollen types was found in B. campestris styles. Hybrid zygotes survived to significantly lower proportions than conspecific zygotes in both species, with the lowest...

  8. Among-species differences in pollen quality and quantity limitation: implications for endemics in biodiverse hotspots.

    Science.gov (United States)

    Alonso, Conchita; Navarro-Fernández, Carmen M; Arceo-Gómez, Gerardo; Meindl, George A; Parra-Tabla, Víctor; Ashman, Tia-Lynn

    2013-11-01

    Insufficient pollination is a function of quantity and quality of pollen receipt, and the relative contribution of each to pollen limitation may vary with intrinsic plant traits and extrinsic ecological properties. Community-level studies are essential to evaluate variation across species in quality limitation under common ecological conditions. This study examined whether endemic species are more limited by pollen quantity or quality than non-endemic co-flowering species in three endemic-rich plant communities located in biodiversity hotspots of different continents (Andalusia, California and Yucatan). Natural variations in pollen receipt and pollen tube formation were analysed for 20 insect-pollinated plants. Endemic and non-endemic species that co-flowered were paired in order to estimate and compare the quantity and quality components of pre-zygotic pollination success, obtained through piecewise regression analysis of the relationship between pollen grains and pollen tubes of naturally pollinated wilted flowers. Pollen tubes did not frequently exceed the number of ovules per flower. Only the combination of abundant and good quality pollen and a low number of ovules per flower conferred relief from pre-zygotic pollen limitation in the three stochastic pollination environments studied. Quality of pollen receipt was found to be as variable as quantity among study species. The relative pollination success of endemic and non-endemic species, and its quantity and quality components, was community dependent. Assessing both quality and quantity of pollen receipt is key to determining the ovule fertilization potential of both endemic and widespread plants in biodiverse hotspot regions. Large natural variation among flowers of the same species in the two components and pollen tube formation deserves further analysis in order to estimate the environmental, phenotypic and intraindividual sources of variation that may affect how plants evolve to overcome this limitation in

  9. A selfish gene governing pollen-pistil compatibility confers reproductive isolation between maize relatives.

    Science.gov (United States)

    Kermicle, Jerry L

    2006-01-01

    Some populations of maize's closest relatives, the annual teosintes of Mexico, are unreceptive to maize pollen. When present in the pistil (silk and ovary) a number of maize genes discriminate against or exclude pollen not carrying the same allele. An analogous gene Tcb1-s was found in some teosinte populations but not in sympatric or parapatric maize. It was polymorphic among populations of teosinte growing wild, but regularly present in populations growing in intimate association with maize as a weed. Introduction of Tcb1-s into maize substantially to fully restored compatibility with Tcb1-s carrying teosintes. Although Tcb1-s pollen can fertilize tcb1 tcb1 maize, it is at a competitive disadvantage relative to tcb1 pollen. Hence, the influence of Tcb1-s on crossability is bidirectional. In the absence of maize, Tcb1-s can increase in teosinte populations without improving their fitness. In the presence of maize, Tcb1-s appears to have been co-opted to provide reproductive isolation for adaptation to a cultivated habitat.

  10. Quantitative proteomics of the tobacco pollen tube secretome identifies novel pollen tube guidance proteins important for fertilization

    Czech Academy of Sciences Publication Activity Database

    Hafidh, Said; Potěšil, D.; Fíla, Jan; Čapková, Věra; Zdráhal, Z.; Honys, David

    2016-01-01

    Roč. 17, MAY 3 (2016), č. článku 81. ISSN 1465-6906 R&D Projects: GA ČR GA15-22720S; GA ČR(CZ) GA14-32292S; GA ČR(CZ) GA15-16050S; GA MŠk(CZ) LD14109; GA MŠk(CZ) LM2015043; GA MŠk(CZ) ED1.1.00/02.0068; GA MŠk(CZ) LQ1601 Institutional support: RVO:61389030 Keywords : Protein secretion * Pollen tube guidance * Cell-cell signaling Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 11.313, year: 2015

  11. ALTERNATIVES TO IMPROVE HYBRIDIZATION EFFICIENCY IN Eucalyptus BREEDING PROGRAMS

    Directory of Open Access Journals (Sweden)

    Roselaine Cristina Pereira

    2002-01-01

    Full Text Available Simple and quick hybridization procedures and ways to keep pollen grains viable for long periods are sought in plant breeding programs to provide greater work flexibility. The presentstudy was carried out to assess the efficiency of pollinations made shortly after flower emasculationand the viability of stored pollen from Eucalyptus camaldulensis and Eucalyptus urophylla clones cultivated in Northwestern Minas Gerais State. Controlled pollinations were carried out at zero, one,three, five and seven days after emasculation. Hybridization efficiency was assessed by thepercentage of viable fruits, number of seeds produced per fruit, percentage of viable seeds and also bycytological observation of the pollen development along the style. Flower buds from clones of the twospecies were collected close to anthesis to assess the viability of pollen grain storage. Pollen was thencollected and stored in a freezer (-18oC for 1, 2 and 3 months. Pollen assessed was carried out by invitro and in vivo germination tests. The efficiency of the pollinations varied with their delay and alsobetween species. The greatest pollination efficiency was obtained when they were carried out on thethird and fifth day after emasculation, but those performed simultaneously with emasculationproduced enough seeds to allow this practice in breeding programs. The decrease in pollen viabilitywith storage was not sufficiently significant to preclude the use of this procedure in artificialhybridization.

  12. Does stronger pollen competition improve offspring fitness when pollen load does not vary?

    Science.gov (United States)

    Pélabon, Christophe; Hennet, Lauriane; Bolstad, Geir H; Albertsen, Elena; Opedal, Øystein H; Ekrem, Runa K; Armbruster, W Scott

    2016-03-01

    Competition among pollen grains from a single donor is expected to increase the quality of the offspring produced because of the recessive deleterious alleles expressed during pollen-tube growth. However, evidence for such an effect is inconclusive; a large number of studies suffer from confounding variation in pollen competition with variation in pollen load. In this study, we tested the effect of pollen competition on offspring performance independently of pollen-load variation. We compared seed mass and early seedling performance in Dalechampia scandens (Euphorbiaceae) between crosses in which variation in pollen competition was achieved, without variation in pollen load, by manipulating the dispersion of pollen grains on the stigmas. Despite a large sample size (211 crosses on 20 maternal plants), we failed to find an effect of pollen competition on seed characteristics or early seedling performance. Paternal effects were always limited, and pollen competition never reduced the within-father (residual) variance. These results suggest that limited within-donor variation in genetic quality of pollen grains reduces the potential benefits of pollen competition in the study population. The lack of paternal effects on early sporophyte performance further suggests that benefits of pollen competition among pollen from multiple donors should be limited as well, and it raises questions about the significance of pollen competition as a mechanism of sexual selection. © 2016 Botanical Society of America.

  13. Multiple BiP genes of Arabidopsis thaliana are required for male gametogenesis and pollen competitiveness.

    Science.gov (United States)

    Maruyama, Daisuke; Sugiyama, Tomoyuki; Endo, Toshiya; Nishikawa, Shuh-Ichi

    2014-04-01

    Immunoglobulin-binding protein (BiP) is a molecular chaperone of the heat shock protein 70 (Hsp70) family. BiP is localized in the endoplasmic reticulum (ER) and plays key roles in protein translocation, protein folding and quality control in the ER. The genomes of flowering plants contain multiple BiP genes. Arabidopsis thaliana has three BiP genes. BIP1 and BIP2 are ubiquitously expressed. BIP3 encodes a less well conserved BiP paralog, and it is expressed only under ER stress conditions in the majority of organs. Here, we report that all BiP genes are expressed and functional in pollen and pollen tubes. Although the bip1 bip2 double mutation does not affect pollen viability, the bip1 bip2 bip3 triple mutation is lethal in pollen. This result indicates that lethality of the bip1 bip2 double mutation is rescued by BiP3 expression. A decrease in the copy number of the ubiquitously expressed BiP genes correlates well with a decrease in pollen tube growth, which leads to reduced fitness of mutant pollen during fertilization. Because an increased protein secretion activity is expected to increase the protein folding demand in the ER, the multiple BiP genes probably cooperate with each other to ensure ER homeostasis in cells with active secretion such as rapidly growing pollen tubes.

  14. Notes on Citrullus spp.: Pollen morphology, C values, and interspecific hybridization

    Science.gov (United States)

    Scanning electron and light microscopy were utilized to examine pollen of the currently recognized species (and forms) within the genus Citrullus (Cucurbitaceae). Materials examined included: C. lanatus (Thunb.) Matsum. & Nakai including the citron (C. amarus Schrad.) and egusi (C. mucosospermus (Fu...

  15. Yield and fruit quality of four sweet corn hybrids (Zea mays) under conventional and integrated fertilization with vermicompost.

    Science.gov (United States)

    Lazcano, Cristina; Revilla, Pedro; Malvar, Rosa Ana; Domínguez, Jorge

    2011-05-01

    Vermicompost has been proposed as a valuable fertilizer for sustainable agriculture. The effects of vermicompost on yield and quality of sweet corn were evaluated in this study. In two field trials, sweet corn plants were grown under (i) a conventional fertilization regime with inorganic fertilizer, and integrated fertilization regimes in which 75% of the nutrients were supplied by the inorganic fertilizer and 25% of the nutrients were supplied by either (ii) rabbit manure, or (iii) vermicompost. All three types of fertilization regime were supplied at two doses. Two pairs of nearly isogenic sweet corn hybrids homozygous for sugary1 and shrunken2 mutants were included in the trials to explore fertilizer × genotype interactions. Growth, yield and ear quality of the plants were evaluated in relation to the three fertilization regimes. In general, the integrated regimes yielded the same productivity levels as the conventional treatment. Moreover, both vermicompost and manure produced significant increases in plant growth and marketable yield, and also affected the chemical composition and quality of the marketable ear. Nevertheless, most of the observed effects of the organic fertilizers were genotype-dependent. The results confirm that the use of organic fertilizers such as vermicompost has a positive effect on crop yield and quality. Nevertheless, these effects were not general, indicating the complexity of the organic amendment-plant interactions and the importance of controlling genetic variation when studying the effects of vermicompost on plant growth. Copyright © 2011 Society of Chemical Industry.

  16. Pollen-Associated Microbiome Correlates with Pollution Parameters and the Allergenicity of Pollen.

    Directory of Open Access Journals (Sweden)

    Andrea Obersteiner

    Full Text Available Pollen allergies have been rapidly increasing over the last decades. Many allergenic proteins and non-allergenic adjuvant compounds of pollen are involved in the plant defense against environmental or microbial stress. The first aim of this study was to analyze and compare the colonizing microbes on allergenic pollen. The second aim was to investigate detectable correlations between pollen microbiota and parameters of air pollution or pollen allergenicity. To reach these aims, bacterial and fungal DNA was isolated from pollen samples of timothy grass (Phleum pratense, n = 20 and birch trees (Betula pendula, n = 55. With this isolated DNA, a terminal restriction fragment length polymorphism analysis was performed. One result was that the microbial diversity on birch tree and timothy grass pollen samples (Shannon/Simpson diversity indices was partly significantly correlated to allergenicity parameters (Bet v 1/Phl p 5, pollen-associated lipid mediators. Furthermore, the microbial diversity on birch pollen samples was correlated to on-site air pollution (nitrogen dioxide (NO2, ammonia (NH3, and ozone (O3. What is more, a significant negative correlation was observed between the microbial diversity on birch pollen and the measured NO2 concentrations on the corresponding trees. Our results showed that the microbial composition of pollen was correlated to environmental exposure parameters alongside with a differential expression of allergen and pollen-associated lipid mediators. This might translate into altered allergenicity of pollen due to environmental and microbial stress.

  17. Experimental Crossing of Two Distinct Species of Leopard Geckos, Eublepharis angramainyu and E. macularius: Viability, Fertility and Phenotypic Variation of the Hybrids.

    Directory of Open Access Journals (Sweden)

    Jitka Jančúchová-Lásková

    Full Text Available Hybridization between distinct species of animals and subsequent genetic introgression plays a considerable role in the speciation process and the emergence of adaptive characters. Fitness of between-species hybrids usually sharply decreases with the divergence time of the concerned species and the divergence depth, which still allows for a successful crossing differs among principal clades of vertebrates. Recently, a review of hybridization events among distinct lizard species revealed that lizards belong to vertebrates with a highly developed ability to hybridize. In spite of this, reliable reports of experimental hybridizations between genetically fairly divergent species are only exceptional. Here, we show the results of the crossing of two distinct allopatric species of eyelid geckos possessing temperature sex determination and lacking sex chromosomes: Eublepharis macularius distributed in Pakistan/Afghanistan area and E. angramainyu, which inhabits Mesopotamia and adjacent areas. We demonstrated that F1 hybrids were viable and fertile, and the introgression of E. angramainyu genes into the E. macularius genome can be enabled via a backcrossing. The examined hybrids (except those of the F2 generation displayed neither malformations nor a reduced survival. Analyses of morphometric and coloration traits confirmed phenotypic distinctness of both parental species and their F1 hybrids. These findings contrast with long-term geographic and an evolutionary separation of the studied species. Thus, the occurrence of fertile hybrids of comparably divergent species, such as E. angramainyu and E. macularius, may also be expected in other taxa of squamates. This would violate the current estimates of species diversity in lizards.

  18. Experimental Crossing of Two Distinct Species of Leopard Geckos, Eublepharis angramainyu and E. macularius: Viability, Fertility and Phenotypic Variation of the Hybrids.

    Science.gov (United States)

    Jančúchová-Lásková, Jitka; Landová, Eva; Frynta, Daniel

    2015-01-01

    Hybridization between distinct species of animals and subsequent genetic introgression plays a considerable role in the speciation process and the emergence of adaptive characters. Fitness of between-species hybrids usually sharply decreases with the divergence time of the concerned species and the divergence depth, which still allows for a successful crossing differs among principal clades of vertebrates. Recently, a review of hybridization events among distinct lizard species revealed that lizards belong to vertebrates with a highly developed ability to hybridize. In spite of this, reliable reports of experimental hybridizations between genetically fairly divergent species are only exceptional. Here, we show the results of the crossing of two distinct allopatric species of eyelid geckos possessing temperature sex determination and lacking sex chromosomes: Eublepharis macularius distributed in Pakistan/Afghanistan area and E. angramainyu, which inhabits Mesopotamia and adjacent areas. We demonstrated that F1 hybrids were viable and fertile, and the introgression of E. angramainyu genes into the E. macularius genome can be enabled via a backcrossing. The examined hybrids (except those of the F2 generation) displayed neither malformations nor a reduced survival. Analyses of morphometric and coloration traits confirmed phenotypic distinctness of both parental species and their F1 hybrids. These findings contrast with long-term geographic and an evolutionary separation of the studied species. Thus, the occurrence of fertile hybrids of comparably divergent species, such as E. angramainyu and E. macularius, may also be expected in other taxa of squamates. This would violate the current estimates of species diversity in lizards.

  19. Factors affecting the production of seeds in fully fertile tomatoes (Lycopersicon esculentum L. Mill. and those showing a tendency to parthenocarpy

    Directory of Open Access Journals (Sweden)

    Barbara Gabara

    2014-01-01

    Full Text Available Comparative studies on the development of the female gametophyte, pollination and fertilization in two lines of Lycopersicon esculentum, Kholodostoykye (Kh, fertile and A33 (with a tendency to parthenocarpy have revealed that seed production is affected by disturbances in embryo sac formation but mainly by its degeneration after anthesis, which is especially visible in line A33. Moreover, delayed development of some embryo sacs and incomplete pollination due to various stigma levels seem to be responsible for the diminution of seed number in line A33. Deep fluorescence of numerous pollen grains as well as whole pollen tubes in 83.3 per cent of A33 stigmas and only 24.1 per cent in the Kh line points to the heterogeneity of pollen. This could be one more reason for reduced fertility. The results of application of plant growth regulators (auxin, PCIB which affect seed production in tomato of line A33 remain inconclusive.

  20. Pollen

    Science.gov (United States)

    ... that pollen can also be transported indoors on people and pets. Dry your clothes in an automatic dryer rather ... that pollen can also be transported indoors on people and pets. Dry your clothes in an automatic dryer rather ...

  1. Meiotic analysis in induced tetraploids of Brachiaria decumbens Stapf

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    Carine Simioni

    2011-01-01

    Full Text Available The meiotic behavior of three tetraploid plants (2n=4x=36 originated from somatic chromosome duplication ofsexually reproducing diploid plants of Brachiaria decumbens was evaluated. All the analyzed plants presented abnormalities relatedto polyploidy, such as irregular chromosome segregation, leading to precocious chromosome migration to the poles and micronucleiduring both meiotic divisions. However, the abnormalities observed did not compromise the meiotic products which were characterizedby regular tetrads and satisfactory pollen fertility varying from 61.36 to 64.86%. Chromosomes paired mostly as bivalents indiakinesis but univalents to tetravalents were also observed. These studies contributed to the choice of compatible fertile sexualgenitors to be crossed to natural tetraploid apomicts in the B. decumbens by identifying abnormalities and verifying pollen fertility.Intraespecific crosses should reduce sterility in the hybrids produced in the breeding program of Brachiaria, a problem observedwith the interspecific hybrids produced so far.

  2. Growth and yield of corn hybrids in response to association with Azospirillum brasilense and nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Deniele Marini

    2015-02-01

    Full Text Available There is a growing interest in optimizing the positive effects of the association between Azospirillum bacteria and corn crop in order to reduce the use of nitrogen fertilizers. This study aimed to evaluate the inoculation efficiency of an A. brasilense-based commercial product in association with different rates of nitrogen fertilization in two corn genotypes. The experiment was arranged in a 2 x 2 x 5 factorial randomized block design, with four replications. The treatments consisted of two corn hybrids (30F53 and CD386; with and without inoculation with a commercial product based on A. brasilense and five nitrogen rates (0, 40, 80, 120 and 160 kg ha-1. The variables plant height, basal stem diameter, leaf area, shoot dry matter, leaf nitrogen content, length and diameter of the cob, weight of 100 grains and grain yield were evaluated. Inoculation with A. brasilense provided increases of 11 and 12% in leaf area and shoot dry matter, respectively. There were differences in the response of the corn hybrids for most variables and the increase in nitrogen supply provided increments in the growth and yield of corn.

  3. Marker-assisted identification of restorer gene(s) in iso-cytoplasmic restorer lines of WA cytoplasm in rice and assessment of their fertility restoration potential across environments.

    Science.gov (United States)

    Kumar, Amit; Bhowmick, Prolay Kumar; Singh, Vikram Jeet; Malik, Manoj; Gupta, Ashish Kumar; Seth, R; Nagarajan, M; Krishnan, S Gopala; Singh, Ashok Kumar

    2017-10-01

    Iso-cytoplasmic restorers possess the same male sterile cytoplasm as the cytoplasmic male sterile (CMS) lines, thereby minimizing the potential cyto-nuclear conflict in the hybrids. Restoration of fertility of the wild abortive CMS is governed by two major genes namely, Rf3 and Rf4 . Therefore, assessing the allelic status of these restorer genes in the iso-cytoplasmic restorers using molecular markers will not only help in estimating the efficiency of these genes either alone or in combination, in fertility restoration in the hybrids in different environments, but will also be useful in determining the efficacy of these markers. In the present study, the efficiency of molecular markers in identifying genotypes carrying restorer allele of the gene(s) Rf3 and Rf4, restoring male fertility of WA cytoplasm in rice was assessed in a set of 100 iso-cytoplasmic rice restorers using gene linked as well as candidate gene based markers. In order to validate the efficacy of markers in identifying the restorers, a sub-set of selected 25 iso-cytoplasmic rice restorers were crossed with four different cytoplasmic male sterile lines namely, IR 79156A, IR 58025A, Pusa 6A and RTN 12A, and the pollen and spikelet fertility of the F 1 s were evaluated at three different locations. Marker analysis showed that Rf4 was the predominant fertility restorer gene in the iso-cytoplasmic restorers and Rf3 had a synergistic effect on fertility restoration. The efficiency of gene based markers, DRCG-RF4-14 and DRRM-RF3-10 for Rf4 (87%) and Rf3 (84%) genes was higher than respective gene-linked SSR markers RM6100 (80%) and RM3873 (82%). It is concluded that the gene based markers can be effectively used in identifying fertility restorer lines obviating the need for making crosses and evaluating the F 1 s. Though gene based markers are more efficient, there is a need to identify functional polymorphisms which can provide 100% efficiency. Three iso-cytoplasmic restorers namely, PRR 300, PRR 363

  4. Gene transfer in Nicotiana rustica by means of irradiated pollen II. Cytogenetical consequences

    International Nuclear Information System (INIS)

    Werner, C.P.; Dunkin, I.M.; Cornish, M.A.; Jones, G.H.

    1984-01-01

    Pollen from Nicotiana paniculata and the V12 variety of N. rustica was irradiated with a range of high doses of gamma-rays up to 100 Krads. Both kinds of pollen were used to pollinate the V27 variety of N. rustica. Radiation treatments above 30 Krads gave no viable seed. A cytological examination of the M 1 progeny from the 20 Krad treatments of both crosses revealed conventional radiation damage in the form of losses of whole chromosomes and parts of chromosomes, and rearrangements. The plants possessed hybrid or aberrantly hybrid phenotypes. It was concluded that they were the products of a conventional fertilisation mechanism rather than the gene transfer mechanism proposed by Pandey (1980). The expression of mutational damage can probably account for most of the maternal trends observed in the intervarietal M 2 of N. rustica examined previously, although post-meiotic selection may also play a role. (author)

  5. In Vitro Pollen Viability and Pollen Germination in Cherry Laurel (Prunus laurocerasus L.

    Directory of Open Access Journals (Sweden)

    Melekber Sulusoglu

    2014-01-01

    Full Text Available Pollen quality is important for growers and breeders. This study was carried out to determine in vitro pollen viability and pollen germination in seven genotypes of cherry laurel (Prunus laurocerasus L.. Two pollen viability tests, TTC (2,3,5-triphenyl tetrazolium chloride and IKI (iodine potassium iodide, were used. Pollen traits of genotypes were studied using an in vitro medium containing 0%, 5%, 10%, 15%, and 20% sucrose to determine the best sucrose concentrations for germination. In the second step, the germinated pollen was counted 1, 4, 6, 10, 12, 24, and 48 hours later until there was no further germination. The viability rates were different according to genotypes and tests used. The IKI and TTC staining tests and pollen germination had low correlation (r2 = 0.0614 and r2 = 0.0015, resp.. Painted pollen rate was higher and pollen was well-stained with IKI test and pollen viability estimated with TTC staining test was better than that estimated with the IKI staining test. 15% sucrose gave the best germination rates in most of the genotypes. Pollen germination rates were recorded periodically from one hour to 48 hours in 15% sucrose and the results showed that pollen germination rates increased after 6 hours of being placed in culture media.

  6. In vitro pollen viability and pollen germination in cherry laurel (Prunus laurocerasus L.).

    Science.gov (United States)

    Sulusoglu, Melekber; Cavusoglu, Aysun

    2014-01-01

    Pollen quality is important for growers and breeders. This study was carried out to determine in vitro pollen viability and pollen germination in seven genotypes of cherry laurel (Prunus laurocerasus L.). Two pollen viability tests, TTC (2,3,5-triphenyl tetrazolium chloride) and IKI (iodine potassium iodide), were used. Pollen traits of genotypes were studied using an in vitro medium containing 0%, 5%, 10%, 15%, and 20% sucrose to determine the best sucrose concentrations for germination. In the second step, the germinated pollen was counted 1, 4, 6, 10, 12, 24, and 48 hours later until there was no further germination. The viability rates were different according to genotypes and tests used. The IKI and TTC staining tests and pollen germination had low correlation (r(2) = 0.0614 and r(2) = 0.0015, resp.). Painted pollen rate was higher and pollen was well-stained with IKI test and pollen viability estimated with TTC staining test was better than that estimated with the IKI staining test. 15% sucrose gave the best germination rates in most of the genotypes. Pollen germination rates were recorded periodically from one hour to 48 hours in 15% sucrose and the results showed that pollen germination rates increased after 6 hours of being placed in culture media.

  7. Ultraviolet irradiation of maize (Zea Mays L.) pollen grains. Pt. 2

    International Nuclear Information System (INIS)

    Pfahler, P.L.; Linskens, H.F.

    1977-01-01

    Mature pollen grains from two single cross (F 1 ) hybrids, Wf9 x H55 and K64 x K55, were exposed to eleven levels (0 to 6.80 erg/cm 2 x 10 5 at 0.68 intervals) of ultraviolet irradiation and then were used to pollinate their source. Height and kernel characteristics (kernel weight, weight/100 kernels, kernel number) of individual F 2 plants produced by the normal F 2 kernels obtained from these pollinations were measured within each level and population. Highly significant exposure x population interactions were found for all characters, indicating that the effect of irradiation depended on the genetic source of the pollen grains. Increasing exposure increased or did not change the mean of Wf9 x H55 and decreased the mean in K64 x K55 for all characters. For coefficient of variation values, the interaction, exposure x population, was not significant for any character measured, indicating that irradiation-induced variability was unrelated to pollen source. The results indicate that pollen source strongly influenced the effect of ultraviolet irradiation on plant means but had no influence on variability. (orig.) [de

  8. [Genetics of fertility restoration in the isocytoplasm allonuclear C-group of cytoplasmic male sterility in maize].

    Science.gov (United States)

    Zhao, Zhuo Fan; Huang, Ling; Liu, Yong Ming; Zhang, Peng; Wei, Gui; Cao, Mo Ju

    2018-05-20

    Maize is one of the first crops to produce hybrids using cytoplasmic male sterile lines. The C-type cytoplasmic male sterile (CMS-C) line is vital for hybrid seed production, and the fertility-restoration reaction along with its stability has a direct bearing on its applications. However, fertility restoration mechanism of CMS-C is complex and is still not clear so far. To further explore the factors affecting the fertility restoration of maize CMS, a series of test crosses were carried out by pollinating the isocytoplasm allonuclear CMS-C lines C48-2, Chuangzaosi and C478 with the test lines 18 bai, zi 330, 5022 and the restorer line A619, respectively. Four F 2 populations and six double-cross combinations were obtained from the self-cross of fertility restored F 1 and pollinating male-sterility-maintained F 1 with the male-fertility-restored F 1 , respectively. Meanwhile, we developed the incomplete diallel-cross combinations using the isocytoplasm allonuclear male sterile lines as maternal parents and their respective maintainer lines 48-2, huangzaosi and 478 as paternal parents. All the F 1 , F 2 and double-cross populations were planted at distinct locations in different years, and the fertility-restoration reaction was scored by field investigation and pollen staining with I 2 -IK. The results were as follows: 1) The same test line could restore the CMS-C line at a certain genetic background, but failed to restore the CMS-C line at the other genetic backgrounds, suggesting that the genetic background of CMS-C lines plays an important role in the fertility restoration. 2) The fertile-to-sterile segregation ratio of (C48-2×A619) F 2 population planted in both Sichuan and Yunnan fited well to 15:1 by the χ 2 test. However, the fertility level of individuals in Yunnan mainly belonged to the 3 and 4grades, but which in Sichuan mainly belonged to the 5 grade, indicating the environmental factors had effect on the fertility-restoration reaction of (C48-2×A619) F

  9. Reproductive fitness of outcrossed hybrids between transgenic broccoli (brassica oleracea) carrying the ipt transgene and conventional varieties of kale, broccoli and cauliflower

    International Nuclear Information System (INIS)

    Ting, P.; Tu, Y.; Lin, C.; Chang, H.; Chen, L.; Litfu, A

    2014-01-01

    Pollens are potential carriers for genetically modified crops to transfer genetic materials horizontally to other plants. For phanerogams, pollen viability and cross-compatibility are critical factors for successful outcross hybridization. To evaluate this possibility, this project investigated pollen viability and pod setting rate by comparing broccoli (Brassica oleracea L. var. italica Planck) and broccoli transformed with the isopentenyl transferase (ipt) gene. Both served as pollen donors and four other varieties as pollen receptors to determine outcross rates. For pollen viability, F1 progeny was higher (p?0.05) for the cross of transgenic ipt broccoli with Li Syue significantly by FDA (fluorescein diacetate) assay. Higher successful hybrids were observed for transgenic ipt broccoli with Fu Yue, Li Syue and Green King. As pollen properties, number and grain diameter were significantly larger (p?0.05) in hybrid combinations of transgenic ipt broccoli with Li Syue and Green King significantly (p?0.05). The pod setting rates were higher while transgenic ipt broccoli served as donor plant. These results analyzing pollen properties between transgenic crops with possible outcross candidates would serve as one of those critical strategies for evaluating environmental biosafety issues for transgenic crops. (author)

  10. Genetic characterization and fine mapping of S25, a hybrid male sterility gene, on rice chromosome 12.

    Science.gov (United States)

    Kubo, Takahiko; Yoshimura, Atsushi; Kurata, Nori

    2018-02-10

    Hybrid male sterility genes are important factors in creating postzygotic reproductive isolation barriers in plants. One such gene, S25, is known to cause severe transmission ratio distortion in inter-subspecific progeny of cultivated rice Oryza sativa ssp. indica and japonica. To further characterize the S25 gene, we fine-mapped and genetically characterized the S25 gene using near-isogenic lines with reciprocal genetic backgrounds. We mapped the S25 locus within the 0.67-1.02 Mb region on rice chromosome 12. Further genetic analyses revealed that S25 substantially reduced male fertility in the japonica background, but not in the indica background. In first-generation hybrid progeny, S25 had a milder effect than it had in the japonica background. These results suggest that the expression of S25 is epistatically regulated by at least one partially dominant gene present in the indica genome. This finding supports our previous studies showing that hybrid male sterility due to pollen killer genes results from epistatic interaction with other genes that are hidden in the genetic background.

  11. Reproductive biology and natural hybridization between two endemic species of Pitcairnia (Bromeliaceae).

    Science.gov (United States)

    Wendt, T; Canela, M B; Gelli de Faria, A P; Rios, R I

    2001-10-01

    We investigated pollination biology and breeding systems in hybridizing populations of Pitcairnia albiflos and P. staminea; both species are endemic to rocky outcrops at Rio de Janeiro, Brazil. These species are morphologically distinct and easily recognized by floral color: white in P. albiflos and red in P. staminea. Putative hybrids show a large range of intermediate pink floral colors. The showy hermaphroditic flowers offer pollen and nectar that attract many visitors including bees, butterflies, hawk moths, and bats. Although the flowers of both parental species and hybrids open at night, only P. albiflos had other adaptations for nocturnal pollination. Flowering times overlapped during three consecutive years of observation. Bees visited both species and putative hybrids. Cross-pollinations were performed within and among parental species and hybrids in a greenhouse using plants transplanted from the field. Pitcairnia staminea and hybrids are self-compatible and could be spontaneously self-pollinated, whereas P. albiflos, though self-compatible, needs pollinators' services for self-pollination. Facultative agamospermy was found in the parental species. Prezygotic and postzygotic reproductive barriers between these taxa were weak. Reciprocal hand-pollinations between parental species and with hybrids yielded high fruit sets with viable seeds. Evaluations of fruit set, seed set, seed germination, and pollen viability were undertaken to compare the fitness of the hybrids relative to their parents. The hybrids showed equivalent fitness, except for lower pollen viability. Some conservation implications are noted.

  12. Allergies, asthma, and pollen

    Science.gov (United States)

    Reactive airway - pollen; Bronchial asthma - pollen; Triggers - pollen; Allergic rhinitis - pollen ... Things that make allergies or asthma worse are called triggers. It is important to know your triggers because avoiding them is your first step toward feeling better. ...

  13. Gamma Irradiation Effects on Oil Palm (Elaies Guineensis) Pollen Viability, Fruits and Bunch Formations

    International Nuclear Information System (INIS)

    Aida Nazlyn Nazari; Azhar Mohamad; Shuhaimi Shamsuddin

    2014-01-01

    Assessing performance and genetic diversity of the wild material of oil palm is important for understanding genetic structure of natural oil palm populations towards improvement of the crops. This information is important for oil palm breeding programs, and also for continued ex-situ conservation of the germplasm and breeding program in Malaysia. Mutation induction is one of the alternative ways in creating variants for selection in the breeding program. In this study, evaluation on the effect of irradiated pollen towards pollen viability, bunches formation and no. of parthenocarpic fruits were conducted. Series of acute gamma radiation at dose 0, 10, 20, 40, 50, 100, 200, 300, 500, 100 and 2000 Gy were exposed to Elaies guineensis pollen. Increasing level of irradiation higher than 200 Grays (Gy) affects pollen viability based on the 12 consecutive days observation evaluated in situ conditions. Besides, at this level of irradiation (> 200 Gy), the pollen tube formation were disrupted and subsequently unable the pollen to reach the ovule which cause the embryo to aborted and contributed to the formation of parthenocarpic fruits and rotten bunches. These observations suggested that at low levels of irradiation (< 200 Gy) may damage only part of the generative nucleus while maintaining its capacity to fertilise the egg cells and lead to hybridization. (author)

  14. Comparative proteomic analysis reveals a dynamic pollen plasma membrane protein map and the membrane landscape of receptor-like kinases and transporters important for pollen tube growth and interaction with pistils in rice.

    Science.gov (United States)

    Yang, Ning; Wang, Tai

    2017-01-05

    The coordination of pollen tube (PT) growth, guidance and timely growth arrest and rupture mediated by PT-pistil interaction is crucial for the PT to transport sperm cells into ovules for double fertilization. The plasma membrane (PM) represents an important interface for cell-cell interaction, and PM proteins of PTs are pioneers for mediating PT integrity and interaction with pistils. Thus, understanding the mechanisms underlying these events is important for proteomics. Using the efficient aqueous polymer two-phase system and alkali buffer treatment, we prepared high-purity PM from mature and germinated pollen of rice. We used iTRAQ quantitative proteomic methods and identified 1,121 PM-related proteins (PMrPs) (matched to 899 loci); 192 showed differential expression in the two pollen cell types, 119 increased and 73 decreased in abundance during germination. The PMrP and differentially expressed PMrP sets all showed a functional skew toward signal transduction, transporters, wall remodeling/metabolism and membrane trafficking. Their genomic loci had strong chromosome bias. We found 37 receptor-like kinases (RLKs) from 8 kinase subfamilies and 209 transporters involved in flux of diversified ions and metabolites. In combination with the rice pollen transcriptome data, we revealed that in general, the protein expression of these PMrPs disagreed with their mRNA expression, with inconsistent mRNA expression for 74% of differentially expressed PMrPs. This study identified genome-wide pollen PMrPs, and provided insights into the membrane profile of receptor-like kinases and transporters important for pollen tube growth and interaction with pistils. These pollen PMrPs and their mRNAs showed discordant expression. This work provides resource and knowledge to further dissect mechanisms by which pollen or the PT controls PMrP abundance and monitors interactions and ion and metabolite exchanges with female cells in rice.

  15. Hybrids between cultivated and wild carrots in natural populations in Denmark

    DEFF Research Database (Denmark)

    Magnussen, L.S.; Hauser, Thure Pavlo

    2007-01-01

    Many cultivated plant species are able to hybridize with related wild plants. However, it is not clear whether their hybrids are able to survive and reproduce outside managed fields, and if cultivar genes introgress into wild populations. In areas where wild carrots co-occur with carrot root......-crops, pollen and seeds may flow from two different sources in the fields to the surrounding wild populations: from pure cultivar plants that occasionally flower, and from flowering 'bolters' that originate from hybridizations between wild (male) and cultivated carrots (female) in seed production fields...... by AFLP. Four hybrids were identified among the 71 plants analysed, and these were most likely F(2) or backcross individuals, sired by pollen from hybrid bolters. Wild populations close to fields were genetically somewhat more similar to cultivars than wild populations far from fields, suggesting...

  16. A pollen-specific RALF from tomato that regulates pollen tube elongation.

    Science.gov (United States)

    Covey, Paul A; Subbaiah, Chalivendra C; Parsons, Ronald L; Pearce, Gregory; Lay, Fung T; Anderson, Marilyn A; Ryan, Clarence A; Bedinger, Patricia A

    2010-06-01

    Rapid Alkalinization Factors (RALFs) are plant peptides that rapidly increase the pH of plant suspension cell culture medium and inhibit root growth. A pollen-specific tomato (Solanum lycopersicum) RALF (SlPRALF) has been identified. The SlPRALF gene encodes a preproprotein that appears to be processed and released from the pollen tube as an active peptide. A synthetic SlPRALF peptide based on the putative active peptide did not affect pollen hydration or viability but inhibited the elongation of normal pollen tubes in an in vitro growth system. Inhibitory effects of SlPRALF were detectable at concentrations as low as 10 nm, and complete inhibition was observed at 1 mum peptide. At least 10-fold higher levels of alkSlPRALF, which lacks disulfide bonds, were required to see similar effects. A greater effect of peptide was observed in low-pH-buffered medium. Inhibition of pollen tube elongation was reversible if peptide was removed within 15 min of exposure. Addition of 100 nm SlPRALF to actively growing pollen tubes inhibited further elongation until tubes were 40 to 60 mum in length, after which pollen tubes became resistant to the peptide. The onset of resistance correlated with the timing of the exit of the male germ unit from the pollen grain into the tube. Thus, exogenous SlPRALF acts as a negative regulator of pollen tube elongation within a specific developmental window.

  17. Knockin' on pollen's door: live cell imaging of early polarization events in germinating Arabidopsis pollen

    Science.gov (United States)

    Vogler, Frank; Konrad, Sebastian S. A.; Sprunck, Stefanie

    2015-01-01

    Pollen tubes are an excellent system for studying the cellular dynamics and complex signaling pathways that coordinate polarized tip growth. Although several signaling mechanisms acting in the tip-growing pollen tube have been described, our knowledge on the subcellular and molecular events during pollen germination and growth site selection at the pollen plasma membrane is rather scarce. To simultaneously track germinating pollen from up to 12 genetically different plants we developed an inexpensive and easy mounting technique, suitable for every standard microscope setup. We performed high magnification live-cell imaging during Arabidopsis pollen activation, germination, and the establishment of pollen tube tip growth by using fluorescent marker lines labeling either the pollen cytoplasm, vesicles, the actin cytoskeleton or the sperm cell nuclei and membranes. Our studies revealed distinctive vesicle and F-actin polarization during pollen activation and characteristic growth kinetics during pollen germination and pollen tube formation. Initially, the germinating Arabidopsis pollen tube grows slowly and forms a uniform roundish bulge, followed by a transition phase with vesicles heavily accumulating at the growth site before switching to rapid tip growth. Furthermore, we found the two sperm cells to be transported into the pollen tube after the phase of rapid tip growth has been initiated. The method presented here is suitable to quantitatively study subcellular events during Arabidopsis pollen germination and growth, and for the detailed analysis of pollen mutants with respect to pollen polarization, bulging, or growth site selection at the pollen plasma membrane. PMID:25954283

  18. Analysis of the meiotic transcriptome reveals the genes related to the regulation of pollen abortion in cytoplasmic male-sterile pepper (Capsicum annuum L.).

    Science.gov (United States)

    Qiu, Yilan; Liao, Lijuan; Jin, Xiaorui; Mao, Dandan; Liu, Rushi

    2018-01-30

    CMS, which refers to the inability to generate functional pollen grains while still producing a normal gynoecium, has been widely used for pepper hybrid seed production. Pepper line 8214A is an excellent CMS line exhibiting 100% male sterility and superior economic characteristics. A TUNEL assay revealed the nuclear DNA is damaged in 8214A PMCs during meiosis. TEM images indicated that the 8214A PMCs exhibited asynchronous meiosis after prophase I, and some PMCs degraded prematurely with morphological features typical of PCD. Additionally, at the end of meiosis, the 8214A PMCs formed abnormal non-tetrahedral tetrads that degraded in situ. To identify the genes involved in the pollen abortion of line 8214A, the transcriptional profiles of the 8214A and the 8214B anthers (i.e., from the fertile maintainer line) during meiosis were analyzed using an RNA-seq approach. A total of 1355 genes were determined to be differentially expressed, including 424 and 931 up- and down- regulated genes, respectively, in the 8214A anthers during meiosis relative to the expression levels in the 8214B. The expression levels of ubiquitin ligase and cell cycle-related genes were apparently down-regulated, while the expression of methyltransferase genes was up-regulated in the 8214A anthers during meiosis, which likely contributed to the PCD of these PMCs during meiosis. Thus, our results may be useful for revealing the molecular mechanism regulating the pollen abortion of CMS pepper. Copyright © 2017. Published by Elsevier B.V.

  19. Higher Temperature at Lower Elevation Sites Fails to Promote Acclimation or Adaptation to Heat Stress During Pollen Germination

    Directory of Open Access Journals (Sweden)

    Lluvia Flores-Rentería

    2018-04-01

    even high pollen production may not result in successful fertilization due to low germination. Acquired thermotolerance might not limit these impacts, but pinyon could avoid heat stress by phenological adjustment of pollen development. Higher pollen viability at the core of the distribution could be explained by an optimal combination of biotic and abiotic environmental factors. The disconnect between measures of growth and pollen production suggests that vigor metrics may not accurately estimate reproduction.

  20. De Novo Transcriptome Sequencing of Olea europaea L. to Identify Genes Involved in the Development of the Pollen Tube.

    Science.gov (United States)

    Iaria, Domenico; Chiappetta, Adriana; Muzzalupo, Innocenzo

    2016-01-01

    In olive (Olea europaea L.), the processes controlling self-incompatibility are still unclear and the molecular basis underlying this process are still not fully characterized. In order to determine compatibility relationships, using next-generation sequencing techniques and a de novo transcriptome assembly strategy, we show that pollen tubes from different olive plants, grown in vitro in a medium containing its own pistil and in combination pollen/pistil from self-sterile and self-fertile cultivars, have a distinct gene expression profile and many of the differentially expressed sequences between the samples fall within gene families involved in the development of the pollen tube, such as lipase, carboxylesterase, pectinesterase, pectin methylesterase, and callose synthase. Moreover, different genes involved in signal transduction, transcription, and growth are overrepresented. The analysis also allowed us to identify members in actin and actin depolymerization factor and fibrin gene family and member of the Ca(2+) binding gene family related to the development and polarization of pollen apical tip. The whole transcriptomic analysis, through the identification of the differentially expressed transcripts set and an extended functional annotation analysis, will lead to a better understanding of the mechanisms of pollen germination and pollen tube growth in the olive.

  1. WRKY2/34–VQ20 Modules in Arabidopsis thaliana Negatively Regulate Expression of a Trio of Related MYB Transcription Factors During Pollen Development

    Directory of Open Access Journals (Sweden)

    Rihua Lei

    2018-03-01

    Full Text Available Male gametogenesis in plants is tightly controlled and involves the complex and precise regulation of transcriptional reprogramming. Interactions between WRKY proteins and VQ motif-containing proteins are required to control these complicated transcriptional networks. However, our understanding of the mechanisms by which these complexes affect downstream gene expression is quite limited. In this study, we found that WRKY2 and WKRY34 repress MYB97, MYB101, and MYB120 expression during male gametogenesis. MYB expression was up-regulated in the wrky2-1 wrky34-1 vq20-1 triple mutant during male gametogenesis. The expression levels of six potential targets of the three MYBs increased the most in the wrky2-1 wrky34-1 vq20-1 triple mutant, followed by the wrky2-1 wrky34-1 double mutant, compared with in wild-type. Yeast one-hybrid and dual luciferase reporter assays indicated that WRKY2 and WRKY34 recognized the MYB97 promoter by binding to its W-boxes. MYB97 overexpression caused defects in pollen germination and pollen tube length, which impacted male fertility. Thus, WRKY2/34–VQ20 complexes appear to negatively regulate the expression of certain MYBs during plant male gametogenesis.

  2. Bee Pollen

    Science.gov (United States)

    ... for nutrition; as an appetite stimulant; to improve stamina and athletic performance; and for premature aging, premenstrual ... use bee pollen as a general tonic, to increase urine flow, and for alcohol intoxication. Bee pollen ...

  3. Insecticide use in hybrid onion seed production affects pre- and postpollination processes.

    Science.gov (United States)

    Gillespie, Sandra; Long, Rachael; Seitz, Nicola; Williams, Neal

    2014-02-01

    Research on threats to pollination service in agro-ecosystems has focused primarily on the negative impacts of land use change and agricultural practices such as insecticide use on pollinator populations. Insecticide use could also affect the pollination process, through nonlethal impacts on pollinator attraction and postpollination processes such as pollen viability or pollen tube growth. Hybrid onion seed (Allium cepa L., Alliaceae) is an important pollinator-dependent crop that has suffered yield declines in California, concurrent with increased insecticide use. Field studies suggest that insecticide use reduces pollination service in this system. We conducted a field experiment manipulating insecticide use to examine the impacts of insecticides on 1) pollinator attraction, 2) pollen/stigma interactions, and 3) seed set and seed quality. Select insecticides had negative impacts on pollinator attraction and pollen/stigma interactions, with certain products dramatically reducing pollen germination and pollen tube growth. Decreased pollen germination was not associated with reduced seed set; however, reduced pollinator attraction was associated with lower seed set and seed quality, for one of the two female lines examined. Our results highlight the importance of pesticide effects on the pollination process. Overuse may lead to yield reductions through impacts on pollinator behavior and postpollination processes. Overall, in hybrid onion seed production, moderation in insecticide use is advised when controlling onion thrips, Thrips tabaci, on commercial fields.

  4. Effect of temperature and duration of maize pollen storage on the seed set rate

    Directory of Open Access Journals (Sweden)

    Babić Vojka

    2017-01-01

    Full Text Available In plant breeding programs, it is often necessary to cross genotypes incompatible in time of flowering. In maize, when the incompatibility in flowering period could not be overcome by different sowing dates, or by the ability of silk to preserve its fertility in 10-15 days, conservation of pollen could be of great importance. For many plant species, the appropriate methods for pollen management have been set up, including methods of collecting, desiccation, testing of viability and longevity, as well as for pollen storage. The longevity of pollen during its storage depends upon plant species, conditions at the time of pollen collecting, pollen moisture content, as well as upon storage temperature and duration. Even within the same plant species, different genotypes exhibit different level of viability preservation during the conservation. Although maize pollen belongs to a tricellular pollen group and rapidly loses viability under field conditions, its preservation is possible. According to the literature, pollen viability could be preserved for 30 days in the conditions of refrigerator (+4°C, while in liquid nitrogen (-196°C up to 120 days. In the majority of studies, pollen viability was evaluated in the laboratory conditions, and the results obtained could largely be differed from those obtained under field conditions, due to impossibility to control a number of environmental factors. This experiment was conducted under field conditions in order to evaluate the ability of pollen from commercial maize inbred line L217, stored under the conditions of +4°C and -20°C, to pollinate maize inbred L73B013 and produce grain. Inbred L73B013 is sown in five sowing dates in order to ensure the longer presence of fresh silk. Pollen samples from line L217 were taken twice, and along with silica gel, stored in refrigerator and freezer. Each of successive pollination included five silks. Except for the expected good ear seed set when silks were

  5. Pollen rain and pollen representation across a forest-páramo ecotone in northern Ecuador

    NARCIS (Netherlands)

    Moscol Olivera, M.; Duivenvoorden, J.F.; Hooghiemstra, H.

    2009-01-01

    Modern pollen spectra were studied in forest and páramo vegetation from the Guandera area, northern Ecuador. Pollen representation was estimated by comparing the presence of plant taxa from a recent vegetation survey with the pollen spectra in moss polsters and pollen traps. In total, 73 pollen taxa

  6. Meiosis in elephant grass (Pennisetum purpureum, pearl millet (Pennisetum glaucum (Poaceae, Poales and their interspecific hybrids

    Directory of Open Access Journals (Sweden)

    Vânia Helena Techio

    2006-01-01

    Full Text Available The cultivated and sexually compatible species Pennisetum purpureum (elephant grass, 2n = 4x = 28 and Pennisetum glaucum (pearl millet, 2n = 2x = 14 can undergo hybridization which favors the amplification of their genetic background and the introgression of favorable alleles into breeding programs. The main problem with interspecific hybrids of these species is infertility due to triploidy (2n = 3x = 21. This study describes meiosis in elephant grass x pearl millet hybrids and their progenitors. Panicles were prepared according to the conventional protocol for meiotic studies and Alexander’s stain was used for assessing pollen viability. Pearl millet accessions presented regular meiosis with seven bivalents and high pollen viability. For elephant grass, 14 bivalents in diakinesis and metaphase I were observed. The BAG 63 elephant grass accession, derived from tissue culture, presented a high frequency of meiotic abnormalities. The three hybrid accessions presented a high frequency of abnormalities characterized by irregular chromosomal segregation which resulted in the formation of sterile pollen.

