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Sample records for reduces pollen viability

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

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    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.

  2. A rat pancreatic ribonuclease fused to a late cotton pollen promoter severely reduces pollen viability in tobacco plants

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    R.B. Bernd-Souza

    2000-06-01

    Full Text Available The effects of an animal RNase fused to the late cotton pollen-specific promoter G9 in a plant system were investigated. Expression of the chimeric genes G9-uidA and G9-RNase in tobacco plants showed that the 1.2-kb promoter fragment of the G9 gene was sufficient to maintain tissue and temporal specificity in a heterologous system. GUS (beta-glucuronidase expression was detected only in pollen from anther stage 6 through anthesis, with maximal GUS activity in pollen from stage 10 anthers. Investigating the effects of the rat RNase on pollen viability at stage 10, we found that pollen viability was reduced from 79 to 8% and from 89 to 40%, in pollen germination and fluoresceine diacetate assays, respectively, in one G9-RNase transgenic line, suggesting a lethal effect of the RNase gene. This indicates that the rat RNase produces deleterious effects in this plant system and may be useful for engineering male sterility.Foram investigados os efeitos da expressão de uma ribonuclease de origem animal em um sistema vegetal, ligando-se esta ao promotor do gene pólen-específico G9 de algodão. Examinou-se a expressão dos genes quiméricos G9-uidA e G9-RNase em plantas de tabaco e determinou-se que o fragmento de 1.2 kb do promotor do gene G9 foi suficiente para manter a especificidade temporal e espacial da expressão, em sistema heterólogo. A expressão do gene GUS foi detectada somente em pólen, do estágio 6 do desenvolvimento da antera até a antese, com atividade máxima em pólen de anteras no estágio 10. Estudos neste estágio com linhagens transgênicas contendo G9-RNase mostraram que um clone transgênico apresentava reduções na viabilidade do pólen de 79 para 8% e de 89 para 40% nos testes de germinação e coloração com diacetato de fluoresceína, respectivamente, sugerindo letalidade na expressão do gene de RNase. Estes resultados indicam que a RNase animal apresenta um efeito deletério em planta e oferece possibilidade de uso

  3. 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 composit

  4. Storage and Viability of Hedychium Pollen

    Science.gov (United States)

    Hedychium species generally flower in the summer and fall, but some bloom in winter and spring times. The different flowering times of the species implies that there is a need to find a way for storing and conserving viable pollen. The maintenance of pollen viability depends on several factors, incl...

  5. Flower numbers, pod production, pollen viability, and pistil function are reduced and flower and pod abortion increased in chickpea (Cicer arietinum L.) under terminal drought.

    Science.gov (United States)

    Fang, Xiangwen; Turner, Neil C; Yan, Guijun; Li, Fengmin; Siddique, Kadambot H M

    2010-01-01

    Terminal drought during the reproductive stage is a major constraint to yield of chickpea in many regions of the world. Termination of watering (WS) during podding in a small-seeded desi chickpea (Cicer arietinum L.) cultivar, Rupali, and a large-seeded kabuli chickpea cultivar, Almaz, induced a decrease in predawn leaf water potential (LWP), in the rate of photosynthesis, and in stomatal conductance. Compared to well-watered (WW) controls, the WS treatment reduced flower production by about two-thirds. In the WW treatment, about 15% of the flowers aborted and 42% (Rupali) and 67% (Almaz) of the pods aborted, whereas in the WS treatment 37% and 56% of the flowers aborted and 54% and 73% of the pods aborted, resulting in seed yields of 33% and 15% of the yields in WW plants in Rupali and Almaz, respectively. In vitro pollen viability and germination in Rupali decreased by 50% and 89% in the WS treatment, and pollen germination decreased by 80% in vivo when pollen from a WS plant was placed on a stigma of a WW plant. While about 37% of the germinated pollen tubes from WW plants and 22% from the WS plants reached the ovary in the WW plants, less than 3% of pollen grains reached the ovary when pollen from either WS or WW plants was placed on a stigma of a WS plant. It is concluded that, in addition to pod abortion, flower abortion is an important factor limiting yield in chickpea exposed to terminal drought and that water deficit impaired the function of the pistil/style more than the pollen.

  6. 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.

  7. Viability of pollen grains of tetraploid banana

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    Taliane Leila Soares

    2016-01-01

    Full Text Available ABSTRACT Obtaining banana tetraploid cultivars from triploid strains results in total or partial reestablishment of fertility, allowing the occurrence of some fruits with seeds, a feature that is undesirable from a marketing perspective. The objective of this study was to assess the viability of pollen of 12 banana tetraploid hybrids (AAAB by means of in vitro germination and two histochemical tests (acetocarmine and 2,3,5-triphenyltetrazolium chloride. The pollen tube growth was evaluated by germinating grains in three culture media — M1: 0.03% Ca(NO3∙4H2O, 0.02% Mg(SO4∙7H2O, 0.01% KNO3, 0.01% H3BO3 and 15% sucrose; M2: 0.03% Ca(NO3∙4H2O, 0.01% KNO3, 0.01% H3BO3 and 10% sucrose; and M3: 0.015% H3BO3, 0.045% Ca3(PO42 and 25% sucrose. The acetocarmine staining indicated high viability (above 80%, except for the genotypes YB42-17 and Caprichosa, which were 76 and 70%, respectively. However, the in vitro germination rate was lower than 50% for all the genotypes, except for the hybrids YB42-17 (M1 and YB42-47 (M1. The medium M1 provided the greatest germination percentage and pollen tube growth. Among the genotypes assessed, YB42-47 presented the highest germination rate (61.5% and tube length (5.0 mm. On the other hand, the Vitória cultivar had the lowest germination percentage (8.2% in medium M1. Studies of meiosis can shed more light on the differences observed in the evaluated tetraploids, since meiotic irregularities can affect pollen viability.

  8. The relationship of storage and viability of Lily pollen

    NARCIS (Netherlands)

    Rhee, H.K.; Lim, Jin Hee; Cho, Hae Ryong; Tuyl, van J.M.

    2003-01-01

    The study was conducted to estimate the pollen viability of eight lily genotypes and optimum storage conditions. Pollen viability was assessed by in vitro germination, FCR (Fluorochromatic raction) test and fruit set test. Pollen grains were stored in the dark chamber where the temperature was maint

  9. Intra-inflorescence pollen viability in accessions of Brachiaria ruziziensis

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    Cristina Maria Pinto de Paula

    2014-05-01

    Full Text Available Knowledge about the pollen viability is important to ensure success in controlled hybridizations and, consequently, support breeding programs. The aims of this study were to evaluate the pollen viability in progenies of artificially induced tetraploid accessions of Brachiaria ruziziensis, and to verify if the position of the flower buds on the raceme affects the pollen viability rate. Staining of aborted and non-aborted pollen (Alexander’s technique was used to determine the viability of the pollen grains. Tetraploid accessions of B. ruziziensis plants had high pollen viability (x = 76.8% to x = 99.6%. Some of these plants had viability rates similar to diploid B. ruziziensis, showing that the induction of chromosome duplication by colchicine did not result in abnormalities in production and morphology of pollen grains. Pollen grains from middle and apical regions of the raceme presented higher viability rates (x = 97.9% and x = 97.7% respectively. The viability of pollen grains in artificially induced tetraploid accessions of B. ruziziensis plants was high, which may favor obtaining fertile descendants in possible crosses

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

    African Journals Online (AJOL)

    Prof. Ogunji

    sub-tropical regions of the world where they serve as staple and cash crops. The cultivated ... viability and germination rate in different crops. For example ..... Pollen fertility in Musa: Viability in cultivar grown in southern Australia. Aust. J. Agric.

  11. Morphology and viability of castor bean genotypes pollen grains

    OpenAIRE

    Maria Selma Alves Silva Diamantino; Maria Angélica Pereira de Carvalho Costa; Taliane Leila Soares; Daniel Vieira Morais; Simone Alves Silva; Everton Hilo Souza

    2016-01-01

    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 germinat...

  12. Morphology and viability of castor bean genotypes pollen grains

    OpenAIRE

    Diamantino,Maria Selma Alves Silva; Costa,Maria Angélica Pereira de Carvalho; Soares,Taliane Leila; Morais,Daniel Vieira; Silva,Simone Alves; Souza,Everton Hilo de

    2016-01-01

    ABSTRACT. 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 vitr...

  13. STUDY ON POLLEN VIABILITY AS BIOINDICATOR OF AIR QUALITY

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    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.

  14. Pollen Viability and Pollen Tube Attrition in Cranberry (Vaccinium macrocarpon)

    Science.gov (United States)

    The content of mature seed in a cranberry fruit increases with stigmatic pollen load. On average, however, only two seeds result for every tetrad of pollen deposited. What then is the fate of the two remaining pollen grains fused in each tetrad? Germination in vitro revealed that most of the grains ...

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

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    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.

  16. 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.

  17. Impact of cytomixis on meiosis, pollen viability and pollen size in wild populations of Himalayan poppy (Meconopsis aculeata Royle)

    Indian Academy of Sciences (India)

    V K Singhal; Puneet Kumar

    2008-09-01

    We report the occurrence of cytomixis in wild populations of Himalayan poppy (Meconopsis aculeata Royle), which is considered to be an important and threatened medicinal plant growing in the high hills of the Himalayas. The impact of cytomixis on meiotic behaviour, reduced pollen viability and heterogeneous-sized pollen grains was also studied. Cytological studies in the seven wild populations from the high hills of Himachal Pradesh revealed that all the Himalayan populations exist uniformly at the tetraploid level (2n=56) on x=14. The phenomenon of chromatin transfer among the proximate pollen mother cells (PMCs) in six populations caused various meiotic abnormalities. Chromatin transfer also resulted in the formation of coenocytes, aneuploid, polyploid and anucleated PMCs. Among individuals that showed chromatin transfer, chromosome stickiness and interbivalent connections were frequently observed in some PMCs. The phenomenon of cytomixis in the species seems to be directly under genetic control; it affects the meiotic course considerably and results in reduced pollen viability.

  18. Morphology and viability of castor bean genotypes pollen grains

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    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.

  19. Using the pollen viability and morphology for fluoride pollution biomonitoring.

    Science.gov (United States)

    Malayeri, Behrooz Eshghi; Noori, Mitra; Jafari, Mehrana

    2012-06-01

    The methods using plants for biomonitoring of air and soil quality are simple, cheap, and fast and can supplement the classical physicochemical methods. In this study, biological pollen characterization of some collected legume species from an aluminum smelter area in Iran (IRALCO) was carried out to determine the actual value of pollen as a bioindicator of the effects of soil and atmospheric pollution. Young buds and flowers of six legumes (Cercis siliquastrum L., Medicago sativa L., Robinia pseudoacacia L., Melilotus officinalis (L.) lam, Trifolium repens L., and Sophora alopecuroides L.) in polluted and control plants were removed and compared. Studies of light and electron microscopic preparation showed some abnormalities during pollen development in affect of fluoride pollution. The viability of pollen grains estimated by staining with acetocarmine shows sharp differences in smearing advanced pollen grains from abnormal ones. Except M. officinalis, the pollen grains of C. siliquastrum, M. sativa, R. pseudoacacia, T. repens, and S. alopecuroides in polluted areas showed light, partial, or no staining with acetocarmine, whereas almost all of the control ones clearly stained. Observation of the pollen grains by light microscopy and scanning electron microscopy showed the significant effect of fluoride on shapes and sizes of pollen grains. The stimulation and inhibition of these pollen characteristics depend on the pollen species as well as on the pollutant and its concentration. Therefore, pollen grains provide essential information on biological impact of pollutants and they are good candidates for biomonitoring the atmospheric and edaphic pollutions.