  7. Genetic characterization of hybridization between native and invasive bittersweet vines (Celastrus spp.)

    Science.gov (United States)

    Zaya, David N.; Leicht-Young, Stacey A.; Pavlovic, Noel B.; Feldheim, Kevin A.; Ashley, Mary V.

    2015-01-01

    Hybridization associated with species introductions can accelerate the decline of native species. The main objective of this study was to determine if the decline of a North American liana (American bittersweet, Celastrus scandens) in the eastern portion of its range is related to hybridization with an introduced congener (oriental bittersweet, C. orbiculatus). We used newly characterized microsatellite loci, a maternally-inherited chloroplast DNA marker, and field observation to survey individuals across the USA to determine the prevalence of hybrids, their importance in the invasion of C. orbiculatus, and the predominant direction of hybridization. We found that only 8.4 % of non-native genotypes were hybrids (20 of 239), and these hybrids were geographically widespread. Hybrids showed reduced seed set (decline of >98 %) and small, likely inviable pollen. Genetic analysis of a maternally inherited chloroplast marker showed that all 20 identified hybrids came from C. scandens seed parents. The strong asymmetry in pollen flow that favors fecundity in introduced males has the potential to greatly accelerate the decline of native species by wasting limited female reproductive effort.

  8. EXO70C2 is a key regulatory factor for optimal tip growth of pollen

    KAUST Repository

    Synek, Lukas

    2017-03-30

    The exocyst, an eukaryotic tethering complex, co-regulates targeted exocytosis as an effector of small GTPases in polarized cell growth. In land plants, several exocyst subunits are encoded by double or triple paralogs, culminating in tens of EXO70 paralogs. Out of 23 Arabidopsis EXO70 isoforms, we analyzed seven isoforms expressed in pollen. Genetic and microscopic analyses of single mutants in EXO70A2, C1, C2, F1, H3, H5, and H6 genes revealed that only a loss-of-function EXO70C2 allele resulted in a significant male-specific transmission defect (segregation 40%:51%:9%) due to aberrant pollen tube growth. Mutant pollen tubes grown in vitro exhibited enhanced growth rate and a decreased thickness of the tip cell wall, causing tip bursts. However, exo70C2 pollen tubes could frequently recover and restart their speedy elongation, resulting in a repetitive stop-and-go growth dynamics. A pollen-specific depletion of the closest paralog, EXO70C1, using ami-RNA in the exo70C2 mutant background resulted in a complete pollen-specific transmission defect, suggesting redundant functions of EXO70C1 and EXO70C2. Both EXO70C1 and EXO70C2, GFP-tagged and expressed under their native promoters, localized in the cytoplasm of pollen grains, pollen tubes, and also root trichoblast cells. Expression of EXO70C2-GFP complemented aberrant growth of exo70C2 pollen tubes. The absent EXO70C2 interactions with core exocyst subunits in the yeast two-hybrid assay, cytoplasmic localization, and genetic effect suggest an unconventional EXO70 function possibly as a regulator of exocytosis outside the exocyst complex. In conclusion, EXO70C2 is a novel factor contributing to the regulation of optimal tip growth of Arabidopsis pollen tubes.

  9. How honey bees carry pollen

    Science.gov (United States)

    Matherne, Marguerite E.; Anyanwu, Gabriel; Leavey, Jennifer K.; Hu, David L.

    2017-11-01

    Honey bees are the tanker of the skies, carrying thirty percent of their weight in pollen per foraging trip using specialized orifices on their body. How do they manage to hang onto those pesky pollen grains? In this experimental study, we investigate the adhesion force of pollen to the honeybee. To affix pollen to themselves, honey bees form a suspension of pollen in nectar, creating a putty-like pollen basket that is skewered by leg hairs. We use tensile tests to show that the viscous force of the pollen basket is more than ten times the honeybee's flight force. This work may provide inspiration for the design of robotic flying pollinators.

  10. On the difficulties of discriminating between major and minor hybrid male sterility factors in Drosophila by examining the segregation ratio of sterile and fertile sons in backcrossing experiments.

    Science.gov (United States)

    Maside, X R; Naveira, H F

    1996-10-01

    The observation of segregation ratios of sterile and fertile males in offspring samples from backcrossed hybrid females is, in principle, a valid method to unveil the genetic basis of hybrid male sterility in Drosophila. When the female parent is heterozygous (hybrid) for a sterility factor with major effects, equal proportions of fertile and sterile sons are expected in her offspring. However, intact (not recombined) chromosome segments of considerable length are expected to give segregation ratios that can not be easily differentiated from the 1:1 ratio expected from a single factor. When the phenotypic character under analysis can be determined by combinations of minor factors from the donor species spanning a certain chromosome length, very large offspring samples may be needed to test this alternative hypothesis against the null hypothesis of a single major factor. This is particularly the case of hybrid male sterility determinants in Drosophila.

  11. Radioprotective effect of the pollen

    International Nuclear Information System (INIS)

    Jiang Ying; Zhu Gengbo; Huang Meiying; Yin Zhiwei; Fang Jixi; Fan Xiudi

    1990-10-01

    The radioprotective injury effect of pollen in animals was studied. Research came to the conclusion that: (1) the acute death rate of animals is decreased by the pollen; (2) the peripheral leukocytes and spleen-B-lymph cells of animals are increased by the pollen; (3) the activity of superoxide dimutase (SOD) in the erythrocytes of animals is increased by the pollen; (4) the pollen has the function of protecting the structure of the organs of thymus and testes and so on; (5) the plasma hydroxyproline of animals is remarkably decreased by the pollen

  12. Comparative genetics of hybrid incompatibility: sterility in two Solanum species crosses.

    Science.gov (United States)

    Moyle, Leonie C; Nakazato, Takuya

    2008-07-01

    The genetic basis of hybrid sterility can provide insight into the genetic and evolutionary origins of species barriers. We examine the genetics of hybrid incompatibility between two diploid plant species in the plant clade Solanum sect. Lycopersicon. Using a set of near-isogenic lines (NILs) representing the wild species Solanum pennellii (formerly Lycopersicon pennellii) in the genetic background of the cultivated tomato S. lycopersicum (formerly L. esculentum), we found that hybrid pollen and seed infertility are each based on a modest number of loci, male (pollen) and other (seed) incompatibility factors are roughly comparable in number, and seed-infertility QTL act additively or recessively. These findings are remarkably consistent with our previous analysis in a different species pair, S. lycopersicum x S. habrochaites. Data from both studies contrast strongly with data from Drosophila. Finally, QTL for pollen and seed sterility from the two Solanum studies were chromosomally colocalized, indicating a shared evolutionary history for these QTL, a nonrandom genomic distribution of loci causing sterility, and/or a proclivity of certain genes to be involved in hybrid sterility. We show that comparative mapping data can delimit the probable timing of evolution of detected QTL and discern which sterility loci likely evolved earliest among species.

  13. Genetic value pollenizer lines of the sugar beet (Beta vulgaris L. ssp. vulgaris var. altissima Doell.

    Directory of Open Access Journals (Sweden)

    А. О. Яценко

    2010-10-01

    Full Text Available The features of sugar beet polygerm seed populations were studied. The ways of creation of combinationaluable pollenizers line –– component hybrid on sterile base were improve. The environment conditions had influenced on reaction of different types of genic interactions in specific sets of hybrids. The positive effects of interaction is a part of heterosis effects. It is proved that plasticity and stability effect depend on environment condition where genotype realization occurs.

  14. PollenCALC: Software for estimation of pollen compatibility of self-incompatible allo- and autotetraploid species

    DEFF Research Database (Denmark)

    Aguirre, Andrea A; Wollenweber, Bernd; Frei, Ursula K

    2012-01-01

    available for predicting pollen haplotype frequencies and pollen compatibility in tetraploid species. Results PollenCALC is a software tool written in C++ programming language that can predict pollen compatibility percentages for polyploid species with a two-locus (S, Z) self-incompatibility system...

  15. Effect of gamma rays doses on pollen germination, polysiphony and pollen tube elongation in Pinus patula Schiede et Deppe

    International Nuclear Information System (INIS)

    Katiyar, S.R.; Chauhan, Y.S.

    1987-01-01

    The present study aimed to study the effects of gamma radiation ( 60 Co) on pollen germination and pollen tube elongation in Pinus patula. Pollen germination and pollen tube elongation are stimulated by low doses of radiation. Although higher doses of radiation inhibit the germination of pollen, pollen tube elongation remains unaffected. Thus in Pinus patula pollen tube elongation is less radiosensitive than pollen germination. Compared to control pollen, irradiated pollen produced more number of long pollen tubes. Therefore pollen tube size can be improved using low doses of radiation. (author). 15 refs., 5 figs., 2 tables

  16. Ozone affects pollen viability and NAD(P)H oxidase release from Ambrosia artemisiifolia pollen

    International Nuclear Information System (INIS)

    Pasqualini, Stefania; Tedeschini, Emma; Frenguelli, Giuseppe; Wopfner, Nicole; Ferreira, Fatima; D'Amato, Gennaro; Ederli, Luisa

    2011-01-01

    Air pollution is frequently proposed as a cause of the increased incidence of allergy in industrialised countries. We investigated the impact of ozone (O 3 ) on reactive oxygen species (ROS) and allergen content of ragweed pollen (Ambrosia artemisiifolia). Pollen was exposed to acute O 3 fumigation, with analysis of pollen viability, ROS and nitric oxide (NO) content, activity of nicotinamide adenine dinucleotide phosphate (NAD[P]H) oxidase, and expression of major allergens. There was decreased pollen viability after O 3 fumigation, which indicates damage to the pollen membrane system, although the ROS and NO contents were not changed or were only slightly induced, respectively. Ozone exposure induced a significant enhancement of the ROS-generating enzyme NAD(P)H oxidase. The expression of the allergen Amb a 1 was not affected by O 3 , determined from the mRNA levels of the major allergens. We conclude that O 3 can increase ragweed pollen allergenicity through stimulation of ROS-generating NAD(P)H oxidase. - Highlights: → O 3 reduces the viability of ragweed pollen. → ROS and allergens of ragweed pollen were not affected by O 3 exposure. → O 3 enhances the activity of the ROS-generating enzyme NAD(P)H oxidase. → O 3 increases ragweed pollen allergenicity through NAD(P)H-oxidase stimulation. - This study focuses on the effects of the atmospheric pollutant ozone on ROS content and NAD(P)H oxidase activity of ragweed pollen grains.

  17. Ozone affects pollen viability and NAD(P)H oxidase release from Ambrosia artemisiifolia pollen

    Energy Technology Data Exchange (ETDEWEB)

    Pasqualini, Stefania, E-mail: spas@unipg.it [Department of Applied Biology, University of Perugia, Perugia (Italy); Tedeschini, Emma; Frenguelli, Giuseppe [Department of Applied Biology, University of Perugia, Perugia (Italy); Wopfner, Nicole; Ferreira, Fatima [Department of Molecular Biology, CD Laboratory for Allergy Diagnosis and Therapy, University of Salzburg, Salzburg (Austria); D' Amato, Gennaro [Division of Respiratory and Allergic Diseases, ' A. Cardarelli' High Speciality Hospital, Naples (Italy); Ederli, Luisa [Department of Applied Biology, University of Perugia, Perugia (Italy)

    2011-10-15

    Air pollution is frequently proposed as a cause of the increased incidence of allergy in industrialised countries. We investigated the impact of ozone (O{sub 3}) on reactive oxygen species (ROS) and allergen content of ragweed pollen (Ambrosia artemisiifolia). Pollen was exposed to acute O{sub 3} fumigation, with analysis of pollen viability, ROS and nitric oxide (NO) content, activity of nicotinamide adenine dinucleotide phosphate (NAD[P]H) oxidase, and expression of major allergens. There was decreased pollen viability after O{sub 3} fumigation, which indicates damage to the pollen membrane system, although the ROS and NO contents were not changed or were only slightly induced, respectively. Ozone exposure induced a significant enhancement of the ROS-generating enzyme NAD(P)H oxidase. The expression of the allergen Amb a 1 was not affected by O{sub 3}, determined from the mRNA levels of the major allergens. We conclude that O{sub 3} can increase ragweed pollen allergenicity through stimulation of ROS-generating NAD(P)H oxidase. - Highlights: > O{sub 3} reduces the viability of ragweed pollen. > ROS and allergens of ragweed pollen were not affected by O{sub 3} exposure. > O{sub 3} enhances the activity of the ROS-generating enzyme NAD(P)H oxidase. > O{sub 3} increases ragweed pollen allergenicity through NAD(P)H-oxidase stimulation. - This study focuses on the effects of the atmospheric pollutant ozone on ROS content and NAD(P)H oxidase activity of ragweed pollen grains.

  18. Pollen characteristics and in vitro pollen germination of Cedrus ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-02

    Nov 2, 2009 ... This study aims to determine the germination characteristics, pollen tube developments, effects of germination media and temperature and incubation durations of the pollens obtained from the four clones (11342, 11344, 11345 and 11351) of Cedrus libani A. Rich. (Lebanon Cedrus) obtained from clonal.

  19. Occupational Allergy to Peach (Prunus persica) Tree Pollen and Potential Cross-Reactivity between Rosaceae Family Pollens.

    Science.gov (United States)

    Jiang, Nannan; Yin, Jia; Mak, Philip; Wen, Liping

    2015-10-01

    Orchard workers in north China are highly exposed to orchard pollens, especially peach and other Rosaceae family pollens during pollination season. The aim of this study was to investigate whether occupational allergy to peach tree pollen as a member of Rosaceae family is IgE-mediated and to evaluate the cross-reactivity among Rosaceae family pollens. Allergen skin test and conjunctival challenge test were performed; enzyme linked immune-sorbent assay (ELISA), inhibiting ELISA, western immunoblotting and inhibiting western immunoblotting were done with Rosaceae family orchard pollens, including peach, apricot, cherry, apple and pear tree pollens. Mass spectrometry was also performed to probe the main allergen component and cross-reactive protein. Sensitizations to peach pollen were found in both skin test and conjunctival challenge in the patients. Serum specific IgE to three pollens (peach, apricot and cherry) were detected through ELISA. When peach pollen used as solid phase, ELISA inhibition revealed other four kinds of pollens capable of inducing partial to strong inhibitions (45% to 87%), with the strongest inhibition belonging to apricot pollen (87%). Western blotting showed predominant IgE binding to a 20 KD protein among these pollens, which appeared to be a cross-reactive allergen component through western blotting inhibition. It was recognized as a protein homologous to glutathione s-transferase 16 from Arabidopsis thaliana. Peach and other Rosaceae family tree pollen may serve as a potential cause of IgE mediated occupational respiratory disease in orchard workers in north China.

  20. Mass production of shortleaf x slash pine hybrids by pollinating unbagged female flowers

    Science.gov (United States)

    Philip C. Wakeley; O.O. Wells; T.E. Campbell

    1966-01-01

    A simple method of mass-producing shortleaf x slash pine hybrids was attempted. Large quantities of slash pine pollen were spread on unbagged shortleaf flowers in the hope of recovering a high percentage of hybrid progeny and thus materially reducing the cost of producing such hybrids by conventional controlled pollination. The hybrid is very promising, but, as Snyder...

  1. Studies on the comparison of pollen morphology and viability of four naturally distributed and commercial varieties of anemone coronaria L

    International Nuclear Information System (INIS)

    Candan, F.

    2015-01-01

    The present study presents a comparison of the pollen morphology and viability of naturally distributed four varieties of Anemone coronaria L. These are A. coronaria var. coccinea (Jord.) Burn, A. coronaria var. rosea (Hanry) Batt, A. coronaria var. cyanea, A. coronaria var. alba Goaty and Pens) and its commercial cultivars. The four varieties were collected from areas near the road side along the Kirkagac-Soma highway in the State of Manisa. The commercial cultivars were obtained from the commercial flower growers in the Urla region of zmir. Pollen viability levels decreased in all commercial cultivars of A. coronaria. The highest reduction in pollen viability was recorded in A. coronaria pink cultivars of de Caen group. The general pollen type is prolate spheroidal in all pure forms, but there are some pollen morphological features which were not observed in the natural ones, although encountered in all commercial cultivars. On the other hand, various non-viable pollen types like wrinkled pollens, with abnormally shaped pollens or pollinia were found in the commercial cultivars. It was concluded that pesticides used to produce more flowers with rapid growth are the major cause for his reduction. Another reason could be the use of tetraploid F1 hybrids of A. coronaria cultivars of de Caen group as commercial samples. (author)

  2. Ontogenetically-regulated male sterility in tissue culture - induced and spontaneous sorghum mutants

    Directory of Open Access Journals (Sweden)

    Elkonin L.A.

    2003-01-01

    Full Text Available Variability of male fertility expression in the AS-1 line, a somaclonal variant obtained from tissue culture of CMS-plant, and in the progeny of revenant '124-1' obtained from fertile tiller, which developed on CMS-plant transferred from the field to the greenhouse, was investigated. Both revertants were characterized by similar expression of male fertility during plant ontogenesis: the panicle on the main tiller was almost completely sterile whereas formation of fertile pollen grains and seed set were observed on the panicles of the shoot tillers. A clear basipetal gradient of male fertility was manifested on all panicles: the base had significantly higher per cent of fertile pollen grains in comparison with the middle part, while in the top the anthers were either absent or had few sterile pollen grains. Such an ontogenetically-regulated restoration of male fertility was controlled by nuclear genes and could be transferred through the pollen in crosses with progenitor CMS-line. Growing of AS-1 plants in the growth chambers simultaneously under a long (16/8 and a short (12/12 daylength conditions demonstrated that differences of fertility level in different tillers was not caused by change of photoperiod during plant ontogenesis and functioning of photoperiod-sensitive fertility restoring gene. Whereas, the ontogenetically-regulated expression of male fertility in both revenants was temperature-dependent and was clearly manifested under relatively cool conditions during 2-week period before the beginning of anthesis of the first panicle (average daily temperature 21°C. The increase of the average daily temperature by 2-3 С resulted in sharp increase of male fertility level. Possibility of using AS-1 line in a new "two-line system" of hybrid seed production, which require only two lines (sterile mutant and fertility restorer, is discussed.

  3. The clinical relevance of sensitization to pollen-related fruits and vegetables in unselected pollen-sensitized adults

    DEFF Research Database (Denmark)

    Osterballe, M.; Hansen, T.K.; Mørtz, Charlotte G

    2005-01-01

    BACKGROUND: Previous studies have described cross-reactivity between fresh fruits, vegetables and pollen. However, no data demonstrates the clinical relevance of sensitization to pollen-related fruits and vegetables in unselected pollen-sensitized adults with and without symptoms in the pollen...... season. OBJECTIVE: The aim of this study was to estimate the clinical relevance of sensitization to pollen-related fruits and vegetables in unselected pollen-sensitized adults and to examine the diagnostic value of skin-prick test (SPT), histamine release and specific IgE compared with the outcome...... of oral challenge. METHODS: In total, 936 unselected adults (female : male 479 : 457, median age 33.7 years) were examined for pollen sensitization and clinical cross-reactivity with pollen-related fruits and vegetables by questionnaire, SPT, histamine release, specific IgE and oral challenge. RESULTS...

  4. Effects of gamma irradiation of pollen on parthenogenetic haploid production in muskmelon (Cucumis melo L.)

    International Nuclear Information System (INIS)

    Cuny, F.; Grotte, M.; Dumas de Vaulx, R.; Rieu, A.

    1993-01-01

    The effects of increasing gamma ray exposures on muskmelon pollen of the Védrantais genotype were evaluated after autofertilization and hybridization with the F1.G1 genotype. Regardless of doses of between 0.15 and 1.6 kGy, fruit set and number of seeds per fruit were comparable to those of the control. The pollen tube from pollen irradiated with up to 2.5 kGy grew in styles and reached the ovules. When pollen was cultivated in vitro, relatively high doses of irradiation (1.6 kGy) were needed to reduce the level of germination. Radiation-induced changes in the generative nucleus led to the formation of two chromosomally unbalanced sperm cells (as indicated by the appearance of morphological dimorphism) which induced parthenogenetic development of the egg to form a haploid embryo. Haploid embryo production by gamma-irradiated pollen was genotype dependent. For exposures of between 0.15 and 2.5 kGy, the production of embryos was the same, about 3.4%; a maximum of 70% of these embryos placed in a specific culture medium produced haploid plants. The ploidy of the plantlets in vitro was determined by flow cytometry. No aneuploidy was detected. All resulting plants exhibited normal phenotypes. (author) [fr

  5. Pollen reference collection digitization

    NARCIS (Netherlands)

    Ercan, F.E.Z.; Donders, T.H.; Bijl, P.K.; Wagner, F.

    2016-01-01

    The extensive Utrecht University pollen reference collection holds thousands of pollen samples of many species and genera from all over the world and has been a basis for the widely-used North West European Pollen Flora. These samples are fixed on glass slides for microscopy use, but the aging

  6. Influence of pollen nutrition on honey bee health: do pollen quality and diversity matter?

    Science.gov (United States)

    Di Pasquale, Garance; Salignon, Marion; Le Conte, Yves; Belzunces, Luc P; Decourtye, Axel; Kretzschmar, André; Suchail, Séverine; Brunet, Jean-Luc; Alaux, Cédric

    2013-01-01

    Honey bee colonies are highly dependent upon the availability of floral resources from which they get the nutrients (notably pollen) necessary to their development and survival. However, foraging areas are currently affected by the intensification of agriculture and landscape alteration. Bees are therefore confronted to disparities in time and space of floral resource abundance, type and diversity, which might provide inadequate nutrition and endanger colonies. The beneficial influence of pollen availability on bee health is well-established but whether quality and diversity of pollen diets can modify bee health remains largely unknown. We therefore tested the influence of pollen diet quality (different monofloral pollens) and diversity (polyfloral pollen diet) on the physiology of young nurse bees, which have a distinct nutritional physiology (e.g. hypopharyngeal gland development and vitellogenin level), and on the tolerance to the microsporidian parasite Nosemaceranae by measuring bee survival and the activity of different enzymes potentially involved in bee health and defense response (glutathione-S-transferase (detoxification), phenoloxidase (immunity) and alkaline phosphatase (metabolism)). We found that both nurse bee physiology and the tolerance to the parasite were affected by pollen quality. Pollen diet diversity had no effect on the nurse bee physiology and the survival of healthy bees. However, when parasitized, bees fed with the polyfloral blend lived longer than bees fed with monofloral pollens, excepted for the protein-richest monofloral pollen. Furthermore, the survival was positively correlated to alkaline phosphatase activity in healthy bees and to phenoloxydase activities in infected bees. Our results support the idea that both the quality and diversity (in a specific context) of pollen can shape bee physiology and might help to better understand the influence of agriculture and land-use intensification on bee nutrition and health.

  7. Influence of pollen nutrition on honey bee health: do pollen quality and diversity matter?

    Directory of Open Access Journals (Sweden)

    Garance Di Pasquale

    Full Text Available Honey bee colonies are highly dependent upon the availability of floral resources from which they get the nutrients (notably pollen necessary to their development and survival. However, foraging areas are currently affected by the intensification of agriculture and landscape alteration. Bees are therefore confronted to disparities in time and space of floral resource abundance, type and diversity, which might provide inadequate nutrition and endanger colonies. The beneficial influence of pollen availability on bee health is well-established but whether quality and diversity of pollen diets can modify bee health remains largely unknown. We therefore tested the influence of pollen diet quality (different monofloral pollens and diversity (polyfloral pollen diet on the physiology of young nurse bees, which have a distinct nutritional physiology (e.g. hypopharyngeal gland development and vitellogenin level, and on the tolerance to the microsporidian parasite Nosemaceranae by measuring bee survival and the activity of different enzymes potentially involved in bee health and defense response (glutathione-S-transferase (detoxification, phenoloxidase (immunity and alkaline phosphatase (metabolism. We found that both nurse bee physiology and the tolerance to the parasite were affected by pollen quality. Pollen diet diversity had no effect on the nurse bee physiology and the survival of healthy bees. However, when parasitized, bees fed with the polyfloral blend lived longer than bees fed with monofloral pollens, excepted for the protein-richest monofloral pollen. Furthermore, the survival was positively correlated to alkaline phosphatase activity in healthy bees and to phenoloxydase activities in infected bees. Our results support the idea that both the quality and diversity (in a specific context of pollen can shape bee physiology and might help to better understand the influence of agriculture and land-use intensification on bee nutrition and health.

  8. Effect of enhanced UV-B radiation on pollen quantity, quality, and seed yield in Brassica rapa (Brassicaceae)

    International Nuclear Information System (INIS)

    Demchik, S.M.; Day, T.A.

    1996-01-01

    Three experiments examined the influence of ultraviolet-B radiation (UV-B; 280-320 nm) exposure on reproduction in Brassica rapa (Brassicacaeae). Plants were grown in a greenhouse under three biologically effective UV-B levels that stimulated either an ambient stratospheric ozone level (control), 16% (open-quotes low enhancedclose quotes), or 32% (open-quotes high enhancedclose quotes) ozone depletion levels at Morgantown, WV, USA in mid-March. In the first experiment,pollen production and viability per flower were reduced by ∼50% under both enhanced UV-B levels relative to ambient controls. While plants under high-enhanced UV-B produced over 40% more flowers than plants under the two lower UV-B treatments, whole-plant production of viable pollen was reduced under low-enhanced UV-B to 34% of ambient controls. In the second experiment, the influence of source-plant UV-B exposure on in vitro pollen from plants was examined and whether source-plant UV-B exposure influenced in vitro pollen germination and viability. Pollen from plants under both enhanced-UV-B was reduced from 65 to 18%. Viability of the pollen from plants grown under both enhanced UV-B treatments was reduced to a much lesser extent: only from ∼43 to 22%. Thus, ambient source-plant pollen was more sensitive to enhanced UV-B levels to fertilize plants growing under ambient-UV-B levels, and assessed subsequent seed production and germination. Seed abortion rates were higher in plants pollinated with pollen from the enhanced UV-B treatments, than from ambient UV-B. Despite this, seed yield (number and mass) per plant was similar, regardless of the UV-B exposure of their pollen source. Our findings demonstrate that enhanced UV-B levels associated with springtime ozone depletion events have the capacity to substantially reduce viable pollen production, and could ultimately reduce reproductive success of B. rapa. 37 refs., 4 figs., 2 tabs

  9. Storage of strawberry pollen

    Directory of Open Access Journals (Sweden)

    Rafet Aslantaş

    2013-12-01

    Full Text Available This study was carried out to determine storage ability of strawberry pollen at different temperatures for three different strawberry cultivars 'Aliso', 'Brio', and 'Cruz'. Strawberry pollen was stored at room temperature (22 ±2°C, +4°C, -4°C and -18°C in stabile humidity conditions. Strawberry poIlen was germinated using the hanging drop method in a 20% sucrose solution. Pollen germination rate increased because of low temperature storage. Pollen stored at room temperature and +4°C, -4°C, and -18°C was kept for 8 months, about one year, and 20 months, respectively. Pollen germination rates decreased as the length of storage period increased. The reaction of all cultivars tested on the duration and temperature of storage was similar.

  10. The Effect of Palm Pollen Extract on Polycystic Ovary Syndrome (POS in Rats

    Directory of Open Access Journals (Sweden)

    Hojatollah Karimi Jashni

    2016-05-01

    Full Text Available The positive effects of Palm pollen extract on the potential of fertility and folliculogenesis process in female genus have been reported in several studies. So, this is study is aimed to evaluate the effects of Palm pollen extract on induced- polycystic ovary syndrome (PCOS in rats. A number of 48 adult female Wistar rats were divided in this experimental study into 6 groups of 8 each. Control group: the rats in this group were kept in a normal condition until the end of the experiment. They did not receive any substances. Sham group: sesame oil (the solvent of estradiol valerate was injected to the rats in this group at the first day of the experiment.After 60 days, they were given distilled water (the solvent of Palm pollen per the body weight for 21consecutive days. 4 mg estradiol valerate in 2 ml sesame oil was injected intramuscularly to the rats in the other groups. Moreover they experienced the special conditions of each group, including: PCOS 1 control group: the rats in this group were killed after 60 days. PCOS 2 control group: the rats in this group were killed after 81 days. The experimental 1 group: after 60 days, the rats in this group were orally administered 200 mg/kg of Palm pollen extract for 21 days. The experimental 2 group: after 60 days, the rats in this group were orally administered 400 mg/kg of Palm pollen extract for 21 days. At the end of the experiment period, blood samples were obtained to evaluate serum levels of FSH, LH, estrogen and progesterone. The ovaries were also removed and studied with light microscopy after weighing and cutting of the tissues. LH and estrogen levels in the PCOS group + 400 mg/kg of Palm pollen extract showed a significant decrease compared to the PCOS group (p<0.05. FSH and progesterone levels in the PCOS group + 400 mg/kg of Palm pollen extract showed a significant increase compared to the PCOS 1 and PCOS 2 groups (p<0.05. A decreased number of cystic follicles and an increased number of

  11. Characterization and fine mapping of a female fertility associated ...

    Indian Academy of Sciences (India)

    2015-03-12

    Mar 12, 2015 ... 1Key Laboratory of Agriculture Responding to Climate Change, Jiangxi ... Female-sterile line can be used as a pollinator which has a great potential for hybrid seeds production. ... Reciprocal crosses and pollen vitality assay suggest that the .... per plant, and seed-setting rate were investigated in ff1(t).

  12. [The development of pollen grains and formation of pollen tubes in higher plants : I. Quantitative measurements of the DNA-content of generative and vegetative nuclei in the pollen grain and pollen tube of Petunia hybrida mutants].

    Science.gov (United States)

    Hesemann, C U

    1971-01-01

    The DNA-content of generative and vegetative nuclei in mature pollen grains of four Petunia hybrida mutants was determined by cytophotometry. In addition the DNA-content of generative and vegetative nuclei in the pollen tube of two of these four mutants (virescens-2 n and ustulata-2 n) was cytophotometrically measured.The DNA-values found in the generative nuclei indicate that the DNA-replication continues in the mature pollen grain and comes to an end only after the migration of the nuclei into the pollen tube. These data are in disagreement with the results of DNA-measurements described for a limited number of other species which all show completion of DNA-synthesis during the maturation stage of the pollen grains.The vegetative nuclei of the four Petunia mutants studied show significant differences in the onset of the degenerative phase. Extreme variation is manifested in the ustulata-2 n mutant in which the degeneration of nuclei may reach the final stage in the maturing pollen grain. However in this mutant vegetative nuclei with an unaltered DNA-content may also be demonstrated in the pollen tube. Some of the vegetative nuclei in the pollen tube of ustulata-2 n exhibit an increased amount of DNA which could be the result of differential DNA-replication in the vegetative nuclei. The decrease of the DNA-content in a certain fraction of the vegetative nuclei in the maturing pollen grain does not agree with observations made in other species by several authors who report DNA constancy until the pollen grain is fully mature.The data obtained from the analysis of the four Petunia hybrida mutants point to an important role of the vegetative nucleus in the development of the pollen tube. The Petunia hybrida mutants may be regarded as especially favourable material for investigations concerning the function of the vegetative cell in the development of the pollen grain and pollen tube.

  13. Selection of suitable fertilizer draw solute for a novel fertilizer-drawn forward osmosis-anaerobic membrane bioreactor hybrid system

    KAUST Repository

    Kim, Youngjin; Chekli, Laura; Shim, Wang-Geun; Phuntsho, Sherub; Li, Sheng; Ghaffour, NorEddine; Leiknes, TorOve; Shon, Ho Kyong

    2016-01-01

    In this study, a protocol for selecting suitable fertilizer draw solute for anaerobic fertilizer-drawn forward osmosis membrane bioreactor (AnFDFOMBR) was proposed. Among eleven commercial fertilizer candidates, six fertilizers were screened further

  14. Identification and expression analysis of BoMF25, a novel polygalacturonase gene involved in pollen development of Brassica oleracea.

    Science.gov (United States)

    Lyu, Meiling; Liang, Ying; Yu, Youjian; Ma, Zhiming; Song, Limin; Yue, Xiaoyan; Cao, Jiashu

    2015-06-01

    BoMF25 acts on pollen wall. Polygalacturonase (PG) is a pectin-digesting enzyme involved in numerous plant developmental processes and is described to be of critical importance for pollen wall development. In the present study, a PG gene, BoMF25, was isolated from Brassica oleracea. BoMF25 is the homologous gene of At4g35670, a PG gene in Arabidopsis thaliana with a high expression level at the tricellular pollen stage. Collinear analysis revealed that the orthologous gene of BoMF25 in Brassica campestris (syn. B. rapa) genome was probably lost because of genome deletion and reshuffling. Sequence analysis indicated that BoMF25 contained four classical conserved domains (I, II, III, and IV) of PG protein. Homology and phylogenetic analyses showed that BoMF25 was clustered in Clade F. The putative promoter sequence, containing classical cis-acting elements and pollen-specific motifs, could drive green fluorescence protein expression in onion epidermal cells. Quantitative RT-PCR analysis suggested that BoMF25 was mainly expressed in the anther at the late stage of pollen development. In situ hybridization analysis also indicated that the strong and specific expression signal of BoMF25 existed in pollen grains at the mature pollen stage. Subcellular localization showed that the fluorescence signal was observed in the cell wall of onion epidermal cells, which suggested that BoMF25 may be a secreted protein localized in the pollen wall.

  15. ROPES reveals past land cover and pollen productivity estimates from single pollen records

    Science.gov (United States)

    Theuerkauf, Martin; Couwenberg, John

    2018-04-01

    Quantitative reconstructions of past vegetation cover commonly require pollen productivity estimates (PPEs). PPEs are calibrated in extensive and rather cumbersome surface-sample studies, and are so far only available for selected regions. Moreover, it may be questioned whether present-day pollen-landcover relationships are valid for palaeo-situations. We here introduce the ROPES approach that simultaneously derives PPEs and mean plant abundances from single pollen records. ROPES requires pollen counts and pollen accumulation rates (PARs, grains cm-2 year-1). Pollen counts are used to reconstruct plant abundances following the REVEALS approach. The principle of ROPES is that changes in plant abundance are linearly represented in observed PAR values. For example, if the PAR of pine doubles, so should the REVEALS reconstructed abundance of pine. Consequently, if a REVEALS reconstruction is ‘correct’ (i.e. ‘correct’ PPEs are used) the ratio ‘PAR over REVEALS’ is constant for each taxon along all samples of a record. With incorrect PPEs, the ratio will instead vary. ROPES starts from random (likely incorrect) PPEs, but then adjusts them using an optimization algorithm with the aim to minimize variation in the ‘PAR over REVEALS’ ratio across the record. ROPES thus simultaneously calculates mean plant abundances and PPEs. We illustrate the approach with test applications on nine synthetic pollen records. The results show that good performance of ROPES requires data sets with high underlying variation, many samples and low noise in the PAR data. ROPES can deliver first landcover reconstructions in regions for which PPEs are not yet available. The PPEs provided by ROPES may then allow for further REVEALS-based reconstructions. Similarly, ROPES can provide insight in pollen productivity during distinct periods of the past such as the Lateglacial. We see a potential to study spatial and temporal variation in pollen productivity for example in relation to site

  16. CHARACTERIZATION OF THE MAIZE POLLEN TRANSCRIPTOME

    Science.gov (United States)

    Pollen is a primary vehicle for transgene flow from engineered plants to their non-transgenic, native or weedy relatives. Hence, gene flow will be affected by pollen fitness (e.g., how well a particular pollen grain can outcompete other pollen present on the stigma and complete ...

  17. Pollen transmission of asparagus virus 2 (AV-2) may facilitate mixed infection by two AV-2 isolates in asparagus plants.

    Science.gov (United States)

    Kawamura, Ryusuke; Shimura, Hanako; Mochizuki, Tomofumi; Ohki, Satoshi T; Masuta, Chikara

    2014-09-01

    Asparagus virus 2 (AV-2) is a member of the genus Ilarvirus and thought to induce the asparagus decline syndrome. AV-2 is known to be transmitted by seed, and the possibility of pollen transmission was proposed 25 years ago but not verified. In AV-2 sequence analyses, we have unexpectedly found mixed infection by two distinct AV-2 isolates in two asparagus plants. Because mixed infections by two related viruses are normally prevented by cross protection, we suspected that pollen transmission of AV-2 is involved in mixed infection. Immunohistochemical analyses and in situ hybridization using AV-2-infected tobacco plants revealed that AV-2 was localized in the meristem and associated with pollen grains. To experimentally produce a mixed infection via pollen transmission, two Nicotiana benthamiana plants that were infected with each of two AV-2 isolates were crossed. Derived cleaved-amplified polymorphic sequence analysis identified each AV-2 isolate in the progeny seedlings, suggesting that pollen transmission could indeed result in a mixed infection, at least in N. benthamiana.

  18. Aerobiology and pollen allergy in Islamabad

    Energy Technology Data Exchange (ETDEWEB)

    Abbas, S [Allergy and Asthma Centre, Islamabad (Pakistan); Raza, S M [Rawalpindi Medical College, Rawalpindi (Pakistan); Khan, M A [Quaid-i-Azam University, Islamabad (Pakistan). Dept. of Plant Sciences

    2009-10-15

    Pollen allergies affect a significant proportion of Islamabad residents. Many patients with pollen allergy Are hospitalized in Islamabad in spring (February to April), fall seasons (July to September) and after monsoons. To determine the type and concentration of airborne pollens causing allergic diseases in the susceptible patients in Islamabad. The study was conducted from January 2005 to December 2006 and Burkard Volumetric Spore Trap' provided by the World Allergy Organization was used. This spore trap was placed in the F-10 area of Islamabad and samples were collected on weekly basis during the whole study period. To obtain the sample, the spore trap drum was loaded with a strip of sticky tape every week. The sampled sticky tape was then collected each week at a specified time and replaced with a fresh strip of sticky tape, which was then collected next week. This cycle , continued for whole study period. From each sample seven permanent slides were made and mounted with gelevitol mounting media; The slides were then examined microscopically. A total of 702 individuals irrespective of age or gender were included in the study. Skin prick tests were performed for pollens using allergen extracts of Hollister-Steir, USA and the results were recorded. The two flowering seasons in Islamabad i.e., spring and fall caused maximum pollen allergies. The Broussonetia papyrifera (paper mulberry) tree in spring, and the Cannabis sativa (bhang) weed in the fall season, Produced the highest seasonal pollen counts. In the spring season of 2005, Broussonetia papyrifera produced the highest pollen count, (73%) of the total pollen count, with a maximum count of 1390 pollen/cu meter of air/hour on 20th of March, while in 2006, it accounted for 75% of the total pollen-count with a maximum count of 1430 pollen/cu meter of air/hour on 10th of March. in fall Season of 2005, Cannabis sativa produced maximum pollen counts of 85 pollens/cu meter of air/hr on 18th of August, while in 2006

  19. Aerobiology and pollen allergy in Islamabad

    International Nuclear Information System (INIS)

    Abbas, S.; Raza, S.M.; Khan, M.A.

    2009-01-01

    Pollen allergies affect a significant proportion of Islamabad residents. Many patients with pollen allergy Are hospitalized in Islamabad in spring (February to April), fall seasons (July to September) and after monsoons. To determine the type and concentration of airborne pollens causing allergic diseases in the susceptible patients in Islamabad. The study was conducted from January 2005 to December 2006 and Burkard Volumetric Spore Trap' provided by the World Allergy Organization was used. This spore trap was placed in the F-10 area of Islamabad and samples were collected on weekly basis during the whole study period. To obtain the sample, the spore trap drum was loaded with a strip of sticky tape every week. The sampled sticky tape was then collected each week at a specified time and replaced with a fresh strip of sticky tape, which was then collected next week. This cycle , continued for whole study period. From each sample seven permanent slides were made and mounted with gelevitol mounting media; The slides were then examined microscopically. A total of 702 individuals irrespective of age or gender were included in the study. Skin prick tests were performed for pollens using allergen extracts of Hollister-Steir, USA and the results were recorded. The two flowering seasons in Islamabad i.e., spring and fall caused maximum pollen allergies. The Broussonetia papyrifera (paper mulberry) tree in spring, and the Cannabis sativa (bhang) weed in the fall season, Produced the highest seasonal pollen counts. In the spring season of 2005, Broussonetia papyrifera produced the highest pollen count, (73%) of the total pollen count, with a maximum count of 1390 pollen/cu meter of air/hour on 20th of March, while in 2006, it accounted for 75% of the total pollen-count with a maximum count of 1430 pollen/cu meter of air/hour on 10th of March. in fall Season of 2005, Cannabis sativa produced maximum pollen counts of 85 pollens/cu meter of air/hr on 18th of August, while in 2006

  20. PCP-B class pollen coat proteins are key regulators of the hydration checkpoint in Arabidopsis thaliana pollen-stigma interactions.

    Science.gov (United States)

    Wang, Ludi; Clarke, Lisa A; Eason, Russell J; Parker, Christopher C; Qi, Baoxiu; Scott, Rod J; Doughty, James

    2017-01-01

    The establishment of pollen-pistil compatibility is strictly regulated by factors derived from both male and female reproductive structures. Highly diverse small cysteine-rich proteins (CRPs) have been found to play multiple roles in plant reproduction, including the earliest stages of the pollen-stigma interaction. Secreted CRPs found in the pollen coat of members of the Brassicaceae, the pollen coat proteins (PCPs), are emerging as important signalling molecules that regulate the pollen-stigma interaction. Using a combination of protein characterization, expression and phylogenetic analyses we identified a novel class of Arabidopsis thaliana pollen-borne CRPs, the PCP-Bs (for pollen coat protein B-class) that are related to embryo surrounding factor (ESF1) developmental regulators. Single and multiple PCP-B mutant lines were utilized in bioassays to assess effects on pollen hydration, adhesion and pollen tube growth. Our results revealed that pollen hydration is severely impaired when multiple PCP-Bs are lost from the pollen coat. The hydration defect also resulted in reduced pollen adhesion and delayed pollen tube growth in all mutants studied. These results demonstrate that AtPCP-Bs are key regulators of the hydration 'checkpoint' in establishment of pollen-stigma compatibility. In addition, we propose that interspecies diversity of PCP-Bs may contribute to reproductive barriers in the Brassicaceae. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  1. De novo post-pollen mitosis II tobacco pollen tube transcriptome

    Czech Academy of Sciences Publication Activity Database

    Hafidh, Said; Breznenová, Katarína; Honys, David

    2012-01-01

    Roč. 7, č. 8 (2012), s. 918-921 ISSN 1559-2316 R&D Projects: GA ČR GPP501/11/P321; GA ČR GA522/09/0858 Institutional research plan: CEZ:AV0Z50380511 Keywords : de novo pollen tube transcriptome * male gametophyte development * pollen tube growth Subject RIV: ED - Physiology

  2. Ion Implantation Hampers Pollen Tube Growth and Disrupts Actin Cytoskeleton Organization in Pollen Tubes of Pinus thunbergii

    International Nuclear Information System (INIS)

    Li Guoping; Yang Lusheng; Huang Qunce; Qin Guangyong

    2008-01-01

    Pollen grains of Pinus thunbergii Parl. (Japanese black pine) were implanted with 30 keV nitrogen ion beams and the effects of nitrogen ion implantation on pollen tube growth in vitro and the organization of actin cytoskeleton in the pollen tube cell were investigated using a confocal laser scanning microscope after fluorescence labeling. Treatment with ion implantation significantly blocked pollen tube growth. Confocal microscopy showed that ion implantation disrupted actin filament cytoskeleton organization in the pollen tube. It was found that there was a distinct correlation between the inhibition of pollen tube growth and the disruption of actin cytoskeleton organization, indicating that an intact actin cytoskeleton is essential for continuous pollen tube elongation in Pinus thunbergii. Although the detailed mechanism for the ion-implantation-induced bioeffect still remains to be elucidated, the present study assumes that the cytoskeleton system in pollen grains may provide a key target in response to ion beam implantation and is involved in mediating certain subsequent cytological changes.

  3. Can we improve pollen season definitions by using the symptom load index in addition to pollen counts?

    International Nuclear Information System (INIS)

    Bastl, Katharina; Kmenta, Maximilian; Geller-Bernstein, Carmi; Berger, Uwe; Jäger, Siegfried

    2015-01-01

    Airborne pollen measurements are the foundation of aerobiological research and provide essential raw data for various disciplines. Pollen itself should be considered a relevant factor in air quality. Symptom data shed light on the relationship of pollen allergy and pollination. The aim of this study is to assess the spatial variation of local, regional and national symptom datasets. Ten pollen season definitions are used to calculate the symptom load index for the birch and grass pollen seasons (2013–2014) in Austria. (1) Local, (2) regional and (3) national symptom datasets are used to examine spatial variations and a consistent pattern was found. In conclusion, national datasets are suitable for first insights where no sufficient local or regional dataset is available and season definitions based on percentages provide a practical solution, as they can be applied in regions with different pollen loads and produce more constant results. - Highlights: • The definition of the pollen season has an impact on the calculated symptom load. • Pollen season definitions based on percentages of total pollen are a practical solution. • The symptom load index is a robust tool to assess the allergy burden in a population. • Local, regional and national burdens of pollen allergy sufferers are comparable. - The symptom load index is a robust tool to assess the allergy burden in a population. Local, regional and national burdens of pollen allergy sufferers are comparable

  4. Patterns of contemporary hybridization inferred from paternity analysis in a four-oak-species forest

    Directory of Open Access Journals (Sweden)

    Gailing Oliver

    2009-12-01

    Full Text Available Abstract Background Few studies address the issue of hybridization in a more than two-species context. The species-rich Quercus complex is one of the systems which can offer such an opportunity. To investigate the contemporary pattern of hybridization we sampled and genotyped 320 offspring from a natural mixed forest comprising four species of the European white oak complex: Quercus robur, Q. petraea, Q. pubescens, and Q. frainetto. Results A total of 165 offspring were assigned unambiguously to one of the pollen donors within the study plot. The minimum amount of effective pollen originating from outside the plot varied markedly among the seed parents, ranging from 0.18 to 0.87. The majority of the successful matings (64.1% occurred between conspecific individuals indicating the existence of reproductive barriers between oak species. However, the isolation was not complete since we found strong evidence for both first-generation (8.4% and later-generation hybrids (27.5%. Only two out of eight seed parents, belonging to Q. petraea and Q. robur, showed a high propensity to hybridize with Q. pubescens and Q. petraea, respectively. Significant structure of the effective pollen pools (Φpt = 0.069, P = 0.01 was detected in our sample. However, no support was found for the isolation by distance hypothesis. The proportion of hybrids was much higher (79% in the seed generation when compared to the adult tree generation. Conclusion First-generation hybrids were observed only between three out of six possible species combinations. Hybrids between one pair of species preferred to mate with one of their parental species. The observation of first and later-generation hybrids in higher frequency in acorns than in adults might be explained by selection against hybrid genotypes, the history of this uneven-aged forest or past introgression between species.

  5. A Review of the Effects of Major Atmospheric Pollutants on Pollen Grains, Pollen Content, and Allergenicity

    Directory of Open Access Journals (Sweden)

    Hélène Sénéchal

    2015-01-01

    Full Text Available This review summarizes the available data related to the effects of air pollution on pollen grains from different plant species. Several studies carried out either on in situ harvested pollen or on pollen exposed in different places more or less polluted are presented and discussed. The different experimental procedures used to monitor the impact of pollution on pollen grains and on various produced external or internal subparticles are listed. Physicochemical and biological effects of artificial pollution (gaseous and particulate on pollen from different plants, in different laboratory conditions, are considered. The effects of polluted pollen grains, subparticles, and derived aeroallergens in animal models, in in vitro cell culture, on healthy human and allergic patients are described. Combined effects of atmospheric pollutants and pollen grains-derived biological material on allergic population are specifically discussed. Within the notion of “polluen,” some methodological biases are underlined and research tracks in this field are proposed.

  6. A Review of the Effects of Major Atmospheric Pollutants on Pollen Grains, Pollen Content, and Allergenicity

    Science.gov (United States)

    Sénéchal, Hélène; Visez, Nicolas; Charpin, Denis; Shahali, Youcef; Peltre, Gabriel; Biolley, Jean-Philippe; Lhuissier, Franck; Couderc, Rémy; Yamada, Ohri; Malrat-Domenge, Audrey; Pham-Thi, Nhân; Poncet, Pascal; Sutra, Jean-Pierre

    2015-01-01

    This review summarizes the available data related to the effects of air pollution on pollen grains from different plant species. Several studies carried out either on in situ harvested pollen or on pollen exposed in different places more or less polluted are presented and discussed. The different experimental procedures used to monitor the impact of pollution on pollen grains and on various produced external or internal subparticles are listed. Physicochemical and biological effects of artificial pollution (gaseous and particulate) on pollen from different plants, in different laboratory conditions, are considered. The effects of polluted pollen grains, subparticles, and derived aeroallergens in animal models, in in vitro cell culture, on healthy human and allergic patients are described. Combined effects of atmospheric pollutants and pollen grains-derived biological material on allergic population are specifically discussed. Within the notion of “polluen,” some methodological biases are underlined and research tracks in this field are proposed. PMID:26819967

  7. Ozone affects pollen viability and NAD(P)H oxidase release from Ambrosia artemisiifolia pollen.

    Science.gov (United States)

    Pasqualini, Stefania; Tedeschini, Emma; Frenguelli, Giuseppe; Wopfner, Nicole; Ferreira, Fatima; D'Amato, Gennaro; Ederli, Luisa

    2011-10-01

    Air pollution is frequently proposed as a cause of the increased incidence of allergy in industrialised countries. We investigated the impact of ozone (O(3)) on reactive oxygen species (ROS) and allergen content of ragweed pollen (Ambrosia artemisiifolia). Pollen was exposed to acute O(3) fumigation, with analysis of pollen viability, ROS and nitric oxide (NO) content, activity of nicotinamide adenine dinucleotide phosphate (NAD[P]H) oxidase, and expression of major allergens. There was decreased pollen viability after O(3) fumigation, which indicates damage to the pollen membrane system, although the ROS and NO contents were not changed or were only slightly induced, respectively. Ozone exposure induced a significant enhancement of the ROS-generating enzyme NAD(P)H oxidase. The expression of the allergen Amb a 1 was not affected by O(3), determined from the mRNA levels of the major allergens. We conclude that O(3) can increase ragweed pollen allergenicity through stimulation of ROS-generating NAD(P)H oxidase. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Simple methods for in vitro pollen germination and pollen preservation of selected species of the genus Agave

    Directory of Open Access Journals (Sweden)

    Sigifredo López Díaz

    2008-01-01

    Full Text Available Simple methods to evaluate the viability and to preserve Agave tequilana Weber var. azul and A. angustifolia Haw pollen were established. Pollen viability was assessed by improving a growing media and evaluating three common pollen germination media components: sucrose, boric acid, and calcium ion. Optimal germination of pollen was obtained at 0.300 M sucrose, 0.324 mM boric acid, and 1.219 mM calcium nitrate and incubated at a temperature of 25°C. Agave pollen was preserved in olive oil and organic solvents. Olive oil, which is immiscible with water, provides an anhydrous environment and limits available oxygen, conditions similar to those provided by some organic solvents. Fresh pollen was put into eppendorf tubes containing n-butanol, n-propanol, isopropanol, extra virgin olive oil and preserved at -20, 4, and 25°C. The germination of the preserved pollen was scored at different time periods during preservation employing the optimal germination medium. The viability of pollen grains preserved at -20°C in olive oil, proved olive oil as an efficient medium for agave pollen preservation for at least 6 months.

  9. Specialist Osmia bees forage indiscriminately among hybridizing Balsamorhiza floral hosts

    Science.gov (United States)

    James H. Cane

    2011-01-01

    Pollinators, even floral generalists (=polyleges), typically specialize during individual foraging bouts, infrequently switching between floral hosts. Such transient floral constancy restricts pollen flow, and thereby gene flow, to conspecific flowers in mixed plant communities. Where incipient flowering species meet, however, weak cross-fertility and often similar...

  10. Breeding for a low pollen variety of Japanese cedar (Cryptomeria japonica)

    International Nuclear Information System (INIS)

    Kondo, Teiji

    1998-01-01

    The number of sufferers of Japanese cedar pollinosis has been increasing recently and this type of pollinosis is a serious allergic disease in Japan, where one of ten persons is suffering it to some extent. Breeding of Japanese cedar trees was attempted to produce less pollen and set fewer male flowers. Because the degree of male flower setting was varied among plus trees, it was thought possible to select the plus trees that set fewer than normal male flowers for use as low pollen varieties. The degree of male flower setting was evaluated under natural conditions and the conditions of gibberellic acid treatment. Since a spontaneous male sterile mutant was previously identified, it was thought possible to induce such mutation. Therefore, the cedars cultivars growing in the γ-field of Institute of Radiation Breeding were examined in respect of male fertility and some abnormal male flowers were obtained. The changes after transplanting these varieties from the γ-field remain to be resolved. Further, it is necessary to monitor the volume and the number of male flowers, and also the allergen content. (M.N.)

  11. Germination and storage of pollen

    NARCIS (Netherlands)

    Visser, T.

    1955-01-01

    Germination of pear pollen markedly improved when boric acid was added to the medium. The pollen was more sensitive to boron in water than in 10 % sugar solution. Supplying weak solutions of boron to pear branches before flowering resulted in a good germination of the pollen in sugar solution

  12. Pollen sources in the Bojanów forest complex identified on honeybee pollen load by microscopic analysis

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    Ernest Stawiarz

    2017-11-01

    Full Text Available The aim of this study was to determine sources of pollen for the honeybee in the Bojanów forest complex, Nowa Dęba Forest District (southeastern Poland. Sampling of pollen loads from bees extended from the beginning of May until the end of September 2016 and was carried out at 7-day intervals using pollen traps mounted at the entrance of beehives. A total of 73 pollen load samples were collected from the study area. Fifty-nine taxa from 31 plant families were identified in the analyzed material. From 4 to 21 taxa (average 9.5 were recorded in one sample. The pollen of Brassicaceae (“others”, Taraxacum type, Solidago type, and Rumex had the highest frequency in the pollen loads examined. Apart from these four taxa, pollen grains of Rubus type, Poaceae (“others”, Calluna, Fagopyrum, Trifolium repens s. l., Phacelia, Aster type, Melampyrum, Quercus, Cornus, and Veronica were recorded in the dominant pollen group. The forest habitat taxa that provided pollen rewards to honeybees in the Bojanów forest complex were the following: Rubus, Calluna, Prunus, Tilia, Frangula alnus, Pinus, Quercus, Cornus, Robinia pseudoacacia, Salix, and Vaccinium. Apart from forest vegetation, the species from meadows and wastelands adjacent to this forest complex, represented by Taraxacum, Rumex, Plantago, Poaceae, Trifolium repens, and Solidago, proved to be an important source of pollen. The study indicates that forest communities are a valuable source of pollen for pollinating insects from early spring through to late fall.

  13. Role of macrophage migration inhibitory factor (MIF in pollen-induced allergic conjunctivitis and pollen dermatitis in mice.

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    Yuka Nagata

    Full Text Available Pollen is a clinically important airborne allergen and one of the major causes of allergic conjunctivitis. A subpopulation of patients with atopic dermatitis (AD are also known to have exacerbated skin eruptions on the face, especially around the eyelids, after contact with pollen. This pollen-induced skin reaction is now known as pollen dermatitis. Macrophage migration inhibitory factor (MIF is a pluripotent cytokine that plays an essential role in allergic inflammation. Recent findings suggest that MIF is involved in several allergic disorders, including AD. In this study, MIF knockout (KO, MIF transgenic (Tg and WT littermate mice were immunized with ragweed (RW pollen or Japanese cedar (JC pollen and challenged via eye drops. We observed that the numbers of conjunctiva- and eyelid-infiltrating eosinophils were significantly increased in RW and JC pollen-sensitized MIF Tg compared with WT mice or MIF KO mice. The mRNA expression levels of eotaxin, interleukin (IL-5 and IL-13 were increased in pollen-sensitized eyelid skin sites of MIF Tg mice. An in vitro analysis revealed that high eotaxin expression was induced in dermal fibroblasts by MIF combined with stimulation of IL-4 or IL-13. This eotaxin expression was inhibited by the treatment with CD74 siRNA in fibroblasts. These findings indicate that MIF can induce eosinophil accumulation in the conjunctiva and eyelid dermis exposed to pollen. Therefore, targeted inhibition of MIF might result as a new option to control pollen-induced allergic conjunctivitis and pollen dermatitis.

  14. Comparative transcript profiling of the fertile and sterile flower buds of pol CMS in B. napus.

    Science.gov (United States)

    An, Hong; Yang, Zonghui; Yi, Bin; Wen, Jing; Shen, Jinxiong; Tu, Jinxing; Ma, Chaozhi; Fu, Tingdong

    2014-04-03

    The Polima (pol) system of cytoplasmic male sterility (CMS) and its fertility restoration gene Rfp have been used in hybrid breeding in Brassica napus, which has greatly improved the yield of rapeseed. However, the mechanism of the male sterility transition in pol CMS remains to be determined. To investigate the transcriptome during the male sterility transition in pol CMS, a near-isogenic line (NIL) of pol CMS was constructed. The phenotypic features and sterility stage were confirmed by anatomical analysis. Subsequently, we compared the genomic expression profiles of fertile and sterile young flower buds by RNA-Seq. A total of 105,481,136 sequences were successfully obtained. These reads were assembled into 112,770 unigenes, which composed the transcriptome of the bud. Among these unigenes, 72,408 (64.21%) were annotated using public protein databases and classified into functional clusters. In addition, we investigated the changes in expression of the fertile and sterile buds; the RNA-seq data showed 1,148 unigenes had significantly different expression and they were mainly distributed in metabolic and protein synthesis pathways. Additionally, some unigenes controlling anther development were dramatically down-regulated in sterile buds. These results suggested that an energy deficiency caused by orf224/atp6 may inhibit a series of genes that regulate pollen development through nuclear-mitochondrial interaction. This results in the sterility of pol CMS by leading to the failure of sporogenous cell differentiation. This study may provide assistance for detailed molecular analysis and a better understanding of pol CMS in B. napus.

  15. Allergenic pollen pollinosis in Madrid.

    Science.gov (United States)

    Subiza, J; Jerez, M; Jiménez, J A; Narganes, M J; Cabrera, M; Varela, S; Subiza, E

    1995-07-01

    A 15-year pollen count was performed in the atmosphere of Madrid, Spain, to determine the months in which the highest concentrations of allergenic pollens occur. Pollen counts were done with a Burkard spore trap (Burkard Manufacturing, Rickmansworth, Herst., U.K.). The results were subsequently compared with results of skin tests in patients with pollinosis born and living in and around Madrid. The highest airborne presence (percent of total yearly pollen counts, mean of counts from 1979 to 1993) was for Quercus spp. (17%); followed by Platanus spp. (15%), Poaceae (15%), Cupressaceae (11%), Olea spp. (9%), Pinus spp. (7%), Populus spp. (4%), and Plantago spp. (4%). The most predominant pollens from January to April are tree pollens (Cupressaceae, Alnus, Fraxinus, Ulmus, Populus, Platanus, and Morus), although these are also abudant in May and June (Quercus, Olea, and Pinus spp.). The grass pollination period shows a double curve: the first peak occurs from February to April (8% of yearly grasses), and the second peak occurs from May to July (90% of yearly grasses). Among allergenically significant weeds, the most notable is Plantago; in contrast, Rumex, Urticaceae, Cheno-Amaranthaceae, and Artemisia spp. have very low concentrations (arizonica (20%). The population of Madrid is exposed to high concentrations of allergenic pollen from February to July, although the most intense period is from May to June. Grass pollens are the most important cause of pollinosis in this area.

  16. Identification of sweet chesnut pollen in bee pollen pellet using using molecular analysis.

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    Jana Žiarovská

    2015-10-01

    Full Text Available Castanea sativa posses many characteristics that are used by human for different purposes, not only as a part of the food. One of them is the utilization of the sweet chesnut pollen for its pharmacological benefits. Actually, no information about the DNA based identification of the sweet chesnut exist. Here, an identification of Castanea sativa based on the specific DNA fragment amplification is described for the first time. Sweet chesnut identification was performed in the very complex sample of bee pollen pellets that were identified as to contain sweet chesnut pollen grains by morphological analysis. First, bioinformatic analysis was performed to find a Castanea sativa conservative part of galactol synthase gene. BLAST alignment of the CDS of GolS1 gene was performed by BLASTtn against plants nucleotide sequences in the NCBI database to ensure for the specifity or existing nucleotide differences. Then, specific primers were subsequently designed and PCR amplification was performed. All the PCRs have run in duplicates for pollen pellet sample and two independent samples of Castanea sativa pure pollen. Restriction cleavage of the PCR amplified fragment was performed to confirm the specifity of the obtained PCR product with the positive confirmation as the predicted three restriction fragments were obtained that fully correspond by the length to those from virtual clevage. Restriction endonuclease Hpy166II was used in restriction cleavage analysis. Castanea sativa pollen grains were confirmed reliable in multifloral pollen pellet by PCR and this approach has the potential to be used effectively for the authentication purposes of sweet chesnut.

  17. Hybrids between wild and cultivated carrots in Danish carrot fields

    DEFF Research Database (Denmark)

    Hauser, T.P.; Bjørn, G.K.

    2001-01-01

    , and as biennials they should normally not flower before harvest of the roots. Still, flowering individuals can be found in most Danish fields, and sometimes in very high numbers. At least 75% of the flowering plants are male fertile, with ca. 83% of the pollen being viable. More than half of the plants produce...... seeds. Pollen and seed dispersal from fields into wild carrot populations is probably rather frequent in Denmark. A closer inspection of the morphology of flowering plants indicate that some of these (2-60%) are bolters of pure cultivar origin, as indicated primarily by orange root colour. The remainder...

  18. Achievements in NS rapeseed hybrids breeding

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    Marjanović-Jeromela Ana

    2016-01-01

    Full Text Available The increased production of oilseed rape (Brassica napus L. is evident on a global scale, but also in Serbia in the last decade. Rapeseed is used primarily for vegetable oil and processing industry, but also as a source of protein for animal feed and green manure. Following the cultivation of varieties, breeding and cultivation of hybrid rapeseed started in the 1990's, to take advantage of heterosis in F1 generation, while protecting the breeder's rights during seed commercialization. The breeding of hybrid oilseed rape requires high quality starting material (lines with good combining abilities for introduction of male sterility. Ogura sterility system is primarily used at the Institute of Field and Vegetable Crops, Novi Sad, Serbia. To use this system, separate lines are modified with genes for cytoplasmic male sterility (cms female line - mother line and restoration of fertility (Rf male lines - father line. In order to maintain the sterility of the mother line it is necessary to produce a maintainer line of cytoplasmic male sterility. Creation of these lines and hybrids at the Institute of Field and Vegetable Crops was successfully monitored with intense use of cytogenetic laboratory methods. The structure and vitality of pollen, including different phases during meiosis were checked so that cms stability was confirmed during the introduction of these genes into different lines. Rapeseed breeding program in Serbia resulted in numerous varieties through collaboration of researchers engaged in breeding and genetics of this plant species. So far, in addition to 12 varieties of winter rapeseed and two varieties of spring rapeseed, a new hybrid of winter rapeseed NS Ras was registered in Serbia. NS Ras is an early-maturing hybrid characterized by high seed yield and oil content. Average yield of NS Ras for two seasons and three sites was 4256 kg ha-1 of seed and 1704 kg ha-1 of oil. Three promising winter rapeseed hybrids are in the process of

  19. Establishment of Alleycropped Hybrid Aspen “Crandon” in Central Iowa, USA: Effects of Topographic Position and Fertilizer Rate on Aboveground Biomass Production and Allocation

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    Richard B. Hall

    2013-07-01

    Full Text Available Hybrid poplars have demonstrated high productivity as short rotation woody crops (SRWC in the Midwest USA, and the hybrid aspen “Crandon” (Populus alba L. × P. grandidenta Michx. has exhibited particularly promising yields on marginal lands. However, a key obstacle for wider deployment is the lack of economic returns early in the rotation. Alleycropping has the potential to address this issue, especially when paired with crops such as winter triticale which complete their growth cycle early in the summer and therefore are expected to exert minimal competition on establishing trees. In addition, well-placed fertilizer in low rates at planting has the potential to improve tree establishment and shorten the rotation, which is also economically desirable. To test the potential productivity of “Crandon” alleycropped with winter triticale, plots were established on five topographic positions with four different rates of fertilizer placed in the planting hole. Trees were then harvested from the plots after each of the first three growing seasons. Fertilization resulted in significant increases in branch, stem, and total aboveground biomass across all years, whereas the effects of topographic position varied by year. Allocation between branches and stems was found to be primarily a function of total aboveground biomass.

  20. Quantifying pollen-vegetation relationships to reconstruct ancient forests using 19th-century forest composition and pollen data

    Science.gov (United States)

    Dawson, Andria; Paciorek, Christopher J.; McLachlan, Jason S.; Goring, Simon; Williams, John W.; Jackson, Stephen T.

    2016-04-01

    Mitigation of climate change and adaptation to its effects relies partly on how effectively land-atmosphere interactions can be quantified. Quantifying composition of past forest ecosystems can help understand processes governing forest dynamics in a changing world. Fossil pollen data provide information about past forest composition, but rigorous interpretation requires development of pollen-vegetation models (PVMs) that account for interspecific differences in pollen production and dispersal. Widespread and intensified land-use over the 19th and 20th centuries may have altered pollen-vegetation relationships. Here we use STEPPS, a Bayesian hierarchical spatial PVM, to estimate key process parameters and associated uncertainties in the pollen-vegetation relationship. We apply alternate dispersal kernels, and calibrate STEPPS using a newly developed Euro-American settlement-era calibration data set constructed from Public Land Survey data and fossil pollen samples matched to the settlement-era using expert elicitation. Models based on the inverse power-law dispersal kernel outperformed those based on the Gaussian dispersal kernel, indicating that pollen dispersal kernels are fat tailed. Pine and birch have the highest pollen productivities. Pollen productivity and dispersal estimates are generally consistent with previous understanding from modern data sets, although source area estimates are larger. Tests of model predictions demonstrate the ability of STEPPS to predict regional compositional patterns.

  1. Quantifying pollen-vegetation relationships to reconstruct ancient forests using 19th-century forest composition and pollen data

    Science.gov (United States)

    Dawson, Andria; Paciorek, Christopher J.; McLachlan, Jason S.; Goring, Simon; Williams, John W.; Jackson, Stephen T.

    2016-01-01

    Mitigation of climate change and adaptation to its effects relies partly on how effectively land-atmosphere interactions can be quantified. Quantifying composition of past forest ecosystems can help understand processes governing forest dynamics in a changing world. Fossil pollen data provide information about past forest composition, but rigorous interpretation requires development of pollen-vegetation models (PVMs) that account for interspecific differences in pollen production and dispersal. Widespread and intensified land-use over the 19th and 20th centuries may have altered pollen-vegetation relationships. Here we use STEPPS, a Bayesian hierarchical spatial PVM, to estimate key process parameters and associated uncertainties in the pollen-vegetation relationship. We apply alternate dispersal kernels, and calibrate STEPPS using a newly developed Euro-American settlement-era calibration data set constructed from Public Land Survey data and fossil pollen samples matched to the settlement-era using expert elicitation. Models based on the inverse power-law dispersal kernel outperformed those based on the Gaussian dispersal kernel, indicating that pollen dispersal kernels are fat tailed. Pine and birch have the highest pollen productivities. Pollen productivity and dispersal estimates are generally consistent with previous understanding from modern data sets, although source area estimates are larger. Tests of model predictions demonstrate the ability of STEPPS to predict regional compositional patterns.

  2. Maize nutrient uptake affected by genotype and fertilization

    Directory of Open Access Journals (Sweden)

    Đalović Ivica

    2015-01-01

    Full Text Available The content of nutrients in maize are commonly related with fertilization and soil quality and rarely explained with the individual hybrid properties. Therefore, the aim of this study is to access a long term fertilization system on ear leaf of Mg, Fe, Mn and Cu content in six maize hybrids(NS 3014, NS 4015, NS 5043, NS 6010, NS 6030 and NS 7020. Samples were collected from a long-term experiment at the Rimski Šančevi experimental field of the Institute of Field and Vegetable Crops in Novi Sad. The study included maize monoculture and 2-year rotations with the application of NPK and manure. Results showed that ear Mg content was influenced with the treatments, hybrid and their interaction and ranged from 1.77-2.69 g kg-1. Iron variability was significantly affected with the treatments and interaction (hybrid x treatments in range from 103.2 to151.9g kg-1. The ear manganese content (41.1-63.6g kg-1 derived from treatments and hybrid effect and Cu (12.3-23.6 g kg-1 was significantly influenced with treatments. Across all treatments, in average, NS6030 had higher values of nutrient and NS3014 was lower in ear nutrient content. This indicates that vegetation length could favor nutrient accumulation. Obtained results suggested that even on fairly productive soil such as Chernozem hybrid selection and the balanced fertilization is crucial for managing the maize nutrient content. [Projekat Ministarsva nauke Republike Srbije, br. TR031073

  3. MICROBIAL QUALITY OF HONEY MIXTURE WITH POLLEN

    Directory of Open Access Journals (Sweden)

    Ján Mareček

    2011-02-01

    Full Text Available Normal 0 21 MicrosoftInternetExplorer4 The aim of this study was evaluation of microbial quality in raw materials (honey, pollen and evaluation of microbial quality in honey mixture with pollen (2.91 % and 3.85 % and also dynamics of microbial groups in honey mixtures with pollen after 14 days storage at the room temperature (approximately 25 °C and in cold store (8 °C. We used dilution plating method for testing of samples. Detections of total plate microbial count (aerobic and anaerobic microorganisms, sporulating bacteria, coliform bacteria, Bifidobacterium sp., Lactobacillus sp. and microscopic fungi were performed. In general, counts of microorganisms decreased in honey mixture with pollen compared to raw pollen and these counts increased compared to natural honey. Total plate count was 5.37 log KTJ.g-1 in pollen; 1.36 log KTJ.g-1 in honey; 2.97 log KTJ.g-1 in honey mixture with 2.91 % pollen and 2.04 log KTJ.g-1 in honey mixture with 3.85 % pollen. Coliform bacteria were detected in pollen (1.77 log KTJ.g-1. Then, we found coliform bacteria in one sample of honey mixtures with pollen (2.91 % - 1.00 log KTJ.g-1.Bifidobacterium species were detected only in raw pollen. We did not findLactobacillus sp. in any of the samples. Microscopic fungi were detected on two cultivating media. Yeasts were present in pollen sample (average 5.39 log KTJ.g-1, honey mixture with 2.91 % pollen (average 2.51 log KTJ.g-1 and honey mixture with 3.85 % pollen (average 1.58 log KTJ.g-1. Filamentous microscopic fungi were detectable in pollen (average 3.38 log KTJ.g-1, in honey (only on one medium: 1.00 log KTJ.g-1, in honey mixture with 2.91 % pollen (average 1.15 log KTJ.g-1 and in honey mixture with 3.85 % pollen (1.71 %. Raw pollen contained microscopic fungi as Absidiasp., Mucor sp., Alternaria sp. andEmericella nidulans. Honey mixture with 2.91 % pollen after storage (14 days contained lower microbial counts when compared with the sample

  4. Identifying Differentially Expressed Genes in Pollen from Self-Incompatible “Wuzishatangju” and Self-Compatible “Shatangju” Mandarins

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    Guibing Hu

    2013-04-01

    Full Text Available Self-incompatibility (SI is one of the important factors that can result in seedless fruit in Citrus. However, the molecular mechanism of SI in Citrus is not yet clear. In this study, two suppression subtractive hybridization (SSH libraries (forward, F and reverse, R were constructed to isolate differentially expressed genes in pollen from “Wuzishatangju” (SI and “Shatangju” (self-compatibility, SC mandarins. Four hundred and sixty-eight differentially expressed cDNA clones from 2077 positive clones were sequenced and identified. Differentially expressed ESTs are possibly involved in the SI reaction of “Wuzishatangju” by regulating pollen development, kinase activity, ubiquitin pathway, pollen-pistil interaction, and calcium ion binding. Twenty five SI candidate genes were obtained, six of which displayed specific expression patterns in various organs and stages after self- and cross-pollination. The expression level of the F-box gene (H304 and S1 (F78 in the pollen of “Wuzishatangju” was 5-fold higher than that in “Shatangju” pollen. The F-box gene, S1, UBE2, UBE3, RNaseHII, and PCP were obviously up-regulated in pistils at 3 d after self-pollination of “Wuzishatangju”, approximately 3-, 2-, 10-, 5-, 5-, and 2-fold higher, respectively than that at the same stage after cross-pollination of “Wuzishatangju” × “Shatangju” pistils. The potential involvement of these genes in the pollen SI reaction of “Wuzishatangju” is discussed.

  5. Pollen Forecast and Dispersion Modelling

    Science.gov (United States)

    Costantini, Monica; Di Giuseppe, Fabio; Medaglia, Carlo Maria; Travaglini, Alessandro; Tocci, Raffaella; Brighetti, M. Antonia; Petitta, Marcello

    2014-05-01

    The aim of this study is monitoring, mapping and forecast of pollen distribution for the city of Rome using in-situ measurements of 10 species of common allergenic pollens and measurements of PM10. The production of daily concentration maps, associated to a mobile phone app, are innovative compared to existing dedicated services to people who suffer from respiratory allergies. The dispersal pollen is one of the most well-known causes of allergic disease that is manifested by disorders of the respiratory functions. Allergies are the third leading cause of chronic disease and it is estimated that tens millions of people in Italy suffer from it. Recent works reveal that during the last few years there was a progressive increase of affected subjects, especially in urban areas. This situation may depend: on the ability to transport of pollutants, on the ability to react between pollutants and pollen and from a combination of other irritants, existing in densely populated and polluted urban areas. The methodology used to produce maps is based on in-situ measurements time series relative to 2012, obtained from networks of air quality and pollen stations in the metropolitan area of Rome. The monitoring station aerobiological of University of Rome "Tor Vergata" is located at the Department of Biology. The instrument used to pollen monitoring is a volumetric sampler type Hirst (Hirst 1952), Model 2000 VPPS Lanzoni; the data acquisition is carried out as reported in Standard UNI 11008:2004 - "Qualità dell'aria - Metodo di campionamento e conteggio dei granuli pollinici e delle spore fungine aerodisperse" - the protocol that describes the procedure for measuring of the concentration of pollen grains and fungal spores dispersed into the atmosphere, and reported in the "Manuale di gestione e qualità della R.I.M.A" (Travaglini et. al. 2009). All 10 allergenic pollen are monitored since 1996. At Tor Vergata university is also operating a meteorological station (SP2000, CAE

  6. Analysis of self-fertilization and meiotic behavior of eleven Brazilian triticale cultivars at two sowing dates

    Directory of Open Access Journals (Sweden)

    Divanilde Guerra

    2011-01-01

    Full Text Available Eleven Brazilian hexaploid triticale cultivars (2n = 6x = 42, from three breeding programs, were evaluated for theirability of self-fertilization in 2006 and for meiotic behavior, meiotic index and pollen viability at two sowing dates in 2007. Highpotential of self-fertilization was observed, with values up to 89.52 %. Many irregularities were found in the meiotic analysis, suchas the presence of univalents, laggard chromosomes and micronuclei in tetrads, which compromised both meiotic behavior andmeiotic index. At the first sowing date, more suitable for normal plant development, overall mean values of 52.68 % for normal cellsand 64.95 % for meiotic index were observed. At the second sowing date, less appropriate for the crop, overall means of 52.23 %for normal cells and 58.24 % for meiotic index were obtained. Despite all the irregularities, considerable pollen viability wasobserved, reaching overall means of 92.08 % and 91.07 % for the first and second sowing dates, respectively.

  7. The plus-hybrid effect on the grain yield of two ZP maize hybrids

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    Božinović Sofija

    2010-01-01

    Full Text Available The combined effect of cytoplasmic male sterility and xenia on maize hybrid traits is referred to as the plus-hybrid effect. Two studied ZP hybrids differently responded to this effect for grain yield. All plus-hybrid combinations of the firstly observed hybrid had a higher yield than their fertile counterparts, but not significantly, while only one combination of the second hybrid positively responded, also without statistical significance. It seems that the observed effect mostly depended on the genotype of the female component.

  8. Differential skin test reactivity to pollens in pollen food allergy syndrome versus allergic rhinitis.

    Science.gov (United States)

    Ta, Von; Scott, David R; Chin, William K; Wineinger, Nathan E; Kelso, John M; White, Andrew A

    2015-01-01

    Pollen food allergy syndrome (PFAS), also called oral allergy syndrome, is a form of food allergy in which uncooked foods cause allergic symptoms generally limited to the oral mucosa. It occurs in a subset of patients with pollen allergy, although not all patients have prominent rhinitis symptoms. PFAS is related to antigenic similarity between the pollen and food allergen. The size of skin test reactions in a group of subjects with pollen sensitivity with PFAS was compared with a group of subjects who were pollen sensitive and without PFAS. Self-reported rhinitis symptoms between the two groups were compared to identify if symptom severity differed. Twenty subjects with PFAS and 20 subjects with seasonal allergic rhinitis without PFAS were enrolled in the study. All the subjects underwent standard skin-prick testing to a panel of common allergens, including select fresh fruits and vegetables. The subjects completed a Mini Rhinoconjunctivitis Quality of Life Questionnaire as part of their clinical evaluation. The subjects with PFAS and those without PFAS were compared statistically. The subjects with PFAS had significantly larger-sized skin-prick test results specific to pollens (p PFAS reported milder nasal symptoms in relation to pollen skin test result size when compared with allergic rhinitis controls without PFAS. Our study outlined basic differences between two seemingly similar patient groups with a particularly striking discordance between skin test result sizes and rhinitis symptoms. This discordance should be explored further to increase mechanistic understanding of allergen cross-reactivity in PFAS.

  9. Selection of suitable fertilizer draw solute for a novel fertilizer-drawn forward osmosis-anaerobic membrane bioreactor hybrid system.

    Science.gov (United States)

    Kim, Youngjin; Chekli, Laura; Shim, Wang-Geun; Phuntsho, Sherub; Li, Sheng; Ghaffour, Noreddine; Leiknes, TorOve; Shon, Ho Kyong

    2016-06-01

    In this study, a protocol for selecting suitable fertilizer draw solute for anaerobic fertilizer-drawn forward osmosis membrane bioreactor (AnFDFOMBR) was proposed. Among eleven commercial fertilizer candidates, six fertilizers were screened further for their FO performance tests and evaluated in terms of water flux and reverse salt flux. Using selected fertilizers, bio-methane potential experiments were conducted to examine the effect of fertilizers on anaerobic activity due to reverse diffusion. Mono-ammonium phosphate (MAP) showed the highest biogas production while other fertilizers exhibited an inhibition effect on anaerobic activity with solute accumulation. Salt accumulation in the bioreactor was also simulated using mass balance simulation models. Results showed that ammonium sulfate and MAP were the most appropriate for AnFDFOMBR since they demonstrated less salt accumulation, relatively higher water flux, and higher dilution capacity of draw solution. Given toxicity of sulfate to anaerobic microorganisms, MAP appears to be the most suitable draw solution for AnFDFOMBR. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. Selection of suitable fertilizer draw solute for a novel fertilizer-drawn forward osmosis-anaerobic membrane bioreactor hybrid system

    KAUST Repository

    Kim, Youngjin

    2016-02-09

    In this study, a protocol for selecting suitable fertilizer draw solute for anaerobic fertilizer-drawn forward osmosis membrane bioreactor (AnFDFOMBR) was proposed. Among eleven commercial fertilizer candidates, six fertilizers were screened further for their FO performance tests and evaluated in terms of water flux and reverse salt flux. Using selected fertilizers, bio-methane potential experiments were conducted to examine the effect of fertilizers on anaerobic activity due to reverse diffusion. Mono-ammonium phosphate (MAP) showed the highest biogas production while other fertilizers exhibited an inhibition effect on anaerobic activity with solute accumulation. Salt accumulation in the bioreactor was also simulated using mass balance simulation models. Results showed that ammonium sulphate and MAP were the most appropriate for AnFDFOMBR since they demonstrated less salt accumulation, relatively higher water flux, and higher dilution capacity of draw solution. Given toxicity of sulphate to anaerobic microorganisms, MAP appears to be the most suitable draw solution for AnFDFOMBR.

  11. Programmed cell death-like behavior in photoperiodsensitive genic ...

    African Journals Online (AJOL)

    This type of control of rice plant fertility can facilitate production of hybrid rice using two lines (photoperiodsensitive genic male sterile (PGMS) and restorer) system. Our objective in this study was to determine anatomical changes in PGMS rice pollen cells induced by long day length and high temperature growth conditions ...

  12. Inherent optical properties of pollen particles: a case study for the morning glory pollen.

    Science.gov (United States)

    Liu, Chao; Yin, Yan

    2016-01-25

    Biological aerosols, such as bacteria, fungal spores, and pollens, play an important role on various atmospheric processes, whereas their inherent optical property is one of the most uncertainties that limit our ability to assess their effects on weather and climate. A numerical model with core-shell structure, hexagonal grids and barbs is developed to represent one kind of realistic pollen particles, and their inherent optical properties are simulated using a pseudo-spectral time domain method. Both the hexagonal grids and barbs substantially affect the modeled pollen optical properties. Results based on the realistic particle model are compared with two equivalent spherical approximations, and the significant differences indicate the importance of considering pollen geometries for their optical properties.

  13. Pollen and spores of terrestrial plants

    Science.gov (United States)

    Bernhardt, Christopher E.; Willard, Debra A.; Shennan, Ian; Long, Antony J.; Horton, Benjamin P.

    2015-01-01

    Pollen and spores are valuable tools in reconstructing past sea level and climate because of their ubiquity, abundance, and durability as well as their reciprocity with source vegetation to environmental change (Cronin, 1999; Traverse, 2007; Willard and Bernhardt, 2011). Pollan is found in many sedimentary environments, from freshwater to saltwater, terrestrial to marine. It can be abundant in a minimal amount of sample material, for example half a gram, as concentrations can be as high as four million grains per gram (Traverse, 2007). The abundance of pollen in a sample lends it to robust statistical analysis for the quantitative reconstruction of environments. The outer cell wall is resistant to decay in sediments and allows palynomorphs (pollen and spores) to record changes in plant communities and sea level over millions of years. These characteristics make pollen and spores a powerful tool to use in sea-level research.This chapter describes the biology of pollen and spores and how they are transported and preserved in sediments. We present a methodology for isolating pollen from sediments and a general language and framework to identify pollen as well as light micrographs of a selection of common pollen grains, We then discuss their utility in sea-level research.

  14. Stigma-pollen recognition: a new look

    Directory of Open Access Journals (Sweden)

    C. Dumas

    2014-01-01

    Full Text Available During the last two decades, there have been several conceptual developments in our understanding of pollen-stigma recognition and molecular mechanisms involved. The main models proposed are compared. Based on additional data a hypothesis to complete these models especially for pollen hydration and adhesion is proposed. After attachment of the pollen to the stigma surface a close interaction exists involving lipoproteic membrane-like compounds (pollenkitt and stigma pellicle and pollen agglutinating ability.

  15. Pollination with heavily irradiated pollen in Nicotiana: induced parthenogenesis and embryological study

    International Nuclear Information System (INIS)

    Musial, K.; Przywara, L.

    1999-01-01

    Nicotiana crosses were pollinated in situ and in vitro with heavily irradiated pollen (500, 700, 1000 Gy) to induce parthenogenesis and to study the development of embryo and endosperm. Haploids were obtained after in situ pollination only; however, parthenogenetic proembryos occurred also after in vitro pollination. It was demonstrated that ovule culture following pollination offers a better chance to produce haploids than undisturbed pollination does. Pollination with irradiated pollen (PwIP) stron gly decreased the number of endosperm cells and the size of embryo sacs, and it affected the development of embryos; no significant differences between applied irradiation doses were found. Ovules with endosperm only, embryo only, and with both embryo and endosperm were observed. The most frequent were the ovules with endosperm only, the rarest with embryo only. A small amount of storage products occurred in the endosperm cells. The diploid chromosome number counted in the endosperm produced after PwIP points to their origin without fertilization. An interesting phenomenon observed after PwIP was vigorous growth of endothelium. (author)

  16. Immunochemical Characterization of Acacia Pollen Allergens and Evaluation of Cross-Reactivity Pattern with the Common Allergenic Pollens

    Science.gov (United States)

    Shamsbiranvand, Mohammad-Hosein; Khodadadi, Ali; Assarehzadegan, Mohammad-Ali; Borsi, Seyed Hamid; Amini, Akram

    2014-01-01

    Pollen from the Acacia has been reported as an important source of pollinosis in tropical and subtropical regions of the world. The aim of this study was to characterize the IgE binding protein of Acacia farnesiana pollen extract and evaluate cross-reactivity with the most allergenic pollens. In this study, pollen extract was fractionated by SDS-PAGE and the allergenic profile was determined by IgE-immunoblotting and specific ELISA using forty-two Acacia allergic patients. Potential cross-reactivity among Acacia and selected allergenic plants was evaluated with ELISA and immunoblotting inhibition experiments. There were several resolved protein fractions on SDS-PAGE which ranged from 12 to 85 kDa. Several allergenic protein bands with molecular weights approximately between 12 and 85 kDa were recognized by IgE-specific antibodies from Acacia allergic patients in the immunoblot assay. The inhibition by the Prosopis juliflora pollen extract was more than those by other pollen extracts. Moreover, the wheal diameters generated by the Acacia pollen extract were highly correlated with those of P. juliflora pollen extracts. The findings suggest that several proteins such as 15, 23, 45, and 50 kDa proteins could be used as diagnostic and therapeutic reagents for patients allergic to A. farnesiana and P. juliflora. PMID:24949020

  17. Proteomic Analysis of Male-Fertility Restoration in CMS Onion

    Science.gov (United States)

    The production of hybrid-onion seed is dependent on cytoplasmic-genic male sterility (CMS) systems. For the most commonly used CMS, male-sterile (S) cytoplasm interacts with a dominant allele at one nuclear male-fertility restoration locus (Ms) to condition male fertility. We are using proteomics ...

  18. Functional immunoglobulin E cross-reactivity between Pas n 1 of Bahia grass pollen and other group 1 grass pollen allergens.

    Science.gov (United States)

    Davies, J M; Dang, T D; Voskamp, A; Drew, A C; Biondo, M; Phung, M; Upham, J W; Rolland, J M; O'Hehir, R E

    2011-02-01

    Grass pollens are major triggers of allergic rhinitis and asthma, but the immunological relationships between pollen allergens of the subtropical Bahia grass, Paspalum notatum, and temperate grasses are unresolved. To assess serum IgE cross-reactivity between subtropical P. notatum and temperate Lolium perenne (Ryegrass) pollen allergens. Serum IgE reactivities of grass pollen-allergic patients with P. notatum, L. perenne and Cynodon dactylon (Bermuda grass) pollen extracts and their respective purified group 1 allergens, Pas n 1, Lol p 1 and Cyn d 1, were compared by immunoblotting, ELISA and basophil activation. In a cohort of 51 patients from a temperate region, a high frequency of IgE reactivity with each grass pollen was detected, but reactivity with L. perenne pollen was substantially greater than with P. notatum and C. dactylon pollen. Similarly, serum IgE reactivity with Lol p 1 was greater than with Pas n 1 or Cyn d 1. For seven of eight sera studied in detail, asymmetric serum IgE cross-reactivity was observed; L. perenne pollen inhibited IgE reactivity with P. notatum pollen but not the converse, and IgE reactivity with Pas n 1 was inhibited by Lol p 1 but IgE reactivity with Lol p 1 was not inhibited by Pas n 1 or Cyn d 1. Importantly, P. notatum pollen and Pas n 1 activated basophils in grass pollen-allergic patients from a temperate region, although stimulation was greater by pollen of L. perenne than P. notatum or C. dactylon, and by Lol p 1 than Pas n 1 or Cyn d 1. In contrast, a cohort of 47 patients from a subtropical region showed similar IgE reactivity with P. notatum and L. perenne pollen, and reciprocal cross-inhibition of IgE reactivity between L. perenne and P. notatum. Pollen allergens of the subtropical P. notatum, including Pas n 1, show clinically relevant IgE cross-reactivity with pollen allergens of L. perenne but also species-specific IgE reactivity. © 2011 Blackwell Publishing Ltd.

  19. Pollen lipidomics: lipid profiling exposes a notable diversity in 22 allergenic pollen and potential biomarkers of the allergic immune response.

    Directory of Open Access Journals (Sweden)

    Mohamed Elfatih H Bashir

    Full Text Available BACKGROUND/AIM: Pollen grains are the male gametophytes that deliver sperm cells to female gametophytes during sexual reproduction of higher plants. Pollen is a major source of aeroallergens and environmental antigens. The pollen coat harbors a plethora of lipids that are required for pollen hydration, germination, and penetration of the stigma by pollen tubes. In addition to proteins, pollen displays a wide array of lipids that interact with the human immune system. Prior searches for pollen allergens have focused on the identification of intracellular allergenic proteins, but have largely overlooked much of the extracellular pollen matrix, a region where the majority of lipid molecules reside. Lipid antigens have attracted attention for their potent immunoregulatory effects. By being in close proximity to allergenic proteins on the pollen surface when they interact with host cells, lipids could modify the antigenic properties of proteins. METHODOLOGY/PRINCIPAL FINDINGS: We performed a comparative pollen lipid profiling of 22 commonly allergenic plant species by the use of gas chromatography-mass spectroscopy, followed by detailed data mining and statistical analysis. Three experiments compared pollen lipid profiles. We built a database library of the pollen lipids by matching acquired pollen-lipid mass spectra and retention times with the NIST/EPA/NIH mass-spectral library. We detected, identified, and relatively quantified more than 106 lipid molecular species including fatty acids, n-alkanes, fatty alcohols, and sterols. Pollen-derived lipids stimulation up-regulate cytokines expression of dendritic and natural killer T cells co-culture. CONCLUSIONS/SIGNIFICANCE: Here we report on a lipidomic analysis of pollen lipids that can serve as a database for identifying potential lipid antigens and/or novel candidate molecules involved in allergy. The database provides a resource that facilitates studies on the role of lipids in the

  20. Pollen-gamma irradiation on pineapple and pollination using irradiated pollen

    International Nuclear Information System (INIS)

    Benega, R.; Cisneros, A.; Martinez, J.; Arias, E.; Yabor, L.; Isidron, M.; Castillo, E.; Fernandez, J.

    1997-01-01

    In order to try to induce haploid plants, pineapple (Ananas comosus (L.) ;err.) pollen grains were gamma-rays irradiated with a Co 60 source at rates of doses from 0 to 300 Gy. The effect of gamma-rays on the generative-nucleus division and vitro pollen viability as well as, seed contents and plantlets obtained after pollinations was analysed. The were reducing in the division frequencies of generative nucleus at all assayed doses. The LD50 was achieved among 200 and 250 Gy. There were not differences on pollen viability in the rates of assayed doses. Seed contents were dose-dependent. The percentages of seed full and seed containing only embryos decreases at increasing of irradiation doses. Contrary effect was observed on the seed empty. Some plantlets regenerated from the different irradiation doses showed phenotypes with small and leaves and short inter nodes

  1. Split-gene system for hybrid wheat seed production.

    Science.gov (United States)

    Kempe, Katja; Rubtsova, Myroslava; Gils, Mario

    2014-06-24

    Hybrid wheat plants are superior in yield and growth characteristics compared with their homozygous parents. The commercial production of wheat hybrids is difficult because of the inbreeding nature of wheat and the lack of a practical fertility control that enforces outcrossing. We describe a hybrid wheat system that relies on the expression of a phytotoxic barnase and provides for male sterility. The barnase coding information is divided and distributed at two loci that are located on allelic positions of the host chromosome and are therefore "linked in repulsion." Functional complementation of the loci is achieved through coexpression of the barnase fragments and intein-mediated ligation of the barnase protein fragments. This system allows for growth and maintenance of male-sterile female crossing partners, whereas the hybrids are fertile. The technology does not require fertility restorers and is based solely on the genetic modification of the female crossing partner.

  2. Saccharomyces cerevisiae Fermentation Effects on Pollen: Archaeological Implications

    Directory of Open Access Journals (Sweden)

    Crystal A. Dozier

    2016-03-01

    Full Text Available Pollen is the reproductive agent of flowering plants; palynology is utilized by archaeologists because sporopollenin, a major component in the exine of pollen grains, is resistant to decay and morphologically distinctive. Wine, beer, and mead have been identified in the archaeological record by palynological assessment due to indicator species or due to a pollen profile similar to that recovered from honey, a common source of sugar in a variety of fermented beverages. While most palynologists have assumed that pollen grains are resistant to alcoholic fermentation, a recent study in food science implies that pollen is a yeast nutrient because pollen-enriched meads produce more alcohol. The experiment presented here explores the potential distortion of the pollen record through fermentation by brewing a traditional, pollen-rich mead with Saccharomyces cerevisiae. In this experiment, the pollen grains did not undergo any discernible morphological changes nor were distorted in the pollen profile. Any nutrition that the yeast garners from the pollen therefore leaves sporopollenin intact. These results support palynological research on residues of alcoholic beverages and confirms that the fermentation process does not distort the pollen profile of the original substance. The paper concludes with the potential and limits of palynological study to assess fermentation within the archaeological record.

  3. Comprehensive analysis of genic male sterility-related genes in Brassica rapa using a newly developed Br300K oligomeric chip.

    Directory of Open Access Journals (Sweden)

    Xiangshu Dong

    Full Text Available To identify genes associated with genic male sterility (GMS that could be useful for hybrid breeding in Chinese cabbage (Brassicarapa ssp. pekinensis, floral bud transcriptome analysis was carried out using a B. rapa microarray with 300,000 probes (Br300K. Among 47,548 clones deposited on a Br300K microarray with seven probes of 60 nt length within the 3' 150 bp region, a total of 10,622 genes were differentially expressed between fertile and sterile floral buds; 4,774 and 5,848 genes were up-regulated over 2-fold in fertile and sterile buds, respectively. However, the expression of 1,413 and 199 genes showed fertile and sterile bud-specific features, respectively. Genes expressed specifically in fertile buds, possibly GMS-related genes, included homologs of several Arabidopsis male sterility-related genes, genes associated with the cell wall and synthesis of its surface proteins, pollen wall and coat components, signaling components, and nutrient supplies. However, most early genes for pollen development, genes for primexine and callose formation, and genes for pollen maturation and anther dehiscence showed no difference in expression between fertile and sterile buds. Some of the known genes associated with Arabidopsis pollen development showed similar expression patterns to those seen in this study, while others did not. BrbHLH89 and BrMYP99 are putative GMS genes. Additionally, 17 novel genes identified only in B. rapa were specifically and highly expressed only in fertile buds, implying the possible involvement in male fertility. All data suggest that Chinese cabbage GMS might be controlled by genes acting in post-meiotic tapetal development that are different from those known to be associated with Arabidopsis male sterility.

  4. Drought, pollen and nectar availability, and pollination success.

    Science.gov (United States)

    Waser, Nickolas M; Price, Mary V

    2016-06-01

    Pollination success of animal-pollinated flowers depends on rate of pollinator visits and on pollen deposition per visit, both of which should vary with the pollen and nectar "neighborhoods" of a plant, i.e., with pollen and nectar availability in nearby plants. One determinant of these neighborhoods is per-flower production of pollen and nectar, which is likely to respond to environmental influences. In this study, we explored environmental effects on pollen and nectar production and on pollination success in order to follow up a surprising result from a previous study: flowers of Ipomopsis aggregata received less pollen in years of high visitation by their hummingbird pollinators. A new analysis of the earlier data indicated that high bird visitation corresponded to drought years. We hypothesized that drought might contribute to the enigmatic prior result if it decreases both nectar and pollen production: in dry years, low nectar availability could cause hummingbirds to visit flowers at a higher rate, and low pollen availability could cause them to deposit less pollen per visit. A greenhouse experiment demonstrated that drought does reduce both pollen and nectar production by I. aggregata flowers. This result was corroborated across 6 yr of variable precipitation and soil moisture in four unmanipulated field populations. In addition, experimental removal of pollen from flowers reduced the pollen received by nearby flowers. We conclude that there is much to learn about how abiotic and biotic environmental drivers jointly affect pollen and nectar production and availability, and how this contributes to pollen and nectar neighborhoods and thus influences pollination success.