  20. Expression of fission yeast cdc25 driven by the wheat ADP-glucose pyrophosphorylase large subunit promoter reduces pollen viability and prevents transmission of the transgene in wheat.

    Science.gov (United States)

    Chrimes, D; Rogers, H J; Francis, D; Jones, H D; Ainsworth, C

    2005-04-01

    Cell number was to be measured in wheat (Triticum aestivum) endosperm expressing Spcdc25 (a fission yeast cell-cycle regulator) controlled by a supposedly endosperm-specific promoter, AGP2 (from the large subunit of ADP glucose pyrophosphorylase). Wheat was transformed by biolistics either with AGP2::GUS or AGP2::Spcdc25. PCR and RT-PCR checked integration and expression of the transgene, respectively. In cv. Chinese Spring, AGP2::GUS was unexpectedly expressed in carpels and pollen, as well as endosperm. In cv. Cadenza, three AGP2::Spcdc25 plants, AGP2::Spcdc25.1, .2 and .3, were generated. Spcdc25 expression was detected in mature leaves of AGP2::Spcdc25.1/.3 which exhibited abnormal spikes, 50% pollen viability and low seed set per plant; both were small compared with the nonexpressing and normal AGP2::Spcdc25.2. Spcdc25 was not transmitted to the T(1) in AGP2::Spcdc25.1 or .3, which developed normally. Spcdc25 was PCR-positive in AGP2::Spcdc25.2, using primers for a central portion, but not with primers for the 5' end, of the ORF, indicating a rearrangement; Spcdc25 was not expressed in either T(0) or T(1). The AGP2 promoter is not tissue-specific and Spcdc25 expression disrupted reproduction.

  1. Pollen viability and storage temperature for Southern highbush and Rabbiteye blueberry breeding

    Science.gov (United States)

    Pollen viability, as measured by tetrad germination, has been reported, but these studies focused on freshly collected pollen and did not address viability of pollen stored at different temperatures over time. Moreover, genetic differences in pollen viability have been reported in blueberry genotype...

  2. In vitro pollen germination and pollen viability in passion fruit (Passiflora spp.

    Directory of Open Access Journals (Sweden)

    Taliane Leila Soares

    2013-12-01

    Full Text Available The use of Passiflora species for ornamental purposes has been recently developed, but little is known about pollen viability and the potential for crossing different species. The objective of this study was to evaluate the pollen viability of six Passiflora species collected from different physiological stages of development through in vitro germination and histochemical analysis using dyes. The pollen was collected in three stages (pre-anthesis, anthesis and post-anthesis. Three compositions of culture medium were used to evaluate the in vitro germination, and two dyes (2,3,5-triphenyltetrazolium chloride, or TTC, and Lugol's solution were used for the histochemical analysis. The culture medium containing 0.03% Ca(NO3 4H2O, 0.02% of Mg(SO4 .7H2O, 0.01% of KNO3, 0,01% of H3BO3, 15% sucrose, and 0.8% agar, pH 7.0, showed a higher percentage of pollen grains germinated. Anthesis is the best time to collect pollen because it promotes high viability and germination. The Lugol's solution and TTC dye overestimated the viability of pollen, as all accessions showed high viability indices when compared with the results obtained in vitro.

  3. Air quality biomonitoring through pollen viability of Fabaceae.

    Science.gov (United States)

    Duro, Anna; Piccione, Vincenzo; Zampino, Daniela

    2013-05-01

    In this study, pollen viability and germination of three plant species, Cercis siliquastrum L., Robinia pseudoacacia L., and Spartium junceum L., belonging to the Fabaceae family, was evaluated in sites with different intensity of road traffic, constantly monitored with continuous analysers for air pollutants (carbon monoxide (CO), sulphur dioxide (SO(2)), and nitrogen dioxide (NO(2))) by the Municipality of Catania. Two sites, in which road traffic was absent, were selected, too. The percentages of viable pollen by 2,3,5-trypheniltetrazolium chloride (TTC) test ranged from 59.0 to 90.2 % in C. siliquastrum, from 61.5 to 83.5 % in S. junceum and from 67.5 to 84.3 % in R. pseudoacacia. The percentages of germination varied from 41.0 to 72.7 % in C. siliquastrum, from 42.0 to 64.7 % in S. junceum and from 38.3 to 66.3 % in R. pseudoacacia. The highest percentages of viable pollens were found in no-road traffic stations by either TTC or germination tests, while the lowest values were detected in a site characterised by heavy road traffic. In the monitored period (2007-2009), pollen viability, germinability and tube length of C. siliquastrum resulted in a significant negative correlation to CO, SO(2) and NO(2), whereas data from TTC and germination tests on S. junceum and R. pseudoacacia pollens were not well correlated to air pollutants. The results showed that pollen viability, germination and tube growth in C. siliquastrum were affected by air pollution. S. junceum and R. pseudoacacia were not very influenced by air pollutants, suggesting a different pollen sensitivity of these species.

  4. STIGMA RECEPTIVITY AND POLLEN VIABILITY OF Melaleuca alternifolia

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    Liliana Baskorowati

    2009-06-01

    Full Text Available Stigma  receptivity based on seed set and pollen  tubes growth  following controlled pollination of flowers  of different  ages was examined  in Melaleuca alternifolia. The stigma secretion during 10 days after anthesis and pollen viability under three different temperatures and five storage times were also observed. These series of research were undertaken because successful controlled pollination of M. alternifolia depends on the application of viable pollen to the receptive compatible  stigma. The objective of this research was therefore to determine the stigma receptivity and pollen viability of M. alternifolia. Results showed that the stigma receptivity began to develop  on day  one and finished  on day  seven after anthesis,  peak receptivity occurred from day three to day six. The stigma receptivity also coincides with the appearance of secretion in the stigma, occurring  from day three to day seven after anthesis. Therefore,  the time for pollination of M. alternifolia appeared to extend for  approximately 7 days after anthesis. Data for M. alternifolia showed that regardless of storage temperature, pollen  was still  viable  after 26 weeks  of storage;  results also demonstrated  that the lowest temperature  (-18oC was the best regime for long term storage.