  5. Interspecific hybrids between Paspalum plicatulum and P. oteroi: a key tool for forage breeding

    Directory of Open Access Journals (Sweden)

    Patricia Elda Novo

    2016-08-01

    Full Text Available ABSTRACT Grama-tio-pedro (Paspalum oteroi Swallen is a rare stoloniferous grass of the Plicatula group of Paspalum, well adapted to continuous grazing in areas subject to seasonal flooding in the Pantanal region, in central western Brazil. The species is a facultative apomictic (asexual reproduction by seed tetraploid, sporadically cultivated on Pantanal farms, propagated either by cuttings or seed. Due to its potential for extensive cultivation and forage quality, Grama-tio-pedro appears as a candidate for genetic improvement within the Plicatula group through plant breeding. We used a colchicine-induced sexual autotetraploid genotype of P. plicatulum Michx. to obtain interspecific hybrids using the apomictic species, P. oteroi, as pollen donor. The very similar meiotic chromosome behavior observed in both parents, with main quadrivalent and bivalent associations, suggested that P. oteroi is a natural autotetraploid. The hybrids showed less irregular meiotic behavior with fewer quadrivalents and more bivalents than either parent. Fertility among interspecific hybrids varied from complete sterility in some of them to seed productions in others that were approximately twice as much as for either parent. The great variability of seed set performance may well be a drastic genetic consequence of joining two homologous chromosome sets of P. plicatulum together with two homologous sets of P. oteroi that, in turn, have some homeology between them. Most hybrids reproduce by sexual means, thus, they could be used as female parents in backcrosses and in crosses with other species of the Plicatula group for interspecific gene transferring in breeding programs.

  6. Trends in airborne pollen and pollen-season-related features of anemophilous species in Jaen (south Spain): A 23-year perspective

    Science.gov (United States)

    Ruiz-Valenzuela, Luis; Aguilera, Fátima

    2018-05-01

    Over the last few decades, global warming is prompting phenological changes in numerous plant species across Europe, and a trend towards rising airborne pollen concentrations has been detected. This study, focused on the most frequent pollen types from arboreal and herbaceous species in the airborne spectrum of Jaen (southern Spain), revealed significant changes in airborne pollen intensity and duration of the pollen season over the 23-year study period. Here Cupressaceae, Olea, Pinus, Platanus, Quercus as arboreal taxa and Plantago as herbaceous taxa were the most important with notable changes of at least three pollen season characteristics. Airborne pollen trends from arboreal taxa with high to very high allergenic potential are rising in line with the local temperature increasing trend, and their pollen seasons tend to end later and last longer. However, both the pollen concentrations and the duration of the pollen season of some herbaceous taxa are declining. The climate conditions projected for south Europe under different greenhouse emissions scenarios could continue to prompt greater pollen release and longer pollen season in tree species, especially those that flowering in winter and early spring, but these warming trends might be adverse for the local development of some herbaceous species and favorable for others sharing the same ecological niche. If similar warming trends accompany long-term climate change, greater exposure times to seasonal allergens may occur with subsequent effects on health.

  7. The use of alternative fertilizers to increase soil fertility and yield of sunflower in North-Eastern Kazakhstan

    Directory of Open Access Journals (Sweden)

    Kulzhanova S.M.

    2018-01-01

    Full Text Available the article contains data from studies conducted in 2015–2016 in the North-Еastern part of Kazakhstan. In the experiments the effect of various doses of non-traditional fertilizer together with mineral fertilizer on the yield of sunflower was investigated. Various doses and ratios of mineral fertilizers have been applied, which can affect the yield of sunflower. As a source material, varieties of sunflower of Russian breeding Zarya and a hybrid of Fortimi USA breeding and non-traditional fertilizers – zeolite are taken. In order to determine the effect on the fertility of soils, the agrochemical characteristics of soils in land areas and the content of mobile forms of nutrients were studied. The main agrochemical characteristics and content of mobile forms of nutrients for soil of land plots are investigated in the article.

  8. Essential minerals and inorganic contaminants (barium, cadmium, lithium, lead and vanadium in dried bee pollen produced in Rio Grande do Sul State, Brazil

    Directory of Open Access Journals (Sweden)

    José Augusto Gasparotto SATTLER

    2016-01-01

    Full Text Available Abstract Like other beehive products, such as honey, royal jelly and propolis, bee pollen has attracted great interest because of the health benefits it can provide when consumed. Bee pollen has high contents of sugars and proteins and a low content of lipids, it is also a rich source of vitamins and other bioactive compounds, which makes it an attractive micronutrient supplement. However, few studies have investigated its composition. Therefore, the aim of this study was to characterize the essential minerals and inorganic contaminants present in bee pollen produced at apiaries in Rio Grande do Sul State, Brazil. Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES revealed the presence of 8 essential minerals (calcium, iron, copper, chromium, manganese, molybdenum, phosphorus and zinc in the 5 analyzed samples; 6 of them were in sufficiently high amounts to meet dietary requirements. Of the 5 inorganic contaminants assessed (barium, cadmium, lithium, lead and vanadium, only cadmium was present at levels over the International Honey Commission’s standards. All bee pollen samples showed a high content of the 8 essential minerals. Contamination usually results from the use of pesticides, fertilizers and other chemicals in agriculture; thus, monitoring of its levels must be included in bee pollen analysis.

  9. High correlation of specific IgE sensitization between birch pollen, soy and apple allergens indicates pollen-food allergy syndrome among birch pollen allergic patients in northern China.

    Science.gov (United States)

    Hao, Guo-Dong; Zheng, Yi-Wu; Wang, Zhi-Xiang; Kong, Xing-Ai; Song, Zhi-Jing; Lai, Xu-Xin; Spangfort, Michael D

    2016-05-01

    Birch pollen sensitization and associated pollen-food syndrome among Chinese allergic patients have not been investigated. Sera from 203 allergic patients from the northern part of China and collected during February to July 2014 were investigated. Specific immunoglobulin E (IgE) against birch pollen extract Bet v and major birch pollen allergen Bet v 1 were measured using the ADVIA Centaur. The presence of major apple allergen Mal d 1 and soy bean allergen Gly m 4 specific IgE was measured by ImmunoCAP 100. Among the 203 sera, 34 sera (16.7%) had specific IgE to Bet v and of these, 28 sera (82.4%) contained Bet v 1-specific IgE. Among the 28 sera with Bet v 1-specific IgE, 27 sera (96.4%) contained Mal d 1-specific IgE and 22 sera (78.6%) contained Gly m 4-specific IgE. Of the 34 Bet v-positive sera, 6 sera (17.6%) contained no specific IgE for Bet v 1, Mal d 1, or Gly m 4. Almost all Bet v-positive sera were donated during the birch pollen season. The prevalence of birch allergy among patients visiting health care during pollen season can be as high as 16.7% in Tangshan City. The majority of Chinese birch allergic patients are IgE-sensitized to the major birch pollen allergen Bet v 1 as well as to the major apple allergen Mal d 1 and soy bean allergen Gly m 4. A relatively high number of patients (17.6%) are IgE-sensitized to birch pollen allergen(s) other than Bet v 1. The high prevalence of specific IgE to Mal d 1 and Gly m 4 among Bet v 1-sensitized patients indicates that pollen-food allergy syndrome could be of clinical relevance in China.

  10. Divergent rules for pollen and nectar foraging bumblebees--a laboratory study with artificial flowers offering diluted nectar substitute and pollen surrogate.

    Directory of Open Access Journals (Sweden)

    Sabine Konzmann

    Full Text Available Almost all bees collect nectar and pollen from flowers. Female bees collect pollen to provision their nest cells, whereas they use nectar for individual energy supply and nest cell provisioning. Bees fine-tune nectar foraging to the amount and to the concentration of nectar, but the individual bees' response to variability of amount and concentration of pollen reward has not yet been studied thoroughly in laboratory settings. We developed an experimental set-up in which bumblebees simultaneously collected sugar solution and pollen from artificial flowers; natural pollen was mixed with cellulose powder or glass powder as a pollen surrogate. Here we show that bumblebee (Bombus terrestris workers do not specialise in nectar or pollen collection, but regularly collect both rewards on the same day. When offered a fixed pollen reward and varied amounts and concentrations of sugar solution, the bumblebees fine-tuned sugar solution foraging dependent on both the volume and concentration, with strong preferences for the highest concentration and the greatest volume. In the reciprocal tests, when offered a fixed sugar reward and varied amounts and concentrations of pollen mixed with a nutrient-free pollen surrogate, the bumblebees follow more an all-or-none rule for pollen, accepting all amounts and concentrations except pure surrogate. It is discussed how the bumblebees' ability to sense sugar, and their apparent inability to sense the pollen protein content, shaped their foraging behaviour. It is argued that the rarity of nectar mimicry and the frequency of pollen mimicry in natural flowers might be interpreted in the context of divergent abilities of nectar and pollen recognition in bees.

  11. Considerations for the preparation of peat samples for palynology, and for the counting of pollen and non-pollen palynomorphs

    Directory of Open Access Journals (Sweden)

    F.M. Chambers

    2011-09-01

    Full Text Available Peat deposits are valuable archives for studying palaeoclimate, the history of local and regional vegetation, and human impact. The most widely applied laboratory analytical technique has been palynology (pollen analysis, which is often limited to the study of pollen and a few easily recognisable spores; however, a variety of other microfossils can be studied in peat deposits and can provide information on past environmental conditions. Among the so-called non-pollen palynomorphs (NPPs are fungal and algal spores that can be used as indicators for local hydrological changes and trophic conditions. This article provides an overview of aspects to consider and sample preparation methods for pollen, spores and other non-pollen palynomorph microfossils in peat deposits; advice on aids to pollen identification and counting; and a brief guide to the range of NPPs that can be counted from prepared subfossil-pollen microslides.

  12. Post-treatment efficacy of discontinuous treatment with 300IR 5-grass pollen sublingual tablet in adults with grass pollen-induced allergic rhinoconjunctivitis

    DEFF Research Database (Denmark)

    Didier, A; Malling, H-J; Worm, Marcel

    2013-01-01

    Sustained efficacy over three pollen seasons of pre- and co-seasonal treatment with 300IR 5-grass pollen sublingual tablet has been demonstrated in adults with moderate-severe grass pollen-associated allergic rhinoconjunctivitis.......Sustained efficacy over three pollen seasons of pre- and co-seasonal treatment with 300IR 5-grass pollen sublingual tablet has been demonstrated in adults with moderate-severe grass pollen-associated allergic rhinoconjunctivitis....

  13. Flotation preferentially selects saccate pollen during conifer pollination.

    Science.gov (United States)

    Leslie, Andrew B

    2010-10-01

    • Among many species of living conifers the presence of pollen with air bladders (saccate pollen) is strongly associated with downward-facing ovules and the production of pollination drops. This combination of features enables saccate pollen grains captured in the pollination drop to float upwards into the ovule. Despite the importance of this mechanism in understanding reproduction in living conifers and in extinct seed plants with similar morphologies, experiments designed to test its effectiveness have yielded equivocal results. • In vitro and in vivo pollination experiments using saccate and nonsaccate pollen were performed using modeled ovules and two Pinus species during their natural pollination period. • Buoyant saccate pollen readily floated through aqueous droplets, separating these grains from nonbuoyant pollen and spores. Ovules that received saccate pollen, nonsaccate pollen or a mixture of both all showed larger amounts and higher proportions of saccate pollen inside ovules after drop secretion. • These results demonstrate that flotation is an effective mechanism of pollen capture and transport in gymnosperms, and suggest that the prevalence of saccate grains and downward-facing ovules in the evolutionary history of seed plants is a result of the widespread use of this mechanism.

  14. Pollen

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past vegetation and climate derived from pollen found in lake and ocean sediments. Parameter keywords describe what was measured in this data set....

  15. Cytomictic Anomalous Male Meiosis and 2n Pollen Grain Formation in Mertensia echioides Benth. (Boraginaceae from Kashmir Himalaya

    Directory of Open Access Journals (Sweden)

    Reyaz Ahmad Malik

    2014-01-01

    Full Text Available Presently Mertensia echioides Benth. (Boraginaceae collected from Kashmir Himalaya, India, is cytologically analyzed for the first time revealing 2n=2x=24 (diploid. Interestingly we found 4.3–6.2% syncytic meiocytes/PMCs with 2n=4x=48 (tetraploid in addition to normal meiocytes (2n=24 during male meiosis. These comparatively larger PMCs (pollen mother cells lead to the formation of fertile giant 2n pollen grains. A frequency of 6.4–13.3% PMCs shows transfer of chromatin material at prophase-I and, therefore, results in aneuploid meiocytes. Whole chromatin transfer by the process of cytomixis could also have led to the formation of tetraploid cells. Translocation heterozygosity is also evident in the form of multivalents in 12–17% diploid (2x meiocytes at diakinesis and metaphase-I and is reported for the first time in this species. The syncytes formed depict open chain hexavalent and quadrivalent formation in the three populations with different frequencies. Moreover chromatin stickiness at metaphase-I is observed in 45% of PMCs in population-1 (P-1. Syncyte or unreduced PMC formation leading to unreduced fertile gametes is here speculated to act as a possible way out for infraspecific polyploidization in the species.

  16. Monitoring, modelling and forecasting of the pollen season

    DEFF Research Database (Denmark)

    Scheifinger, Helfried; Belmonte, Jordina; Buters, Jeroen

    2013-01-01

    The section about monitoring covers the development of phenological networks, remote sensing of the season cycle of the vegetation, the emergence of the science of aerobiology and, more specifically, aeropalynology, pollen sampling instruments, pollen counting techniques, applications of aeropaly......The section about monitoring covers the development of phenological networks, remote sensing of the season cycle of the vegetation, the emergence of the science of aerobiology and, more specifically, aeropalynology, pollen sampling instruments, pollen counting techniques, applications...... of aeropalynology in agriculture and the European Pollen Information System. Three data sources are directly related with aeropalynology: phenological observations, pollen counts and remote sensing of the vegetation activity. The main future challenge is the assimilation of these data streams into numerical pollen...

  17. Multiple-geographic-scale genetic structure of two mangrove tree species: the roles of mating system, hybridization, limited dispersal and extrinsic factors.

    Directory of Open Access Journals (Sweden)

    Gustavo M Mori

    Full Text Available Mangrove plants comprise a unique group of organisms that grow within the intertidal zones of tropical and subtropical regions and whose distributions are influenced by both biotic and abiotic factors. To understand how these extrinsic and intrinsic processes influence a more fundamental level of the biological hierarchy of mangroves, we studied the genetic diversity of two Neotropical mangrove trees, Avicenniagerminans and A. schaueriana, using microsatellites markers. As reported for other sea-dispersed species, there was a strong differentiation between A. germinans and A. schaueriana populations sampled north and south of the northeastern extremity of South America, likely due to the influence of marine superficial currents. Moreover, we observed fine-scale genetic structures even when no obvious physical barriers were present, indicating pollen and propagule dispersal limitation, which could be explained by isolation-by-distance coupled with mating system differences. We report the first evidence of ongoing hybridization between Avicennia species and that these hybrids are fertile, although this interspecific crossing has not contributed to an increase in the genetic diversity the populations where A. germinans and A. schaueriana hybridize. These findings highlight the complex interplay between intrinsic and extrinsic factors that shape the distribution of the genetic diversity in these sea-dispersed colonizer species.

  18. Multiple and asymmetrical origin of polyploid dog rose hybrids (Rosa L. sect. Caninae (DC.) Ser.) involving unreduced gametes.

    Science.gov (United States)

    Herklotz, V; Ritz, C M

    2017-08-01

    Polyploidy and hybridization are important factors for generating diversity in plants. The species-rich dog roses ( Rosa sect. Caninae ) originated by allopolyploidy and are characterized by unbalanced meiosis producing polyploid egg cells (usually 4 x ) and haploid sperm cells (1 x ). In extant natural stands species hybridize spontaneously, but the extent of natural hybridization is unknown. The aim of the study was to document the frequency of reciprocal hybridization between the subsections Rubigineae and Caninae with special reference to the contribution of unreduced egg cells (5 x ) producing 6 x offspring after fertilization with reduced (1 x ) sperm cells. We tested whether hybrids arose by independent multiple events or via a single or few incidences followed by a subsequent spread of hybrids. Population genetics of 45 mixed stands of dog roses across central and south-eastern Europe were analysed using microsatellite markers and flow cytometry. Hybrids were recognized by the presence of diagnostic alleles and multivariate statistics were used to display the relationships between parental species and hybrids. Among plants classified to subsect. Rubigineae , 32 % hybridogenic individuals were detected but only 8 % hybrids were found in plants assigned to subsect. Caninae . This bias between reciprocal crossings was accompanied by a higher ploidy level in Rubigineae hybrids, which originated more frequently by unreduced egg cells. Genetic patterns of hybrids were strongly geographically structured, supporting their independent origin. The biased crossing barriers between subsections are explained by the facilitated production of unreduced gametes in subsect. Rubigineae . Unreduced egg cells probably provide the highly homologous chromosome sets required for correct chromosome pairing in hybrids. Furthermore, the higher frequency of Rubigineae hybrids is probably influenced by abundance effects because the plants of subsect. Caninae are much more abundant

  19. Antimicrobial effect of bee collected pollen extract to Enterobacteriaceae genera after application of bee collected pollen in their feeding

    Directory of Open Access Journals (Sweden)

    Lukáš Hleba

    2013-10-01

    Full Text Available In this study we researched antimicrobial activity of bee pollen extracts to Enterobacteriaceae genera isolated from chicken intestinal tract after application of bee collected pollen in their feeding. We used well plate agar diffusion method for antimicrobial testing of bee pollen extract and disc diffusion method for antibiotic susceptibility testing of bacteria by EUCAST. Identification of bacteria was done by test kit Enterotest 24. We identified tree bacterial strains: E. coli, P. mirabilis and K. oxytoca. We determined that K. oxytoca was resistant to ampicillin only and others identified strain were sensitive to used antibiotics. Also we determined antimicrobial effect of bee pollen extract to all tested strains of Enterobacteriaceae genera which were isolated from intestinal tract of chicken after application of bee collected pollen extract in their feeding. From obtained results we could be conclude that bacteria isolated from chicken after application of bee pollen extract had more resistance to bee collected pollen extract in in vitro experiment as E. coli CCM 3988, which did not be in contact with bee pollen extract.

  20. Pollen of Southeast Asian Alchornea (Euphorbiaceae), with an overview of the pollen fossil record

    NARCIS (Netherlands)

    Bulalacao, L.J.; Ham, van der R.W.J.M.

    2003-01-01

    In order to evaluate pollen morphological descriptions of Alchornea in the literature, which are almost completely based on African and American species, the pollen of eight Southeast Asian species of Alchornea was investigated, using light and scanning electron microscopy. Very little variation

  1. Seasonal variation in diurnal atmospheric grass pollen concentration profiles

    DEFF Research Database (Denmark)

    Peel, Robert George; Ørby, Pia Viuf; Skjøth, Carsten Ambelas

    2014-01-01

    the time of day when peak concentrations are most likely to occur using seasonally averaged diurnal profiles. Atmospheric pollen loads are highly dependent upon emissions, and different species of grass are known to flower and emit pollen at different times of the day and during different periods......In this study, the diurnal atmospheric grass pollen concentration profile within the Danish city of Aarhus was shown to change in a systematic manner as the pollen season progressed. Although diurnal grass pollen profiles can differ greatly from day-to-day, it is common practice to establish...... of the pollen season. Pollen concentrations are also influenced by meteorological factors - directly through those parameters that govern pollen dispersion and transport, and indirectly through the weather-driven flowering process. We found that three different profiles dominated the grass pollen season...

  2. A combinatorial approach to angiosperm pollen morphology.

    Science.gov (United States)

    Mander, Luke

    2016-11-30

    Angiosperms (flowering plants) are strikingly diverse. This is clearly expressed in the morphology of their pollen grains, which are characterized by enormous variety in their shape and patterning. In this paper, I approach angiosperm pollen morphology from the perspective of enumerative combinatorics. This involves generating angiosperm pollen morphotypes by algorithmically combining character states and enumerating the results of these combinations. I use this approach to generate 3 643 200 pollen morphotypes, which I visualize using a parallel-coordinates plot. This represents a raw morphospace. To compare real-world and theoretical morphologies, I map the pollen of 1008 species of Neotropical angiosperms growing on Barro Colorado Island (BCI), Panama, onto this raw morphospace. This highlights that, in addition to their well-documented taxonomic diversity, Neotropical rainforests also represent an enormous reservoir of morphological diversity. Angiosperm pollen morphospace at BCI has been filled mostly by pollen morphotypes that are unique to single plant species. Repetition of pollen morphotypes among higher taxa at BCI reflects both constraint and convergence. This combinatorial approach to morphology addresses the complexity that results from large numbers of discrete character combinations and could be employed in any situation where organismal form can be captured by discrete morphological characters. © 2016 The Author(s).

  3. Effect of drought stress on male fertility restoration in A3 CMS-inducing cytoplasm of sorghum

    Directory of Open Access Journals (Sweden)

    Valentin V. Kozhemyakin

    2017-08-01

    Full Text Available Use of cytoplasmic male sterility (CMS in hybrid breeding requires effective male fertility-restoring lines. In sorghum, very few restoring lines that can restore fertility in A3 CMS have been reported. To identify the reasons for this deficiency, F1 and F2 hybrids of an A3 CMS line crossed with the line IS1112C, a donor of fertility-restoring (Rf genes for A3 cytoplasm, and testcrosses of fertile plants to A3 CMS lines were grown under contrasting water availability regimes in dryland and irrigated field plots. In the irrigated plots the frequency of fertile plants in testcrosses was twice that in dryland plots (P < 0.05. Fertile plants from the F2 family grown in the irrigated plots showed significantly higher restoration ability than fertile plants from the same family grown in dryland plots. F3 plants from the F2 family grown in irrigated plots yielded on average a sixfold higher frequency of fertile plants in testcrosses than F3 plants derived from dryland plots (P < 0.01. Fertility of testcross hybrids correlated negatively with air vapor pressure deficit (VPD at flowering (r = −0.96; P < 0.01 suggesting that VPD is a trigger for downregulation of Rf genes for A3 cytoplasm.

  4. The revised edition of korean calendar for allergenic pollens.

    Science.gov (United States)

    Oh, Jae-Won; Lee, Ha-Baik; Kang, Im-Joo; Kim, Seong-Won; Park, Kang-Seo; Kook, Myung-Hee; Kim, Bong-Seong; Baek, Hey-Sung; Kim, Joo-Hwa; Kim, Ja-Kyung; Lee, Dong-Jin; Kim, Kyu-Rang; Choi, Young-Jin

    2012-01-01

    The old calendar of pollens did not reflect current pollen distribution and concentrations that can be influenced by changes of weather and environment of each region in South Korea. A new pollen calendar of allergenic pollens was made based on the data on pollen concentrations obtained in eight regions nationwide between 1997 and 2009. The distribution of pollen was assessed every day at 8 areas (Seoul, Guri, Busan, Daegu, Jeonju, Kwangju, Kangneung, and Jeju) for 12 years between July 1, 1997 and June 30, 2009. Pollens were collected by using Burkard 7-day sampler (Burkard Manufacturing Co Ltd, UK). Pollens which were stained with Calberla's fuchsin staining solution were identified and counted. Pine became the highest pollen in May, and the pollen concentrations of oak and birch also became high. Ragweed appeared in the middle of August and showed the highest pollen concentration in the middles of September. Japanese hop showed a high concentration between the middle of August and the end of September, and mugwort appeared in the middles of August and its concentration increased up until early September. In Kangneung, birch appeared earlier, pine showed a higher pollen concentration than in the other areas. In Daegu, Oriental thuja and alder produced a large concentration of pollens. Pine produced a large concentration of pollens between the middle of April and the end of May. Weeds showed higher concentrations in September and mugwort appeared earlier than ragweed. In Busan the time of flowering is relatively early, and alder and Oriental thuja appeared earliest among all areas. In Kwangju, Oriental thuja and hazelnut appeared in early February. Japanese cedar showed the highest pollen concentration in March in Jeju. In conclusion, update information on pollen calendar in South Korea should be provided for allergic patients through the website to manage and prevent the pollinosis.

  5. Ultrastructure of Withania Somnifera (L.) Dunal pollen grains

    International Nuclear Information System (INIS)

    Alwadie, H.M.

    2002-01-01

    Light, scanning and transmission electron microscopy were used to study the morphology and ultrastructure of Withania Somnifera (L.) Dunall pollen grains. Light microscopic examination revealed that the pollen grains are tri- or tetrazonocoplate grains, approximately as long as broad, measuring 29-um. Scanning electron microscopic observation showed that surface sculpturing of the pollen is scarbate-granulate. Ultrathin sections as examined by transmission electron microscope showed that the pollen contained numerous starch grains, lipid droplets, endoplasmic reticulum and vesicles of dictyosomes. Two layers of the pollen wall were also distinguished, the outer wall (exine) divided into ektexine and endexine as well as the inner layer (intine). The nutritive values of Withania pollen are discussed. The importance of studying the ultrastructure of pollen grains as a new tool in palynology is also discussed. (author)

  6. A simple genetic incompatibility causes hybrid male sterility in mimulus.

    Science.gov (United States)

    Sweigart, Andrea L; Fishman, Lila; Willis, John H

    2006-04-01

    Much evidence has shown that postzygotic reproductive isolation (hybrid inviability or sterility) evolves by the accumulation of interlocus incompatibilities between diverging populations. Although in theory only a single pair of incompatible loci is needed to isolate species, empirical work in Drosophila has revealed that hybrid fertility problems often are highly polygenic and complex. In this article we investigate the genetic basis of hybrid sterility between two closely related species of monkeyflower, Mimulus guttatus and M. nasutus. In striking contrast to Drosophila systems, we demonstrate that nearly complete hybrid male sterility in Mimulus results from a simple genetic incompatibility between a single pair of heterospecific loci. We have genetically mapped this sterility effect: the M. guttatus allele at the hybrid male sterility 1 (hms1) locus acts dominantly in combination with recessive M. nasutus alleles at the hybrid male sterility 2 (hms2) locus to cause nearly complete hybrid male sterility. In a preliminary screen to find additional small-effect male sterility factors, we identified one additional locus that also contributes to some of the variation in hybrid male fertility. Interestingly, hms1 and hms2 also cause a significant reduction in hybrid female fertility, suggesting that sex-specific hybrid defects might share a common genetic basis. This possibility is supported by our discovery that recombination is reduced dramatically in a cross involving a parent with the hms1-hms2 incompatibility.

  7. Pollen food allergy syndrome in Turkey: Clinical characteristics and evaluation of its association with skin test reactivity to pollens.

    Science.gov (United States)

    Özdemir, Seςil Kepil; Özgüςlü, Selcan

    2017-09-17

    There is limited data regarding pollen food allergy syndrome (PFAS) in Turkey. To investigate the clinical characteristics and possible risk factors of PFAS in Turkey, and to evaluate if there was an association between skin test reactivity to pollens and presence of PFAS. A total of 254 consecutive adult patients with pollen sensitivity were prospectively recruited. Patients were interviewed with a questionnaire including a list of pollen-associated foods. Patients were classified as having PFAS if they reported clear allergic symptoms compatible with PFAS. All participants underwent skin prick tests (SPT) to a panel of common aeroallergens, prick-to-prick tests with culprit fresh foods were performed in patients who gave consent. Self-reported PFAS was observed in 49 patients (19.3%). The most common culprit foods were kiwi, peach, tomato, melon and watermelon. Multiple logistic regression analysis showed that potential risk factors for PFAS were having asthma (OR=2.392, P=0.044) and tree pollen sensitization (OR=2.904, P=0.004). There were no significant differences in the SPT wheal sizes to individual pollen extracts between patients with and without PFAS with a positive SPT result for that pollen extract (P> 0.05). PFAS is frequent in pollen sensitized adults in Turkey. The most commonly implicated foods are kiwi, peach,tomato, melon and watermelon, in our geographical region. SPT wheal sizes to pollen extracts seems to be similar in patients with and without PFAS.

  8. Juniper Pollen Hotspots in the Southwest

    Science.gov (United States)

    Bunderson, L. D.; VandeWater, P.; Luvall, J.; Levetin, E.

    2013-01-01

    Rationale: Juniperus pollen is a major allergen in Texas, Oklahoma, and New Mexico. While the bulk of pollen may be released in rural areas, large amounts of pollen can be transported to urban areas. Major juniper species in the region include: Juniperus ashei, J. virginiana, J. pinchotii, and J. monosperma. Pollen release is virtually continuous beginning in late September with J. pinchotii and ending in May with J. monosperma. Urban areas in the region were evaluated for the potential of overlapping seasons in order to inform sensitive individuals. Methods: Burkard volumetric pollen traps were established for two consecutive spring seasons at 6 sites in northern New Mexico and 6 sites for two consecutive winter and fall seasons in Texas and Oklahoma Standard methods were used in the preparation and analysis of slides. Results: The Dallas-Fort Worth Metroplex is home to over 6 million people. It is adjacent to populations of J. pinchotii, J. virginiana, and J. ashei. Peak concentration near Dallas for J. ashei in 2011 was 5891 pollen grains/m3 in January 7th. The peak date for J. pinchotii at an upwind sampling location in San Marcos, TX was November 1, 2010 and peak for J. virginiana at a nearby station in Tulsa, OK was November 1, 2010 and peak for J. virginiana at a nearby station in Tulsa, OK was February 20, 2011. Amarillo, TX is adjacent to J. pinchotii, J. ashei, and J. monosperma populations and may be subject to juniper pollen from September through May. Conclusions: Considering the overlapping distributions of juniper trees and the overlapping temporal release of pollen, sensitive patients may benefit from avoiding hotspots.

  9. Male sterility in chestnuts. A tentative plan for the seed propagation of fruit trees

    Energy Technology Data Exchange (ETDEWEB)

    Omura, Mitsuo; Akihama, Tomoya [Fruit Tree Research Station, Yatabe, Ibaraki (Japan)

    1982-03-01

    A tentative plan was proposed for chestnuts based on their pollination system, male sterility and restoration. The studies on the male sterility of 1,063 cultivars and clones suggested that there were three types of male sterility. The first type (S-1) was characterized by antherless florets. In the second type (S-2), the catkins fell before anthesis, and the third type (S-3) appeared to develop normally in gross floral morphology, but the pollen grains were abnormal in shape and did not have germinating power. In an interspecific hybrid clone CS which belonged to S-1, fertility was restored in an open pollinated progeny. The use of CS and CSO-3 with its restored fertility, permitted the planning of breeding the chestnut hybrid cultivars propagated by seeds. The inbred clones with either male sterility or restorer genes are first bred mainly by back crossing with parents with favorable pollen. The clones are selected individually for early bearing, wasp and disease resistance, and restoration. Then, the hybrid seedling lines between male sterile and restorer inbreds are evaluated for homogenity in nut characters and tree habits. Next, the hybrid seedling lines selected will be examined for crop yield, vigor and cross compatibility. The superior seedling lines are finally selected, and the parental inbreds are grafted to be propagated for seed production orchards.

  10. Male sterility in chestnuts

    International Nuclear Information System (INIS)

    Omura, Mitsuo; Akihama, Tomoya

    1982-01-01

    A tentative plan was proposed for chestnuts based on their pollination system, male sterility and restoration. The studies on the male sterility of 1,063 cultivars and clones suggested that there were three types of male sterility. The first type (S-1) was characterized by antherless florets. In the second type (S-2), the catkins fell before anthesis, and the third type (S-3) appeared to develop normally in gross floral morphology, but the pollen grains were abnormal in shape and did not have germinating power. In an interspecific hybrid clone CS which belonged to S-1, fertility was restored in an open pollinated progeny. The use of CS and CSO-3 with its restored fertility, permitted the planning of breeding the chestnut hybrid cultivars propagated by seeds. The inbred clones with either male sterility or restorer genes are first bred mainly by back crossing with parents with favorable pollen. The clones are selected individually for early bearing, wasp and disease resistance, and restoration. Then, the hybrid seedling lines between male sterile and restorer inbreds are evaluated for homogenity in nut characters and tree habits. Next, the hybrid seedling lines selected will be examined for crop yield, vigor and cross compatibility. The superior seedling lines are finally selected, and the parental inbreds are grafted to be propagated for seed production orchards. (Kaihara, S.)

  11. VIABILIDADE DO PÓLEN EM VARIEDADES DE LARANJA DOCE POLLEN VIABILITY IN SWEET ORANGE VARIETIES

    Directory of Open Access Journals (Sweden)

    Edson Tobias Domingues

    1999-01-01

    sexual hybridization, but on the other hand, it has economic importance in leading to fewer seeds per fruit in some citrus varieties. In order to characterize 44 sweet orange varieties (Citrus sinensis [L.] osbeck for pollen viability, anthers were collected from the varieties grafted on Cleopatra mandarin. The varieties investigated represented the major sweet orange groups: acidic oranges (as 'Pera' orange, low acidic oranges (as 'Lima' orange, navel oranges (as 'Bahia' orange and bloody oranges (as 'Rubi Blood' orange. The percent of viable pollen was evaluated using acetic carmine stain under optic microscopy. The values ranged from 12.0% for 'Pera Sem Sementes' orange to 88.8% for 'Hamlin Reserva' orange. The 'Hamlin' clones showed the largest percent of viable pollen. Absence of pollen in navel oranges, originated from 'Bahia' variety was observed. The varieties 'Pera', 'Valência' and 'Natal', which are the main sweet orange cultivars in São Paulo State and Brazil, presented low percent of viable pollen.

  12. The Effect of Altered Soil Moisture on Hybridization Rate in a Crop-Wild System (Raphanus spp..

    Directory of Open Access Journals (Sweden)

    Lesley G Campbell

    Full Text Available Since plant mating choices are flexible and responsive to the environment, rates of spontaneous hybridization may vary across ecological clines. Developing a robust and predictive framework for rates of plant gene flow requires assessing the role of environmental sensitivity on plant reproductive traits, relative abundance, and pollen vectors. Therefore, across a soil moisture gradient, we quantified pollinator movement, life-history trait variation, and unidirectional hybridization rates from crop (Raphanus sativus to wild (Raphanus raphanistrum radish populations. Both radish species were grown together in relatively dry (no rain, relatively wet (double rain, or control soil moisture conditions in Ohio, USA. We measured wild and crop radish life-history, phenology and pollinator visitation patterns. To quantify hybridization rates from crop-to-wild species, we used a simply inherited morphological marker to detect F1 hybrid progeny. Although crop-to-wild hybridization did not respond to watering treatments, the abundance of hybrid offspring was higher in fruits produced late in the period of phenological overlap, when both species had roughly equal numbers of open flowers. Therefore, the timing of fruit production and its relationship to flowering overlap may be more important to hybrid zone formation in Raphanus spp. than soil moisture or pollen vector movements.

  13. Identification of IgE- binding pollen protein from Cannabis sativa in pollen-hypersensitive patients from north Pakistan.

    Science.gov (United States)

    Choudhary, Shazia; Murad, Sheeba; Hayat, Muhammad Qasim; Shakoor, Zahid; Arshad, Muhammad

    2017-01-01

    Cannabis sativa (C.sativa) is well-known for its medicinal, industrial and recreational use. However, allergies in relation to Cannabis sativa (C.sativa) are rarely reported. C. sativa is one of the common weeds found in Pakistan and its pollen grains are common in spring and fall season. Although categorized as an aeroallergen, there are limited number of reports regarding allergenic potential in C. sativa. Therefore, the current study is aimed at exploring the IgE- binding potential among the C. sativa pollen in local pollen allergic patients. Initial screening of C. sativa sensitized individuals was carried out by dot blot from the sera of pollen allergic patients. Proteins from the pollen grains were extracted and resolved on 10% gel. Eight bands were visible on gel however only one protein fragment i.e. of 14KDa size was found to bind to IgE as analyzed through protein gel blot analysis. Strong IgE affinity of a 14 kDa protein fragment from C. sativa pollen extract suggests its allergenic potential. Further study is required to find the exact nature of this protein fragment.

  14. Investigation of Differences in Fertility among Progenies from Self-Pollinated Chrysanthemum

    Directory of Open Access Journals (Sweden)

    Fan Wang

    2018-03-01

    Full Text Available Most chrysanthemum cultivars are self-incompatible, so it is very difficult to create pure lines that are important in chrysanthemum breeding and theoretical studies. In our previous study, we obtained a self-compatible chrysanthemum cultivar and its self-pollinated seed set was 56.50%. It was interesting that the seed set of its ten progenies ranged from 0% to 37.23%. Examination of the factors causing the differences in the seed set will lead to an improved understanding of chrysanthemum self-incompatibility, and provide valuable information for creating pure lines. Pollen morphology, pollen germination percentage, pistil receptivity and embryo development were investigated using the in vitro culture method, the paraffin section technique, scanning electron microscopy and transmission electron microscopy. Moreover, RNA sequencing and bioinformatics were applied to analyzing the transcriptomic profiles of mature stigmas and anthers. It was found that the self-pollinated seed set of “Q10-33-1①”,”Q10-33-1③”,”Q10-33-1④” and “Q10-33-1⑩” were 37.23%, 26.77%, 7.97% and 0%, respectively. The differences in fertility among four progenies were mainly attributable to differences in pollen germination percentage and pistil receptivity. Failure of the seed set in “Q10-33-1⑩” was possibly due to self-incompatibility. In the transcriptomic files, 22 potential stigma S genes and 8 potential pollen S genes were found out.

  15. Chromosomal heterozygosity and fertility in house mice (Mus musculus domesticus) from Northern Italy.

    Science.gov (United States)

    Hauffe, H C; Searle, J B

    1998-11-01

    Following the discovery of over 40 Robertsonian (Rb) races of Mus musculus domesticus in Europe and North Africa, the house mouse has been studied extensively as an ideal model to determine the chromosomal changes that may cause or accompany speciation. Current models of chromosomal speciation are based on the assumption that heterozygous individuals have a particularly low fertility, although recent studies indicate otherwise. Despite their importance, fertility estimates for the house mouse are incomplete because traditional measurements, such as anaphase I nondisjunction and germ cell death, are rarely estimated in conjunction with litter size. In an attempt to bridge this gap, we have taken advantage of the house mouse hybrid zone in Upper Valtellina (Lombardy, Italy) in which five Rb races interbreed. We present data on the fertility of naturally occurring ("wild-caught") hybrids and of offspring from laboratory crosses of wild-caught mice ("laboratory-reared"), using various measurements. Wild-caught mice heterozygous for one fusion were more infertile than predicted from past studies, possibly due to genic hybridity; laboratory-reared heterozygotes carrying seven or eight trivalents at meiosis I and heterozygotes carrying one pentavalent also had low fertilities. These low fertilities are especially significant given the probable occurrence of a reinforcement event in Upper Valtellina.

  16. Investigating Pollen and Gene Flow of WYMV-Resistant Transgenic Wheat N12-1 Using a Dwarf Male-Sterile Line as the Pollen Receptor.

    Science.gov (United States)

    Dong, Shanshan; Liu, Yan; Yu, Cigang; Zhang, Zhenhua; Chen, Ming; Wang, Changyong

    2016-01-01

    Pollen-mediated gene flow (PMGF) is the main mode of transgene flow in flowering plants. The study of pollen and gene flow of transgenic wheat can help to establish the corresponding strategy for preventing transgene escape and contamination between compatible genotypes in wheat. To investigate the pollen dispersal and gene flow frequency in various directions and distances around the pollen source and detect the association between frequency of transgene flow and pollen density from transgenic wheat, a concentric circle design was adopted to conduct a field experiment using transgenic wheat with resistance to wheat yellow mosaic virus (WYMV) as the pollen donor and dwarf male-sterile wheat as the pollen receptor. The results showed that the pollen and gene flow of transgenic wheat varied significantly among the different compass sectors. A higher pollen density and gene flow frequency was observed in the downwind SW and W sectors, with average frequencies of transgene flow of 26.37 and 23.69% respectively. The pollen and gene flow of transgenic wheat declined dramatically with increasing distance from its source. Most of the pollen grains concentrated within 5 m and only a few pollen grains were detected beyond 30 m. The percentage of transgene flow was the highest where adjacent to the pollen source, with an average of 48.24% for all eight compass directions at 0 m distance. Transgene flow was reduced to 50% and 95% between 1.61 to 3.15 m, and 10.71 to 20.93 m, respectively. Our results suggest that climate conditions, especially wind direction, may significantly affect pollen dispersal and gene flow of wheat. The isolation-by-distance model is one of the most effective methods for achieving stringent transgene confinement in wheat. The frequency of transgene flow is directly correlated with the relative density of GM pollen grains in air currents, and pollen competition may be a major factor influencing transgene flow.

  17. Investigating Pollen and Gene Flow of WYMV-Resistant Transgenic Wheat N12-1 Using a Dwarf Male-Sterile Line as the Pollen Receptor.

    Directory of Open Access Journals (Sweden)

    Shanshan Dong

    Full Text Available Pollen-mediated gene flow (PMGF is the main mode of transgene flow in flowering plants. The study of pollen and gene flow of transgenic wheat can help to establish the corresponding strategy for preventing transgene escape and contamination between compatible genotypes in wheat. To investigate the pollen dispersal and gene flow frequency in various directions and distances around the pollen source and detect the association between frequency of transgene flow and pollen density from transgenic wheat, a concentric circle design was adopted to conduct a field experiment using transgenic wheat with resistance to wheat yellow mosaic virus (WYMV as the pollen donor and dwarf male-sterile wheat as the pollen receptor. The results showed that the pollen and gene flow of transgenic wheat varied significantly among the different compass sectors. A higher pollen density and gene flow frequency was observed in the downwind SW and W sectors, with average frequencies of transgene flow of 26.37 and 23.69% respectively. The pollen and gene flow of transgenic wheat declined dramatically with increasing distance from its source. Most of the pollen grains concentrated within 5 m and only a few pollen grains were detected beyond 30 m. The percentage of transgene flow was the highest where adjacent to the pollen source, with an average of 48.24% for all eight compass directions at 0 m distance. Transgene flow was reduced to 50% and 95% between 1.61 to 3.15 m, and 10.71 to 20.93 m, respectively. Our results suggest that climate conditions, especially wind direction, may significantly affect pollen dispersal and gene flow of wheat. The isolation-by-distance model is one of the most effective methods for achieving stringent transgene confinement in wheat. The frequency of transgene flow is directly correlated with the relative density of GM pollen grains in air currents, and pollen competition may be a major factor influencing transgene flow.

  18. Gamma ray induced male sterility mutant in lentil

    International Nuclear Information System (INIS)

    Srivastava, A.; Yadav, A.K.

    2001-01-01

    Full text: Male sterility refers to the failure of pollen grains to bring about effective fertilization, either due to structural default or physiological disfunctioning and has special significance in hybridization programmes. Male steriles have been produced in a number of crop plants like red gram, pigeon pea, mung bean, khesari and lentil. A completely male sterile mutant was isolated in Lens culinaris Medik, after seed treatment with 100 Gy dose of gamma rays. The male sterile mutant showed 100% pollen sterility but was morphologically more vigorous than the parent plants. It showed more branches and its leaves were bigger, more oblong and dark green. The number of flowers borne by the mutant was significantly higher than any other plant of the treatment. The size of the flowers was also increased but the anthers were smaller in size. Pollen grains were few in number, round in shape but empty and did not take up any stain, indicating that normal microsporogenesis had not taken place. This male sterile mutant was used as the female parent and pollinated with pollen of a parent. Four pods with one seed in each were formed indicating that the mutant was female fertile. The seeds were smaller than those of the parent variety and also dark coloured. The mutant showed increased vigour and flower number as compared to parental plants. Lentil is an important pulse crop and induction of variability in its germplasm is necessary for its improvement. Male steriles can be used conveniently in lentil hybridization programmes. (author)

  19. Restorer-of-Fertility Mutations Recovered in Transposon-Active Lines of S Male-Sterile Maize

    Directory of Open Access Journals (Sweden)

    Susan Gabay-Laughnan

    2018-01-01

    Full Text Available Mitochondria execute key pathways of central metabolism and serve as cellular sensing and signaling entities, functions that depend upon interactions between mitochondrial and nuclear genetic systems. This is exemplified in cytoplasmic male sterility type S (CMS-S of Zea mays, where novel mitochondrial open reading frames are associated with a pollen collapse phenotype, but nuclear restorer-of-fertility (restorer mutations rescue pollen function. To better understand these genetic interactions, we screened Activator-Dissociation (Ac-Ds, Enhancer/Suppressor-mutator (En/Spm, and Mutator (Mu transposon-active CMS-S stocks to recover new restorer mutants. The frequency of restorer mutations increased in transposon-active stocks compared to transposon-inactive stocks, but most mutants recovered from Ac-Ds and En/Spm stocks were unstable, reverting upon backcrossing to CMS-S inbred lines. However, 10 independent restorer mutations recovered from CMS-S Mu transposon stocks were stable upon backcrossing. Many restorer mutations condition seed-lethal phenotypes that provide a convenient test for allelism. Eight such mutants recovered in this study included one pair of allelic mutations that were also allelic to the previously described rfl2-1 mutant. Targeted analysis of mitochondrial proteins by immunoblot identified two features that consistently distinguished restored CMS-S pollen from comparably staged, normal-cytoplasm, nonmutant pollen: increased abundance of nuclear-encoded alternative oxidase relative to mitochondria-encoded cytochrome oxidase and decreased abundance of mitochondria-encoded ATP synthase subunit 1 compared to nuclear-encoded ATP synthase subunit 2. CMS-S restorer mutants thus revealed a metabolic plasticity in maize pollen, and further study of these mutants will provide new insights into mitochondrial functions that are critical to pollen and seed development.

  20. Interspecific hybridization between Crassostrea angulata and C. ariakensis

    Science.gov (United States)

    Yao, Tuo; Zhang, Yuehuan; Yan, Xiwu; Wang, Zhaoping; Li, Dongchun; Su, Jiaqi; Yu, Ruihai

    2015-08-01

    Interspecific hybridization can generate heterosis, which is proven to be a useful tool in selective breeding programs for oyster culture. Crassostrea angulata and C. ariakensis are two important economic shellfish species in China. We conducted 2 × 2 reciprocal crosses to determine whether these two species can cross-fertilize and their hybrids can hatch, survive and perform heterosis. Fertilization was found symmetrical without delay. The rate of fertilization success of C. angulata ♀ × C. ariakensis ♂ was lower than that of C. ariakensis ♀ × C. angulata ♂, and the success rate of both hybridizations was lower than that of two intraspecific crosses each. During the planktonic period, survival rate of the progeny was lower in the hybrid crosses than in the intraspecific crosses. On day 360, mean shell height of the progeny of C. angulata ♀ × C. angulata ♂ was highest, which was followed by that of C. angulata ♀ × C. ariakensis ♂, C. ariakensis ♀ × C. ariakensis ♂ and C. ariakensis ♀ × C. angulata ♂ in a descending order. Morphology of adults produced by the hybrid crosses was similar to that of C. angulata. Both hybrids underwent normal gonad development and produced mature gametes in the mating season. This study provided new insights into the quantitative traits in interspecific crosses of Crassostrea species, thus being of guidance value for selective breeding of oyster.

  1. Mitotic and meiotic irregularities in somatic hybrids of Lycopersicon esculentum and Solanum tuberosum.

    Science.gov (United States)

    Wolters, A M; Schoenmakers, H C; Kamstra, S; Eden, J; Koornneef, M; Jong, J H

    1994-10-01

    Chromosome numbers were determined in metaphase complements of root-tip meristems of 107 tomato (+) potato somatic hybrids, obtained from five different combinations of parental genotypes. Of these hybrids 79% were aneuploid, lacking one or two chromosomes in most cases. All four hybrids that were studied at mitotic anaphase of root tips showed laggards and bridges, the three aneuploids in a higher frequency than the single euploid. Hybrid K2H2-1C, which showed the highest percentage of aberrant anaphases, possessed 46 chromosomes. Fluorescence in situ hybridization with total genomic DNA showed that this hybrid contained 23 tomato, 22 potato, and 1 recombinant chromosome consisting of a tomato chromosome arm and a potato chromosome arm. The potato parent of K2H2-1C was aneusomatic in its root tips with a high frequency of monosomic and trisomic cells and a relatively high frequency of cells with one fragment or telosome. Meiotic analyses of three tomato (+) potato somatic hybrids revealed laggards, which occurred most frequently in the triploid hybrids, and bridges, which were frequently present in pollen mother cells (PMCs) at anaphase I of hypotetraploid K2H2-1C. We observed putative trivalents in PMCs at diakinesis and metaphase I of eutriploid A7-82A and quadrivalents in part of the PMCs of hypotetraploid K2H2-1C, suggesting that homoeologous recombination between tomato and potato chromosomes occurred in these hybrids. All three hybrids showed a high percentage of first division restitution, giving rise to unreduced gametes. However, shortly after the tetrad stage all microspores completely degenerated, resulting in exclusively sterile pollen.

  2. Pollen as indicator of radionuclide pollution

    International Nuclear Information System (INIS)

    Kirkham, M.B.; Corey, J.C.

    1977-01-01

    To assess hazards of radioactivity in the environment, agricultural scientists must identify plant and animal species which can be used as biological indicators of radionuclide contamination. In this experiments, the pollen-bee-honey system was chosen to study movement of radioactive elements in the plant-animal-man food chain. Pollen, bees, and honey were collected from different locations at a nuclear facility in South Carolina. They were analyzed for nine radionuclides and 22 stable elements. The results showed that pollen is a more sensitive indicator of pollution than bees or honey. If pollen-monitoring shows that an area has become polluted, hives and other sources of human and animal food should not be placed in the region until it is no longer contaminated. (author)

  3. Hybrid male sterility and genome-wide misexpression of male reproductive proteases.

    Science.gov (United States)

    Gomes, Suzanne; Civetta, Alberto

    2015-07-06

    Hybrid male sterility is a common barrier to gene flow between species. Previous studies have posited a link between misregulation of spermatogenesis genes in interspecies hybrids and sterility. However, in the absence of fully fertile control hybrids, it is impossible to differentiate between misregulation associated with sterility vs. fast male gene regulatory evolution. Here, we differentiate between these two possibilities using a D. pseudoobscura species pair that experiences unidirectional hybrid sterility. We identify genes uniquely misexpressed in sterile hybrid male reproductive tracts via RNA-seq. The sterile male hybrids had more misregulated and more over or under expressed genes relative to parental species than the fertile male hybrids. Proteases were the only gene ontology class overrepresented among uniquely misexpressed genes, with four located within a previously identified hybrid male sterility locus. This result highlights the potential role of a previously unexplored class of genes in interspecific hybrid male sterility and speciation.

  4. Pollen morphology of the Alangiaceae

    NARCIS (Netherlands)

    Reitsma, Tj.

    1970-01-01

    This paper presents a pollen-morphological study of Alangium, a genus mainly restricted to the tropics of the Old World, of which 18 of the 19 known species were studied. The pollen grains, studied with the use of a light microscope, a transmission electron microscope and a scanning electron

  5. The breeding of a wheat mutant pollen-derived variety Chuanfu No.5 and the related techniques

    International Nuclear Information System (INIS)

    Xuan Pu; Yin Chunrong; Yue Chunfang; Qu Shihong

    2002-01-01

    With the treatment of 150 Gy 60 Co-γ irradiation to the dry F 1 (Mianyang 88-334 x 8811525) hybrid seeds and the donor plants chosen from MF 2 , wheat anther culture was made based on MW 14 and modified MS media and the pure diploid lines of MH 1 derived from anther pollen were obtained. In 1996, the new mutant line 6086 and its sibling lines, 6086 and 6087, were selected and bred successfully. In 2002, the mutant pollen-derived line 6086 was denominated as Chuanfu No.5 by Sichuan Crop Variety Identification Committee and became the first mutant variety via anther culture of wheat in Sichuan. The success of Chuanfu No.5 shown that combining radiation induction and anther technique could shorten the breeding period and increase the efficiency of breeding of wheat

  6. Pollen Contaminated With Field-Relevant Levels of Cyhalothrin Affects Honey Bee Survival, Nutritional Physiology, and Pollen Consumption Behavior.

    Science.gov (United States)

    Dolezal, Adam G; Carrillo-Tripp, Jimena; Miller, W Allen; Bonning, Bryony C; Toth, Amy L

    2016-02-01

    Honey bees are exposed to a variety of environmental factors that impact their health, including nutritional stress, pathogens, and pesticides. In particular, there has been increasing evidence that sublethal exposure to pesticides can cause subtle, yet important effects on honey bee health and behavior. Here, we add to this body of knowledge by presenting data on bee-collected pollen containing sublethal levels of cyhalothrin, a pyrethroid insecticide, which, when fed to young honey bees, resulted in significant changes in lifespan, nutritional physiology,and behavior. For the first time, we show that when young, nest-aged bees are presented with pollen containing field-relevant levels of cyhalothrin, they reduce their consumption of contaminated pollen. This indicates that, at least for some chemicals, young bees are able to detect contamination in pollen and change their behavioral response, even if the contamination levels do not prevent foraging honey bees from collecting the contaminated pollen.

  7. A tight relationship between the solitary bee Calliopsis (Ceroliopoeum laeta (Andrenidae, Panurginae and Prosopis pollen hosts (Fabaceae, Mimosoideae in xeric South American woodlands

    Directory of Open Access Journals (Sweden)

    Favio Gerardo Vossler

    2014-10-01

    Full Text Available The large genus Calliopsis (Andrenidae, Panurginae is composed of ten subgenera with polylectic and presumably oligolectic species. These categories have been mainly developed from floral visits of female bees collecting pollen. In the present study, pollen analyses of nest provisions and scopal loads from museum specimens of the monotypic subgenus Ceroliopoeum were carried out to assess its degree of specialization to pollen host-plants. Despite the great variety of floral resources close to two active nest aggregations in the Chaco sites (83 and 44 melittophilous taxa from 36 and 17 families, respectively, the only host-plant recorded in all nest pollen samples was Prosopis. This genus was represented by six species and their hybrids, all having similar pollen morphology. The nesting sites in Monte scrub also contained several Prosopis species, some of which had different pollen morphology from those of the Chaco forest. Two different Prosopis pollen types were identified in all samples. Since the whole geographic distribution of C. laeta matches with the range of Prosopis, its strong association with this pollen host seems to be well supported. However, the low number of study populations (four could erroneously indicate oligolectism. A broader sampling is necessary to ensure the character of specialization. Most Calliopsis species have been identified as oligolectic. Yet, this categorization has mainly been based on floral visits and a large diversity of floral hosts has been recorded for each bee species. Further analyses are necessary to confirm the relationship of this genus with its pollen hosts. Moreover, as most of them have short to medium phenologies (up to 4 months their presumably oligolecty can be due to a local specialization (i.e. variable according to location typical of polylecty.

  8. Pollen viability, physiology, and production of maize plants exposed to pyraclostrobin+epoxiconazole.

    Science.gov (United States)

    Junqueira, Verônica Barbosa; Costa, Alan Carlos; Boff, Tatiana; Müller, Caroline; Mendonça, Maria Andréia Corrêa; Batista, Priscila Ferreira

    2017-04-01

    The use of fungicides in maize has been more frequent due to an increase in the incidence of diseases and also the possible physiological benefits that some of these products may cause. However, some of these products (e.g., strobilurins and triazoles) may interfere with physiological processes and the formation of reproductive organs. Therefore, the effect of these products on plants at different developmental stages needs to be better understood to reduce losses and maximize production. The effect of the fungicide pyraclostrobin+epoxiconazole (P+E) was evaluated at different growth stages in meiosis, pollen grain viability and germination, physiology, and production of maize plants in the absence of disease. An experiment was carried out with the hybrid DKB390 PROII and the application of pyraclostrobin+epoxiconazole at the recommended dose and an untreated control at 3 different timings (S1 - V10; S2 - V14; S3 - R1) with 5 replications. Gas exchange, chlorophyll fluorescence, pollen viability and germination, as well as the hundred-grain weight were evaluated. Anthers were collected from plants of S1 for cytogenetic analysis. The fungicide pyraclostrobin+epoxiconazole reduced the viability of pollen grains (1.4%), but this was not enough to reduce production. Moreover, no differences were observed in any of the other parameters analyzed, suggesting that P+E at the recommended dose and the tested stages does not cause toxic effects. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Fraxinus pollen as a source of environmental pollution

    Directory of Open Access Journals (Sweden)

    María Fernández-González

    2016-06-01

    Full Text Available In Southern Europe there are but a few studies focused on the allergenic impact of ash (Fraxinus pollen as a result of its scarce distribution. In the city of Ourense this type of pollen represents 2% of the total atmospheric pollen recorded. The goal of this study is to determine the atmospheric concentrations of Fraxinus pollen and its allergen in Ourense’s atmosphere in 2015, and to assess their relationship with the main meteorological variables. The aim is to assess whether the pollen counts match the actual exposure conditions for allergen-sensitive patients. A Lanzoni VPPS-2000 volumetric sampler was used for pollen sampling, whereas a Burkard Cyclone sampler was used for allergen detection.The flowering period of Fraxinus was long, having a duration of 76 days between the third week of January and the rst week of April as consequence of the asynchronous flowering of the different species growing in the study area. The presence of the ash allergen in the atmosphere can be detected using the main olive tree allergen, Ole e 1. Our study indicates that the combination of pollen counts and allergen quanti cation should be contemplated to estimate the real exposure of sensitive people. In the case of Fraxinus pollen, there may be allergy risk periods before and after the occurrence of the highest pollen concentrations in the atmosphere as a result of special rain and humidity conditions during its flowering period.

  10. Characterisation of particulate matter on airborne pollen grains

    International Nuclear Information System (INIS)

    Ribeiro, Helena; Guimarães, Fernanda; Duque, Laura; Noronha, Fernando; Abreu, Ilda

    2015-01-01

    A characterization of the physical–chemical composition of the atmospheric PM adsorbed to airborne pollen was performed. Airborne pollen was sampled using a Hirst-type volumetric spore sampler and observed using a Field Emission Electron Probe Microanalyser for PM analysis. A secondary electron image was taken of each pollen grain and EDS spectra were obtained for individually adsorbed particles. All images were analysed and the size parameters of the particles adsorbed to pollen was determined. The measured particles’ equivalent diameter varied between 0.1 and 25.8 μm, mostly in the fine fraction. The dominant particulates identified were Si-rich, Organic-rich, SO-rich, Metals & Oxides and Cl-rich. Significant daily differences were observed in the physical–chemical characteristics of particles adsorbed to the airborne pollen wall. These differences were correlated with weather parameters and atmospheric PM concentration. Airborne pollen has the ability to adsorb fine particles that may enhance its allergenicity. - Highlights: • Airborne pollen sorbs other PM found in suspension. • 84% of the particles sorbed belonged to the fine aerosol fraction. • Adsorbed PM presented daily physical–chemical variations. • Particles sorbed dominated by Si-rich, Organic-rich, SO-rich, Fe-rich and Cl-rich. - Airborne pollen is able to transport finer particulate matter, which presents daily physical–chemical variations.

  11. The use of ion beam to overcome interspecific hybrid inviability in plants

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Masayoshi [Kyoto Prefectural Univ. (Japan); Watanabe, Hiroshi

    1997-03-01

    In order to overcome sexual incompatibility between distantly related species in Nicotiana, the crosses with {sup 4}He{sup 2+} beam-irradiated pollen were carried out, and survival hybrids were obtained. They were resistant to tobacco mosaic virus and green peach aphid. (author)

  12. Quality of durable cookies enriched with rape bee pollen

    Directory of Open Access Journals (Sweden)

    Miriam Solgajová

    2014-03-01

    Full Text Available The objective of this study was to enrich durable cookies with different additions of rape (Brassica napus var. napus bee pollen to increase nutritional properties of cookie samples and to improve technological and sensorial properties as well. Bee pollen is an important raw material due to its nutritional and functional properties. Cookie samples were prepared by substituting wheat flour with rape bee pollen in the amount of 16 % (1 g of bee pollen per cookie and 32 % (2 g of bee pollen per cookie using bee pollen from two localities Lenártovce and Nové Zámky. In baked samples beside sensory properties also chemical parameters and technological parameters of cookies were evaluated. It was found out that with the gradual addition of rape bee pollen the amount of ash content increased and the highest ash content was analysed in variants II and IV (0.71 and 0.77 % using 32 % addition of rape bee pollen. In terms of reducing sugars, addition of bee pollen caused that the content of reducing sugars in the products increased slightly. The highest reducing sugar content was determined in variant II. (24.59 %. On the other hand amount of crude protein the most considerably raised by addition of 2 g of pollen per cookie. The highest content of crude protein was analysed in variants II and IV (8.72 and 9.00 %. From the results of a linear models in which the dependent variables were the ash, crude protein and moisture it was determined the significant effect (p <0.05 only of the pollen addition. In the case of the model with the dependent variable reducing sugars it was found out significant effect (p<0.0001 of pollen addition and locality and their interactions. With the gradual addition of bee pollen values of technological parameters such as diameter and weight of cookies increased and thickness of products decreased. Based on sensory scores using a 9-point Hedonic scale the best sensorial acceptability (7.4 was found in variant I (1 g of bee

  13. The formation of pollen in male flowers and yearly atmospheric pollen counts of Cryptomeria japonica in the following year

    Directory of Open Access Journals (Sweden)

    Hideaki Taira

    1998-01-01

    Full Text Available Prediction of yearly atmospheric pollen counts is a very important component in the prevention of allergenic symptoms. We investigated the relationship between atomspheric pollen counts and the formation of male flowers of Cryptomeriajaponica D. Don (C. japonica. An atmospheric pollen survey of C. japonica was conducted from 1983 to 1996 using a Durham’s sampler. A regression analysis was performed between the total pollen count and July temperature in previous years. The atmospheric pollen counts of C. japonica had a high positive correlation with the mean temperature in July of the previous year. However, the predicted using average mean July temperature records of the previous year were insufficient, especially in years following high pollen count. In experimental conditions, using 60 C. japonica trees in pots, the formation of male flowers was shown to increase with a rise in incubation temperature. In a forest of C. japonica, our results showed that the length and weight of new needle growth from old needles, which produced many flowers in the previous year, were shorter and lighter, respectively. These aerobiological and plant physiological studies provide evidence that a smaller number of pollen counts are a common result in a year following one in which many male flowers are produced, even if the mean July temperature of that year was high.

  14. Pollen Ultrastructure of Genus Dendrobium Orchids as a Learning Resource

    Directory of Open Access Journals (Sweden)

    Lika Dwi Apriani

    2016-11-01

    Full Text Available Anggrek genus Dendrobium merupakan salah satu genus dari divisi spermatophyta yang merupakan kelompok tumbuhan yang berkembang dengan menggunakan biji. Tumbuhan berbiji tentu memiliki bunga sebagai alat perkembangan generatifnya. Perkembangan generatif pada bunga artinya pertemuan antara sel gamet jantan dan sel gamet betina. Sel gamet betina pada tumbuhan dihasilkan oleh putik, sedangkan sel gamet jantan disebut serbuk sari atau pollen. Genus Dendrobium merupakan salah satu kekayaan alam Indonesia, jumlahnya diperkirakan mencapai 275 spesies. Penelitian ini bertujuan untuk mengetahui bagaimana ultrastruktur pollen anggrek genus Dendrobium dari sepuluh spesies yang diamati menggunakan SEM. Jenis penelitian ini adalah deskriptif kualitatif. Hasil penelitian menunjukkan unit pollen untuk semua spesies yaitu kategori pollinia, sedangkan untuk polaritas pollen adalah apolar. Jenis aperture kesepuluh spesies yang diamati mempunyai aperture dengan pola yang tidak beraturan dan lebih dari enam yang disebut colpate. Bentuk pollen dari semua spesies yang diteliti bentuknya adalah subprolate hingga prolate dan ukuran pollen termasuk dalam kategori minuta hingga media. Ornamentasi pollen atau skluptur pollen tidak teridentifikasi dikarenakan ukuran pollen yang terlalu kecil, permukaan pollen terlihat kurang jelas. Sumber belajar yang digunakan adalah atlas.

  15. Pollen Flora of Pakistan-LXV, berberidaceae

    International Nuclear Information System (INIS)

    Perveen, A.

    2010-01-01

    Pollen morphology of 12 species representing 2 genera of the family Berberidaceae from Pakistan has been examined by light and scanning electron microscope. Pollen grains usually radially symmetrical, iso polar or apolar, spheroidal or sub-prolate, spiroaperturate rarely colpate (3- more), sexine thicker than nexine. Tectal surface mostly foveolate-fossulate or sub-psilate, often rugulate - reticulate. On the basis of apertutal types and exine ornamentation four distinct pollen types are recognized, viz., Berberis calliobotrys-type, Berberis jaeschkeana-type, Berberis kunawurensis-type and Epimedium elatum-type. (author)

  16. Tracking maize pollen development by the Leaf Collar Method.

    Science.gov (United States)

    Begcy, Kevin; Dresselhaus, Thomas

    2017-12-01

    An easy and highly reproducible nondestructive method named the Leaf Collar Method is described to identify and characterize the different stages of pollen development in maize. In plants, many cellular events such as meiosis, asymmetric cell division, cell cycle regulation, cell fate determination, nucleus movement, vacuole formation, chromatin condensation and epigenetic modifications take place during pollen development. In maize, pollen development occurs in tassels that are confined within the internal stalk of the plant. Hence, identification of the different pollen developmental stages as a tool to investigate above biological processes is impossible without dissecting the entire plant. Therefore, an efficient and reproducible method is necessary to isolate homogeneous cell populations at individual stages throughout pollen development without destroying the plant. Here, we describe a method to identify the various stages of pollen development in maize. Using the Leaf Collar Method in the maize inbreed line B73, we have determined the duration of each stage from pollen mother cells before meiosis to mature tricellular pollen. Anther and tassel size as well as percentage of pollen stages were correlated with vegetative stages, which are easily recognized. The identification of stage-specific genes indicates the reproducibility of the method. In summary, we present an easy and highly reproducible nondestructive method to identify and characterize the different stages of pollen development in maize. This method now opens the way for many subsequent physiological, morphological and molecular analyses to study, for instance, transcriptomics, metabolomics, DNA methylation and chromatin patterns during normal and stressful conditions throughout pollen development in one of the economically most important grass species.

  17. Ragweed (Ambrosia) pollen source inventory for Austria.

    Science.gov (United States)

    Karrer, G; Skjøth, C A; Šikoparija, B; Smith, M; Berger, U; Essl, F

    2015-08-01

    This study improves the spatial coverage of top-down Ambrosia pollen source inventories for Europe by expanding the methodology to Austria, a country that is challenging in terms of topography and the distribution of ragweed plants. The inventory combines annual ragweed pollen counts from 19 pollen-monitoring stations in Austria (2004-2013), 657 geographical observations of Ambrosia plants, a Digital Elevation Model (DEM), local knowledge of ragweed ecology and CORINE land cover information from the source area. The highest mean annual ragweed pollen concentrations were generally recorded in the East of Austria where the highest densities of possible growth habitats for Ambrosia were situated. Approximately 99% of all observations of Ambrosia populations were below 745m. The European infection level varies from 0.1% at Freistadt in Northern Austria to 12.8% at Rosalia in Eastern Austria. More top-down Ambrosia pollen source inventories are required for other parts of Europe. A method for constructing top-down pollen source inventories for invasive ragweed plants in Austria, a country that is challenging in terms of topography and ragweed distribution. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

  18. Evaluation of interspecific hybrids and cultivars of Brachiaria spp. submitted to sourcers and levels of nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Márcia Atauri Cardelli Lucena

    2012-12-01

    Full Text Available The management of nitrogen supply (N is a very important issue concerned to plant growth and the environment healthy. For farmers, to know how much N the plant requires enables the application of appropriate amounts of nitrogen fertilizer, maximizing the use of this material. The availability of N has been identified as one of the main limiting factors, but also a management tool in the production of grasses. The nitrogen in the soil either, as a constituent of organic matter or in the mineral form (ammonium and nitrate, has a limited supply and can be depleted rapidly in a few crops. The aim of this study was to evaluate the effects of sources and nitrogen levels in four genotypes of Brachiaria (Brachiaria brizantha cv. Marandu, Brachiaria brizantha cv. Piata and two interspecific hybrids of Brachiaria spp on the total and the leaf dry matter production, leaf percentage and leaf: stem ratio. The soil was an Psament-Entisol, coming from a pasture of Brachiaria decumbens with low organic matter content. The experiment was conducted in greenhouse, in Nova Odessa, Sao Paulo, from October 2009 to April 2010. The experimental design was in randomized complete blocks and the treatments were arranged in a factorial 4 x 2 x 4, four genotypes of Brachiaria , two N sources (urea and ammonium nitrate and four nitrogen rates (0, 75, 150 or 225 mg dm-3 with five replicates, totaling 160 pots with a capacity of 3.34 dm3 of soil. Two cuts were performed in the plants. After the second cut a soil sample was collected from each experimental unit. Two evaluations were performed on plants. The first one 52 days after sowing, and the second 56 days after the first cut. Data were analyzed by the mixed procedure of SAS V. 9.2; average qualitative factors were compared by Tukey test at 5% probability. The degrees of freedom related to N rates (quantitative factor were decomposed into orthogonal polynomials; to obtain the best equation fits the data. The variables

  19. Urtica dioica pollen allergy: Clinical, biological, and allergomics analysis.

    Science.gov (United States)

    Tiotiu, Angelica; Brazdova, Andrea; Longé, Cyril; Gallet, Patrice; Morisset, Martine; Leduc, Virginie; Hilger, Christiane; Broussard, Cédric; Couderc, Rémy; Sutra, Jean-Pierre; Sénéchal, Hélène; Poncet, Pascal

    2016-11-01

    The most emblematic members of Urticaceae at allergic risk level are wall pellitories (Parietaria), whereas nettle (Urtica) pollen is considered as poorly allergenic. No allergen from nettle pollen has yet been characterized, whereas 4 are listed for Parietaria pollen by the International Union of Immunological Societies. Clinical and biological profiles of 2 adult men who developed symptoms against nettle pollen and/or leaves were studied. To characterize the allergic reaction and identify the potential nettle pollen sensitizing allergens. IgE-mediated reaction to nettle pollen extract was evaluated by skin prick test, immunoassay, nasal provocation, and basophil activation test. To characterize specific nettle pollen allergens, an allergomic (IgE immunoproteomic) analysis was performed combining 1- and 2-dimensional electrophoresis, IgE immunoblots of nettle pollen extract, identification of allergens by mass spectrometry, and database queries. The results of biological and immunochemical analyses revealed that the allergic rhinitis was due to Urtica dioica pollen in both patients. The allergomic analysis of nettle pollen extract allowed the characterization of 4 basic protein allergens: a thaumatin-like protein (osmotin) with a relative molecular mass of 27 to 29 kDa, a pectinesterase (relative molecular mass, 40 kDa), and 2 other basic proteins with relative molecular masses of 14 to 16 kDa and 43 kDa. There is no or only very weak allergen associations between pellitory and nettle pollen. Exposure to nettle pollen can be responsible of allergic symptoms, and several allergens were characterized. Unravelling the allergens of this underestimated allergy might help to improve diagnosis and care for patients, to predict cross-reactivities and design adapted specific immunotherapy. Copyright © 2016 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  20. Pollen-mediated gene flow in wheat (Triticum aestivum L.) in a semiarid field environment in Spain.

    Science.gov (United States)

    Loureiro, Iñigo; Escorial, María-Concepción; González, Águeda; Chueca, María-Cristina

    2012-12-01

    Transgenic wheat (Triticum aestivum L.) varieties are being developed and field-tested in various countries. Concerns regarding gene flow from genetically modified (GM) crops to non-GM crops have stimulated research to estimate outcrossing in wheat prior to the release and commercialization of any transgenic cultivars. The aim is to ensure that coexistence of all types of wheat with GM wheat is feasible in accordance with current regulations. The present study describes the result of a field experiment under the semi-arid climate conditions of Madrid, Spain, at two locations ("La Canaleja" and "El Encin" experimental stations) in Madrid over a 3-year period, from 2005 to 2007. The experimental design consisted of a 50 × 50 m wheat pollen source sown with wheat cultivars resistant to the herbicide chlortoluron ('Deganit' and 'Castan' respectively) and three susceptible receptor cultivars ('Abental', 'Altria' and 'Recital') sown in replicated 1 × 1 m plots at different distances (0, 1, 3, 5, 10, 20, 40, 80 and 100 m) and four directions. Outcrossing rates were measured as a percentage of herbicide-resistant hybrids using an herbicide-screening assay. Outcrossing was greatest near the pollen source, averaging 0.029% at 0 m distance at "La Canaleja" and 0.337% at "El Encin", both below the 0.9% European Union regulated threshold, although a maximum outcrossing rate of 3.5% was detected in one recipient plot. These percentages declined rapidly as the distance increased, but hybrids were detected at different rates at distances of up to 100 m, the maximum distance of the experiment. Environmental conditions, as drought in 2004-2005 and 2005-2006, may have influenced the extent of outcrossing. These assays carried out in wheat under semi-arid conditions in Europe provide a more complete assessment of pollen-mediated gene flow in this crop.

  1. Modern pollen data from the Canadian Arctic, 1972-1973

    Science.gov (United States)

    Nichols, Harvey; Stolze, Susann

    2017-05-01

    This data descriptor reports results of a 1972-73 baseline study of modern pollen deposition in the Canadian Arctic to originally aid interpretation of Holocene pollen diagrams from that region, especially focussed on the arctic tree-line. The data set is geographically unique due to its extent, and allows the assessment of the effects of modern climate change on northern ecosystems, including fluctuations of the a arctic tree-line. Repeated sampling was conducted along an interior transect at 29 sites from the Boreal Forest to the High Arctic, with five additional coastal sites covering a total distance of 3,200 km. Static pollen samplers captured both local pollen and long-distance pollen wind-blown from the Boreal Forest. Moss and lichen polsters provided multi-year pollen fallout to assess the effectiveness of the static pollen samplers. The local vegetation was recorded at each site. This descriptor provides information on data archived at the World Data Center PANGAEA, which includes spreadsheets detailing site and sample information as well as raw and processed pollen data obtained on over 500 samples.

  2. Pollen Processing Behavior of Heliconius Butterflies: A Derived Grooming Behavior

    Science.gov (United States)

    Hikl, Anna-Laetitia; Krenn, Harald W.

    2011-01-01

    Pollen feeding behaviors Heliconius and Laparus (Lepidoptera: Nymphalidae) represent a key innovation that has shaped other life history traits of these neotropical butterflies. Although all flower visiting Lepidoptera regularly come in contact with pollen, only Heliconius and Laparus butterflies actively collect pollen with the proboscis and subsequently take up nutrients from the pollen grains. This study focused on the behavior of pollen processing and compared the movement patterns with proboscis grooming behavior in various nymphalid butterflies using video analysis. The proboscis movements of pollen processing behavior consisted of a lengthy series of repeated coiling and uncoiling movements in a loosely coiled proboscis position combined with up and down movements and the release of saliva. The proboscis-grooming behavior was triggered by contamination of the proboscis in both pollen feeding and non-pollen feeding nymphalid butterflies. Proboscis grooming movements included interrupted series of coiling and uncoiling movements, characteristic sideways movements, proboscis lifting, and occasionally full extension of the proboscis. Discharge of saliva was more pronounced in pollen feeding species than in non-pollen feeding butterfly species. We conclude that the pollen processing behavior of Heliconius and Laparus is a modified proboscis grooming behavior that originally served to clean the proboscis after contamination with particles. PMID:22208893

  3. Pollen and spore monitoring in the world.

    Science.gov (United States)

    Buters, J T M; Antunes, C; Galveias, A; Bergmann, K C; Thibaudon, M; Galán, C; Schmidt-Weber, C; Oteros, J

    2018-01-01

    Ambient air quality monitoring is a governmental duty that is widely carried out in order to detect non-biological ("chemical") components in ambient air, such as particles of monitoring networks are publicly funded and air quality data are open to the public. The situation for biological particles that have detrimental effects on health, as is the case of pollen and fungal spores, is however very different. Most pollen and spore monitoring networks are not publicly funded and data are not freely available. The information regarding which biological particle is being monitored, where and by whom, is consequently often not known, even by aerobiologists themselves. This is a considerable problem, as local pollen data are an important tool for the prevention of allergic symptoms. The aim of this study was to review pollen monitoring stations throughout the world and to create an interactive visualization of their distribution. The method employed to collect information was based on: (a) a review of the recent and historical bibliography related to pollen and fungal spore monitoring, and (b) personal surveys of the managers of national and regional monitoring networks. The interactive application was developed using the R programming language. We have created an inventory of the active pollen and spore monitoring stations in the world. There are at least 879 active pollen monitoring stations in the world, most of which are in Europe (> 500). The prevalent monitoring method is based on the Hirst principle (> 600 stations). The inventory is visualised as an interactive and on-line map. It can be searched, its appearance can be adjusted to the users' needs and it is updated regularly, as new stations or changes to those that already exist can be submitted online. The map shows the current situation of pollen and spore monitoring and facilitates collaboration among those individuals who are interested in pollen and spore counts. It might also help to improve the

  4. Pollen flora of pakistan-lxxi. rosaceae

    International Nuclear Information System (INIS)

    Perveen, A.; Qaiser, M.

    2014-01-01

    Pollen morphology of 50 species representing 17 genera of the family Rosaceae i.e., Alchemilla, Argimonia, Cotoneaster, Crataegus, Duchesnea, Fragaria, Eriybotyra, Filipandula, Geum, Malus, Prunus, Potentilla, Pyrus , Rosa, Sibbaldia, Sorbaria and Sorbus has been studied from Pakistan by light and scanning electron microscope. Pollen grains are usually free, radially symmetrical, isopolar, prolate-spheroidal to subprolate or oblate-spheroidal rarely perprolate, tricolporate rarely tricolpate. Tectum mostly coarsely-finely striate, rarely striate-rugulate, scabrate or spinulose often reticulate. Rosaceae is more or less eurypalynous family. Significant variation is found in P/E ratio, shape and exine ornamentation and on the basis of these characters family has been divided into seven pollen types viz., Agrimonia eupatoria-type, Alchemilla ypsilotoma-type, Cotoneaster affinis-type, Fragaria nubicola-type, Geum roylei-type, Malus pumila-type, Potentilla pamirica-type. Pollen data is useful at specific and generic level. (author)

  5. Cloning and characterisation of a putative pollen-specific polygalacturonase gene (CpPG1) differentially regulated during pollen development in zucchini (Cucurbita pepo L.).

    Science.gov (United States)

    Carvajal, F; Garrido, D; Jamilena, M; Rosales, R

    2014-03-01

    Studies in zucchini (Cucurbita pepo L. spp. pepo) pollen have been limited to the viability and morphology of the mature pollen grain. The enzyme polygalacturonase (PG) is involved in pollen development and pollination in many species. In this work, we study anther and pollen development of C. pepo and present the cloning and characterisation of a putative PG CpPG1 (Accession no. HQ232488) from pollen cDNA in C. pepo. The predicted protein for CpPG1 has 416 amino acids, with a high homology to other pollen PGs, such as P22 from Oenothera organensis (76%) and PGA3 from Arabidopsis thaliana (73%). CpPG1 belongs to clade C, which comprises PGs expressed in pollen, and presents a 34 amino acid signal peptide for secretion towards the cell wall. DNA-blot analysis revealed that there are at least another two genes that code for PGs in C. pepo. The spatial and temporal accumulation of CpPG1 was studied by semi-quantitative- and qRT-PCR. In addition, mRNA was detected only in anthers, pollen and the rudimentary anthers of bisexual flowers (only present in some zucchini cultivars under certain environmental conditions that trigger anther development in the third whorl of female flowers). However, no expression was detected in cotyledons, stem or fruit. Furthermore, CpPG1 mRNA was accumulated throughout anther development, with the highest expression found in mature pollen. Similarly, exo-PG activity increased from immature anther stages to mature anthers and mature pollen. Overall, these data support the pollen specificity of this gene and suggest an involvement of CpPG1 in pollen development in C. pepo. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  6. Variations in pollen counts largely explained by climate and weather

    Science.gov (United States)

    Jung, Stephan; Damialis, Athanasios; Estrella, Nicole; Jochner, Susanne; Menzel, Annette

    2017-04-01

    The interaction between climate and vegetation is well studied within phenology. Climatic / weather conditions affect e.g. flowering date, length of vegetation period, start and end of the season and the plant growth. Besides phenological stages also pollen counts can be used to investigate the interaction between climate and vegetation. Pollen emission and distribution is directly influenced by temperature, wind speed, wind direction and humidity/precipitation. The objective of this project is to study daily/sub daily variations in pollen counts of woody and herbaceous plant species along an altitudinal gradient with different climatic conditions during the vegetation period. Measurements of pollen were carried out with three volumetric pollen traps installed at the altitudes 450 m a.s.l (Freising), 700 m a.s.l (Garmisch-Partenkirchen), and 2700 m a.s.l (Schneefernerhaus near Zugspitze) representing gradient from north of Munich towards the highest mountain of Germany. Airborne pollen concentrations were recorded during the years 2014-2015. The altitudinal range of these three stations accompanied by different microclimates ("space for time approach") can be used as proxy for climate change and to assess its impact on pollen counts and thus allergenic risk for human health. For example the pollen season is shortened and pollen amount is reduced at higher sites. For detailed investigations pollen of the species Plantago, Quercus, Poaceae, Cupressaceae, Cyperacea, Betula and Platanus were chosen, because those are found in appropriate quantities. In general, pollen captured in the pollen traps to a certain extent has its origin from the immediate surrounding. Thus, it mirrors local species distribution. But furthermore the distance of pollen transport is also based on (micro-) climatic conditions, land cover and topography. The pollen trap shortly below the summit of Zugspitze (Schneefernerhaus) has an alpine environment without vegetation nearby. Therefore, this

  7. The importance of cross-reactivity in grass pollen allergy

    Directory of Open Access Journals (Sweden)

    Aleksić Ivana

    2014-01-01

    Full Text Available According to the data obtained from in vivo and in vitro testing in Serbia, a significant number of patients have allergic symptoms caused by grass pollen. We examined the protein composition of grass pollens (Dactylis glomerata, Lolium perenne and Phleum pratense and cross-reactivity in patients allergic to grass pollen from our region. The grass pollen allergen extract was characterized by SDS-PAGE, while cross-reactivity of single grass pollens was revealed by immunoblot analysis. A high degree of cross-reactivity was demonstrated for all three single pollens in the sera of allergic patients compared to the grass pollen extract mixture. Confirmation of the existence of cross-reactivity between different antigenic sources facilitates the use of monovalent vaccines, which are easier to standardize and at the same time prevent further sensitization of patients and reduces adverse reactions. [Projekat Ministarstva nauke Republike Srbije, br. 172049 i br. 172024

  8. Analysis of airborne pollen grains in Konya, Turkey, 2005

    International Nuclear Information System (INIS)

    Altunoglu, M.K.; Bicakci, A.; Temel, M.; Kargioglu, M.

    2010-01-01

    In this study, airborne pollen grains of Konya province were investigated using Durham sampler from January to December 2005. A total of 4420 pollen grains/cm/sup 2/ which belonged to 29 taxa and 9 unidentified pollen grains were recorded. From identified taxa, 19 belong to arboreal and 10 taxa to non-arboreal plants. Total pollen grains consist of 87,49% arboreal, 12,31% non-arboreal plants and 0,20% unidentified pollen grains. In the investigated region, from arboreal plant taxa Pinus spp. (21,63%), Fraxinus spp. (21,13%), Cupressaceae (15,84%), Ailanthus spp. (7,47%), Platanus spp. (3,80%), Acer spp. (3,28%), Populus spp. (1,86%), Sophora spp. (3,85%) and from non-arboreal plant taxa Chenopodiaceae / Amaranthaceae (4,77%), Poaceae (3,67%) were responsible for the greatest amount of pollen. During the study period, the pollen fall reached its highest level in March. (author)

  9. Immunochemical characterization of prosopis juliflora pollen allergens and evaluation of cross-reactivity pattern with the most allergenic pollens in tropical areas.

    Science.gov (United States)

    Assarehzadegan, Mohammad-Ali; Khodadadi, Ali; Amini, Akram; Shakurnia, Abdol-Hosein; Marashi, Seyed Saeid; Ali-Sadeghi, Hosein; Zarinhadideh, Farnoosh; Sepahi, Najmeh

    2015-02-01

    Allergy to Prosopis juliflora (mesquite) pollen is one of the common causes of respiratory allergy in tropical countries. Mesquite is widely used as street trees in towns and ornamental shade trees in parks and gardens throughout arid and semiarid regions of Iran. The inhalation of mesquite pollen and several species of Amaranthus/Chenopodiaceae family is the most important cause of allergic respiratory symptoms in Khuzestan province. This study was designed to evaluate IgE banding proteins of mesquite pollen extract and its IgE cross-reactivity with other allergenic plants. Twenty patients with allergic symptoms and positive skin prick tests (SPT) for mesquite pollen extract participated in the study. Crude pollen extract was prepared from local mesquite trees and used for the evaluation of allergenic profiles of P. juliflora pollen extract by Sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) and IgE-immunoblotting. There were several protein bands in mesquite pollen extract using SDS-PAGE with the approximate range of molecular weight of 10-85 kDa. The most frequent IgE reactive bands among the patients' sera were approximately 20 and 66 kDa. However, there were other IgE reactive protein bands among the patients' sera with molecular weights of 10, 15, 35, 45, 55 and 85 kDa. Inhibition experiments revealed high IgE cross-reactivity between mesquite and acacia. There are several IgE-binding proteins in P. juliflora pollen extract. Results of this study indicate that proteins with a molecular weight of 10 to 85 kDa are the major allergens in P. juliflora pollen extract.

  10. The miRNAs and their regulatory networks responsible for pollen abortion in Ogura-CMS Chinese cabbage revealed by high-throughput sequencing of miRNAs, degradomes, and transcriptomes.

    Science.gov (United States)

    Wei, Xiaochun; Zhang, Xiaohui; Yao, Qiuju; Yuan, Yuxiang; Li, Xixiang; Wei, Fang; Zhao, Yanyan; Zhang, Qiang; Wang, Zhiyong; Jiang, Wusheng; Zhang, Xiaowei

    2015-01-01

    Chinese cabbage (Brassica rapa ssp. pekinensis) is one of the most important vegetables in Asia and is cultivated across the world. Ogura-type cytoplasmic male sterility (Ogura-CMS) has been widely used in the hybrid breeding industry for Chinese cabbage and many other cruciferous vegetables. Although, the cause of Ogura-CMS has been localized to the orf138 locus in the mitochondrial genome, however, the mechanism by which nuclear genes respond to the mutation of the mitochondrial orf138 locus is unclear. In this study, a series of whole genome small RNA, degradome and transcriptome analyses were performed on both Ogura-CMS and its maintainer Chinese cabbage buds using deep sequencing technology. A total of 289 known miRNAs derived from 69 families (including 23 new families first reported in B. rapa) and 426 novel miRNAs were identified. Among these novel miRNAs, both 3-p and 5-p miRNAs were detected on the hairpin arms of 138 precursors. Ten known and 49 novel miRNAs were down-regulated, while one known and 27 novel miRNAs were up-regulated in Ogura-CMS buds compared to the fertile plants. Using degradome analysis, a total of 376 mRNAs were identified as targets of 30 known miRNA families and 100 novel miRNAs. A large fraction of the targets were annotated as reproductive development related. Our transcriptome profiling revealed that the expression of the targets was finely tuned by the miRNAs. Two novel miRNAs were identified that were specifically highly expressed in Ogura-CMS buds and sufficiently suppressed two pollen development essential genes: sucrose transporter SUC1 and H (+) -ATPase 6. These findings provide clues for the contribution of a potential miRNA regulatory network to bud development and pollen engenderation. This study contributes new insights to the communication between the mitochondria and chromosome and takes one step toward filling the gap in the regulatory network from the orf138 locus to pollen abortion in Ogura-CMS plants from a mi

  11. The miRNAs and their regulatory networks responsible for pollen abortion in Ogura-CMS Chinese cabbage revealed by high-throughput sequencing of miRNAs, degradomes and transcriptomes

    Directory of Open Access Journals (Sweden)

    Xiaochun eWei

    2015-10-01

    Full Text Available Chinese cabbage (Brassica rapa ssp. pekinensis is one of the most important vegetables in Asia and is cultivated across the world. Ogura-type cytoplasmic male sterility (Ogura-CMS has been widely used in the hybrid breeding industry for Chinese cabbage and many other cruciferous vegetables. Although, the cause of Ogura-CMS has been localized to the orf138 locus in the mitochondrial genome, however, the mechanism by which nuclear genes respond to the mutation of the mitochondrial orf138 locus is unclear. In this study, a series of whole genome small RNA, degradome and transcriptome analyses were performed on both Ogura-CMS and its maintainer Chinese cabbage buds using deep sequencing technology. A total of 289 known miRNAs derived from 69 families (including 23 new families first reported in B. rapa and 426 novel miRNAs were identified. Among these novel miRNAs, both 3-p and 5-p miRNAs were detected on the hairpin arms of 138 precursors. Ten known and 49 novel miRNAs were down-regulated, while one known and 27 novel miRNAs were up-regulated in Ogura-CMS buds compared to the fertile plants. Using degradome analysis, a total of 376 mRNAs were identified as targets of 30 known miRNA families and 100 novel miRNAs. A large fraction of the targets were annotated as reproductive development related. Our transcriptome profiling revealed that the expression of the targets was finely tuned by the miRNAs. Two novel miRNAs were identified that were specifically highly expressed in Ogura-CMS buds and sufficiently suppressed two pollen development essential genes: sucrose transporter SUC1 and H+-ATPase 6. These findings provide clues for the contribution of a potential miRNA regulatory network to bud development and pollen engenderation. This study contributes new insights to the communication between the mitochondria and chromosome and takes one step toward filling the gap in the regulatory network from the orf138 locus to pollen abortion in Ogura-CMS plants

  12. Adaptation of the Pivotal-Differential Genome Pattern for the Induction of Intergenomic Chromosome Recombination in Hybrids of Synthetic Amphidiploids within Triticeae Tribe

    Directory of Open Access Journals (Sweden)

    Michal T. Kwiatek

    2017-07-01

    Full Text Available A pivotal-differential evolution pattern is when two allopolyploids share a common genome, which is called pivotal, and differ with respect to the other genome or genomes, called differential. This feature induces the intergenomic recombination between chromosomes of differential genomes, which can lead to speciation. Our study is a cytomolecular insight into this mechanism which was adapted for the induction of intergenomic chromosome recombination in hybrids of synthetic amphidiploids Aegilops biuncialis × S. cereale (UUMMRR and triticale (AABBRR where R-genome was pivotal. We observed chromosome recombination events which were induced by both: (1 random chromosome fragmentation and non-homologous chromosome end joining at mitosis of root meristem cells and (2 intergenomic chromosome associations at meiosis of pollen mother cells (PMCs of F1 hybrids. Reciprocal chromosome translocations were identified in six F1 plants and 15 plants of F2 generation using fluorescence in situ hybridization (FISH with DNA clones (pTa-86, pTa-k374, pTa-465, pTa-535, pTa-k566, and pTa-713. We observed signals of pTa-86, pTa-535, and pTa-k566 probes in several chromosome breakpoints. The comparison of the DNA clone sequences distinguished a number of common motifs, which can be considered as characteristics of chromosome breakpoint loci. Immunodetection of synaptonemal complex proteins and genomic in situ hybridization analysis at meiosis of PMCs of F1 hybrids showed, that the homologous pairing of pivotal R—genome chromosomes is crucial for the fertility of F1 hybrids, however, these chromosomes can be also involved in the intergeneric recombination.

  13. Chemical constituents and free radical scavenging activity of corn pollen collected from Apis mellifera hives compared to floral corn pollen at Nan, Thailand

    Directory of Open Access Journals (Sweden)

    Chantarudee Atip

    2012-04-01

    Full Text Available Abstract Background Bee pollen is composed of floral pollen mixed with nectar and bee secretion that is collected by foraging honey (Apis sp. and stingless bees. It is rich in nutrients, such as sugars, proteins, lipids, vitamins and flavonoids, and has been ascribed antiproliferative, anti-allergenic, anti-angiogenic and free radical scavenging activities. This research aimed at a preliminary investigation of the chemical constituents and free radical scavenging activity in A. mellifera bee pollen. Methods Bee pollen was directly collected from A. mellifera colonies in Nan province, Thailand, in June, 2010, whilst floral corn (Zea mays L. pollen was collected from the nearby corn fields. The pollen was then sequentially extracted with methanol, dichloromethane (DCM and hexane, and each crude extract was tested for free radical scavenging activity using the DPPH assay, evaluating the percentage scavenging activity and the effective concentration at 50% (EC50. The most active crude fraction from the bee pollen was then further enriched for bioactive components by silica gel 60 quick and adsorption or Sephadex LH-20 size exclusion chromatography. The purity of all fractions in each step was observed by thin layer chromatography and the bioactivity assessed by the DPPH assay. The chemical structures of the most active fractions were analyzed by nuclear magnetic resonance. Results The crude DCM extract of both the bee corn pollen and floral corn pollen provided the highest active free radical scavenging activity of the three solvent extracts, but it was significantly (over 28-fold higher in the bee corn pollen (EC50 = 7.42 ± 0.12 μg/ml, than the floral corn pollen (EC50 = 212 ± 13.6% μg/ml. After fractionation to homogeneity, the phenolic hydroquinone and the flavone 7-O-R-apigenin were found as the minor and major bioactive compounds, respectively. Bee corn pollen contained a reasonably diverse array of nutritional components, including

  14. Genetics of cryptic speciation within an Arctic mustard, Draba nivalis.

    Directory of Open Access Journals (Sweden)

    A Lovisa S Gustafsson

    Full Text Available Crossing experiments indicate that hybrid sterility barriers frequently have developed within diploid, circumpolar plant species of the genus Draba. To gain insight into the rapid evolution of postzygotic reproductive isolation in this system, we augmented the linkage map of one of these species, D. nivalis, and searched for quantitative trait loci (QTLs associated with reproductive isolation. The map adds 63 new dominant markers to a previously published dataset of 31 co-dominant microsatellites. These markers include 52 amplified fragment length polymorphisms (AFLPs and 11 sequence-specific amplified polymorphisms (SSAPs based on retrotransposon sequence. 22 markers displaying transmission ratio distortion were further included in the map. We resolved eight linkage groups with a total map length of 894 cM. Significant genotype-trait associations, or quantitative trait loci (QTL, were detected for reproductive phenotypes including pollen fertility (4 QTLs, seed set (3 QTLs, flowering time (3 QTLs and number of flowers (4 QTLs. Observed patterns of inheritance were consistent with the influence of both nuclear-nuclear interactions and chromosomal changes on these traits. All seed set QTLs and one pollen fertility QTL displayed underdominant effects suggestive of the involvement of chromosomal rearrangements in hybrid sterility. Interestingly, D. nivalis is predominantly self-fertilizing, which may facilitate the establishment of underdominant loci and contribute to reproductive isolation.

  15. The effect of irradiation on date palm pollen grains

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, M M; Alajaily, F R [The National Academy for Scientific Research Tripoli (Libyan Arab Jamahiriya)

    1995-10-01

    The evaluation of male date palm is very important in date palm culture, it is very well known that the source of pollen has its influence on fruit set, physical and chemical characters of the fruits. Date pollen was collected from previously studied male date palm trees. The pollen was subjected to the following irradiation treatments: 0,5, 10, 20, 40, 80 krad. The irradiated pollen was treated with acetocarmine and its viability was studied under the light microscope. No differences were observed between the treated pollen and the control. The pollen was germinated on agar, sucrose and boric acid media in an incubator at 27 degree C for hours. Germination count under the light microscope indicated that there were no significant differences between 5, 10, 20 krad treatments and the control, but the high doses reduced the germination percentage. The irradiated pollen used to pollinate date palm trees and the effect of metaxynia was studied. 3 tabs.

  16. Exceptional preservation of Miocene pollen: plasmolysis captured in salt?

    Energy Technology Data Exchange (ETDEWEB)

    Durska, W.

    2016-07-01

    Exceptionally well-preserved Miocene pollen from the Bochnia salt mine of southern Poland is reported herein. The halite deposits within the salt mine belonging to Late Badenian (Miocene) marine evaporites originated in the Paratethys. Rounded and angular structures are present inside pollen grains. On the basis of the similarity with plasmolyzed pollen grains of modern plants, these structures are considered to represent cytoplasms plasmolyzed in the condensed brine prior to fossilization. Two forms of plasmolyzed cytoplasms (concave and convex) can be observed in modern pollen. Both are distinguished in the investigated fossil material. In porate and colporate grains the shape of the plasmolyzed cellular content is concave while in inaperturate it is convex. The plasmolysis form depends on the type of apertures and pollen shape. The percentage of pollen with fossilized cytoplasms within individual taxa is a valuable environmental indicator, as it depends on the proximity of the pollen-producing plant assemblages to the depositional setting. (Author)

  17. A statistical mixture model for estimating the proportion of unreduced pollen grains in perennial ryegrass (Lolium perenne L.) via the size of pollen grains

    NARCIS (Netherlands)

    Jansen, R.C.; Nijs, A.P.M. den

    1993-01-01

    The size of pollen grains is commonly used to indicate the ploidy level of pollen grains. In this paper observations of the diameter of pollen grains are evaluated from one diploid accession of perennial ryegrass (Lolium perenne L.), which was expected to produce diploid (unreduced) pollen grains in

  18. Next generation immunotherapy for tree pollen allergies.

    Science.gov (United States)

    Su, Yan; Romeu-Bonilla, Eliezer; Heiland, Teri

    2017-10-03

    Tree pollen induced allergies are one of the major medical and public health burdens in the industrialized world. Allergen-Specific Immunotherapy (AIT) through subcutaneous injection or sublingual delivery is the only approved therapy with curative potential to pollen induced allergies. AIT often is associated with severe side effects and requires long-term treatment. Safer, more effective and convenient allergen specific immunotherapies remain an unmet need. In this review article, we discuss the current progress in applying protein and peptide-based approaches and DNA vaccines to the clinical challenges posed by tree pollen allergies through the lens of preclinical animal models and clinical trials, with an emphasis on the birch and Japanese red cedar pollen induced allergies.