  5. 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.

  6. Viability and seasonal distribution patterns of Scots pine pollen in Finland.

    Science.gov (United States)

    Pulkkinen, P.; Rantio-Lehtimäki, A.

    1995-01-01

    Germination ability and airborne counts of Scots pine (Pinus sylvestris L.) pollen were studied during the spring of 1993 at Turku in southern Finland (60 degrees 32' N, 22 degrees 28' E) and at Utsjoki in northern Finland (69 degrees 45' N, 27 degrees 01' E). Pollen waas trapped from the beginning of May to the end of June in a high-volume air sampler. Germination tests were performed to determine the in vitro pollen viability of the trapped pollen. Airborne pine pollen counts were obtained from a continuously operating Burkard trap located near each high-volume sampler. When male flowering began, phenological observations were carried out on pollen grains collected in rotored samplers located in pine and spruce stands and open fields near Turku and Utsjoki. In southern Finland, the peak period of pine pollen production was short, lasting for only 3 days, but it accounted for about 80% of the total germinating pine pollen yield for the year. The peak count was on May 20, with over 2000 germinating pollen grains per cubic meter of air. Pollen germination rates of up to 70% were obtained during the week preceding the local pollen peak, and rates reached almost 90% on the peak day. Pollen viability remained at 45 to 65% for 1 week after the peak. There was no significant difference between the pollen counts for day and night, indicating that during the main pollen season, the pollen source was close to Turku. Before the local pollen peak, the counts of living pine pollen were low, indicating that pine pollen transported over long distances was of little ecological importance in 1993 in the Turku area. In northern Finland, the first pollen grains were caught on July 4, and the peak day was July 13. However, no viable pollen was observed during this period, indicating that there was little gene drift from southern to northern Finland in 1993.

  7. Pollen viability reduction as a potential cost of ant association for Acacia constricta (Fabaceae).

    Science.gov (United States)

    Wagner, D

    2000-05-01

    Field studies investigating the impact of ants on the reproduction of plants bearing extrafloral nectaries have traditionally focused on seed production, a component of female fitness. The purpose of this study was to test whether ants can affect the pollen viability, a component of male fitness, when they visit flowers of the shrub Acacia constricta. Acacia constricta inflorescences hand-pollinated with flowers over which Formica perpilosa ants had crawled set significantly fewer seed pods than inflorescences hand-pollinated by control flowers that had no contact with ants. Many ant species secrete antibiotic substances onto the integument that render pollen inviable, and these secretions are probably the mechanism for reduced pollen viability in this study. The ratio of seed pods produced by self-pollinated inflorescences to those produced by cross-pollinated inflorescences was 0.16, indicating that A. constricta is largely self-incompatible. Because F. perpilosa workers forage primarily on the acacia tree under which they nest, they are unlikely to serve as efficient vectors of outcrossing. Previous work showed that A. constricta shrubs with F. perpilosa ants produce approximately twice as many seeds as similarly sized plants not so associated. The results indicate that association with F. perpilosa could cause a reproductive trade-off for A. constricta: benefits to female function may be accompanied by costs to male function. Selection to discourage ant visitation to flowers may have affected the pollination biology of this and other ant-associated plant species.

  8. Morphology and viability of pollen grains from passion fruit species (Passiflora spp.

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    Taliane Leila Soares

    2013-12-01

    Full Text Available The characterization and viability of pollen grains are useful tools to guide crosses in breeding programs. The objective of this study was to describe the morphological patterns and viability of pollen grains from five accessions of Passiflora edulis f. flavicarpa O. Deg. and five accessions of Passiflora setacea DC. Pollen morphology descriptions were made using light microscopy and scanning electron microscopy, whereas the viability analysis was performed by in vitro germination and histochemical analysis (Lugol's solution and 2,3,5-triphenyltetrazolium chloride. Pollen grains assessed for germination were inoculated in culture medium containing Ca(NO3.4H2O (0.03%, Mg(SO4.7H2O (0.02%, KNO3 (0.01%, H3BO3 (0.01%, sucrose (15% and agar (0.8%. Although P. edulis and P. setacea showed the same shape and type of pollen aperture, the two differed in terms of their morphology and exine ornamentation pattern. In vitro analysis showed that one of the P. edulis f. flavicarpa accessions (designated BGP 330 presented the highest germination rate (53.98% and longest pollen tube (2.18 mm. The histochemical analysis overestimated pollen viability when compared with the in vitro results. The results of this study contribute to the breeding of Passiflora species by increasing the understanding of their morphology and pollen grain viability.

  9. Pollen viability and its effect on fruit set of oil palm (Elaeis guineensis Jacq.

    Directory of Open Access Journals (Sweden)

    ALFIN WIDIASTUTI

    2008-01-01

    Full Text Available The research was aimed at studying (1 the decline of pollen viability during storage, and (2 the effect of pollen amount on fruit set of oil palm (Elaeis guineensis Jacq.. The experiment was conducted at PT. Dami Mas Sejahtera and PT. Sinar Mas Agro Resource and Technology (SMART Tbk, Riau from February to August 2004. The first experiment was investigated up to six months storage period in the refrigerator, whereas in the second experiment a randomized complete block design with two factors was used: length of storage, i.e. 0, 1 and 2 months and amount of pollen, i.e. 0.022, 0.044, 0.066, 0.088, and 0.11 g mixed with powder to 10g to pollinate an inflorescence. The result showed that the viability of pollen started to decline three months after storage from about 92% to 83%, and declined to about 75% after six months of storage. Result of the second experiment showed that storage of pollen up to two months did not affect percentage of normal fruit, although the percentage of parthenocarpic fruits was decreased. This could be due to the high viability of pollen as the viability was remained high (about 90% after being stored for two months in the refrigerator. Pollen with high viability could be used in a smaller amount to pollinate a female inflorescence without affecting fruit set of about 70-76%.SD037 had a higher reproductive success than SD038 and SD39.