  19. Differential Effects of Carbohydrates on Arabidopsis Pollen Germination.

    Science.gov (United States)

    Hirsche, Jörg; García Fernández, José M; Stabentheiner, Edith; Großkinsky, Dominik K; Roitsch, Thomas

    2017-04-01

    Pollen germination as a crucial process in plant development strongly depends on the accessibility of carbon as energy source. Carbohydrates, however, function not only as a primary energy source, but also as important signaling components. In a comprehensive study, we analyzed various aspects of the impact of 32 different sugars on in vitro germination of Arabidopsis pollen comprising about 150 variations of individual sugars and combinations. Twenty-six structurally different mono-, di- and oligosaccharides, and sugar analogs were initially tested for their ability to support pollen germination. Whereas several di- and oligosaccharides supported pollen germination, hexoses such as glucose, fructose and mannose did not support and even considerably inhibited pollen germination when added to germination-supporting medium. Complementary experiments using glucose analogs with varying functional features, the hexokinase inhibitor mannoheptulose and the glucose-insensitive hexokinase-deficient Arabidopsis mutant gin2-1 suggested that mannose- and glucose-mediated inhibition of sucrose-supported pollen germination depends partially on hexokinase signaling. The results suggest that, in addition to their role as energy source, sugars act as signaling molecules differentially regulating the complex process of pollen germination depending on their structural properties. Thus, a sugar-dependent multilayer regulation of Arabidopsis pollen germination is supported, which makes this approach a valuable experimental system for future studies addressing sugar sensing and signaling. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  20. [Allergic responses to date palm and pecan pollen in Israel].

    Science.gov (United States)

    Waisel, Y; Keynan, N; Gil, T; Tayar, D; Bezerano, A; Goldberg, A; Geller-Bernstein, C; Dolev, Z; Tamir, R; Levy, I

    1994-03-15

    Date palm (Phoenix dactylifera) and pecan (Carya illinoensis) trees are commonly planted in Israel for fruit, for shade, or as ornamental plants. Pollen grains of both species are allergenic; however, the extent of exposure to such pollen and the incidence of allergic response have not been studied here. We therefore investigated skin-test responses to pollen extracts of 12 varieties of palm and 9 of pecan in 705 allergic patients living in 3 cities and 19 rural settlements. Sensitivity to the pollen extracts of both species was much higher among residents of rural than of urban communities. Moreover, there was a definite relationship between the abundance of these trees in a region and the incidence of skin responders to their pollen. Sensitivity was frequent in settlements rich in these 2 species, such as those with nearby commercial date or pecan plantations. In general, sensitivity to date pollen extracts was lower than to pecan. However, differences in skin responses to pollen extracts of various clones were substantiated. Air sampling revealed that pollen pollution decreased considerably with distance from the trees. At approximately 100 m from a source concentrations of airborne pollen were low. Since planting of male palm and pecan trees in population centers would increase pollen pollution, it should be avoided.

  1. Consumptive emasculation: the ecological and evolutionary consequences of pollen theft.

    Science.gov (United States)

    Hargreaves, Anna L; Harder, Lawrence D; Johnson, Steven D

    2009-05-01

    Many of the diverse animals that consume floral rewards act as efficient pollinators; however, others 'steal' rewards without 'paying' for them by pollinating. In contrast to the extensive studies of the ecological and evolutionary consequences of nectar theft, pollen theft and its implications remain largely neglected, even though it affects plant reproduction more directly. Here we review existing studies of pollen theft and find that: (1) most pollen thieves pollinate other plant species, suggesting that theft generally arises from a mismatch between the flower and thief that precludes pollen deposition, (2) bees are the most commonly documented pollen thieves, and (3) the floral traits that typically facilitate pollen theft involve either spatial or temporal separation of sex function within flowers (herkogamy and dichogamy, respectively). Given that herkogamy and dichogamy occur commonly and that bees are globally the most important floral visitors, pollen theft is likely a greatly under-appreciated component of floral ecology and influence on floral evolution. We identify the mechanisms by which pollen theft can affect plant fitness, and review the evidence for theft-induced ecological effects, including pollen limitation. We then explore the consequences of pollen theft for the evolution of floral traits and sexual systems, and conclude by identifying key directions for future research.

  2. Species integrity enhanced by a predation cost to hybrids in the wild

    DEFF Research Database (Denmark)

    Nilsson, P. A.; Hulthén, Kaj; Chapman, Ben B.

    2017-01-01

    Species integrity can be challenged, and even eroded, if closely related species can hybridize and produce fertile offspring of comparable fitness to that of parental species. The maintenance of newly diverged or closely related species therefore hinges on the establishment and effectiveness of pre...... barrier to gene flow in the wild. Cyprinid fishes commonly produce fertile, viable hybrid offspring and therefore make excellent study organisms to investigate ecological costs to hybrids. We electronically tagged two freshwater cyprinid fish species (roach Rutilus rutilus and bream Abramis brama...... to directly test for a predation cost to hybrids in the wild. Hybrid individuals were found significantly more susceptible to cormorant predation than individuals from either parental species. Such ecological selection against hybrids contributes to species integrity, and can enhance species diversification....

  3. Pollen Contents Of Commercial Honeys Of Opi, Nsukka, Enugu ...

    African Journals Online (AJOL)

    Pollen Contents Of Commercial Honeys Of Opi, Nsukka, Enugu State, Nigeria. ... Abstract. Pollen analyses of seven honey samples from Opi-Nsukka Mini market were evaluated for their pollen composition. The results ... HOW TO USE AJOL.

  4. Molecular cloning of plane pollen allergen Pla a 3 and its utility as diagnostic marker for peach associated plane pollen allergy.

    Science.gov (United States)

    Wangorsch, A; Larsson, H; Messmer, M; García-Moral, A; Lauer, I; Wolfheimer, S; Schülke, S; Bartra, J; Vieths, S; Lidholm, J; Scheurer, S

    2016-05-01

    Non-specific lipid transfer proteins (nsLTP) are considered to provoke allergic symptoms to plane tree pollen, which are frequently associated with peach allergy. The objective was to clone the cDNA of plane pollen nsLTP Pla a 3, to characterize IgE-binding and allergenic potency of recombinant Pla a 3 in comparison to its natural counterpart and peach nsLTP Pru p 3. Natural Pla a 3 was purified from plane pollen and analysed by mass spectrometry (MS). Recombinant Pla a 3 was characterized by SDS-PAGE and CD spectroscopy. Specific IgE to extract, components of plane pollen and Pru p 3 was measured by ImmunoCAP in sera of patients allergic to either plane pollen (n = 10), peach (n = 15) or both (n = 15). Biological potency of the proteins was investigated by in vitro mediator release assays and IgE cross-reactivity by competitive ELISA. Two Pla a 3 isoforms were identified. Recombinant Pla a 3 showed high purity, structural integrity, IgE-binding capacity comparable to nPla a 3 and biological potency. Sensitization to plane pollen extract was confirmed in 24/25 plane pollen allergics. The frequency of sensitization to Pla a 3 was 53% among patients allergic to both plane pollen and peach and 10% among plane pollen allergics tolerating peach where most patients were sensitized to Pla a 1. Pla a 3 and Pru p 3 showed strong bi-directional IgE cross-reactivity in patients allergic to peach and plane pollen, but not in peach allergics tolerating plane pollen. Levels of IgE-binding were generally higher to Pru p 3 than to Pla a 3. Sensitization to Pla a 3 is relevant in a subgroup of plane pollen allergics with concomitant peach allergy. IgE testing with Pla a 3 may serve as a marker to identify plane pollen allergic patients at risk of LTP-mediated food reactions and thereby improve in vitro diagnostic procedures. © 2016 John Wiley & Sons Ltd.

  5. Efficiency of soil and fertilizer nitrogen in relation to variety and application time, using N-15 labelled fertilizer. Part of a coordinated programme on agricultural nitrogen residues with particular reference to their conservation as fertilizers and behaviour as potential pollutants

    International Nuclear Information System (INIS)

    Park, H.

    1979-12-01

    A series of experiments with flooded rice were carried out on 36 locations to study the influence of rice variety, fertilizer source, frequency of fertilizer application and soil conditions on the uptake of fertilizer N and grain yield. 15 N-labelled fertilizer was used in this study. The results show that (i) urea is a better source of N than ammonium sulphate on saline soils and also for the leading local rice variety (Milyang 15). The new variety Tongil utilized ammonium sulphate more efficiently; (ii) Fertilizer was more efficiently utilized on high organic matter soils; (iii) Varieties differed in fertilizer use efficiency; (iv) Hybrid Tongil lines gave higher grain yields than the local varieties, and made better use of fertilizer N, especially on saline soil, when applied at transplanting; (v) Sulphur-coated urea gave higher yield than urea on saline soils (27-39%), virgin soils (20%) and unmatured soils (10%)

  6. Determination of pollen quality and quantity in mulberry (morus alba l.)

    International Nuclear Information System (INIS)

    Erdogan, U.

    2015-01-01

    In this study, the pollen grains of eight different mulberry types in I.spir and Pazaryolu districts of Erzurum were tested for the determination of viability, germination rates, pollen production levels and morphologically homogeneity. Viability of the pollens was determined by TTC (2, 3, 5-triphenly tetrazolium chlorid) and IKI (iodine + potassium iodide) tests. Pollen germination experiments were performed with Agar-plate (1%) method in sucrose solutions of 0, 5, 10, 15, 20 and 25% concentrations. In addition, pollen production and morphologically homogeneity were determined by the Hemacytometric method. The pollen viability of all types used in this study was obtained in high ratios. Pollen germination rates were the highest for 15% and 20% sucrose solutions. The highest pollen production level was obtained from the genotype 6. The morphologically homogeneity levels of pollens changed from 97.36 to 98.86% in types. (author)

  7. Long-term storage method for soft X-ray irradiated 'Hyuganatsu' pollen

    International Nuclear Information System (INIS)

    Yano, S.; Tanaka, M.; Ohara, N.

    2008-01-01

    The long-term storage conditions for 'Hyuganatsu ' pollen that had been irradiated with soft X-rays was examined. This study, was aimed at production of 'Tosa-buntan' without formation of nuclear fruit. 1. We evaluated the germination rate of pollen that had been irradiated with soft X-ray (500 or 1,000 Gy) and stored at 3 deg C, -20 deg C, and -40 deg C. The germination rate was the same as that of unirradiated pollen, even after storage for 1 year. Soft X-ray irradiation did not influence the storage attributes of pollen. 2. In unirradiated pollen and pollen that had been irradiated with soft X-ray (500 or 1,000 Gy), temperature conditions necessary for storing from 3 months to 1 year were -20 deg C or less, and pollen stored at -40 deg C had a higher germination rate after 1 year. 3. The germination rate was 1% or less in 4 months if silica gel was sealed into a gas barrier bag with 1,000 Gy-irradiated pollen at a rate of 10:1 (w/w). The ability to germinate was completely lost after 1 year in these conditions. 4. We evaluated the effect of sealing methods on 1,000 Gy-irradiated pollen stored at -20 deg C. There was no difference in germination rates among pollen stored in gas-barrier bags, vacuum-packaged pollen, and pollen stored with nitrogen in gas-barrier bags. Moreover, the germination rate of 750 Gy-irradiated pollen stored at -20 deg C decreased from 3 months onwards when pollen was stored with a free-oxygen absorber (Ageless ZP). 5. Pollen that was treated with acetone before or after soft X-ray irradiation (750 Gy) withstood long-term storage of 1 year. Long-term storage was possible if pollen was stored at -20 deg C, as is the case for rough pollen

  8. Pollen viability and membrane lipid composition

    NARCIS (Netherlands)

    Bilsen, van D.G.J.L.

    1993-01-01

    In this thesis membrane lipid composition is studied in relation to pollen viability during storage. Chapter 1 reviews pollen viability, membranes in the dry state and membrane changes associated with cellular aging. This chapter is followed by a study of age-related changes in phospholipid

  9. Calcium in pollen-pistil interaction in Petunia hybrida Hort. I. Localization of Ca2+ ions in mature pollen grain using pyroantimonate and autoradiographic methods.

    Science.gov (United States)

    Bednarska, E; Butowt, R

    1994-01-01

    The localization of Ca2+ in the mature pollen grain and the flow of these ions from the somatic tissues of the anther to the pollen grains has been studied using pyroantimonate and autoradiographic methods. In the pollen grain, Ca2+ ions have been localized in the sporoderm and in the cytoplasmic vesicles of probably dictyosomal origin. Calcium ions were transported into the sporoderm together with the compounds of degenerating tapetum. The material of degenerating tapetum forms pollen coat surrounding the mature pollen grain.

  10. Influence of airborne pollen counts and length of pollen season of selected allergenic plants on the concentration of sIgE antibodies on the population of Bratislava, Slovakia

    Directory of Open Access Journals (Sweden)

    Jana Ščevková

    2015-09-01

    Full Text Available Introduction and objective. The association between airborne pollen counts or duration of pollen season and allergy symptoms is not always distinguished. The purpose of this study was to examine the correlation between pollen exposure (annual total pollen quantity and main pollen season length of selected allergenic plants in the atmosphere of Bratislava, and concentration of allergen-specific immunoglobulin E (sIgE in serum of patients with seasonal allergy during 2002–2003. Materials and methods. The concentration of pollen was monitored by a Burkard volumetric pollen trap. At the same time, 198 pollen allergic patients were testing to determine the values of sIgE antibodies against selected pollen allergens; a panel of 8 purified allergens was used. Results. The highest percentages of sensitization were detected for Poaceae and [i]Ambrosia[/i] pollen allergens. The most abundant airborne pollen types were Urticaceae, [i]Betula[/i], [i]Populus[/i], Fraxinus, Pinus and Poaceae. The length of the pollen season varied. The longest pollen season was that of the [i]Plantago[/i] – 105 days, and the shortest, [i]Corylus[/i] – 20 days. A significant correlation was found between annual total pollen quantity and median sIgE values, especially in 2002. Conclusions. A strong and significant positive correlation was observed between pollen counts, excluding [i]Betula[/i], and sIgE levels in both analysed years. The correlation was weaker and negative in the case of length of pollen season and sIgE values.

  11. Cotton transformation via pollen tube pathway.

    Science.gov (United States)

    Wang, Min; Zhang, Baohong; Wang, Qinglian

    2013-01-01

    Although many gene transfer methods have been employed for successfully obtaining transgenic cotton, the major constraint in cotton improvement is the limitation of genotype because the majority of transgenic methods require plant regeneration from a single transformed cell which is limited by cotton tissue culture. Comparing with other plant species, it is difficult to induce plant regeneration from cotton; currently, only a limited number of cotton cultivars can be cultured for obtaining regenerated plants. Thus, development of a simple and genotype-independent genetic transformation method is particularly important for cotton community. In this chapter, we present a simple, cost-efficient, and genotype-independent cotton transformation method-pollen tube pathway-mediated transformation. This method uses pollen tube pathway to deliver transgene into cotton embryo sacs and then insert foreign genes into cotton genome. There are three major steps for pollen tube pathway-mediated genetic transformation, which include injection of -foreign genes into pollen tube, integration of foreign genes into plant genome, and selection of transgenic plants.

  12. Use of MODIS Satellite Data to Evaluate Juniperus spp. Pollen Phenology to Support a Pollen Dispersal Model, PREAM, to Support Public Health Allergy Alerts

    Science.gov (United States)

    Luvall, J. C.; Sprigg, W. A.; Levetin, E.; Huete, A.; Nickovic, S.; Prasad, A.; Pejanovic, G. A.; Vukovic, A.; VandeWater, P. K.; Budge, A. M.; hide

    2013-01-01

    Pollen can be transported great distances. Van de Water et. al., 2003 reported Juniperus spp. pollen was transported 200-600 km. Hence local observations of plant phenology may not be consistent with the timing and source of pollen collected by pollen sampling instruments. The DREAM (Dust REgional Atmospheric Model) is a verified model for atmospheric dust transport modeling using MODIS data products to identify source regions and concentrations of dust. We are modifying the DREAM model to incorporate pollen transport. Pollen emission is based on MODIS-derived phenology of Juniperus spp. communities. Ground-based observational records of pollen release timing and quantities will be used as model verification. This information will be used to support the Centers for Disease Control and Prevention s National Environmental Public Health Tracking Program and the State of New Mexico environmental public health decision support for asthma and allergies alerts

  13. Use of MODIS Satellite Data to Evaluate Juniperus spp. Pollen Phenology to Support a Pollen Dispersal Model, PREAM, to Support Public Health Allergy Alerts

    Science.gov (United States)

    Luvall, J. C.; Sprigg, W. A.; Levetin, E.; Huete, A. R.; Nickovic, S.; Prasad, A. K.; Pejanovic, G.; Vukovic, A.; Van De Water, P. K.; Budge, A.; Hudspeth, W. B.; Krapfl, H.; Toth, B.; Zelicoff, A.; Myers, O.; Bunderson, L.; Ponce-Campos, G.; Menache, M.; Crimmins, T. M.; Vujadinovic, M.

    2012-12-01

    Pollen can be transported great distances. Van de Water et. al., 2003 reported Juniperus spp. pollen was transported 200-600 km. Hence local observations of plant phenology may not be consistent with the timing and source of pollen collected by pollen sampling instruments. The DREAM (Dust REgional Atmospheric Model, Nickovic et al. 2001) is a verified model for atmospheric dust transport modeling using MODIS data products to identify source regions and concentrations of dust. We are modifying the DREAM model to incorporate pollen transport. Pollen emission is based on MODIS-derived phenology of Juniperus spp. communities. Ground-based observational records of pollen release timing and quantities will be used as model verification. This information will be used to support the Centers for Disease Control and Prevention's National Environmental Public Health Tracking Program and the State of New Mexico environmental public health decision support for asthma and allergies alerts.

  14. Fusion-fission hybrid reactors

    International Nuclear Information System (INIS)

    Greenspan, E.

    1984-01-01

    This chapter discusses the range of characteristics attainable from hybrid reactor blankets; blanket design considerations; hybrid reactor designs; alternative fuel hybrid reactors; multi-purpose hybrid reactors; and hybrid reactors and the energy economy. Hybrid reactors are driven by a fusion neutron source and include fertile and/or fissile material. The fusion component provides a copious source of fusion neutrons which interact with a subcritical fission component located adjacent to the plasma or pellet chamber. Fissile fuel and/or energy are the main products of hybrid reactors. Topics include high F/M blankets, the fissile (and tritium) breeding ratio, effects of composition on blanket properties, geometrical considerations, power density and first wall loading, variations of blanket properties with irradiation, thermal-hydraulic and mechanical design considerations, safety considerations, tokamak hybrid reactors, tandem-mirror hybrid reactors, inertial confinement hybrid reactors, fusion neutron sources, fissile-fuel and energy production ability, simultaneous production of combustible and fissile fuels, fusion reactors for waste transmutation and fissile breeding, nuclear pumped laser hybrid reactors, Hybrid Fuel Factories (HFFs), and scenarios for hybrid contribution. The appendix offers hybrid reactor fundamentals. Numerous references are provided

  15. In vitro pollen quantity, viability and germination tests in quince ...

    African Journals Online (AJOL)

    Quince (Cydonia oblonga Mill.) cvs. Ekmek, Esme, Limon, Ege 2, Ege 22, Ege 25 and Quince-A rootstock pollens were collected in April from the unopened pink balloon-stage flowers on mature trees. The pollen amount was between 20063 pollen/flower ('Ege 25') and 11906 pollen/flower ('Limon') with hemacytometer.

  16. Interference of the Histone Deacetylase Inhibits Pollen Germination and Pollen Tube Growth in Picea wilsonii Mast.

    Directory of Open Access Journals (Sweden)

    Yaning Cui

    Full Text Available Histone deacetylase (HDAC is a crucial component in the regulation of gene expression in various cellular processes in animal and plant cells. HDAC has been reported to play a role in embryogenesis. However, the effect of HDAC on androgamete development remains unclear, especially in gymnosperms. In this study, we used the HDAC inhibitors trichostatin A (TSA and sodium butyrate (NaB to examine the role of HDAC in Picea wilsonii pollen germination and pollen tube elongation. Measurements of the tip-focused Ca2+ gradient revealed that TSA and NaB influenced this gradient. Immunofluorescence showed that actin filaments were disrupted into disorganized fragments. As a result, the vesicle trafficking was disturbed, as determined by FM4-64 labeling. Moreover, the distribution of pectins and callose in cell walls was significantly altered in response to TSA and NaB. Our results suggest that HDAC affects pollen germination and polarized pollen tube growth in Picea wilsonii by affecting the intracellular Ca2+ concentration gradient, actin organization patterns, vesicle trafficking, as well as the deposition and configuration of cell wall components.

  17. POLLEN MORPHOLOGY OF CROCUS L.(IRIDACEAE IN BULGARIA

    Directory of Open Access Journals (Sweden)

    UZUNDZHALIEVA KATYA SPASOVA

    2012-06-01

    Full Text Available The pollen of the wild species from the genus Crocus L., spread in Bulgaria has been analyzed. The investigations, made by light microscope show that the pollen of these species is spherical in shape and round in outlines, comparatively big. These morphological characteristics of the pollen of the wild Bulgarian Crocuses define it as a primitive one [6]. The Scanning Electron Microscope investigations, made by Beug [1], established two types of pollen morphology. The results of our investigation led to the conclusion that the same types are also presented in Bulgarian species: – C.biflorus –type, or syncolpate and C.vernus – type, or inaperturate. Eight of the species belong to the first type and only C. pallasii belongs to the second. The pollen of C. reticulatus is with quite unclear aperture – maybe transition to the inaperturate type.

  18. 219 The Revised Edition of Korean Calendar for Allergenic Pollens

    Science.gov (United States)

    Oh, Jae-won; Kim, Joo-Hwa; Kim, Seong-Won; Kang, Im-Joo; Kim, Bong-Seong; Kook, Myung-Hee; Park, Kang-Seo; Lee, Ha-Baik; Kim, Kyu Rang; Choi, Young-Jean

    2012-01-01

    Background The old version of pollen calendar was used until this year in South Korea. That calendar did not reflect current pollen distribution and concentrations that can be influenced by changes in weather and environment. A new pollen calendar of allergenic pollens was made based on the data on pollen concentrations obtained in 8 regions nationwide between 1997 and 2009 in South Korea. Methods The distribution of pollen grains was assessed every day at 8 areas (Seoul, Guri, Busan, Daegu, Jeonju, Kwangju, Kangneung, and Jeju) nationwide for 12 years between July 1, 1997 and June 30, 2009. Pollen were collected by using Burkard 7-day sampler (Burkard manufacturing Co Ltd, Hertfordshire, UK), and the collected pollens were sent every week to Hanyang Guri Hospital. Then pollens were strained with Calberla's fuchsin staining solution and were identified. The number of pollen grains per m3 was calculated. Results Alder, birch and Japanese cedar started to appear in February. Japanese cedar showed a highest pollen concentration in Jeju. Pine became the highest pollen in May, and the pollen concentrations of oak and birch also became high. Common ragweed appeared in the middle of August and showed the highest pollen concentration in the middles of September. Japanese hop showed a high concentration between the middle of August and the end of September, and mugwort appeared in the middles of August and its concentration increased up until early September. Birch appeared earlier in Kangneung, and pine showed a higher pollen concentration than in the other areas. In Daegu, Oriental thuja, alder and juniper produced a large concentration of pollens. Pine produced a large concentration of pollens between the middle of April and the end of May. Weeds showed higher concentrations in September and mugwort appeared earlier than common ragweed. In Busan where is the southeast city, the time of flowering is relatively early, and alder and Oriental thuja appeared earliest among

  19. Forensic Pollen Evidence from Clothes by the Tape Adhesive Method

    Directory of Open Access Journals (Sweden)

    Chun-Liang Wu

    2006-06-01

    Full Text Available Collection and identification of pollen is becoming important in forensic applications. Many criminal cases have been reported to link suspects to the crime scene by analysis of pollen. Several methods have been used in the pollen collection and analysis, but they are expensive and tedious. Therefore, it is important to develop a simple method to collect pollen grains from clothes. We tried to recover pollen from clothing surface by using the sticky tapes method. The tape adhesive method has been widely used for sample collection for various purposes, but the efficiency of recovery of invisible pollen from clothes has rarely been reported. Therefore, to test the efficiency of the tape adhesive method in recovering pollen from clothes is important. The first author wore clothes that were made from textile S made by the mixture of cotton 60% and polyester fiber 40% to collect pollen from 26 different areas mostly in the northern part of Taiwan and then used cellophane tape D (Sirchie Finger Print Lab., Inc-No. 131LT4 to recover them from different body parts. Twenty-six pollen taxa were detected in different parts of clothes depending upon what kind of plant the first author stayed near. From the results, we concluded that the tape adhesive method is suitable in recovering pollen from clothes. We have suggested that the tape adhesive method could be part of methods for collecting pollen from clothes of suspects. It is simpler, faster and less expensive than other methods.

  20. National Allergy Bureau Pollen and Mold Report

    Science.gov (United States)

    ... Search AAAAI National Allergy Bureau Pollen and Mold Report Date: May 19, 2018 Location: San Antonio (2), ... 18/2018 ( click here to view ). Our Allergen Report Email Service can automatically email you daily pollen ...

  1. Aberrant Classopollis pollen reveals evidence for unreduced (2n) pollen in the conifer family Cheirolepidiaceae during the Triassic–Jurassic transition

    Science.gov (United States)

    Kürschner, Wolfram M.; Batenburg, Sietske J.; Mander, Luke

    2013-01-01

    Polyploidy (or whole-genome doubling) is a key mechanism for plant speciation leading to new evolutionary lineages. Several lines of evidence show that most species among flowering plants had polyploidy ancestry, but it is virtually unknown for conifers. Here, we study variability in pollen tetrad morphology and the size of the conifer pollen type Classopollis extracted from sediments of the Triassic–Jurassic transition, 200 Ma. Classopollis producing Cheirolepidiaceae were one of the most dominant and diverse groups of conifers during the Mesozoic. We show that aberrant pollen Classopollis tetrads, triads and dyads, and the large variation in pollen size indicates the presence of unreduced (2n) pollen, which is one of the main mechanisms in modern polyploid formation. Polyploid speciation may explain the high variability of growth forms and adaptation of these conifers to different environments and their resistance to extreme growth conditions. We suggest that polyploidy may have also reduced the extinction risk of these conifers during the End-Triassic biotic crisis. PMID:23926159

  2. Raman spectroscopy as a tool for the characterization and classification of pollen; Raman-Spektroskopie als Werkzeug fuer die Charakterisierung und Klassifizierung von Pollen

    Energy Technology Data Exchange (ETDEWEB)

    Schulte, Franziska

    2010-09-20

    The chemical composition of pollen, the physiological containers that produce the male gametophytes of seed plants, has been a subject of research of plant physiologists, biochemists, and lately even material scientists for various reasons. The aim of this work was the analysis of whole pollen grains and pollen components by Raman Spectroscopy. These experiments were complemented by other techniques such as Enviromental Scanning Electron Microscopy (ESEM), High-Performance- Thin-Layer-Chromatography (HPTLC), Infrared Spectroscopy (IR) and Nuclear-Magnetic-Resonance Spectroscopy (NMR). As reported here, individual fresh pollen grains and their morphological constituents can be characterized and also classified in situ without prior preparation. Classification of pollen is based on their biochemical fingerprint revealed in their Raman spectrum. Raman spectroscopy is nondestructive and can be carried out with single pollen grains or fragments. It could be shown that the biochemical makeup of the pollen (as a part of the recognition/mating system) is altered during formation of a new biological species and that the species-specific chemical similarities and dissimilarities indeed reflect in the Raman spectral fingerprint. On the basis of the chemical information, unsupervised multivariate analysis consisting of hierarchical clustering revealed in most cases chemical similarities between species that were indicative of both phylogenetic relationship and matin behavior. Therefore experiments were conducted that gave the in situ Raman spectroscopic signatures ot the carotenoid molecules. As the data indicates, the in situ Raman spectra of the carotenoid molecules measured in single intact pollen grains provide in situ evidence of interspecies variations in pollen carotenoid content, structure, and/or assembly without prior purification. Results from HPTLC confirmed that carotenoid composition varied greatly between species and that the different in situ spectral

  3. Modern pollen data from the Canadian Arctic, 1972–1973

    Science.gov (United States)

    Nichols, Harvey; Stolze, Susann

    2017-01-01

    This data descriptor reports results of a 1972–73 baseline study of modern pollen deposition in the Canadian Arctic to originally aid interpretation of Holocene pollen diagrams from that region, especially focussed on the arctic tree-line. The data set is geographically unique due to its extent, and allows the assessment of the effects of modern climate change on northern ecosystems, including fluctuations of the a arctic tree-line. Repeated sampling was conducted along an interior transect at 29 sites from the Boreal Forest to the High Arctic, with five additional coastal sites covering a total distance of 3,200 km. Static pollen samplers captured both local pollen and long-distance pollen wind-blown from the Boreal Forest. Moss and lichen polsters provided multi-year pollen fallout to assess the effectiveness of the static pollen samplers. The local vegetation was recorded at each site. This descriptor provides information on data archived at the World Data Center PANGAEA, which includes spreadsheets detailing site and sample information as well as raw and processed pollen data obtained on over 500 samples. PMID:28509898

  4. Herbivory in spiders: the importance of pollen for orb-weavers.

    Science.gov (United States)

    Eggs, Benjamin; Sanders, Dirk

    2013-01-01

    Orb-weaving spiders (Araneidae) are commonly regarded as generalist insect predators but resources provided by plants such as pollen may be an important dietary supplementation. Their webs snare insect prey, but can also trap aerial plankton like pollen and fungal spores. When recycling their orb webs, the spiders may therefore also feed on adhering pollen grains or fungal spores via extraoral digestion. In this study we measured stable isotope ratios in the bodies of two araneid species (Aculepeira ceropegia and Araneus diadematus), their potential prey and pollen to determine the relative contribution of pollen to their diet. We found that about 25% of juvenile orb-weaving spiders' diet consisted of pollen, the other 75% of flying insects, mainly small dipterans and hymenopterans. The pollen grains in our study were too large to be taken up accidentally by the spiders and had first to be digested extraorally by enzymes in an active act of consumption. Therefore, pollen can be seen as a substantial component of the spiders' diet. This finding suggests that these spiders need to be classified as omnivores rather than pure carnivores.

  5. Diurnal Variations of Airborne Pollen and Spores in Taipei City, Taiwan

    Directory of Open Access Journals (Sweden)

    Yueh-Lin Yang

    2003-09-01

    Full Text Available The diurnal variation of airborne pollen and spores in Taipei City, Taiwan, was investigated during a two-year survey from 1993 to 1994. The pollen and spores were sampled using a Burkard seven-day volumetric pollen trap. The diurnal trends of the total amount of pollen and spores in 1993 and in 1994 were similar to each other, and peaked at 3 to 10 o’clock. The diurnal patterns of airborne pollen and spores of Broussonetia, Fraxinus, Cyathea and Gramineae in 1993 were similar to those in 1994. High concentrations of Broussonetia and Fraxinus were obtained from midnight to the next morning. Cyathea spores peaked from morning till noon, and Gramineae peaked in the afternoon. The diurnal patterns of airborne pollen of Bischofia, Juniperus, Mallotus, Morus, Trema and Urticaceae in 1993 were different to those in 1994. Regular diurnal patterns also associated with the taxa, which produce large pollen or spores, such as Gramineae and Cyathea. In contrast, Bischofia, Juniperus, Mallotus, Morus, Trema and Urticaceae produce relatively small pollen and the diurnal patterns of their airborne pollen were found irregular. The source plants Broussonetia and Fraxinus were close to the collection site so the diurnal patterns of their airborne pollen were regular, suggesting that the diurnal fluctuations of the pollen or spores in air might be affected by the source of plants and the sizes of pollen or spores. The transportation of the smaller pollen or spores in air is probably more easily affected by instability of air currents; they are therefore more likely to exhibit irregular diurnal patterns.

  6. Genomics for greater efficiency in pigeonpea hybrid breeding

    Directory of Open Access Journals (Sweden)

    Rachit K Saxena

    2015-10-01

    Full Text Available Cytoplasmic genic male sterility based hybrid technology has demonstrated its immense potential in increasing the productivity of various crops, including pigeonpea. This technology has shown promise for breaking the long-standing yield stagnation in pigeonpea. There are difficulties in commercial hybrid seed production due to non-availability of field-oriented technologies such as time-bound assessment of genetic purity of hybrid seeds. Besides this, there are other routine breeding activities which are labour oriented and need more resources. These include breeding and maintenance of new fertility restorers and maintainer lines, diversification of cytoplasm, and incorporation of biotic and abiotic stress resistances. The recent progress in genomics research could accelerate the existing traditional efforts to strengthen the hybrid breeding technology. Marker based seed purity assessment, identification of heterotic groups; selection of new fertility restorers are few areas which have already been initiated. In this paper efforts have been made to identify critical areas and opportunities where genomics can play a leading role and assist breeders in accelerating various activities related to breeding and commercialization of pigeonpea hybrids.

  7. Performance of Hybrid Corn in Different Environmental Conditions in the Region Of Sinop-MT

    Directory of Open Access Journals (Sweden)

    D. C. T. Souza

    2013-07-01

    Full Text Available Abstract: The aim of this study was to evaluate the agronomic performance of corn hybrids in environmental conditions favorable and unfavorable. For this, two experiments were conducted at Sinop / MT, being considered as favorable environmental conditions the use of fertilizer recommended for the crop at planting and coverage, and unfavorable conditions only recommended fertilization at planting. The experimental design was a randomized block with three replicates, with plots of 2 rows of 3 meters. The treatments were: double hybrid (Balu 761, single hybrids (AG 7088 and 30F90Y and triple hybrid (2B688. The characteristics evaluated were number of spikes, husked spikes weight, plant height and height of first spike. Regarding the number of ears, under favorable conditions, the hybrid double (Balu 761 and the triple hybrid (2B688 stood out against the simple hybrid. For the character number of spikes per plant, the husked spike weight in kg the triple hybrid 2B688 stood in relation to other unfavorable conditions. Considering the character plant height and first spike insertion, single hibrid 30F90Y, showed higher estimate in unfavorable conditions. In conclusion, the agronomic performance of types of hybrids varies in relation to environmental conditions and genotypes composition, and in this study the triple hybrid stood out in relation to others. Keywords: Zea mays, fertilization and breeding.

  8. Radioresistance of experimentally-produced hybrid of Indian spinach (Beta palonga Basu and Mukherjee)

    International Nuclear Information System (INIS)

    Mukherjee, K.K.; Basu, R.K.

    1975-01-01

    An experimentally-produced hybrid between red and green plants of Beta palonga and the segregating population in F 2 showed more resistance to acute X-irradiation of seed than did their parents, as measured by seed germination, plant height, abnormal plant growth, chromosomal abnormality during meiosis and pollen grain sterility. In every measurement the F 2 plants were more sensitive than the F 1 hybrid. The radiosensitivity could not be interpreted in terms of average interphase chromosome volume. The resistance of the hybrid is suggested to be due to factors associated with heterozygosity and heterosis, although this has not been definately established. (author)

  9. Poaceae pollen as the leading aeroallergen worldwide: A review.

    Science.gov (United States)

    García-Mozo, H

    2017-12-01

    The Poaceae family comprises over 12 000 wind-pollinated species, which release large amounts of pollen into the atmosphere. Poaceae pollen is currently regarded as the leading airborne biological pollutant and the chief cause of pollen allergy worldwide. Sensitization rates vary by country, and those variations are reviewed here. Grass pollen allergens are grouped according to their protein structure and function. In Poaceae, although species belonging to different subfamilies are characterized by distinct allergen subsets, there is a considerable degree of cross-reactivity between many species. Cross-reactivity between grass pollen protein and fresh fruit pan-allergens is associated with the appearance of food allergies. The additional influence of urban pollution may prompt a more severe immunological response. The timing and the intensity of the pollen season are governed by species genetics, but plant phenology is also influenced by climate; as a result, climate changes may affect airborne pollen concentrations. This article reviews the findings of worldwide research which has highlighted the major impact of climate change on plant phenology and also on the prevalence and severity of allergic disease. © 2017 EAACI and John Wiley and Sons A/S. Published by John Wiley and Sons Ltd.

  10. Morphology and viability of castor bean genotypes pollen grains

    Directory of Open Access Journals (Sweden)

    Maria Selma Alves Silva Diamantino

    2016-01-01

    Full Text Available The objective of this work was to characterize the morphology and viability of the pollen of 15 genotypes of castor bean (Ricinus communis L. and to generate information that can assist in the selection of highly promising male parents for future use in genetic improvement programs aimed at producing seeds for oil extraction. Acetolysis and scanning electron microscopy was used to characterize the morphology of the pollen. The viability of the pollen grains was estimated by in vitro germination and colorimetric analysis (acetocarmine 2% and 2, 3, 5-triphenyltetrazolium chloride 1%. For the in vitro germination, pollen grains were grown in 10 types of solidified culture medium consisting of different concentrations of sucrose, boric acid, calcium nitrate, magnesium sulfate and potassium nitrate. The pollen grains had the following characteristics: medium size, isopolar and subspheroidal shape, radial symmetry, circular ambit, 3-colporate, elongated endoapertures, tectate exine and granulated sexine. The acetocarmine dye overestimated pollen viability. The media M5 and M8 were the most efficient at promoting the germination of pollen grains. The studied genotypes had high levels of viability and can therefore be used as male parents in genetic improvement programs.

  11. On the Relationship between Pollen Size and Genome Size

    Directory of Open Access Journals (Sweden)

    Charles A. Knight

    2010-01-01

    Full Text Available Here we test whether genome size is a predictor of pollen size. If it were, inferences of ancient genome size would be possible using the abundant paleo-palynolgical record. We performed regression analyses across 464 species of pollen width and genome size. We found a significant positive trend. However, regression analysis using phylogentically independent contrasts did not support the correlated evolution of these traits. Instead, a large split between angiosperms and gymnosperms for both pollen width and genome size was revealed. Sister taxa were not more likely to show a positive contrast when compared to deeper nodes. However, significantly more congeneric species had a positive trend than expected by chance. These results may reflect the strong selection pressure for pollen to be small. Also, because pollen grains are not metabolically active when measured, their biology is different than other cells which have been shown to be strongly related to genome size, such as guard cells. Our findings contrast with previously published research. It was our hope that pollen size could be used as a proxy for inferring the genome size of ancient species. However, our results suggest pollen is not a good candidate for such endeavors.

  12. Calcium in pollen-pistil interaction in 'Petunia hybrida Hor'. Pt. 1. Localization of Ca2+ ions in mature pollen grain using pyroantimonate and autoradiographic methods

    International Nuclear Information System (INIS)

    Bednarska, E.; Butowt, R.

    1994-01-01

    The localization of Ca 2+ in the mature pollen grain and the flow of these ions the somatic tissues of the anther to the pollen grains has been studied using pyroantimonate and autoradiographic methods. In the pollen grain, Ca 2+ ions have been localized in the sporoderm in the cytoplasmic vesicles of probably dictyosomal origin. Calcium ions were transported into the sporoderm together with the compounds of degenerating tapetum. The material of degenerating tapetum forms pollen coat surrounding the mature pollen grains. (author). 18 refs, 9 figs

  13. Fertilization in Flowering Plants

    Indian Academy of Sciences (India)

    ... for the right pollen,the pistil imposes a tough competition amongst them, comparableto a swayamvara of Indian mythology, to select the bestavailable pollen. Flowering plants have evolved into a matriarchalsociety. The selection of the male partner is totally theprerogative of the mother (pistil); the boy (pollen grain) andthe ...

  14. Pollen Dispersion Forecast At Regional Scale

    Science.gov (United States)

    Mangin, A.; Asthma Forecast System Team

    The forecast of the pollen concentration is generally based on an identification of sim- ilar coincidence of measured pollen at given points and meteorological data that is searched in an archive and which, with the help of experts, allows building a predicted value. This may be classified under the family of statistical approaches for forecast- ing. While palynologists make these methods more and more accurate with the help of innovative techniques of regression against empirical rules and/or evolving mathe- matical structures (e.g. neural networks), the spatial dispersion of the pollen is not or poorly considered, mainly because it requires a lot of means and technique that are not familiar to this scientific discipline. The research on pollen forecasts are presently mainly focused on the problematic of modeling the behavior of pollen trends and sea- sons at one location regardless of the topography, the locations of emitters, the relative strengths of emitter, in one word the Sspatial backgroundT. This research work was a & cedil;successful attempt to go a step further combining this SlocalT approach with a trans- & cedil;port/dispersion modeling allowing the access to mapping of concentration. The areas of interest that were selected for the demonstration of feasibility were 200x200km zones centered on Cordoba, Barcelona and Bologna and four pollen types were ex- amined, namely: Cupressaceae, Olea europaea, Poaceae and Parietaria. At the end of this three-year European project in December 2001, the system was fully deployed and validated. The multidisciplinary team will present the original methodologies that were derived for modeling the numerous aspects of this problem and also some con- clusions regarding potential extent to other areas and taxa.

  15. Bee pollen: a dangerous food for allergic children. Identification of responsible allergens.

    Science.gov (United States)

    Martín-Muñoz, M F; Bartolome, B; Caminoa, M; Bobolea, I; Ara, M C Garcia; Quirce, S

    2010-01-01

    Bee pollen has been proposed as a food supplement, but it can be a dangerous food for people with allergy. We study an allergic reaction after ingestion of bee pollen in a 4-year-old boy who had developed rhinitis in the last spring and autumn. We performed a prick-by-prick test with bee pollen and skin prick tests with the most important local pollens, house dust mites, common fungi, and animal danders. The levels of serum tryptase, serum total IgE and specific IgE against bee venom and local pollen extracts were determined. The composition of the bee pollen was analysed and SDS-PAGE immunoblotting and blotting-inhibition were carried out. Prick tests were positive to bee pollen and all local pollens extracts and negative to any other allergen sources. The bee pollen sample contained pollens from Quercus genus, and Asteraceae (Compositae) and Rosaceae families. Total IgE was 435 kU/l. Serum specific IgE to bee pollen was 6 kU/l and greater than 0.35 kU/L against pollens from Artemisia vulgaris, Taraxacum officinalis, Cupressus arizonica, Olea europaea, Platanus acerifolia and Lolium perenne as well as to n Art v 1 and other pollen marker allergens. Tryptase level was 3.5 mcg/mL. SDS-PAGE immunoblotting-inhibition points to Asteraceae pollen as the possible cause of the allergic reaction. Foods derived from bees can be dangerous to people with allergy to pollen. Copyright © 2009 SEICAP. Published by Elsevier Espana. All rights reserved.

  16. Vacuum storage of yellow-poplar pollen

    Science.gov (United States)

    James R. Wilcox

    1966-01-01

    Vacuum-drying, followed by storage in vacuo or in an inert gas, is effective for storing pollen of many species. It permits storage at room environments without rigid controls of either temperature or humidity, an advantage that becomes paramount during long-distance transfers of pollen when critical storage conditions are impossible to maintain. In...

  17. [Sensitization to Castanea sativa pollen and pollinosis in northern Extremadura (Spain)].

    Science.gov (United States)

    Cosmes Martín, P M; Moreno Ancillo, A; Domínguez Noche, C; Gutiérrez Vivas, A; Belmonte Soler, J; Roure Nolla, J M

    2005-01-01

    Castanea sativa pollen allergy has generally been considered to be uncommon and clinically insignificant. In our geographical area (Plasencia, Cáceres, Spain) Castanea sativa pollen is a major pollen. To determine the atmospheric fluctuations and prevalence of patients sensitized to Castanea pollen in our region and to compare this sensitization with sensitizations to other pollens. Patients with respiratory symptoms attending our outpatient clinic for the first time in 2003 were studied. The patients underwent skin prick tests with commercial extracts of a battery of inhalants including Castanea sativa pollen. Serologic specific IgE to Castanea sativa pollen was determined using the CAP system (Pharmacia and Upjohn, Uppsala, Sweden). Airborne pollen counts in our city were obtained using Cour collection apparatus over a 4-year period (2000 to 2003). The most predominant pollens detected were (mean of the maximal weekly concentrations over 4 years in pollen grains/m3): Quercus 968, Poacea 660, Olea 325, Platanus 229, Pinus 126, Cupresaceae 117, Plantago 109, Alnus 41, Populus 40, Castanea 32. We studied 346 patients (mean age: 24.1 years). In 210 patients with a diagnosis of pollinosis, the percentages of sensitization were: Dactylis glomerata 80.4%, Olea europea 71.9%, Fraxinus excelsior 68%, Plantago lanceolata 62.8%, Chenopodium album 60.9%, Robinia pseudoacacia 49%, Artemisia vulgaris 43.8%, Platanus acerifolia 36.6%, Parietaria judaica 36.1%, Populus nigra 32.3%, Betula alba 27.6%, Quercus ilex 21.4%, Alnus glutinosa 20.9%, Cupressus arizonica 7.6% and Castanea sativa 7.1%. Fifteen patients were sensitized to Castanea sativa and 14 had seasonal rhinoconjunctivitis and asthma. Ten patients had serum specific IgE to Castanea pollen (maximum value: 17.4 Ku/l). Castanea pollen is present in our area in large amounts from the 23rd to the 28th weeks of the year, with a peak pollen count in the 25th week. The most important allergenic pollens in northern Extremadura

  18. Aerobiology of Juniperus Pollen in Oklahoma, Texas, and New Mexico

    Science.gov (United States)

    Levetin, Estelle; Bunderson, Landon; VandeWater, Pete; Luvall, Jeff

    2014-01-01

    Pollen from members of the Cupressaceae are major aeroallergens in many parts of the world. In the south central and southwest United States, Juniperus pollen is the most important member of this family with J. ashei (JA) responsible for severe winter allergy symptoms in Texas and Oklahoma. In New Mexico, pollen from J. monosperma (JM) and other Juniperus species are important contributors to spring allergies, while J. pinchotii (JP) pollinates in the fall affecting sensitive individuals in west Texas, southwest Oklahoma and eastern New Mexico. Throughout this region, JA, JM, and JP occur in dense woodland populations. Generally monitoring for airborne allergens is conducted in urban areas, although the source for tree pollen may be forested areas distant from the sampling sites. Improved pollen forecasts require a better understanding of pollen production at the source. The current study was undertaken to examine the aerobiology of several Juniperus species at their source areas for the development of new pollen forecasting initiatives.

  19. Analysis of protein profile and pollen morphology of guaiacum officinale linn

    International Nuclear Information System (INIS)

    Zeb, S.

    2017-01-01

    Asthma and allergic rhinitis is triggered by the pollen of trees, grasses and weeds. Guaiacum officinale L. tree is widely cultivated along with the road side. This species was selected to check its allergenic role.Pollen morphology of Guaiacum officinale was examined by Light microsco4pe (LM) and Scanning electron microscope (SEM). Pollen grains of Guaiacum officinale were prolate shape, having tricolpate aperture, and rugulate tectum. Pollen protein concentration of G. officinale was determined by Bradford's assay and qualitative protein analysis of pollen was done by SDS-PAGE(Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis).Total protein content in the pollen extract was 24.28mg/g of pollen. The SDS-PAGE pollen grains protein analysis showed 07 different protein bands. The molecular weight of separated proteins ranged from 25 to 65kDa. Biochemical analysis of G. officinale pollen grains revealed the presence of low molecular weight proteins therefore it is strongly suggested that this species must be considered as a potent allergy causing species. This research would help for the proper diagnosis and treatment of the bronchial allergy suffering patients. (author)

  20. Pollen Biology of Ornamental Ginger (Hedychium spp. J. Koenig)

    Science.gov (United States)

    An improved in vitro pollen germination assay was developed to assess the viability of stored Hedychium pollen. The effect of polyethylene glycol (PEG) (10, 15, and 20% w/v) on pollen germination and tube growth was evaluated for H. longicornutum and two commercial Hedychium cultivars, ‘Orange Brush...

  1. Effect of smoke derivatives on in vitro pollen germination and pollen tube elongation of species from different plant families

    Czech Academy of Sciences Publication Activity Database

    Kumari, A.; Papenfus, H. B.; Kulkarni, M. G.; Pošta, Martin; van Staden, J.