  10. Pollen viability of Polygala paniculata L. (Polygalaceae) using different staining methods.

    Science.gov (United States)

    Frescura, Viviane Dal-Souto; Laughinghouse, Haywood Dail; do Canto-Dorow, Thais Scotti; Tedesco, Solange Bosio

    2012-12-01

    Polygala paniculata L. is a medicinal plant that grows in the Brazilian Atlantic coast, known as 'barba-de-São-João', 'barba-de-bode', 'vassourinha branca', and 'mimosa'. In this study, pollen viability was estimated by three different staining methods: 2% acetic orcein, 2% acetic carmine, and Alexander's stain. The young inflorescences of twenty accessions were collected and fixed in a solution of ethanol: acetic acid (3:1) for 24 hours, then stored in ethanol 70% under refrigeration. Six slides per plant, two for each stain, were prepared by squashing, and 300 pollen grains per slide were analyzed. Pollen viability was high (> 70%) for most accessions of P. paniculata using the Alexander's stain, which proved the most adequate method to estimate pollen viability.

  11. 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.

  12. In vitro germination and viability of pollen grain of coconut accessions1

    Directory of Open Access Journals (Sweden)

    Catrine Regina Feitosa Moura

    Full Text Available Storage as a means of maintaining the pollen viability is important for the preservation of the genetic variability, facilitates the exchange of germplasm and greatly contributes to the generation of variability obtained from artificial crosses, increasing the efficiency of breeding programs. The objective of this study was to select different culture media for the in vitro germination of pollen grain of dwarf and tall coconut accessions, as well as to determine the viability of pollen grain at room temperature conditions. For this purpose, Brazil Green Dwarf (BGD and Brazilian Tall (BRA pollen grains derived from the Coconut Active Germplasm Bank of Embrapa Coastal Tablelands Sergipe were used. To evaluate the effect of different culture media on the in vitro germination of pollen grains of anão verde do Brasil de Jiqui (AVeBrJ and gigante do Brasil Praia do Forte (GBrPF accessions, they were inoculated on to Petri dishes containing 2 ml of culture media. The pollen viability was assessed by staining with 1% acetic carmine and in vitro germination at 0, 24, 48 and 72 hours. The culture medium of Lora is suitable to assess the in vitrogermination of pollen grain of the AVeBrJ and GBrPF accessions. The pollen grain of the AVeBrJ accession showed intermediate viability (66.87% at room temperature up to 23.14 hours by in vitro germination. The pollen grain of the GBrPF accession showed high viability, above 70%, at room temperature up to 120 hours by in vitro germination.

  13. STIGMATIC RECEPTIVITY AND POLLEN VIABILITY OF Theobroma subincanum Mart.:FRUIT SPECIES FROM THE AMAZON REGION

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    MAICON DOUGLAS ARENAS-DE-SOUZA

    Full Text Available ABSTRACT Theobroma subincanum (cupuí is a fruit species native to the Amazon region. Fruits are enjoyed by local people and consumed both as fresh fruit such as juice, nectar or soft drinks. Reproductive biology studies provide contributions to conservation strategies and plant improvement. The present study aimed to analyze the stigmatic receptivity and pollen viability of T. subincanum. This study was developed in a forest fragment located in the urban perimeter of the municipality of Alta Floresta, MT. In the flowering period, flower buds or flowers were collected in seven different times, as follows: 10 pm, 02 am, 06 am, 10 am, 2 pm, 6 pm, and 10 pm. Pollen viability was estimated by reactive Alexander (1969 and stigmatic receptivity using 3% hydrogen peroxide. Pollen viability averages were submitted to analysis of variance, while stigmatic receptivity was analyzed by average percentage in each interval. Four floral stages were characterized based on flower opening, and from 6 am, fully opened flowers have already been found (stage IV. The percentage of pollen viability was not affected by collection times. In the stigmatic receptivity analysis, it was observed that in all floral stages, stigma was receptive; however, the highest percentages of stigmatic receptivity were found from 2 am to 10 am of the same day, which is the most propitious time for fertilization. Pollen collection of T. subincanum may be performed in any of schedules evaluated in this study, since it is held with high viability percentage.

  14. FT-IR Characterization of Pollen Biochemistry, Viability, and Germination Capacity in Saintpaulia H. Wendl. Genotypes

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    Erzsebet Buta

    2015-01-01

    Full Text Available FT-IR characterization of pollen biochemistry was analyzed to detect possible connection with the viability (by staining with potassium iodide, 25% and the germination capacity (on solid nutrient medium, in 15 Saintpaulia genotypes. Vibrational spectroscopy indicates that the pollen of S. ionantha genotype “Red Velvet” is rich in proteins, lipids, triglycerides, and esters and has a viability of 88.4% and a low germination capacity (27.16%. For S. ionantha “Jolly Red” and “Lucky Ladybug” genotypes, pollen showed high viability (88.81–91.49% and low germination capacity (23.02–9.17%, even though the pollen is rich in carbohydrates. S. ionantha “Aloha Orchid” genotype has the highest percentage of viability (94.32% and germination capacity (45.73% and a rich content of carbohydrates and polygalacturonic acids. In S. rupicola and S. ionantha genotypes, the rich content of polygalacturonic acids, lipids, and carbohydrates favourably influenced the germination capacity. Spectroscopic result indicates, through different absorbance band intensity, a possible link between biochemical composition, viability, and germination capacity of Saintpaulia pollen. To determine exactly the relation between biochemistry and biological processes, it is necessary to initiate quantitative researches.