    2015-01-01

    Roč. 17, č. 4 (2015), s. 825-830 ISSN 1435-8603 Institutional support: RVO:61388963 Keywords : karrikinolide * pollen germination * pollen tube growth * smoke-water * trimethylbutenolide Subject RIV: CC - Organic Chemistry Impact factor: 2.216, year: 2015

  2. Bee Pollen: Chemical Composition and Therapeutic Application

    Directory of Open Access Journals (Sweden)

    Katarzyna Komosinska-Vassev

    2015-01-01

    Full Text Available Bee pollen is a valuable apitherapeutic product greatly appreciated by the natural medicine because of its potential medical and nutritional applications. It demonstrates a series of actions such as antifungal, antimicrobial, antiviral, anti-inflammatory, hepatoprotective, anticancer immunostimulating, and local analgesic. Its radical scavenging potential has also been reported. Beneficial properties of bee pollen and the validity for their therapeutic use in various pathological condition have been discussed in this study and with the currently known mechanisms, by which bee pollen modulates burn wound healing process.

  3. Pollen morphology of the Onobrychis sect. Heliobrychis in Iran

    Directory of Open Access Journals (Sweden)

    Roya Karamian

    2010-01-01

    Full Text Available Pollen morphology of 20 species belonging to Onobrychis sect. Heliobrychis was studied in Iran. The pollen grains from the herbarium specimens were prepared by acetolysis method and then 8 quantitative characters were studied by light microscopy. Data analysis was carried out by cluster analysis and principal component analysis methods. Pollen grains of the sections were 3-colpate with reticulate ornamentation. Results of the study showed that although the pollen grains in the section were comparatively homogenous, but had a considerable variation in the studied quantitative characters. However among the studied characters, equatorial and polar diameters of pollen grains were the most significant characters. The members of the section can be divided into 3 groups based on these characters.

  4. Effect of self-pollination monitored by microsatellite markers on maize kernel weight

    Directory of Open Access Journals (Sweden)

    Marcio Balestre

    2007-01-01

    Full Text Available The objective of this study was to evaluate the effect of fertilization by autopollen on maize kernel weight. Fivesingle cross hybrids (30F90. A2555, DKB333B, 2223, and 2324 were planted and hybrid leaf samples taken for DNAextraction. The crosses 2223XDKB333B; 2223XA2555; 2324XDKB333B and 2324XP30F90 were performed. Ten kernels ofeach ear of each cross were separated, sown in a greenhouse and the DNA of the respective seedlings was extracted, to identifythe kernel origin. The results obtained here demonstrated that allopollen increased the mean kernel weight by 16.5mg (gainof 4.65%. The proportion of sampled allopollen to self pollen was statistically equal, according to the c2 test, demonstratingthat there were no significant differences between the proportion of fertilized and sampled allopollen and autopollen in the ear.It was concluded that compared to autopollen, allopollen increases the mean weight of fertilized grain.

  5. The tokamak hybrid reactor

    International Nuclear Information System (INIS)

    Kelly, J.L.; Rose, R.P.

    1981-01-01

    At a time when the potential benefits of various energy options are being seriously evaluated in many countries through-out the world, it is both timely and important to evaluate the practical application of fusion reactors for their economical production of nuclear fissile fuels from fertile fuels. The fusion hybrid reactor represents a concept that could assure the availability of adequate fuel supplies for a proven nuclear technology and have the potential of being an electrical energy source as opposed to an energy consumer as are the present fuel enrichment processes. Westinghouse Fusion Power Systems Department, under Contract No. EG-77-C-02-4544 with the Department of Energy, Office of Fusion Energy, has developed a preliminary conceptual design for an early twenty-first century fusion hybrid reactor called the commercial Tokamak Hybrid Reactor (CTHR). This design was developed as a first generation commercial plant producing fissile fuel to support a significant number of client Light Water Reactor (LWR) Plants. To the depth this study has been performed, no insurmountable technical problems have been identified. The study has provided a basis for reasonable cost estimates of the hybrid plants as well as the hybrid/LWR system busbar electricity costs. This energy system can be optimized to have a net cost of busbar electricity that is equivalent to the conventional LWR plant, yet is not dependent on uranium ore prices or standard enrichment costs, since the fusion hybrid can be fueled by numerous fertile fuel resources. A nearer-term concept is also defined using a beam driven fusion driver in lieu of the longer term ignited operating mode. (orig.)

  6. In vitro pollen germination of five citrus species

    International Nuclear Information System (INIS)

    Khan, S.A.; Perveen, A.

    2014-01-01

    The aim of present study is In vitro germination of the pollen grains of five Citrus species belonging to the family Rutaceae viz., Citrus aurantium L. var., aurantium Hook.f., C. limon (L.) Brum. f., C. paradisii Macfad, C. reticulata Blanco and C. sinensis (L.) Osbeck. using hanging drop technique. The germination was checked up to 48 weeks, for the pollen stored at different temperatures like 4 degree C, -20 degree C, -30 degree C and -60 degree C. The study indicates that low temperature and low relative humidity is better than high temperature and humidity with respect to pollen germination capacity and viability. Freeze dryer (-60 degree C) seems to be the best method to maintain pollen viability of stored pollen grains for a long period of time. Among five species Citrus aurantium, C. limon and C. sinensis showed high percentage of germination as compared to C. reticulata and C. paradisii. (author)

  7. Evaluation of the botanical origin of commercial dry bee pollen load batches using pollen analysis: a proposal for technical standardization

    Directory of Open Access Journals (Sweden)

    Ortrud M. Barth

    2010-12-01

    Full Text Available High quality of bee pollen for commercial purpose is required. In order to attend the consumer with the best identification of the botanical and floral origin of the product, 25 bee pollen batches were investigated using two techniques of pollen grain preparation. The first started to identify pollen loads of different colors in two grams of each well mixed batch, and the second to identify pollen grains in a pool made of all the pollen loads comprised in two grams. The best result was obtained by this last technique, when a pollen grain suspension was dropped on a microscope slide and circa 500 pollen grains were counted per sample. This analysis resulted in the recognition of monofloral and bifloral pollen batches, while the use of the first technique resulted in all samples receiving a heterofloral diagnosis.É exigida alta qualidade para a comercialização de pólen apícola. A fim de atender o consumidor com a melhor identificação da origem botânica e floral do produto, 25 partidas de pólen apícola feram investigadas usande duas diferentes técnicas na preparação dos grãos de pólen. A primeira partiu da identificação das cargas polínicas contidas em dois gramas de cada partida bem misturada segundo suas cores. A segunda visava identificar os grãos de pólen de um agrupamento ("pool" de todas as cargas polínicas contidas em dois gramas de cada amostra. O melhor resultado foi obtido pela última técnica, quando uma suspensão de grãos de pólen era gotejada sobre uma lâmina de microscopia e cerca de 500 grãos de pólen eram centades por amostra. Esta análise resultou no reconhecimento de partidas monoflorais e biflorais de pólen apícola, enquanto que usando a primeira técnica, todas as amostras receberam a diagnose heterefloral.

  8. Response of sunflower hybrids to management practices under ...

    African Journals Online (AJOL)

    user

    2011-04-04

    Apr 4, 2011 ... sunflower (Helianthus annuus L.) and canola (Brassica napus L.), etc. The total edible oil ... hybrids with high fertilizer requirements. The farmers are applying ... Crop growth and productivity can be discussed in terms of biomass ... the interactive effects of hybrids, planting geometries and nitrogen rates on ...

  9. Atmospheric conditions during high ragweed pollen concentrations in Zagreb, Croatia

    Science.gov (United States)

    Prtenjak, Maja Telišman; Srnec, Lidija; Peternel, Renata; Madžarević, Valentina; Hrga, Ivana; Stjepanović, Barbara

    2012-11-01

    We examined the atmospheric conditions favourable to the occurrence of maximum concentrations of ragweed pollen with an extremely high risk of producing allergy. Over the 2002-2009 period, daily pollen data collected in Zagreb were used to identify two periods of high pollen concentration (> 600 grains/m3) for our analysis: period A (3-4 September 2002) and period B (6-7 September 2003). Synoptic conditions in both periods were very similar: Croatia was under the influence of a lower sector high pressure system moving slowly eastward over Eastern Europe. During the 2002-2009 period, this type of weather pattern (on ~ 70% of days), in conjunction with almost non-gradient surface pressure conditions in the area (on ~ 30% of days) characterised days when the daily pollen concentrations were higher than 400 grains/m3. Numerical experiments using a mesoscale model at fine resolution showed successful multi-day simulations reproducing the local topographic influence on wind flow and in reasonable agreement with available observations. According to the model, the relatively weak synoptic flow (predominantly from the eastern direction) allowed local thermal circulations to develop over Zagreb during both high pollen episodes. Two-hour pollen concentrations and 48-h back-trajectories indicated that regional-range transport of pollen grains from the central Pannonian Plain was the cause of the high pollen concentrations during period A. During period B, the north-westward regional-range transport in Zagreb was supplemented significantly by pronounced horizontal recirculation of pollen grains. This recirculation happened within the diurnal local circulation over the city, causing a late-evening increase in pollen concentration.

  10. Grass pollen symptoms interfere with the recollection of birch pollen symptoms - a prospective study of suspected, asymptomatic skin sensitization

    DEFF Research Database (Denmark)

    Assing, K; Bødtger, Uffe; Poulsen, L K

    2007-01-01

    of seasonal allergic symptoms and prospective seasonal symptom registration among subjects with AS. METHODS: On the basis of a population survey, autumn 2002, including skin prick tests (positive if > or =3 mm) and a screening questionnaire, 87 subjects with AS to birch and/or grass pollen, birch and/or grass...... days. RESULTS: Eleven AS subjects (birch: n = 10) subsequently developed allergic symptoms, yet nine admitted, at follow up, to have had symptoms before inclusion, or even denied pollen-related symptoms despite a significant diary. Compared with AS subjects sensitized to grass pollen, AS subjects...

  11. Spatial variability in airborne pollen concentrations.

    Science.gov (United States)

    Raynor, G S; Ogden, E C; Hayes, J V

    1975-03-01

    Tests were conducted to determine the relationship between airborne pollen concentrations and distance. Simultaneous samples were taken in 171 tests with sets of eight rotoslide samplers spaced from one to 486 M. apart in straight lines. Use of all possible pairs gave 28 separation distances. Tests were conducted over a 2-year period in urban and rural locations distant from major pollen sources during both tree and ragweed pollen seasons. Samples were taken at a height of 1.5 M. during 5-to 20-minute periods. Tests were grouped by pollen type, location, year, and direction of the wind relative to the line. Data were analyzed to evaluate variability without regard to sampler spacing and variability as a function of separation distance. The mean, standard deviation, coefficient of variation, ratio of maximum to the mean, and ratio of minimum to the mean were calculated for each test, each group of tests, and all cases. The average coefficient of variation is 0.21, the maximum over the mean, 1.39 and the minimum over the mean, 0.69. No relationship was found with experimental conditions. Samples taken at the minimum separation distance had a mean difference of 18 per cent. Differences between pairs of samples increased with distance in 10 of 13 groups. These results suggest that airborne pollens are not always well mixed in the lower atmosphere and that a sample becomes less representative with increasing distance from the sampling location.

  12. Dose-response relationship of a new Timothy grass pollen allergoid in comparison with a 6-grass pollen allergoid.

    Science.gov (United States)

    Pfaar, O; Hohlfeld, J M; Al-Kadah, B; Hauswald, B; Homey, B; Hunzelmann, N; Schliemann, S; Velling, P; Worm, M; Klimek, L

    2017-11-01

    Subcutaneous allergen immunotherapy with grass pollen allergoids has been proven to be effective and safe in the treatment of patients with allergic rhinoconjunctivitis. Based on the extensive cross-reactivity among Pooideae species, it has been suggested that grass pollen extracts could be prepared from a single species, rather than from a multiple species mixture. To find the optimal dose of a Phleum pratense (P. pratense) allergoid preparation and compare its efficacy and safety to a 6-grass pollen allergoid preparation. In this double-blind, placebo-controlled study (EudraCT: 2011-000674-58), three doses of P. pratense allergoid (1800 therapeutic units (TU), standard-dose 6000 TU and 18 000 TU) were compared with placebo and the marketed 6-grass pollen allergoid (6000 TU). In a pre-seasonal dosing regimen, 102 patients were randomized to five treatment groups and received nine subcutaneous injections. The primary efficacy endpoint was the change in weal size (late-phase reaction [LPR]) in response to the intracutaneous testing (ICT) before and after treatment, comparing the active allergoids to placebo. Secondary outcomes were the change in Total Nasal Symptom Score (TNSS) assessed in the allergen exposure chamber (AEC), the changes in P. pratense-serum-specific IgG 4 and the incidence of adverse events (AEs). All three doses of the P. pratense and the 6-grass pollen allergoid preparations were significantly superior to placebo for the primary outcome, whereas there were no significant differences in the change in TNSS. Compared to the standard-dose, the high-dose of P. pratense did not produce any additional significant benefit, but showed a slight increase in AEs. Yet this increase in AEs was lower than for the 6-grass pollen preparation. The standard-dose of the new P. pratense allergoid was comparable to the marketed 6-grass pollen preparation at equal dose for the parameters measured. © 2017 The Authors. Clinical & Experimental Allergy Published by John

  13. Pollen diversity, viability and floral structure of some Musa genotypes

    African Journals Online (AJOL)

    Pollen diversity, viability and floral structure of some Musa genotypes. ... This experiment was designed to study the floral structure, pollen morphology and the potential pollen viability of five Musa genotypes obtained ... HOW TO USE AJOL.

  14. CHEMICAL COMPOSITION OF MUSCLE AFTER POLLEN APPLICATION IN NUTRITION OF BROILER CHICKENS

    Directory of Open Access Journals (Sweden)

    Vladimíra Kňazovická

    2012-04-01

    Full Text Available Normal 0 21 false false false SK X-NONE X-NONE Principle purpose of this study was to monitor the chemical composition of breast and thigh muscular part of chickens of hybrid combination Ross 308 and to verify the differences due to use of pollen extract in feed mixture at a dose of 400 and 800 mg.kg-1 during the feeding of 42 days. We did not find significant differences (P≥0.05 in followed chemical compounds of thigh muscle with the skin and subcutaneous fat between the groups with and without application of pollen extract: in contents of water (68.49-70.12 g.100g-1, protein (18.82-18.98 g.100g-1, fat (9.96-11.53 g.100g-1 and in energy value (692.20-752.36 kJ.100g-1. Significant differences (P≤0.05 were found only in protein content of breast muscle between the control group (23.96 g.100g-1 and experimental group I (23.28 g.100g-1. Values of water content (73.97-74.32 g.100g-1, fat content (1.07-1.40 g.100g-1 and energy (441.65-446.64 kJ.100g-1 in breast muscle between the evaluated groups were balanced (P≥0.05. The results show that pollen extract at the concentration used in feed mixture did not effect basic chemical composition of the most valuable parts of the chicken Ross 308 carcass and we can apply it in their nutrition. Application at a dose of 800 mg.kg-1 seems to be more positive.doi:10.5219/190

  15. Microwave-Assisted Drying for the Conservation of Honeybee Pollen

    Directory of Open Access Journals (Sweden)

    Angelo Canale

    2016-05-01

    Full Text Available Bee pollen is becoming an important product thanks to its nutritional properties, including a high content of bioactive compounds such as essential amino acids, antioxidants, and vitamins. Fresh bee pollen has a high water content (15%–30% wt %, thus it is a good substrate for microorganisms. Traditional conservation methods include drying in a hot air chamber and/or freezing. These techniques may significantly affect the pollen organoleptic properties and its content of bioactive compounds. Here, a new conservation method, microwave drying, is introduced and investigated. The method implies irradiating the fresh pollen with microwaves under vacuum, in order to reduce the water content without reaching temperatures capable of thermally deteriorating important bioactive compounds. The method was evaluated by taking into account the nutritional properties after the treatment. The analyzed parameters were phenols, flavonoids, with special reference to rutin content, and amino acids. Results showed that microwave drying offers important advantages for the conservation of bee pollen. Irrespective of microwave power and treatment time, phenol and flavonoid content did not vary over untreated fresh pollen. Similarly, rutin content was unaffected by the microwave drying, suggesting that the microwave-assisted drying could be a powerful technology to preserve bioprotective compounds in fresh pollen.

  16. Therapeutic effect of bee pollens on acute radiation sickness

    International Nuclear Information System (INIS)

    Wang Mingsuo; Huang Chaoqun; Chen Zhen; Huang Meiying; Jiang Ying; Wang Tao

    1997-09-01

    The therapeutic effect of bee pollens on acute radiation sickness were evaluated by observing the changes in the peripheral white blood cell (PWBC) count, the total activity of superoxide dismutase (SOD) and the levels of lipid peroxides (LPO) in sera of the irradiated rats following P.O. administration of bee pollens. It was found that bee pollens could remarkably help irradiated rats recover from radiation-induced injury. The functions of bee pollens might be summarized as follows: (1) Stimulating Proliferation of PWBC. The PWBC count of the bee pollens group showed no significant difference as compared with the normal control group on the 30 th day postirradiation. (2) Enhancing antioxidative effect of clearing free radicals. The total activity of serum SOD in the bee pollens group increased by 6.48% as compared with the normal control group on the 30 th day after irradiation, and the LPO levels i.e. MDA and POV in sera of the irradiated rats decreased by 54.73% and 21.60% respectively. The result suggests that using bee pollens as antiradiation and health-promoting agents in clinical treatment of acute radiation sickness and during radiotherapy of patients with tumors may has certain practical value. (12 refs., 2 figs., 2 tabs.)

  17. [Does a lateral gradient of membrane potential on the plasma membrane of growing pollen tube of germinating pollen grain exist?].

    Science.gov (United States)

    Andreev, I M

    2011-01-01

    The data presented in the article by Breigina et al. (2009) "Changes in the membrane potential during pollen grain germination and pollen tube growth" (Tsitologiya. 51 (10): 815-823) and concerning the measurement of electric membrane potential (Delta Psi) on the plasma membrane of growing pollen tube of germinating pollen grain with the use of fluorescent potential-sensitive dye, di-4-ANEPPS, were critically analyzed in order to clarify whether a lateral gradient of Delta Psi on this membrane indeed exists. This analysis showed that the main conclusion of the authors of the above article on the existence of polar distribution of Delta Psi along the pollen tube plasma membrane is not in accordance with a number of known peculiarities of di-4-ANEPPS behavior in biological membranes and requires a significant revision. The findings in question reported by the authors, in my opinion, might be interpreted as evidence for the presence on the plasma membrane of growing pollen tube not only the membrane potential Delta Psi but also lateral gradient of so called intra-membrane dipole potential. Based on the comments made, another interpretation of the experimental results described by Breigina et al. has been offered. In addition, some drawbacks in the methodology used by the authors for measurement of Delta Psi with other fluorescent potential-sensitive dye, DiBAC3(3), are also shortly considered.

  18. Some problems of using irradiated pollen in genetics and selection of winter soft wheat (Triticum acstivum)

    International Nuclear Information System (INIS)

    Bovkis, E.N.

    1978-01-01

    For the first time the mutagenous efficiency of gamma-irradiation of male gametes(pollen) for genetic and selection purposes has been studied using three sorts of winter wheat. It is shown, that a critical irradiation dose for soft wheat in respect of degree of reducing the mass of 1000 grains and survive is 2.0 krad. Application of irradiated pollen results in a wide spectrum of mutagenous changeability, at that, one part of forms remains constant and the other is splitted according to the type of intraspecific hybrids. Pollen irradiation doses are grounded to produce mutants having some important selection features. Irradiation doses from 0.25 to 0.5 krad are most effective to produce mutants with productive ears and from 1.0 to 1.5 krad to produce short-stem ones. More than 80 mutants are studied in respect of productivity and other indications in a control nursery. Combination productivity value of some short-stem mutants has been studied; it is shown, that as a rule it is preserved at the level of initial sorts. The use of historical method for understanding the regularities of mutant appearance is of great theoretical interest during the investigations. It has been established, that mutants relating to different varieties appear with unequal frequency, which, possibly, is due to the species genotype

  19. A fertilidade do polen e sua correlação com o número de sementes, em espécies e formas do gênero citrus

    Directory of Open Access Journals (Sweden)

    Sílvio Moreira

    1941-12-01

    Full Text Available 1 - The present paper deals with the results of studies on pollen fertility, number of seeds per fruit and frequency of polyembryony in Citrus. 2 - The pollen may be divided into four groups of which the first consists of the living and functional grains, colouring deeply with carmín acetic, germinating in sugar solutions fairly well. The remainny three types : half filled grains, empty grains, and small deformed grains are all inviable. 3 - The grains are generally spherical, 15 to 40ix in diameter. The smallest grains were found in Citrus hystrix and Citrus mitis (fig. 3 and 4, while citron and the grape-fruits have the largest grains (fig. 1, 2 and 5. 4 - Size and form are reasonably constant, except the hybrid "Citran-gequat", "limão galego" without spines, orange "Ruby" (fig. 6 to 8. 5 - Percentages of viable pollen grains are given in quadros IV to X. Tahiti Lime, probably a triploid, is completely sterile. "Baía" orange (Washington Navel orange is completely male sterile, while the fruits of it may have some seeds. The two seedless varieties of "lima" and "pera" have 37,1 and 9,3% of viable pollen respectively. Regarding pollen viability oranges are the most variable. They show from 0 to 90% of good pollen (quadros IV and V. In lemons and limes the percentages vary from 50% and 80% (quadros VI to VIII. Tangerines, with exception of Satsuma owari, have generally more than 60% of good pollen. The grape-fruits, except the case of "Marsh-seedless", are characterized by a relative high pollen fertility. 6 - There is a certain variation of pollen fertility due to the external conditions. It seems to exist also a certain effect of the rootstock, on viability of pollen grains, as shown for the rootstock of "sour orange" and "rough lemon". 7 - The number of seeds per fruit was also determined and is given in the respective quadros (IV-X. 8 - There does not exist any consistent difference between open pollinated and selfed flowers in regard to

  20. Mycobiota and mycotoxins in bee pollen collected from different areas of Slovakia.

    Science.gov (United States)

    Kačániová, Miroslava; Juráček, Miroslav; Chlebo, Róbert; Kňazovická, Vladimíra; Kadasi-Horáková, Miriam; Kunová, Simona; Lejková, Jadža; Haščík, Peter; Mareček, Ján; Simko, Milan

    2011-01-01

    Contamination by microscopic fungi and mycotoxins in different bee pollen samples, which were stored under three different ways of storing as freezing, drying and UV radiation, was investigated. During spring 2009, 45 samples of bee-collected pollen were gathered from beekeepers who placed their bee colonies on monocultures of sunflower, rape and poppy fields within their flying distance. Bee pollen was collected from bees' legs by special devices placed at the entrance to hives. Samples were examined for the concentration and identification of microscopic fungi able to grow on Malt and Czapek-Dox agar and mycotoxins content [deoxynivalenol (DON), T-2 toxin (T-2), zearalenone (ZON) and total aflatoxins (AFL), fumonisins (FUM), ochratoxins (OTA)] by direct competitive enzyme-linked immunosorbent assays (ELISA). The total number of microscopic fungi in this study ranged from 2.98 ± 0.02 in frozen sunflower bee pollen to 4.06 ± 0.10 log cfu.g(-1) in sunflower bee pollen after UV radiation. In this study, 449 isolates belonging to 21 fungal species representing 9 genera were found in 45 samples of bee pollen. The total isolates were detected in frozen poppy pollen 29, rape pollen 40, sunflower pollen 80, in dried poppy pollen 12, rape pollen 36, sunflower 78, in poppy pollen after UV radiation treatment 54, rape 59 and sunflower 58. The most frequent isolates of microscopic fungi found in bee pollen samples of all prevalent species were Mucor mucedo (49 isolates), Alternaria alternata (40 isolates), Mucor hiemalis (40 isolates), Aspergillus fumigatus (33 isolates) and Cladosporium cladosporioides (31 isolates). The most frequently found isolates were detected in sunflower bee pollen frozen (80 isolates) and the lowest number of isolates was observed in poppy bee pollen dried (12 isolates). The most prevalent mycotoxin of poppy bee pollen was ZON (361.55 ± 0.26 μg.kg(-1)), in rape bee pollen T-2 toxin (265.40 ± 0.18 μg.kg(-1)) and in sunflower bee pollen T-2 toxin

  1. Rapid male-specific regulatory divergence and down regulation of spermatogenesis genes in Drosophila species hybrids.

    Directory of Open Access Journals (Sweden)

    Jennifer Ferguson

    Full Text Available In most crosses between closely related species of Drosophila, the male hybrids are sterile and show postmeiotic abnormalities. A series of gene expression studies using genomic approaches have found significant down regulation of postmeiotic spermatogenesis genes in sterile male hybrids. These results have led some to suggest a direct relationship between down regulation in gene expression and hybrid sterility. An alternative explanation to a cause-and-effect relationship between misregulation of gene expression and male sterility is rapid divergence of male sex regulatory elements leading to incompatible interactions in an interspecies hybrid genome. To test the effect of regulatory divergence in spermatogenesis gene expression, we isolated 35 fertile D. simulans strains with D. mauritiana introgressions in either the X, second or third chromosome. We analyzed gene expression in these fertile hybrid strains for a subset of spermatogenesis genes previously reported as significantly under expressed in sterile hybrids relative to D. simulans. We found that fertile autosomal introgressions can cause levels of gene down regulation similar to that of sterile hybrids. We also found that X chromosome heterospecific introgressions cause significantly less gene down regulation than autosomal introgressions. Our results provide evidence that rapid male sex gene regulatory divergence can explain misexpression of spermatogenesis genes in hybrids.

  2. Pollen aroma fingerprint of two sunflower (Helianthus annuus L.) genotypes characterized by different pollen colors.

    Science.gov (United States)

    Bertoli, Alessandra; Fambrini, Marco; Doveri, Silvia; Leonardi, Michele; Pugliesi, Claudio; Pistelli, Luisa

    2011-09-01

    Samples of fresh pollen grains, collected from capitula in full bloom from two genotypes of sunflower (Helianthus annuus L.) and characterized by a different color, i.e., white-cream (WC) and orange (O), were analyzed by the HS-SPME (headspacesolid phase microextraction)/GC/MS technique. This study defined for the first time the fingerprint of the sunflower pollen, separated from the disc flowers, to define its contribution to the inflorescence aroma. In the GC/MS fingerprints of the WC and O genotypes, 61 and 62 volatile compounds were identified, respectively. Monoterpene hydrocarbons (34% in O vs. 28% in WC) and sesquiterpene hydrocarbons (37% in O vs. 31% in WC) were ubiquitous in all samples analyzed and represented the main chemical classes. α-Pinene (21% in O vs. 20% in WC) and sabinene (11% in O vs. 6% in WC) were the dominant volatiles, but also a full range of aliphatic hydrocarbons and their oxygenated derivatives gave a decisive contribution to the aroma composition (10% in O vs. 12% in WC). In addition, dendrolasin (3% in O vs. 4% in WC) and some minor constituents such as (E)-hex-2-en-1-ol (0.4% in O vs. 0.1% in WC) were pointed out not only for their contribution to the pollen scent, but also for their well-known role in the plant ecological relationships. Having evaluated two pollen morphs with different carotenoid-based colors, the study sought to highlight also the presence of some volatile precursors or derivatives of these pigments in the aroma. However, the pollen aroma of the two selected genotypes made a specific chemical contribution to the sunflower inflorescence scent without any influence on carotenoid derivatives. 2011 Verlag Helvetica Chimica Acta AG, Zürich.

  3. A DNA barcoding approach to characterize pollen collected by honeybees.

    Directory of Open Access Journals (Sweden)

    Andrea Galimberti

    Full Text Available In the present study, we investigated DNA barcoding effectiveness to characterize honeybee pollen pellets, a food supplement largely used for human nutrition due to its therapeutic properties. We collected pollen pellets using modified beehives placed in three zones within an alpine protected area (Grigna Settentrionale Regional Park, Italy. A DNA barcoding reference database, including rbcL and trnH-psbA sequences from 693 plant species (104 sequenced in this study was assembled. The database was used to identify pollen collected from the hives. Fifty-two plant species were identified at the molecular level. Results suggested rbcL alone could not distinguish among congeneric plants; however, psbA-trnH identified most of the pollen samples at the species level. Substantial variability in pollen composition was observed between the highest elevation locality (Alpe Moconodeno, characterized by arid grasslands and a rocky substrate, and the other two sites (Cornisella and Ortanella at lower altitudes. Pollen from Ortanella and Cornisella showed the presence of typical deciduous forest species; however in samples collected at Ortanella, pollen of the invasive Lonicera japonica, and the ornamental Pelargonium x hortorum were observed. Our results indicated pollen composition was largely influenced by floristic local biodiversity, plant phenology, and the presence of alien flowering species. Therefore, pollen molecular characterization based on DNA barcoding might serve useful to beekeepers in obtaining honeybee products with specific nutritional or therapeutic characteristics desired by food market demands.

  4. Pollen loads and specificity of native pollinators of lowbush blueberry.

    Science.gov (United States)

    Moisan-Deserres, J; Girard, M; Chagnon, M; Fournier, V

    2014-06-01

    The reproduction of lowbush blueberry (Vaccinium angustifolium Aiton) is closely tied to insect pollination, owing to self-incompatibility. Many species are known to have greater pollination efficiency than the introduced Apis mellifera L., commonly used for commercial purposes. In this study, we measured the pollen loads of several antophilous insect species, mostly Apoidea and Syrphidae, present in four lowbush blueberry fields in Lac-St-Jean, Québec. To measure pollen loads and species specificity toward V. angustifolium, we net-collected 627 specimens of pollinators, retrieved their pollen loads, identified pollen taxa, and counted pollen grains. We found that the sizes of pollen loads were highly variable among species, ranging from a few hundred to more than 118,000 pollen grains per individual. Bombus and Andrena species in particular carried large amounts of Vaccinium pollen and thus may have greater pollination efficiency. Also, two species (Andrena bradleyi Viereck and Andrena carolina Viereck) showed nearly monolectic behavior toward lowbush blueberry. Finally, we identified alternative forage plants visited by native pollinators, notably species of Acer, Rubus, Ilex mucronata, Ledum groenlandicum, and Taraxacum. Protecting these flowering plants should be part of management practices to maintain healthy pollinator communities in a lowbush blueberry agroecosystem.

  5. Overexpression of the tomato pollen receptor kinase LePRK1 rewires pollen tube growth to a blebbling mode

    Science.gov (United States)

    The tubular growth of a pollen tube cell is crucial for the sexual reproduction of flowering plants. LePRK1 is a pollen-specific and plasma membrane–localized receptor-like kinase from tomato (Solanum lycopersicum). LePRK1 interacts with another receptor, LePRK2, and with KINASE PARTNER PROTEIN (KPP...

  6. Evaluation of pollen dispersal and cross pollination using transgenic grapevine plants.

    Science.gov (United States)

    Harst, Margit; Cobanov, Beatrix-Axinja; Hausmann, Ludger; Eibach, Rudolf; Töpfer, Reinhard

    2009-01-01

    Public debate about the possible risk of genetically modified plants often concerns putative effects of pollen dispersal and out-crossing into conventional fields in the neighborhood of transgenic plants. Though Vitis vinifera (grapevine) is generally considered to be self-pollinating, it cannot be excluded that vertical gene transfer might occur. For monitoring pollen flow and out-crossing events, transgenic plants of Vitis vinifera cv. 'Dornfelder' harboring the gus-int gene were planted in the center of a field experiment in Southwest Germany in 1999. The rate of pollen dispersal was determined by pollen traps placed at radial distances of 5-150 m from the pollen-donor plants, at 1.00 and 1.80 m above ground. Transgenic pollen was evaluated by GUS staining, and could clearly be distinguished from pollen originating from non-transgenic grapevine plants. Transgenic pollen was observed up to 150 m from the pollen donors. The rate of out-crossing was determined by sampling seeds of selected grapevines at a distance of 10 m to the pollen source, and of a sector at 20 m distance, respectively, followed by GUS analysis of seedlings. The average cross-pollination rate during the experiment (2002-2004) was 2.7% at a distance of 20 m. The results of this first pilot study present a good base for further assessment under the conditions of normal viticulture practice.

  7. Calcium in pollen-pistil interaction in `Petunia hybrida Hor`. Pt. 1. Localization of Ca{sup 2+} ions in mature pollen grain using pyroantimonate and autoradiographic methods

    Energy Technology Data Exchange (ETDEWEB)

    Bednarska, E.; Butowt, R. [Uniwersytet Mikolaja Kopernika, Torun (Poland)

    1994-12-31

    The localization of Ca{sup 2+} in the mature pollen grain and the flow of these ions the somatic tissues of the anther to the pollen grains has been studied using pyroantimonate and autoradiographic methods. In the pollen grain, Ca{sup 2+} ions have been localized in the sporoderm in the cytoplasmic vesicles of probably dictyosomal origin. Calcium ions were transported into the sporoderm together with the compounds of degenerating tapetum. The material of degenerating tapetum forms pollen coat surrounding the mature pollen grains. (author). 18 refs, 9 figs.

  8. Climate Change and Future Pollen Allergy in Europe.

    Science.gov (United States)

    Lake, Iain R; Jones, Natalia R; Agnew, Maureen; Goodess, Clare M; Giorgi, Filippo; Hamaoui-Laguel, Lynda; Semenov, Mikhail A; Solomon, Fabien; Storkey, Jonathan; Vautard, Robert; Epstein, Michelle M

    2017-03-01

    Globally, pollen allergy is a major public health problem, but a fundamental unknown is the likely impact of climate change. To our knowledge, this is the first study to quantify the consequences of climate change upon pollen allergy in humans. We produced quantitative estimates of the potential impact of climate change upon pollen allergy in humans, focusing upon common ragweed ( Ambrosia artemisiifolia ) in Europe. A process-based model estimated the change in ragweed's range under climate change. A second model simulated current and future ragweed pollen levels. These findings were translated into health burdens using a dose-response curve generated from a systematic review and from current and future population data. Models considered two different suites of regional climate/pollen models, two greenhouse gas emissions scenarios [Representative Concentration Pathways (RCPs) 4.5 and 8.5], and three different plant invasion scenarios. Our primary estimates indicated that sensitization to ragweed will more than double in Europe, from 33 to 77 million people, by 2041-2060. According to our projections, sensitization will increase in countries with an existing ragweed problem (e.g., Hungary, the Balkans), but the greatest proportional increases will occur where sensitization is uncommon (e.g., Germany, Poland, France). Higher pollen concentrations and a longer pollen season may also increase the severity of symptoms. Our model projections were driven predominantly by changes in climate (66%) but were also influenced by current trends in the spread of this invasive plant species. Assumptions about the rate at which ragweed spreads throughout Europe had a large influence upon the results. Our quantitative estimates indicate that ragweed pollen allergy will become a common health problem across Europe, expanding into areas where it is currently uncommon. Control of ragweed spread may be an important adaptation strategy in response to climate change. Citation: Lake IR

  9. Analysis of IgE binding proteins of mesquite (Prosopis juliflora) pollen and cross-reactivity with predominant tree pollens.

    Science.gov (United States)

    Dhyani, Anamika; Arora, Naveen; Gaur, Shailendra N; Jain, Vikram K; Sridhara, Susheela; Singh, Bhanu P

    2006-01-01

    Pollen from the mesquite tree, Prosopis juliflora, is an important source of respiratory allergy in tropical countries. Our aim was to partially characterize the IgE binding proteins of P. juliflora pollen extract and study cross-reactivity with prevalent tree pollen allergens. Intradermal tests with P. juliflora and five other tree pollen extracts were performed on respiratory allergy patients from Bikaner (arid) and Delhi (semi arid). Prosopis extract elicited positive skin reactions in 71/220 of the patients. Sera were collected from 38 of these 71 patients and all demonstrated elevated specific IgE to P. juliflora. Immunoblotting with pooled patients' sera demonstrated 16 IgE binding components, with components of 24, 26, 29, 31, 35, 52, 58, 66 and 95 kDa recognized by more than 80% of individual patients' sera. P. juliflora extract is allergenically potent requiring 73 ng of self-protein for 50% inhibition of IgE binding in ELISA inhibition. Cross-inhibition assays showed close relationship among P. juliflora, Ailanthus excelsa, Cassia siamea and Salvadora persica. IgE binding components of 14, 41, 52 and 66 kDa were shared allergens whereas 26 and 29 kDa were specific to P. juliflora. The findings suggest that purification of cross-reactive allergens will be helpful for diagnosis and immunotherapy of tree pollen allergic patients.

  10. Analysis of [Gossypium capitis-viridis × (G.hirsutum × G.australe2] Trispecific Hybrid and Selected Characteristics.

    Directory of Open Access Journals (Sweden)

    Di Chen

    Full Text Available Speciation is always a contentious and challenging issue following with the presence of gene flow. In Gossypium, there are many valuable resources and wild diploid cotton especially C and B genome species possess some excellent traits which cultivated cotton always lacks. In order to explore character transferring rule from wild cotton to upland tetraploid cotton, the [G. capitis-viridis × (G. hirsutum × G. australe2] triple hybrid was synthesized by interspecies hybridization and chromosome doubling. Morphology comparisons were measured among this hybrid and its parents. It showed that trispecific hybrid F1 had some intermediate morphological characters like leaf style between its parents and some different characters from its parents, like crawl growth characteristics and two kind flower color. It is highly resistant to insects comparing with other cotton species by four year field investigation. By cytogenetic analysis, triple hybrid was further confirmed by meiosis behavior of pollen mother cells. Comparing with regular meiosis of its three parents, it was distinguished by the occurrence of polyads with various numbers of unbalanced microspores and finally generating various abnormal pollen grains. All this phenomenon results in the sterility of this hybrid. This hybrid was further identified by SSR marker from DNA molecular level. It showed that 98 selected polymorphism primers amplified effective bands in this hybrids and its parents. The genetic proportion of three parents in this hybrid is 47.8% from G. hirsutum, 14.3% from G. australe, 7.0% from G. capitis-viridis, and 30.9% recombination bands respectively. It was testified that wild genetic material has been transferred into cultivated cotton and this new germplasm can be incorporated into cotton breeding program.

  11. Considerations for the preparation of peat samples for palynology, and for the counting of pollen and non-pollen palynomorphs

    NARCIS (Netherlands)

    Chambers, F.M.; van Geel, B.; van der Linden, M.

    2011-01-01

    Peat deposits are valuable archives for studying palaeoclimate, the history of local and regional vegetation, and human impact. The most widely applied laboratory analytical technique has been palynology (pollen analysis), which is often limited to the study of pollen and a few easily recognisable

  12. Protoplast isolation from Ulmus americana l. Pollen mother cells, tetrads, and microspores

    Energy Technology Data Exchange (ETDEWEB)

    Redenbaugh, M K; Westfall, R D; Karnosky, D F

    1980-01-01

    Meiotic protoplasts of U. amerciana are potentially valuable for producing interspecific elm hybrids through protoplast fusion. Meiotic cells(pollen mother cells, tetrads, and microspores) were incubated in either a cellulase, hemicellylase and pectinase enzyme solution of a beta-1,3-glucanase (lainarinase) solution. Respective protoplast isolation frequencies for the three meiotic cell types were 100, 50, and 10%. Exclusion staining with 0.2% Evans blue and 0.1% methyl blue suggested protoplast viability. Some of the microspore protoplasts were vacuolated, which is an important condition for cell division. Although attempts of regenerating cell walls and inducing cell division were unsuccessful, these two problems may be superceded by protoplast fusion with more regenerative protoplasts.

  13. Pollen parameters estimates of genetic variability among newly ...

    African Journals Online (AJOL)

    Pollen parameters estimates of genetic variability among newly selected Nigerian roselle (Hibiscus sabdariffa L.) genotypes. ... Estimates of some pollen parameters where used to assess the genetic diversity among ... HOW TO USE AJOL.

  14. Studies on fertilizing process of multi-maleparents of poplar using 3H-labelled nucleic acids

    International Nuclear Information System (INIS)

    Han Yifan; Du Shengming; Pang Guangchang

    1986-01-01

    P. Poplar is a hybrib by crossing P. simonii with P. pyramisaliz and Salix matsudana. The hybrid is highly toleant to infertile and soil. In this experiment the second male parent (Salix matsudana) was labelled by 3 H-thymidine and 3 H-adenosine to study its function in fertilization process. The results showed the nucleic acid of Salix matsudana has entered into the fertilized embryo sac, as shown by the silver spots on the radiogaraphs of paraffin section from embryo sac 5-8 days after pollination. The radiation intensity of the hybrid seeds of Salix matsudana labelled with 3 H-A+ 3 H-T as male parent was about two times higher than that of the background and also higher than that of the controls. The more important character was that the trunk color and the winter-bud of P. poplar were similar to those of Salix matsutana. In conclusion, not only the nucleic acids of Salix matsudana entered into the fertilized egg, but also some characters of salix matsudana in the hybrid

  15. A prognostic pollen emissions model for climate models (PECM1.0

    Directory of Open Access Journals (Sweden)

    M. C. Wozniak

    2017-11-01

    Full Text Available We develop a prognostic model called Pollen Emissions for Climate Models (PECM for use within regional and global climate models to simulate pollen counts over the seasonal cycle based on geography, vegetation type, and meteorological parameters. Using modern surface pollen count data, empirical relationships between prior-year annual average temperature and pollen season start dates and end dates are developed for deciduous broadleaf trees (Acer, Alnus, Betula, Fraxinus, Morus, Platanus, Populus, Quercus, Ulmus, evergreen needleleaf trees (Cupressaceae, Pinaceae, grasses (Poaceae; C3, C4, and ragweed (Ambrosia. This regression model explains as much as 57 % of the variance in pollen phenological dates, and it is used to create a climate-flexible phenology that can be used to study the response of wind-driven pollen emissions to climate change. The emissions model is evaluated in the Regional Climate Model version 4 (RegCM4 over the continental United States by prescribing an emission potential from PECM and transporting pollen as aerosol tracers. We evaluate two different pollen emissions scenarios in the model using (1 a taxa-specific land cover database, phenology, and emission potential, and (2 a plant functional type (PFT land cover, phenology, and emission potential. The simulated surface pollen concentrations for both simulations are evaluated against observed surface pollen counts in five climatic subregions. Given prescribed pollen emissions, the RegCM4 simulates observed concentrations within an order of magnitude, although the performance of the simulations in any subregion is strongly related to the land cover representation and the number of observation sites used to create the empirical phenological relationship. The taxa-based model provides a better representation of the phenology of tree-based pollen counts than the PFT-based model; however, we note that the PFT-based version provides a useful and climate-flexible emissions

  16. Effects of Alternaria alternata f.sp. lycopersici toxins on pollen

    NARCIS (Netherlands)

    Bino, R.J.; Franken, J.; Witsenboer, H.M.A.; Hille, J.; Dons, J.J.M.

    1988-01-01

    Effects of the phytotoxic compounds (AAL-toxins) isolated from cell-free culture filtrates of Alternaria alternata f.sp. lycopersici on in vitro pollen development were studied. AAL-toxins inhibited both germination and tube growth of pollen from several Lycopersicon genotypes. Pollen from

  17. Influence of boundary-layer dynamics on pollen dispersion and viability

    Science.gov (United States)

    Arritt, Raymond W.; Viner, Brian J.; Westgate, Mark E.

    2013-04-01

    Adoption of genetically modified (GM) crops has raised concerns that GM traits can accidentally cross into conventional crops or wild relatives through the transport of wind-borne pollen. In order to evaluate this risk it is necessary to account both for dispersion of the pollen grains and environmental influences on pollen viability. The Lagrangian approach is suited to this problem because it allows tracking the environmental temperature and moisture that pollen grains experience as they travel. Taking advantage of this capability we have combined a high-resolution version of the WRF meteorological model with a Lagrangian particle dispersion model to predict maize pollen dispersion and viability. WRF is used to obtain fields of wind, turbulence kinetic energy, temperature, and humidity which are then used as input to the Lagrangian dispersion model. The dispersion model in turn predicts transport of a statistical sample of a pollen cloud from source plants to receptors. We also use the three-dimensional temperature and moisture fields from WRF to diagnose changes in moisture content of the pollen grains and consequent loss of viability. Results show that turbulent motions in the convective boundary layer counteract the large terminal velocity of maize pollen grains and lift them to heights of several hundred meters, so that they can be transported long distances before settling to the ground. We also found that pollen lifted into the upper part of the boundary layer remains more viable than has been inferred using surface observations of temperature and humidity. This is attributed to the thermal and moisture structure that typifies the daytime atmospheric boundary layer, producing an environment of low vapor pressure deficit in the upper boundary layer which helps maintain pollen viability.

  18. A Taxonomic Reduced-Space Pollen Model for Paleoclimate Reconstruction

    Science.gov (United States)

    Wahl, E. R.; Schoelzel, C.

    2010-12-01

    Paleoenvironmental reconstruction from fossil pollen often attempts to take advantage of the rich taxonomic diversity in such data. Here, a taxonomically "reduced-space" reconstruction model is explored that would be parsimonious in introducing parameters needing to be estimated within a Bayesian Hierarchical Modeling context. This work involves a refinement of the traditional pollen ratio method. This method is useful when one (or a few) dominant pollen type(s) in a region have a strong positive correlation with a climate variable of interest and another (or a few) dominant pollen type(s) have a strong negative correlation. When, e.g., counts of pollen taxa a and b (r >0) are combined with pollen types c and d (r logistic generalized linear model (GLM). The GLM can readily model this relationship in the forward form, pollen = g(climate), which is more physically realistic than inverse models often used in paleoclimate reconstruction [climate = f(pollen)]. The specification of the model is: rnum Bin(n,p), where E(r|T) = p = exp(η)/[1+exp(η)], and η = α + β(T); r is the pollen ratio formed as above, rnum is the ratio numerator, n is the ratio denominator (i.e., the sum of pollen counts), the denominator-specific count is (n - rnum), and T is the temperature at each site corresponding to a specific value of r. Ecological and empirical screening identified the model (Spruce+Birch) / (Spruce+Birch+Oak+Hickory) for use in temperate eastern N. America. α and β were estimated using both "traditional" and Bayesian GLM algorithms (in R). Although it includes only four pollen types, the ratio model yields more explained variation ( 80%) in the pollen-temperature relationship of the study region than a 64-taxon modern analog technique (MAT). Thus, the new pollen ratio method represents an information-rich, reduced space data model that can be efficiently employed in a BHM framework. The ratio model can directly reconstruct past temperature by solving the GLM equations

  19. Male fitness of oilseed rape (¤Brassica napus¤), weedy ¤B-rapa¤ and their F1 hybrids when pollinating ¤B-rapa¤ seeds

    DEFF Research Database (Denmark)

    Pertl, M.; Hauser, T.P.; Damgaard, C.

    2002-01-01

    The likelihood that two species hybridise and backcross may depend strongly on environmental conditions, and possibly on competitive interactions between parents and hybrids. We studied the paternity of seeds produced by weedy Brassica rapa growing in mixtures with oilseed rape (B. napus) and the...... is strongly influenced by their local frequencies, and that male fitness of F(1)hybrids, when pollinating B. rapa seeds, is low even when their female fitness (seed set) is high.......The likelihood that two species hybridise and backcross may depend strongly on environmental conditions, and possibly on competitive interactions between parents and hybrids. We studied the paternity of seeds produced by weedy Brassica rapa growing in mixtures with oilseed rape (B. napus......) and their F(1) hybrids at different frequencies and densities. Paternity was determined by the presence of a transgene, morphology, and AFLP markers. In addition, observations of flower and pollen production, and published data on pollen fertilisation success, zygote survival, and seed germination, allowed us...

  20. The importance of pollen counts in the air: an example

    Directory of Open Access Journals (Sweden)

    Francisco José González Minero

    2016-06-01

    Full Text Available The Bay of Cádiz in general and Sanlúcar de Barrameda in particular were pioneering places for aerobiological analysis in Spain. This study presents unpublished pollen data collected with a Hirst spore trap during a year. Results are structured in pollen calendar form which is easy to interpret by health professionals. This article also intends to pay tribute to those medical pioneers who began their studies in Sanlúcar de Barrameda. On this subject, we discuss the data obtained in 1941 and we relate them with data collected in 2009. The Mediterranean climate and the geographical location of Sanlúcar de Barrameda bring about an archetypical pollen calendar of the towns of the Iberian Peninsula’s southern coast. A total of 21 pollen types are quanti ed, Olea europaea L. (25.1%, Quercus (17.5%, Pinaceae (12.3%, Poaceae (10.2% and Cupressaceae (8.1% being the more abundant types . The months of highest pollen concentration are April and May. The maximum daily concentration was reached on May 13 with 825 grains/m3 of Olea europaea L. pollen. Daily concentrations of grass pollen and other herbaceous plants are not exceptionally high, but they do have a continued presence throughout the year, so the risk of pollen allergies cannot be con ned to spring.