  15. The influence of pleiotropy between viability and pollen fates on mating system evolution.

    Science.gov (United States)

    Jordan, Crispin Y

    2015-02-01

    Floral displays are functionally and genetically integrated structures, so modifications to display will likely affect multiple fitness components (pleiotropy), including pollen export and self-pollination, and therefore selfing rate. Consequently, the great diversities of floral displays and of mating systems found among angiosperms have likely co-evolved. I extend previous models of mating system evolution to determine how pleiotropy that links viability (e.g., probability of survival to reproduction) and the allocation of pollen for export and selfing affects the evolution of selfing, outcrossing, and in particular, mixed mating. I show that the outcome depends on how pollen shifts from being exported, unused, or used for selfing. Furthermore, pleiotropy that affects viability can explain observations not addressed by previous theory, including the evolution of mixed mating despite high inbreeding depression in the absence of pollen-limitation. Therefore, pleiotropy may play a key role in explaining selfing rates for such species that exhibit otherwise enigmatic mating systems.

  16. Meiotic behavior and pollen viability in Moringa oleifera (Moringaceae) cultivated in southern Brazil.

    Science.gov (United States)

    Silva, N; Mendes-Bonato, A B; Sales, J G C; Pagliarini, M S

    2011-01-01

    Although originally from India, Moringa oleifera is now cultivated throughout most of the tropics, including Brazil. Despite its multipurpose value for food and traditional medicine, little is known about the meiotic behavior and pollen viability of M. oleifera. We evaluated microsporogenesis and pollen viability in eleven plants grown in southern Brazil (Maringá, Paraná). Bud flowers were collected in different stages of development. All plants that we analyzed presented 2n = 28 chromosomes, as previously reported for this species. Chromosomes paired as bivalents. Meiotic abnormalities were rare and metaphase I was the most affected phase. Pollen viability was superior to 88%. Tripolar spindles in metaphase II, leading to the formation of unreduced gametes, were recorded in some plants at a low frequency.

  17. [Pollen viability, stigma receptivity and fruiting characteristics of botanical origin of Jinxianlian].

    Science.gov (United States)

    Shao, Qing-song; Wang, Yong; Hu, Run-huai; Zhang, Wang-shu; Li, Ming-yan

    2015-03-01

    The viability and life span of pollen were evaluated by TTC (2,3,5-triphenyl tetrazlium chloride) and the peroxidase solution, the stigma receptivity were estimated by benzidine-H2O2 method and the fruiting characteristics were investigated. The results showed that (1) Anoectochilus roxburghii and A. formosanus appeared the same up-and-down trend of the pollen viability, increased and then decreased. The storage temperature and storage time had significant impact on the pollen viability. With the extension of storage time, the pollen activity decreased. 4 degrees C refrigerator storage may be extended the pollen vitality. (2) The stigma had receptivity in 1st day and reached the highest level in the 4th day after blooming. A. roxburghii lost receptivity in the 8th day while A. formosanus lost receptivity in the 10th day after blooming. (3) The different pollination had significant impact on seed setting rate. The seed setting rate of artificial cross-pollination was higher than that of the artificial self-pollination. Collecting pollen in the 3rd day and carrying out artificial cross-pollination in the 4th day after blooming can significantly improve seed setting rate. The results provided technical assurance for A. roxburghii and A. formosanus breeding of new varieties and seed breeding.

  18. Influence of gamma irradiation on pollen viability, germination ability ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-12-15

    Dec 15, 2009 ... cannot fertilize the egg-cell and the polar nuclei. These .... irradiated pollens by sitting drop culture method (Zaman, 2006). The medium was ... and 24 h for germination ability tests of setting the experiment. (Şensoy et al.

  19. Banana nectar as a medium for testing pollen viability and ...

    African Journals Online (AJOL)

    Administrator

    2007-05-16

    May 16, 2007 ... poor depend on bananas for food and cash income, a decline in banana .... The objectives of this study were (i) to compare the rate of banana pollen .... acuminata and M. balbisiana in Australia was given as. 71% and 98% ...

  20. Chromosome number, microsporogenesis, microgametogenesis, and pollen viability in the Brazilian native grass Mesosetum chaseae (Poaceae).

    Science.gov (United States)

    Silva, L A C; Pagliarini, M S; Santos, S A; Silva, N; Souza, V F

    2012-11-28

    The genus Mesosetum is a primarily South American genus with 42 species. Mesosetum chaseae, regionally known as 'grama-do-cerrado', is abundant in the Pantanal Matogrossense (Brazil); it is a valuable resource for livestock and for environmental conservation. We collected specimens from the Nhecolandia sub-region of the Brazilian Pantanal, located in Corumbá, Mato Grosso do Sul, Brazil. We examined chromosome number, ploidy level, meiotic behavior, microgametogenesis, and pollen viability of 10 accessions. All the accessions were diploid, derived from x = 8, presenting 2n = 2x = 16 chromosomes. Chromosomes paired as bivalents showing, predominantly, two terminal chiasmata. Interstitial chiasmata were rare. Meiosis was quite normal producing only a few abnormal tetrads in some accessions. Microgametogenesis, after two mitotic divisions, produced three-celled pollen grains. Pollen viability was variable among plant and accessions and was not correlated with meiotic abnormalities.

  1. Glufosinate does not affect floral morphology and pollen viability in glufosinate-resistant cotton (Gossypium hirsutum)

    Science.gov (United States)

    Studies were conducted to determine whether glufosinate treatments to glufosinate-resistant cotton caused changes in floral morphology, pollen viability, and seed set. Four glufosinate treatments were included: (1) glufosinate applied postemergence over the top (POST) at the four-leaf stage, (2) glu...