  1. Regulatory networks in pollen development under cold stress

    Directory of Open Access Journals (Sweden)

    Kamal Dev Sharma

    2016-03-01

    Full Text Available Cold stress modifies anthers’ metabolic pathways to induce pollen sterility. Cold-tolerant plants, unlike the susceptible ones, produce high proportion of viable pollen. Anthers in susceptible plants, when exposed to cold stress, increase abscisic acid (ABA metabolism and reduce ABA catabolism. Increased ABA negatively regulates expression of tapetum cell wall bound invertase and monosaccharide transport genes resulting in distorted carbohydrate pool in anther. Cold-stress also reduces endogenous levels of the bioactive gibberellins (GAs, GA4 and GA7, in susceptible anthers by repression of the GA biosynthesis genes. Here we discuss recent findings on mechanisms of cold susceptibility in anthers which determine pollen sterility. We also discuss differences in regulatory pathways between cold-stressed anthers of susceptible and tolerant plants that decide pollen sterility or viability.

  2. Effects of pollen dilution on infection of Nosema ceranae in honey bees.

    Science.gov (United States)

    Jack, Cameron J; Uppala, Sai Sree; Lucas, Hannah M; Sagili, Ramesh R

    2016-04-01

    Multiple stressors are currently threatening honey bee health, including pests and pathogens. Among honey bee pathogens, Nosema ceranae is a microsporidian found parasitizing the western honey bee (Apis mellifera) relatively recently. Honey bee colonies are fed pollen or protein substitute during pollen dearth to boost colony growth and immunity against pests and pathogens. Here we hypothesize that N. ceranae intensity and prevalence will be low in bees receiving high pollen diets, and that honey bees on high pollen diets will have higher survival and/or increased longevity. To test this hypothesis we examined the effects of different quantities of pollen on (a) the intensity and prevalence of N. ceranae and (b) longevity and nutritional physiology of bees inoculated with N. ceranae. Significantly higher spore intensities were observed in treatments that received higher pollen quantities (1:0 and 1:1 pollen:cellulose) when compared to treatments that received relatively lower pollen quantities. There were no significant differences in N. ceranae prevalence among different pollen diet treatments. Interestingly, the bees in higher pollen quantity treatments also had significantly higher survival despite higher intensities of N. ceranae. Significantly higher hypopharyngeal gland protein was observed in the control (no Nosema infection, and receiving a diet of 1:0 pollen:cellulose), followed by 1:0 pollen:cellulose treatment that was inoculated with N. ceranae. Here we demonstrate that diet with higher pollen quantity increases N. ceranae intensity, but also enhances the survival or longevity of honey bees. The information from this study could potentially help beekeepers formulate appropriate protein feeding regimens for their colonies to mitigate N. ceranae problems. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. Food allergy to apple and specific immunotherapy with birch pollen

    DEFF Research Database (Denmark)

    Hansen, K.S.; Khinchi, M.S.; Skov, P.S.

    2004-01-01

    Conflicting results concerning the effect of specific pollen immunotherapy (SIT) on allergy to plant foods have been reported. The aim of this study was to investigate the effect of SIT using a birch pollen extract on food allergy with focus on allergy to apple. Seventy-four birch pollen-allergic......Conflicting results concerning the effect of specific pollen immunotherapy (SIT) on allergy to plant foods have been reported. The aim of this study was to investigate the effect of SIT using a birch pollen extract on food allergy with focus on allergy to apple. Seventy-four birch pollen......-allergic patients were included in a double-blind, double-dummy, and placebo-controlled comparison of sublingual-swallow (SLIT) and subcutaneous (SCIT) administration of a birch pollen extract. Sixty-nine percent of these patients reported allergy to apple. The clinical reactivity to apple was evaluated by open...... oral challenges with fresh apple and a questionnaire. The immunoglobulin E (IgE)-reactivity was assessed by skin prick test (SPT), specific IgE, and leukocyte histamine release (HR). Forty patients were included in the final evaluation of the effect of SIT. The challenges were positive in 9 (SCIT), 6...

  4. Meiotic polyploidization with homoeologous recombination induced by caffeine treatment in interspecific lily hybrids

    NARCIS (Netherlands)

    Lim, K.B.; Barba Gonzalez, R.; Shujun Zhou,; Ramanna, M.S.; Tuyl, van J.M.

    2005-01-01

    Caffeine solution was injected into the flower bud to recover F, fertility of the intersectional diploid Lilium species hybrid (2n=2x=24). 0.3% of caffeine solution was the most effective concentration to produce fertile 2n-gametes. The male and female gametes had a range of fertility following

  5. Pollen morphology and variability of Tulipa hungarica Borb

    African Journals Online (AJOL)

    Yomi

    2012-01-10

    Jan 10, 2012 ... Pollen morphology of the endemic species Tulipa hungarica Borb was investigated with the goal of ... pollen size may balance the competitive advantages of .... (2009). Comparative analysis of microspore size variability in the.

  6. STUDY ON POLLEN VIABILITY AS BIOINDICATOR OF AIR QUALITY

    Directory of Open Access Journals (Sweden)

    Florentina ŞTEFLEA

    2012-01-01

    Full Text Available The aim of this research is to estimate the relationship between pollen viability and atmospheric pollution (in polluted and non-polluted conditions. The study was carried out in the city of Timisoara. Two areas, with different intensity of road traffic (very high and absent but all characterized by the presence of the same plant species, were selected. The pollen of herbaceous spontaneous species, arboreal species and a shrub species was used (Robinia pseudacacia, Aesculus x carnea, Catalpa bignonioides, Albizzia julibrissin, Rosa canina, Sambucus nigra, Malva neglecta, Ranunculus acer, Trifolium repens, Cichorium intybus. The pollen of these species was treated with TTC (2, 3, 5 Tryphenil-Tetrazolium-Chloride staining solution and viability was then estimated by light microscopy. The results of the mean pollen viability percentage of the examined species are reported. Pollen viability of herbaceous plants is significantly different between the two environments.

  7. Pollen Flora of Yuenyang Lake Nature Preserve, Taiwan (IV

    Directory of Open Access Journals (Sweden)

    Yu-Fa Wang

    2002-06-01

    Full Text Available Yuenyang Lake is an acidic lake situated within a nature preserve in northern Taiwan. The pollen of nineteen taxa, belonging to five families, was collected from this nature preserve and investigated with light and scanning electron microscopy. The results of this investigation are supplementary work to the previous publications in this journal (Chen and Wang, 1999, 2001; Wang and Chen, 2001. A total of 4 pollen classes were identified on the basis of the aperture on the pollen wall: 3-colpate, 6-colpate, 3-colporate, and 4-7-colporate pollen. These results could be useful in the reconstruction of vegetation history around the Yuenyang Lake.

  8. SCFSLF-mediated cytosolic degradation of S-RNase is required for cross-pollen compatibility in S-RNase-based self-incompatibility in Petunia hybrida

    Directory of Open Access Journals (Sweden)

    Yongbiao eXue

    2014-07-01

    Full Text Available Many flowering plants adopt self-incompatibility (SI to maintain their genetic diversity. In species of Solanaceae, Plantaginaceae and Rosaceae, SI is genetically controlled by a single S-locus with multiple haplotypes. The S-locus has been shown to encode S-RNases expressed in pistil and multiple SLF (S-locus F-box proteins in pollen controlling the female and male specificity of SI, respectively. S-RNases appear to function as a cytotoxin to reject self-pollen. In addition, SLFs have been shown to form SCF (SKP1/Cullin1/F-box complexes to serve as putative E3 ubiquitin ligase to interact with S-RNases. Previously, two different mechanisms, the S-RNase degradation and the S-RNase compartmentalization, have been proposed as the restriction mechanisms of S-RNase cytotoxicity allowing compatible pollination. In this study, we have provided several lines of evidence in support of the S-RNase degradation mechanism by a combination of cellular, biochemical and molecular biology approaches. First, both immunogold labeling and subcellular fractionation assays showed that two key pollen SI factors, PhSLF-S3L and PhSSK1 (SLF-interacting SKP1-like1 from Petunia hybrida, a Solanaceous species, are co-localized in cytosols of both pollen grains and tubes. Second, PhS3L-RNases are mainly detected in the cytosols of both self and non-self pollen tubes after pollination. Third, we found that both PhS3-RNases and PhS3L-RNases directly interact with PhSLF-S3L by yeast two-hybrid and co-immunoprecipitation assays. Fourth, S-RNases are specifically degraded in compatible pollen tubes by non-self SLF action. Taken together, our results demonstrate that SCFSLF-mediated non-self S-RNase degradation occurs in the cytosol of pollen tube through the ubiquitin/26S proteasome system serving as the major mechanism to neutralize S-RNase cytotoxicity during compatible pollination in P. hybrida.

  9. Profiling and functional classification of esterases in olive (Olea europaea) pollen during germination.

    Science.gov (United States)

    Rejón, Juan D; Zienkiewicz, Agnieszka; Rodríguez-García, María Isabel; Castro, Antonio J

    2012-10-01

    A pollen grain contains a number of esterases, many of which are released upon contact with the stigma surface. However, the identity and function of most of these esterases remain unknown. In this work, esterases from olive pollen during its germination were identifided and functionally characterized. The esterolytic capacity of olive (Olea europaea) pollen was examined using in vitro and in-gel enzymatic assays with different enzyme substrates. The functional analysis of pollen esterases was achieved by inhibition assays by using specific inhibitors. The cellular localization of esterase activities was performed using histochemical methods. Olive pollen showed high levels of non-specific esterase activity, which remained steady after hydration and germination. Up to 20 esterolytic bands were identified on polyacrylamide gels. All the inhibitors decreased pollen germinability, but only diisopropyl fluorophosphate (DIFP) hampered pollen tube growth. Non-specific esterase activity is localized on the surface of oil bodies (OBs) and small vesicles, in the pollen intine and in the callose layer of the pollen tube wall. Acetylcholinesterase (AChE) activity was mostly observed in the apertures, exine and pollen coat, and attached to the pollen tube wall surface and to small cytoplasmic vesicles. In this work, for the first time a systematic functional characterization of esterase enzymes in pollen from a plant species with wet stigma has been carried out. Olive pollen esterases belong to four different functional groups: carboxylesterases, acetylesterases, AChEs and lipases. The cellular localization of esterase activity indicates that the intine is a putative storage site for esterolytic enzymes in olive pollen. Based on inhibition assays and cellular localization of enzymatic activities, it can be concluded that these enzymes are likely to be involved in pollen germination, and pollen tube growth and penetration of the stigma.

  10. Pollen Characterization in Size Segregated Atmospheric Aerosol

    Science.gov (United States)

    Kolpakova, Anna; Hovorka, Jan; Klán, Miroslav

    2017-12-01

    The first stage of a High Volumetric Cascade Impactor - HiVol (BGI-900), used for sampling of aerosol particles larger than 10 micrometres in aerodynamic diameter, was tested for bioaerosol sampling. Low air flow-rate and low pressure-drop at the jets of the first stage and high air volume are advantageous parameters, which would favour the use of the first stage for bioaerosol sampling. The sampling went in urban, rural and background localities, Prague, Brezno and Laz respectively in the Czech Republic, in summer and autumn. Pollen was separated from the impaction substrate, polyurethane foam, into homogeneous deposit on Nylon filter. The homogeneity of the deposit varied within 4%. Representative portion of the deposit was analysed by a scanning electron microscopy - SEM. There were taken 485 SEM images from 12 samples in 3 localities. Pollen grains were identified in 295 SEM images and determined into 9 genus and 4 families. Median pollen grain concentrations/deformities were 9m-3/24%, 3m-3/18%, 8m-3/50% for Prague, Brezno and Láz localities respectively. The pollen grains of the Poaceae family were found with the highest frequency in all localities. Number of pollen increased with total aerosol mass in Prague locality only. There were also identified brochosomes, rather unique insect secretion products, in the samples from the Láz locality.

  11. Assessment of Salix spp. pollen availability to insects based on aerobiological investigations

    Directory of Open Access Journals (Sweden)

    Elżbieta Weryszko-Chmielewska

    2017-06-01

    Full Text Available Pollen and nectar produced by flowers of species from the genus Salix are an important source of food for various insect groups in early spring. Most willows are entomophilous species; however, substantial amounts of airborne Salix pollen can be noted. The aim of the study was to evaluate the content of pollen of this taxon in the air of Lublin (central-east Poland in 2001–2016 and to identify the period of its greatest availability to insects. In 2015, we compared the course of the Salix pollen season in Lublin (51°14'37" N; 22°32'25" E and in the Roztoczański National Park (50°34'57" N; 23°04'24" E, Poland. We found that the date of the pollen season onset fluctuated greatly between March 16 and April 17. The greatest availability of Salix pollen to insects was noted from the end of the first 10-day-period of April to the first 10-day-period of May. The mean annual sum of airborne Salix pollen grains was 833. In Lublin, Salix pollen accounted for ca. 1.25% of the total airborne pollen content of different plant taxa. The investigations have demonstrated a 2-year cycle of Salix pollen abundance. The comparison of the pollen seasons in Lublin and in the Roztoczański National Park indicates that considerably greater amounts of pollen occur in the urban area than in the air of the Roztoczański National Park.

  12. SEED AND POLLEN TTRANSMISSION OF A NEW UNIDENTIFIED MOTTLE DISORDER OF MAIZE IN INDONESIA

    Directory of Open Access Journals (Sweden)

    W. Wakman

    2018-01-01

    Full Text Available A new unidentified mottle disorder of maize Indonesia was found at the Research Institute for Maize and Other Cereals (RIMOC, Maros, South Sulawesi in 1995. Attempts to identify the disorder were made by mechanical inoculation, insect vector (Rhopalosiphum maidis and Peregrinus maidis transmission, seed and pollen transmission, electron microscopy, and serological test. Fifty seeds from each of 22 ears of Arjuna maize plants showing the disorder were planted and symptoms on the seedlings were recorder at 1, 2, and 3 weeks after planting. The percentage of seedlings showing the disorder ranged from 40 to 100. Pollen of affected Arjuna was then used to pollinate four sweet corn female flowers. Hybrid seeds (50 per ear of the crosses were planted and symptoms were recorded at 1, 2, and 3 weeks after planting. The results showed that percentage of seedlings showing the disorder ranged from 22 to 84. Electron microscopy and ELISA tests on 15 viruses and one phytospiroplasma antiserum however, gave negative results. Therefore, maize disorder at Maros was not identical to any known viral disease of maize. It could be a genetical disorder and has been given the name maize mottle.

  13. The Effect of Pollen on Some Reproductive Parameters of Male Rats

    Directory of Open Access Journals (Sweden)

    Güldeniz Selmanoğlu

    2009-01-01

    Full Text Available Honeybee pollen is consumed as natural food in healthy human diet in many European and Asian countries. The aim of this study was to investigate the effect of pollen use on some reproductive parameters. In this study, mature male rats were fed on pollen of three different plant sources (Trifolium spp., Raphanus spp. and Cistus spp. at 60 mg/per animal/ per day over a 30-day period. At the end of the treatment, testosterone levels of rats were analysed and weights of testis, epididymis, prostate and seminal vesicle were recorded. In addition, epididymal sperms were counted. There were increases in testosterone levels, sperm counts and daily sperm production of rats fed with pollen of Raphanus spp. and Cistus spp. There were no significant changes in absolute weights, except in prostate weights. Also there were no changes in relative testis,prostate and seminal vesicle weights of rats fed on pollen, but relative epididymis weights of rats in pollen groups decreased. The results of this study show that bee pollen caused an increase in testosterone level and sperm counts of male rats. We suggest that bee pollen has an androgenic effect.

  14. Seasonal and intradiurnal variation of airborne pollen concentrations in Bodrum, SW Turkey.

    Science.gov (United States)

    Tosunoglu, Aycan; Bicakci, Adem

    2015-04-01

    An aeropalynological study was performed in Bodrum, the famous tourism center in southwestern Turkey with a Hirst-type volumetric 7-day pollen and spore trap for 2 years (2007-2008). In Bodrum, 25,099 pollen grains as a mean value belonging to 41 taxa were recorded annually during the study period, and pollen grains from woody plant taxa had the largest atmospheric contribution of 86.99% and 24 taxa. However, 17 herbaceous plant taxa constituted 12.82% of the annual total pollen count, and 0.19% were unidentified. An average annual pollen index of 22.66% was recorded in March, despite differences from year to year. The highest pollen variability of 34 taxa was recorded in April and May. Predominant pollen types belonged to Cupressaceae/Taxaceae (42.73%), Quercus (15.95%), Pinus (9.78%), Olea europaea (9.04%), Poaceae (5.50%), Betula (1.82%), Pistacia (1.74%), Morus (1.72%), Urticaceae (1.46%), and Plantago (1.28%) and generated 91.03 of the annual total. In total, 32.59% of the mean annual total pollen index was recorded in the morning, and less pollen was recorded in the evening (18.71%). Maximum pollen concentration was recorded between 11:00 and 12:00 a.m.

  15. Application of pollen treated with ionizing radiation in grapes breeding

    International Nuclear Information System (INIS)

    Semin, V.S.

    1988-01-01

    Problem concerning the priority of investigations into transformation inducing using plant pollen irradiation method is raised. Data on investigations into grape predominant type pollen irradiation with rigid 1-100 Gy dose gamma rays are considered. Using grape seedling morphological index analysis it is shown that gene transformation inducing is possible using high dose pollen irradiation for cross pollination process. Advantages of the given method are indicated: application of irradiated pollen for pollination allows one to transmit certain characters to progeny at some stages - without impregnation (1); with pollen irradiation dose increase the number of male plant characters transmitted to progeny is reduced (2); deep recessive characters of one of the parent plants can be manifested in progeny or valuable neoplasms can even occur

  16. ANTIOXIDANT ACTIVITY AND POLYPHENOL CONTENT OF MALT BEVERAGES ENRICHED WITH BEE POLLEN

    Directory of Open Access Journals (Sweden)

    Miriam Solgajová

    2014-02-01

    Full Text Available In food industry, especially among the brewers, using of natural ingredients is increasingly growing demand. Beer is one of the most popular beverages in the world with evident positive effects on the overall health condition. It can be used as a base for developing a variety of products with specific physiological activity. Bee pollen is considered to be one of the possible sources of active ingredients for that purpose. Activity of phenolic and flavonoid compounds in bee pollen can contribute to the antioxidant potential of beer. The objective of this study was to examine the influence of different types and content of bee pollen on the antioxidant properties of malt beverages and to compare phenolic and flavonoid profiles. The technological process of malt beverages preparation with addition of bee pollen was also verified. It was found out that all beverages enriched with bee pollen had higher polyphenol, flavonoid content and antioxidant potential than control sample – pure wort. The higher antioxidant activities of all extracts was measured in sample R2 - wort with 0.6% of dry rapeseed pollen and sample R4 - wort with 0.6% of frozen rapeseed pollen. The higher phenolic content than in other samples was measured in sample M4 - wort with 0.6% of frozen poppy pollen and sample M1 - wort with 0.256% of dry poppy pollen. Higher total flavonoid content was found out in sample M2 - wort with 0.6% of dry poppy pollen and M4 - wort with 0.6% of frozen poppy pollen. In conclusion, the most noticeable results of antioxidant activity, phenolic and flavonoid content were achieved in samples with higher 0.6% addition of bee pollen, mostly poppy (Papaver somniferum L. pollen.

  17. Backcrosses in interspecific hybridization in sunflower

    Directory of Open Access Journals (Sweden)

    Atlagić Jovanka

    2003-01-01

    Full Text Available When incorporating desirable traits (resistance to causal agents of various diseases from the wild relatives into the cultivated sunflower, some undesirable ones are introduced too (branching, small head diameter, low oil content, etc. To overcome this problem, backcrosses (F1 interspecific hybrids x cultivated sunflower are used, although very often desirable traits are lost in the process. Cytological analysis (meiosis and pollen viability and molecular markers (RAPD were used to estimate what portion of the parental species genome was present in (be interspecific hybrids of the F1 and BC1F1 generations. The results showed that the percentage of irregularities at meiosis increased from F1 to BC1F1 gen. They also indicated the presence of aneuploids and sterility in the cross between the hexaploid species H.rigidus and cultivated sunflower. The genetic distance between the parents was 83%, that between H.rigidus and the F1 hybrid 54 61%, and that between H.annuus and F1 hybrid 70-76%. In the BC1F1 generation, the genetic distance from Hannuus decreased to 58-66% and that from H.rigidus increased to 69-76%.

  18. Region-specific sensitivity of anemophilous pollen deposition to temperature and precipitation.

    Directory of Open Access Journals (Sweden)

    Timme H Donders

    Full Text Available Understanding relations between climate and pollen production is important for several societal and ecological challenges, importantly pollen forecasting for pollinosis treatment, forensic studies, global change biology, and high-resolution palaeoecological studies of past vegetation and climate fluctuations. For these purposes, we investigate the role of climate variables on annual-scale variations in pollen influx, test the regional consistency of observed patterns, and evaluate the potential to reconstruct high-frequency signals from sediment archives. A 43-year pollen-trap record from the Netherlands is used to investigate relations between annual pollen influx, climate variables (monthly and seasonal temperature and precipitation values, and the North Atlantic Oscillation climate index. Spearman rank correlation analysis shows that specifically in Alnus, Betula, Corylus, Fraxinus, Quercus and Plantago both temperature in the year prior to (T-1, as well as in the growing season (T, are highly significant factors (TApril rs between 0.30 [P<0.05[ and 0.58 [P<0.0001]; TJuli-1 rs between 0.32 [P<0.05[ and 0.56 [P<0.0001] in the annual pollen influx of wind-pollinated plants. Total annual pollen prediction models based on multiple climate variables yield R2 between 0.38 and 0.62 (P<0.0001. The effect of precipitation is minimal. A second trapping station in the SE Netherlands, shows consistent trends and annual variability, suggesting the climate factors are regionally relevant. Summer temperature is thought to influence the formation of reproductive structures, while temperature during the flowering season influences pollen release. This study provides a first predictive model for seasonal pollen forecasting, and also aides forensic studies. Furthermore, variations in pollen accumulation rates from a sub-fossil peat deposit are comparable with the pollen trap data. This suggests that high frequency variability pollen records from natural

  19. Use of MODIS Satellite Data to Evaluate Juniperus spp. Pollen Phenology to Support a Pollen Dispersal Model, PREAM, to Support Public Health Allergy Alerts

    Science.gov (United States)

    Luvall, J. C.; Sprigg, W.; Levetin, E.; Huete, A.; Nickovic, S.; Pejanovic, G. A.; Vukovic, A.; VandeWater, P.; Budge, A.; Hudspeth, W.; hide

    2012-01-01

    Juniperus spp. pollen is a significant aeroallergen that can be transported 200-600 km from the source. Local observations of Juniperus spp. phenology may not be consistent with the timing and source of pollen collected by pollen sampling instruments. Methods: The Dust REgional Atmospheric Model (DREAM)is a verified model for atmospheric dust transport modeling using MODIS data products to identify source regions and quantities of dust. We successfully modified the DREAM model to incorporate pollen transport (PREAM) and used MODIS satellite images to develop Juniperus ashei pollen input source masks. The Pollen Release Potential Source Map, also referred to as a source mask in model applications, may use different satellite platforms and sensors and a variety of data sets other than the USGS GAP data we used to map J. ashei cover type. MODIS derived percent tree cover is obtained from MODIS Vegetation Continuous Fields (VCF) product (collection 3 and 4, MOD44B, 500 and 250 m grid resolution). We use updated 2010 values to calculate pollen concentration at source (J. ashei ). The original MODIS derived values are converted from native approx. 250 m to 990m (approx. 1 km) for the calculation of a mask to fit the model (PREAM) resolution. Results: The simulation period is chosen following the information that in the last 2 weeks of December 2010. The PREAM modeled near-surface concentrations (Nm-3) shows the transport patterns of J. ashei pollen over a 5 day period (Fig. 2). Typical scales of the simulated transport process are regional.

  20. Sporophytic control of pollen tube growth and guidance in maize

    Science.gov (United States)

    Lausser, Andreas; Kliwer, Irina; Srilunchang, Kanok-orn; Dresselhaus, Thomas

    2010-01-01

    Pollen tube germination, growth, and guidance (progamic phase) culminating in sperm discharge is a multi-stage process including complex interactions between the male gametophyte as well as sporophytic tissues and the female gametophyte (embryo sac), respectively. Inter- and intra-specific crossing barriers in maize and Tripsacum have been studied and a precise description of progamic pollen tube development in maize is reported here. It was found that pollen germination and initial tube growth are rather unspecific, but an early, first crossing barrier was detected before arrival at the transmitting tract. Pollination of maize silks with Tripsacum pollen and incompatible pollination of Ga1s/Ga1s-maize silks with ga1-maize pollen revealed another two incompatibility barriers, namely transmitting tract mistargeting and insufficient growth support. Attraction and growth support by the transmitting tract seem to play key roles for progamic pollen tube growth. After leaving transmitting tracts, pollen tubes have to navigate across the ovule in the ovular cavity. Pollination of an embryo sac-less maize RNAi-line allowed the role of the female gametophyte for pollen tube guidance to be determined in maize. It was found that female gametophyte controlled guidance is restricted to a small region around the micropyle, approximately 50–100 μm in diameter. This area is comparable to the area of influence of previously described ZmEA1-based short-range female gametophyte signalling. In conclusion, the progamic phase is almost completely under sporophytic control in maize. PMID:19926683

  1. Influence of fertilizer draw solution properties on the process performance and microbial community structure in a side-stream anaerobic fertilizer-drawn forward osmosis – ultrafiltration bioreactor

    KAUST Repository

    Kim, Youngjin; Li, Sheng; Chekli, Laura; Phuntsho, Sherub; Ghaffour, NorEddine; Leiknes, TorOve; Shon, Ho Kyong

    2017-01-01

    In this study, a side-stream anaerobic fertilizer-drawn forward osmosis (FDFO) and ultrafiltration (UF) membrane bioreactor (MBR) hybrid system was proposed and operated for 55 days. The FDFO performance was first investigated in terms of flux

  2. Own-Choice Marriage and Fertility in Turkey.

    Science.gov (United States)

    Manglos-Weber, Nicolette D; Weinreb, Alexander A

    2017-04-01

    Goode's foundational work on the fertility transition identified own-choice marriage as a factor driving fertility decline, part of a widening repertoire of choice pertaining to marriage and childbearing. Yet research supporting this connection in today's transitional societies is scarce and somewhat contradictory, and it is unclear how other marital traditions, such as consanguineous marriage, shape this relationship. This study evaluates Goode's theorized connection using pooled Demographic and Health Survey data from Turkey, comparing children ever born, use of contraception, and parity progression across four types of marriage: own-choice and arranged marriage; and marriage to a cousin versus an unrelated spouse. Results are largely consistent with the idea that a move towards own-choice marriage reflects a widening repertoire of choice that also leads to fertility decline. However, they also show that hybrid models like own-choice marriage to a cousin tempers these effects.

  3. Own-Choice Marriage and Fertility in Turkey

    Science.gov (United States)

    Weinreb, Alexander A.

    2016-01-01

    Goode’s foundational work on the fertility transition identified own-choice marriage as a factor driving fertility decline, part of a widening repertoire of choice pertaining to marriage and childbearing. Yet research supporting this connection in today’s transitional societies is scarce and somewhat contradictory, and it is unclear how other marital traditions, such as consanguineous marriage, shape this relationship. This study evaluates Goode’s theorized connection using pooled Demographic and Health Survey data from Turkey, comparing children ever born, use of contraception, and parity progression across four types of marriage: own-choice and arranged marriage; and marriage to a cousin versus an unrelated spouse. Results are largely consistent with the idea that a move towards own-choice marriage reflects a widening repertoire of choice that also leads to fertility decline. However, they also show that hybrid models like own-choice marriage to a cousin tempers these effects. PMID:28316343

  4. Nitric Oxide Binds to and Modulates the Activity of a Pollen Specific Arabidopsis Diacylglycerol Kinase

    KAUST Repository

    Wong, Aloysius Tze

    2014-06-01

    NO responses. Specifically, the mis-expressing atdgk4 pollen tubes have growth rates that were less affected by NO and showed reduced bending angles when challenged by an NO source. Further works on atdgk4 knockout/knockdown mutants will reveal the biological functions of ATDGK4 in NO and/or cGMP signaling in the pollen, and in the broader fertilization process.

  5. Review of probabilistic pollen-climate transfer methods

    Science.gov (United States)

    Ohlwein, Christian; Wahl, Eugene R.

    2012-01-01

    Pollen-climate transfer methods are reviewed from a Bayesian perspective and with a special focus on the formulation of uncertainties. This approach is motivated by recent developments of spatial multi-proxy Bayesian hierarchical models (BHM), which allow synthesizing local reconstructions from different proxies for a spatially complete picture of past climate. In order to enhance the pollen realism in these models we try to bridge the gap between spatial statistics and paleoclimatology and show how far classical pollen-climate transfer concepts such as regression methods, mutual climatic range, modern analogues, plant functional types, and biomes can be understood in novel ways by refining the data models used in BHMs. As a case study, we discuss modeling of uncertainty by introducing a new probabilistic pollen ratio model, which is a simplified variation of the modern analogue technique (MAT) including the concept of response surfaces and designed for later inclusion in a spatial multiproxy BHM. Applications to fossil pollen data from varved sediments in three nearby lakes in west-central Wisconsin, USA and for a Holocene fossil pollen record from southern California, USA provide local climate reconstructions of summer temperature for the past millennium and the Holocene respectively. The performance of the probabilistic model is generally similar in comparison to MAT-derived reconstructions using the same data. Furthermore, the combination of co-location and precise dating for the three fossil sites in Wisconsin allows us to study the issue of site-specific uncertainty and to test the assumption of ergodicity in a real-world example. A multivariate ensemble kernel dressing approach derived from the post-processing of climate simulations reveals that the overall interpretation based on the individual reconstructions remains essentially unchanged, but the single-site reconstructions underestimate the overall uncertainty.

  6. Variation patterns of pollen production in palm flowers

    DEFF Research Database (Denmark)

    Alapetite, Elodie; Barfod, Anders; Albert, Beatrice

    2016-01-01

    pollen production and stamen number has never been so far investigated. The diversity in stamen number observed among palms species and genera provides an ideal case study to test for such a correlation, taking into account phylogenetic constraints. Based on a survey of flowers from 82 species...... representative of the various palm tribes and compared it to stamen number, we show that pollen production in palms ranges from hundreds to millions grains. There is a relationship between stamen number and pollen production in our sampling, particularly in Coryphoideae and Arecoideae where there is a tendency...

  7. Efficacy of recombinant birch pollen vaccine for the treatment of birch-allergic rhinoconjunctivitis

    DEFF Research Database (Denmark)

    Pauli, Gabrielle; Larsen, Tina H; Rak, Sabina

    2008-01-01

    BACKGROUND: Recombinant DNA technology has the potential to produce allergen-specific immunotherapy vaccines with defined composition. OBJECTIVE: To evaluate the effectiveness of a new recombinant birch pollen allergen vaccine in patients with birch pollen allergy. METHODS: A multicenter, randomi......-treated group. CONCLUSION: The rBet v 1-based vaccine was safe and effective in treating birch pollen allergy, and induced a highly specific immune response.......BACKGROUND: Recombinant DNA technology has the potential to produce allergen-specific immunotherapy vaccines with defined composition. OBJECTIVE: To evaluate the effectiveness of a new recombinant birch pollen allergen vaccine in patients with birch pollen allergy. METHODS: A multicenter......, randomized, double-blind, placebo-controlled trial was undertaken to compare the following 3 vaccines in 134 adults with birch pollen allergy: recombinant birch pollen allergen vaccine (rBet v 1a), licensed birch pollen extract, natural purified birch pollen allergen (nBet v 1), and placebo. Patients...

  8. DNA methylation profiles correlated to striped bass sperm fertility

    Science.gov (United States)

    Striped bass (Morone saxatilis) spermatozoa are used to fertilize in vitro the eggs of white bass (Morone chrysops) to produce the preferred hybrid for the striped bass aquaculture industry. Currently, only one source of domestic striped bass juveniles are available to growers that are not obtained ...

  9. Securing maximum diversity of Non Pollen Palynomorphs in palynological samples

    DEFF Research Database (Denmark)

    Enevold, Renée; Odgaard, Bent Vad

    2015-01-01

    Palynology is no longer synonymous with analysis of pollen with the addition of a few fern spores. A wide range of Non Pollen Palynomorphs are now described and are potential palaeoenvironmental proxies in the palynological surveys. The contribution of NPP’s has proven important to the interpreta......Palynology is no longer synonymous with analysis of pollen with the addition of a few fern spores. A wide range of Non Pollen Palynomorphs are now described and are potential palaeoenvironmental proxies in the palynological surveys. The contribution of NPP’s has proven important...

  10. Airborne pollen trends in the Iberian Peninsula.

    Science.gov (United States)

    Galán, C; Alcázar, P; Oteros, J; García-Mozo, H; Aira, M J; Belmonte, J; Diaz de la Guardia, C; Fernández-González, D; Gutierrez-Bustillo, M; Moreno-Grau, S; Pérez-Badía, R; Rodríguez-Rajo, J; Ruiz-Valenzuela, L; Tormo, R; Trigo, M M; Domínguez-Vilches, E

    2016-04-15

    Airborne pollen monitoring is an effective tool for studying the reproductive phenology of anemophilous plants, an important bioindicator of plant behavior. Recent decades have revealed a trend towards rising airborne pollen concentrations in Europe, attributing these trends to an increase in anthropogenic CO2 emissions and temperature. However, the lack of water availability in southern Europe may prompt a trend towards lower flowering intensity, especially in herbaceous plants. Here we show variations in flowering intensity by analyzing the Annual Pollen Index (API) of 12 anemophilous taxa across 12 locations in the Iberian Peninsula, over the last two decades, and detecting the influence of the North Atlantic Oscillation (NAO). Results revealed differences in the distribution and flowering intensity of anemophilous species. A negative correlation was observed between airborne pollen concentrations and winter averages of the NAO index. This study confirms that changes in rainfall in the Mediterranean region, attributed to climate change, have an important impact on the phenology of plants. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. In vivo and in vitro pollen maturation in Lilium: influence of carbohydrates

    Directory of Open Access Journals (Sweden)

    Christophe Clement

    2014-01-01

    Full Text Available The purpose of this study was to develop a protocol for in vitro conform pollen maturation, as a model to study the involvement of carbohydrates on pollen maturation in Lilium. In vivo and in vitro pollen maturations were followed and compared by transmission electron microscopy, and several in vitro parameters were tested in terms of carbohydrate physiology. In vivo, pollen maturation was initiated at the vacuolated microspore stage, and consisted of two successive phases. The first phase was characterized by reactivation of microspore organelles, followed by microspore mitosis, starch synthesis and vacuole breakdown. During the second phase, starch was progressively degraded whereas lipid and phytine reserves accumulated. In vivo, pollen maturation occured within 14 days and pollen germination rate was 73.6 ± 2.2%. We then attempted to realise in vitro pollen maturation starting from the vacuolated microspore stage. The best results were obtained with flower buds cultivated at 26oC, in 100 µmol/m2/s light, with a 16h/8h photoperiod on a modified Heller's medium supplemented with NAA (10-2 mg/l and sucrose (M/6. In these conditions, pollen maturation occured within 7 days only. In vitro matured pollen is cytologically comparable to in vivo developed pollen grains and the germination rate was 72.4 ± 3.7%. When flower buds were cultivated in the dark, the germination rate decreased, but this could be compensated by providing high sucrose concentrations (1M in the medium. Further, photosynthesis inhibitors had the same effect on pollen maturation than the darkness, strongly suggesting that photosynthesis occurs in the flower bud and is important for pollen maturation in Lilium.

  12. Variation in pollen limitation and floral parasitism across a mating system transition in a Pacific coastal dune plant: evolutionary causes or ecological consequences?

    Science.gov (United States)

    Dart, Sara; Eckert, Christopher G

    2015-02-01

    Evolutionary transitions from outcrossing to self-fertilization are thought to occur because selfing provides reproductive assurance when pollinators or mates are scarce, but they could also occur via selection to reduce floral vulnerability to herbivores. This study investigated geographic covariation between floral morphology, fruit set, pollen limitation and florivory across the geographic range of Camissoniopsis cheiranthifolia, a Pacific coastal dune endemic that varies strikingly in flower size and mating system. Fruit set was quantified in 75 populations, and in 41 of these floral herbivory by larvae of a specialized moth (Mompha sp.) that consumes anthers in developing buds was also quantified. Experimental pollen supplementation was performed to quantify pollen limitation in three large-flowered, outcrossing and two small-flowered, selfing populations. These parameters were also compared between large- and small-flowered phenotypes within three mixed populations. Fruit set was much lower in large-flowered populations, and also much lower among large- than small-flowered plants within populations. Pollen supplementation increased per flower seed production in large-flowered but not small-flowered populations, but fruit set was not pollen limited. Hence inadequate pollination cannot account for the low fruit set of large-flowered plants. Floral herbivory was much more frequent in large-flowered populations and correlated negatively with fruit set. However, florivores did not preferentially attack large-flowered plants in three large-flowered populations or in two of three mixed populations. Selfing alleviated pollen limitation of seeds per fruit, but florivory better explains the marked variation in fruit set. Although florivory was more frequent in large-flowered populations, large-flowered individuals were not generally more vulnerable within populations. Rather than a causative selective factor, reduced florivory in small-flowered, selfing populations is

  13. Selective suppression of antibody production with the aid of radiolabelled birch pollen allergen

    International Nuclear Information System (INIS)

    Filipp, G.; Biro, G.; Hartung, W.D.; Lehmann, G.

    1981-01-01

    In accordance with the clonal selection theory we intended to prevent the development of artificially induced birch pollen allergy in rabbits with the aid of of the radiolabelled pollen allergen (75-1000 μCi 125 I-pollen/animal) intravenously administered prior to pollen sensitization. The birch pollen allergen, in accordance with Burnet's working hypothesis, reacts only with a genetically determining B cell subpopulation. The fixation of the radiolabelled birch pollen allergen to the receptors of the competent B cell clone causes the lesion of the latter. Compared with the control group, this group of rabbits showed an extensive suppression of anaphylactic reagin-like PCA-antibodies, and haemagglutinating antibodies in the blood as well as in nasal secretion. In addition, we tried to influence the already ongoing synthesis of the antibodies with the aid of a subsequent intravenously administered radiolabelled birch pollen allergen (750-1000μCi 125 I-pollen/animal). An intensive suppression of the synthesis of antibodies could also be proved in this case. The simultaneous immunization of the control rabbits with birch pollen and egg albumin resulted in the production of antibodies against both antigens, as expected. The hot-labelled birch pollen antigen intravenously injected before or after immunization with egg albumin and birch pollen led selectively to suppression of anti-birch-pollen PCA antibodies. The synthesis of anti-egg albumin PCA antibodies was unaffected. (author)

  14. Natural hybridization and asymmetric introgression at the distribution margin of two Buddleja species with a large overlap.

    Science.gov (United States)

    Liao, Rong-Li; Ma, Yong-Peng; Gong, Wei-Chang; Chen, Gao; Sun, Wei-Bang; Zhou, Ren-Chao; Marczewski, Tobias

    2015-06-18

    Natural hybridization in plants is universal and plays an important role in evolution. Based on morphology it has been presumed that hybridization occurred in the genus Buddleja, though genetic studies confirming this assumption have not been conducted to date. The two species B. crispa and B. officinalis overlap in their distributions over a wide range in South-West China, and we aimed to provide genetic evidence for ongoing hybridization in this study. We investigated the occurrence of hybrids between the two species at the southern-most edge of the distribution of B. crispa using five nuclear loci and pollination experiments. The genetic data suggest substantial differentiation between the two species as species-specific alleles are separated by at least 7-28 mutations. The natural hybrids found were nearly all F1s (21 of 23), but backcrosses were detected, and some individuals, morphologically indistinguishable from the parental species, showed introgression. Pollen viability test shows that the percentage of viable pollen grains was 50 ± 4% for B. crispa, and 81 ± 2% for B. officinalis. This difference is highly significant (t = 7.382, p < 0.0001). Hand cross-pollination experiments showed that B. crispa is not successful as pollen-parent, but B. officinalis is able to pollinate B. crispa to produce viable hybrid seed. Inter-specific seed-set is low (8 seeds per fruit, as opposed to about 65 for intra-specific pollinations), suggesting post-zygotic reproductive barriers. In addition, one of the reference populations also suggests a history of introgression at other localities. The occurrence of morphologically intermediate individuals between B. crispa and B. officinalis at Xishan Mountain is unequivocally linked to hybridization and almost all examined individuals of the putative hybrids were likely F1s. Despite pollination experiments indicating higher chances for introgression into B. officinalis (hybrids only produced viable seed when

  15. The Impact of the Invasive Alien Plant, Impatiens glandulifera, on Pollen Transfer Networks.

    Directory of Open Access Journals (Sweden)

    Carine Emer

    Full Text Available Biological invasions are a threat to the maintenance of ecological processes, including pollination. Plant-flower visitor networks are traditionally used as a surrogated for pollination at the community level, despite they do not represent the pollination process, which takes place at the stigma of plants where pollen grains are deposited. Here we investigated whether the invasion of the alien plant Impatiens glandulifera (Balsaminaceae affects pollen transfer at the community level. We asked whether more alien pollen is deposited on the stigmas of plants on invaded sites, whether deposition is affected by stigma type (dry, semidry and wet and whether the invasion of I. glandulifera changes the structure of the resulting pollen transfer networks. We sampled stigmas of plants on 10 sites invaded by I. glandulifera (hereafter, balsam and 10 non-invaded control sites. All 20 networks had interactions with balsam pollen, although significantly more balsam pollen was found on plants with dry stigmas in invaded areas. Balsam pollen deposition was restricted to a small subset of plant species, which is surprising because pollinators are known to carry high loads of balsam pollen. Balsam invasion did not affect the loading of native pollen, nor did it affect pollen transfer network properties; networks were modular and poorly nested, both of which are likely to be related to the specificity of pollen transfer interactions. Our results indicate that pollination networks become more specialized when moving from the flower visitation to the level of pollen transfer networks. Therefore, caution is needed when inferring pollination from patterns of insect visitation or insect pollen loads as the relationship between these and pollen deposition is not straightforward.

  16. Physicochemical characteristics of pollen collected by Amazonian stingless bees

    Directory of Open Access Journals (Sweden)

    Kemilla Sarmento Rebelo

    2016-05-01

    Full Text Available ABSTRACT: The purpose of this study was to determine the physicochemical characteristics of pollen collected by the Amazonian stingless bees Melipona seminigra and Melipona interrupta , in order to verify whether their characteristics meet the physicochemical requirements established by the Brazilian Technical Regulation for Identity and Quality of Bee Pollen. Physicochemical analyses were performed through official analytical methods. Results of pollen analyses collected by M. seminigra and M. interrupta were respectively as follows: moisture: 53.39 and 37.12%; protein: 37.63 and 24.00%; lipids: 10.81 and 6.47%; ash: 4.03 and 2.74%; crude fiber: 9.30 and 13.65%; carbohydrates: 25.66 and 44.27%; energy: 350.47 and 331.33kcal%; pH: 3.70 and 3.34; total solids: 46.60 and 62.87%, and water activity: 0.91 and 0.85. The percentages of moisture and pH in pollen collected by both studied bees are not in agreement with the Technical Regulation for bee pollen. Since some characteristics, which are inherent to the Melipona pollen, were not in conform to the current Regulation, we recommend that further studies should be conducted to better characterize it, and correct the Regulation, if necessary.

  17. Nursing protects honeybee larvae from secondary metabolites of pollen.

    Science.gov (United States)

    Lucchetti, Matteo A; Kilchenmann, Verena; Glauser, Gaetan; Praz, Christophe; Kast, Christina

    2018-03-28

    The pollen of many plants contains toxic secondary compounds, sometimes in concentrations higher than those found in the flowers or leaves. The ecological significance of these compounds remains unclear, and their impact on bees is largely unexplored. Here, we studied the impact of pyrrolizidine alkaloids (PAs) found in the pollen of Echium vulgare on honeybee adults and larvae. Echimidine, a PA present in E. vulgare pollen, was isolated and added to the honeybee diets in order to perform toxicity bioassays. While adult bees showed relatively high tolerance to PAs, larvae were much more sensitive. In contrast to other bees, the honeybee larval diet typically contains only traces of pollen and consists predominantly of hypopharyngeal and mandibular secretions produced by nurse bees, which feed on large quantities of pollen-containing bee bread. We quantified the transfer of PAs to nursing secretions produced by bees that had previously consumed bee bread supplemented with PAs. The PA concentration in these secretions was reduced by three orders of magnitude as compared to the PA content in the nurse diet and was well below the toxicity threshold for larvae. Our results suggest that larval nursing protects honeybee larvae from the toxic effect of secondary metabolites of pollen. © 2018 The Authors.

  18. Nursing protects honeybee larvae from secondary metabolites of pollen

    Science.gov (United States)

    Lucchetti, Matteo A.; Kilchenmann, Verena; Glauser, Gaetan; Praz, Christophe

    2018-01-01

    The pollen of many plants contains toxic secondary compounds, sometimes in concentrations higher than those found in the flowers or leaves. The ecological significance of these compounds remains unclear, and their impact on bees is largely unexplored. Here, we studied the impact of pyrrolizidine alkaloids (PAs) found in the pollen of Echium vulgare on honeybee adults and larvae. Echimidine, a PA present in E. vulgare pollen, was isolated and added to the honeybee diets in order to perform toxicity bioassays. While adult bees showed relatively high tolerance to PAs, larvae were much more sensitive. In contrast to other bees, the honeybee larval diet typically contains only traces of pollen and consists predominantly of hypopharyngeal and mandibular secretions produced by nurse bees, which feed on large quantities of pollen-containing bee bread. We quantified the transfer of PAs to nursing secretions produced by bees that had previously consumed bee bread supplemented with PAs. The PA concentration in these secretions was reduced by three orders of magnitude as compared to the PA content in the nurse diet and was well below the toxicity threshold for larvae. Our results suggest that larval nursing protects honeybee larvae from the toxic effect of secondary metabolites of pollen. PMID:29563265

  19. Phytochemical composition and antioxidant activity of Tuscan bee pollen of different botanic origins

    Directory of Open Access Journals (Sweden)

    V. Domenici

    2015-06-01

    Full Text Available Within the apicultural products, the honey bee-pollen is growing in commercial interest due to its high nutritional properties. For the first time, bee-pollen samples from Tuscany (Italy were studied to evaluate botanical origin, phytochemical composition and antioxidant activity. The investigated pollen loads were composed of three botanical families: Castanea, Rubus and Cistus.The highest levels of proteins and lipids were detected in Rubus pollen. Castanea pollen contained greater polyphenols, flavonoids and anthocyanins content, while the highest flavonols level wasdetected in Cistus pollen. These results were also confirmed by front-face fluorescence spectroscopy, used here, for the first time, as a fast tool to characterize bee-pollens.

  20. Influence of fertilizer draw solution properties on the process performance and microbial community structure in a side-stream anaerobic fertilizer-drawn forward osmosis - ultrafiltration bioreactor.

    Science.gov (United States)

    Kim, Youngjin; Li, Sheng; Chekli, Laura; Phuntsho, Sherub; Ghaffour, Noreddine; Leiknes, TorOve; Shon, Ho Kyong

    2017-09-01

    In this study, a side-stream anaerobic fertilizer-drawn forward osmosis (FDFO) and ultrafiltration (UF) membrane bioreactor (MBR) hybrid system was proposed and operated for 55days. The FDFO performance was first investigated in terms of flux decline with various fertilizers draw solution. Flux decline was very severe with all fertilizers due to the absence of aeration and the sticky property of sludge. Flux recovery by physical cleaning varied significantly amongst tested fertilizers which seriously affected biofouling in FDFO via reverse salt flux (RSF). Besides, RSF had a significant impact on nutrient accumulation in the bioreactor. These results indicated that nutrient accumulation negatively influenced the anaerobic activity. To elucidate these phenomena, bacterial and archaeal community structures were analyzed by pyrosequencing. Results showed that bacterial community structure was affected by fertilizer properties with less impact on archaeal community structure, which resulted in a reduction in biogas production and an increase in nitrogen content. Copyright © 2017 Elsevier Ltd. All rights reserved.