  2. Cell biological analyses of anther morphogenesis and pollen viability in Arabidopsis and rice.

    Science.gov (United States)

    Chang, Fang; Zhang, Zaibao; Jin, Yue; Ma, Hong

    2014-01-01

    Major advances have been made in recent years in our understanding of anther development through a combination of genetic studies, cell biological technologies, biochemical analysis, microarray and high-throughput sequencing-based approaches. In this chapter, we summarize the widely used protocols for pollen viability staining; the investigation of anther morphogenesis by light microscopy of semi-thin sections; TUNEL assay for programmed tapetum cell death; and laser microdissection procedures to obtain specialized cells or cell layers for carrying out transcriptomics.

  3. Pollen Viability, Pistil Receptivity, and Embryo Development in Hybridization of Nelumbo nucifera Gaertn

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    Yan-Li Wang

    2012-01-01

    Full Text Available Seed set is usually low and differs for different crosses of flower lotus (Nelumbo nucifera Gaertn.. The reasons remain unknown, and this has a negative impact on lotus breeding. To determine the causes, we carried out two crosses of flower lotus, that is, “Jinsenianhua” × “Qinhuaihuadeng” and “Qinhuaihuadeng” × “Jinsenianhua” and pollen viability, pistil receptivity, and embryo development were investigated. The pollen grains collected at 05:00-06:00 hrs had the highest viability, and the viabilities of “Jinsenianhua” and “Qinhuaihuadeng” were 20.6 and 15.7%, respectively. At 4 h after artificial pollination, the number of pollen grains germinating on each stigma reached a peak: 63.0 and 17.2 per stigma in “Jinsenianhua” × “Qinhuaihuadeng” and “Qinhuaihuadeng” × “Jinsenianhua”, respectively. At 1 d after artificial pollination, the percentages of normal embryos in the two crosses were 55.0 and 21.9%, respectively; however, at 11 d after pollination, the corresponding percentages were 20.8 and 11.2%. Seed sets of the two crosses were 17.9 and 8.0%, respectively. The results suggested that low pistil receptivity and embryo abortion caused low seed set in “Qinhuaihuadeng” × “Jinsenianhua”, whereas low fecundity of “Jinsenianhua” × “Qinhuaihuadeng” was mainly attributable to embryo abortion.

  4. 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.

  5. Cytoembryological evaluation, meiotic behavior and pollen viability of Paspalum notatum tetraploidized plants

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    Karine Cristina Krycki

    2016-11-01

    Full Text Available This study evaluated the mode of reproduction, the meiotic behavior and the pollen viability of three tetraploid plants (2n=4x=40 originated from somatic chromosome duplication of Paspalum notatum plants. The plant WKS 3 changed the mode of reproduction after duplication and became apomictic. The plants WKS 63 and WKS 92 confirmed sexual mode of reproduction identical to that of the original genotype. The analyzed plants presented meiotic abnormalities related to tetraploidy, and the chromosome pairing were variable, but it did not hinder the meiotic products, which were characterized by regular tetrads and satisfactory pollen fertility, ranging from 88.7 to 95.7%. Results show that all plants are meiotically stable and that they can be used in intraspecific crosses in the breeding program of Paspalum notatum.

  6. Folding of Pollen Grains

    Science.gov (United States)

    Katifori, Eleni; Alben, Silas; Cerda, Enrique; Nelson, David; Dumais, Jacques

    2008-03-01

    At dehiscence, which occurs when the anther reaches maturity and opens, pollen grains dehydrate and their volume is reduced. The pollen wall deforms to accommodate the volume loss, and the deformation pathway depends on the initial turgid pollen grain geometry and the mechanical properties of the pollen wall. We demonstrate, using both experimental and theoretical approaches, that the design of the apertures (areas on the pollen wall where the stretching and the bending modulus are reduced) is critical for controlling the folding pattern, and ensures the pollen grain viability. An excellent fit to the experiments is obtained using a discretized version of the theory of thin elastic shells.

  7. The influence of pollen viability on seed set and fruit mass in strawberry (fragaria x ananassa duch.

    Directory of Open Access Journals (Sweden)

    Elżbieta Kaczmarska

    2012-12-01

    Full Text Available This research was conducted in 2006 in the Experimental Station of the Department of Genetics and Horticultural Plant Breeding in Felin near Lublin. It included 7 cultivars of strawberry ('Pastel', 'Salut', 'Teresa', 'Jota', 'Paula', 'Senga Sengana', 'Plena' and two selected clones: 2395 and 3995 that belonged to the Department. Analysis of pollen fertility was carried out on the basis of materials collected on five occasions: on May 17 (at the beginning of florescence, May 20 and May 24 (the peak of florescence and on June 2 and June 13 (the end of florescence. Smear preparations stained with 2% acetocarmin and glycerin solution (1:1 were used to test pollen viability. The highest percent of viable pollen in 2006 was in cultivar 'Jota' (70.88%. The lowest viability had pollen of 'Teresa' cultivar (33.83%. The average content of viable pollen grains was the lowest on May 20 (36.79%. The highest pollen fertility was noted on June 2 (62.15%, the percent of fertile pollen on a similar level was observed on May 17 and 24 and June13. The cultivar 'Jota' was characterized by an increased level of pollen fertility that was quite high during the whole period of florescence. The number of seeds has a great influence on the proper development of spurious strawberry fruit. The mass of seeds from a single fruit has a great influence on the mass of fruits in both large and small fruit categories. Pollen viability affected the mass of seeds on big fruits (r = 0.444, but there is no clear direct relationship between pollen fertility and mass of strawberry fruit(r = -0.193 and r = -0.052.

  8. Aegilops-Secale amphiploids: chromosome categorisation, pollen viability and identification of fungal disease resistance genes.

    Science.gov (United States)

    Kwiatek, M; Błaszczyk, L; Wiśniewska, H; Apolinarska, B

    2012-02-01

    The aim of this study was to assess the potential breeding value of goatgrass-rye amphiploids, which we are using as a "bridge" in a transfer of Aegilops chromatin (containing, e.g. leaf rust resistance genes) into triticale. We analysed the chromosomal constitution (by genomic in situ hybridisation, GISH), fertility (by pollen viability tests) and the presence of leaf rust and eyespot resistance genes (by molecular and endopeptidase assays) in a collection of 6× and 4× amphiploids originating from crosses between five Aegilops species and Secale cereale. In the five hexaploid amphiploids Aegilops kotschyi × Secale cereale (genome UUSSRR), Ae. variabilis × S. cereale (UUSSRR), Ae. biuncialis × S. cereale (UUMMRR; two lines) and Ae. ovata × S. cereale (UUMMRR), 28 Aegilops chromosomes were recognised, while in the Ae. tauschii × S. cereale amphiploid (4×; DDRR), only 14 such chromosomes were identified. In the materials, the number of rye chromosomes varied from 14 to 16. In one line of Ae. ovata × S. cereale, the U-R translocation was found. Pollen viability varied from 24.4 to 75.4%. The leaf rust resistance genes Lr22, Lr39 and Lr41 were identified in Ae. tauschii and the 4× amphiploid Ae. tauschii × S. cereale. For the first time, the leaf rust resistance gene Lr37 was found in Ae. kotschyi, Ae. ovata, Ae. biuncialis and amphiploids derived from those parental species. No eyespot resistance gene Pch1 was found in the amphiploids.

  9. Studies on Viability and Storage Characteristics of Pollen of Groundcover Chrysanthemum%地被菊花粉活力和储藏性研究

    Institute of Scientific and Technical Information of China (English)

    吕晋慧; 赵耀; 王媛; 冯雁梦; 李艳锋; 孔一昌

    2012-01-01

    以地被菊(groundcover chrysanthemum)品种‘毛白玉’、‘粉芙蓉’的新鲜花粉为材料,采用离体萌发法对花粉活力进行测定,并观察花粉萌发及花粉管生长情况。试验结果表明:外源ca2+显著促进了花粉萌发和花粉管生长,硼酸对花粉萌发没有显著影响;花序中部筒状花的花粉活力显著高于花序外部和内部筒状花的花粉;遮荫降低了花粉活力;‘毛白玉’和‘粉芙蓉’花粉在室温下可分别储藏8和6d,4℃下可分别储藏25d和20d,-20℃下可储藏25d,-80℃下可分别储藏21和18d。-80℃储藏前干燥处理2h的花粉,储藏后花粉活力显著高于干燥处理4h和6h的花粉。预冻处理显著降低了花粉活力。-80℃储藏的花粉采用35℃解冻2min或冰上解冻效果较好。%In the study, the pollen viability of the cultivars 'Maobaiyu' and 'Fenfurong' was determined via culture in vitro, and the pollen germination and pollen tube growth were observed. The results showed that the pollen germination rate and growth of pollen tubes were promoted significantly by Ca2+ but not influenced by H3BO3 ; The viability of pollen collected from middle parts of inflorescences was significantly higher than that from external or inside of inflorescence. Shading decreased pollen viability. Pollen viability decreased with increasing storage time under different temperatures. The appropriate storage time of pollen was 8 days and 6 days at room temperature, 25 days and 20 days at 4 ℃, 21 days and 18 days at - 80 ℃ respectively for 'Maobaiyu' and 'Fenfurong', and 25 days at - 20℃ for both cultivars. Desiccation duration for 2 hours could increase the viability of pollen stored at - 80 ℃, producing better results than that of 4 hours and 6 hours treatments. The pre-freezing treatment reduced pollen germination. The methods of defrosting frozen pollens at 35 ℃ for two minutes or in trash ice were better than other defrosting

  10. Decreased Pollen Viability and Thicken Pollen Intine in Antisense Silenced Brassica campestris Mutant of BcMF19

    Institute of Scientific and Technical Information of China (English)

    LIU Jin-long; GAO Ming-hui; LIU Ying; CAO Jia-shu

    2014-01-01

    Brassica campestris male fertility 19 (BcMF19;GenBank accession number GQ902048.1), a gene that is specially expressed in tapetum cells and microspores during anther development in B. campestris ssp. chinensis, which is learned from the previous in situ hybridization study. In the present study, we constructed antisense-silenced plants of BcMF19 using B. campestris ssp. chinensis to validate this prediction. The morphology of the pistils, long anthers, and short anthers was signiifcantly affected in 35sbcmf19 compared with the control samples. 4´-6-Diamidino-2-phenylindole staining revealed that two generative nuclei and one large vegetative nucleus were not affected in the mutant compared with control. Statistical analysis of Alexander’s staining results showed that 96% of the control pollen grains had vitality, whereas only 86% of the mutant pollen grains did. Under scanning electron microscopy, the mutant demonstrated numerous abnormal pollen grains and resembled dried persimmon. The frequency of normal pollen grains was approximately 18%. Under transmission electron microscopy, the pollen intine during the binucleate and mature pollen stages in 35sbcmf19 exhibited abnormal thickening, especially at the germinal furrows, compared with control. In vitro pollen germination test showed that the tips of the mutant pollen tubes transformed into globular alveoli and stopped growing compared with control. On the other hand, in vivo pollen germination test suggested that BcMF19 affected the pollen tube extension in the pistil. These ifndings indicate that BcMF19 is essential to the pollen development and pollen tube extension of B. campestris ssp. chinensis.

  11. Effect of bee pollen supplement on antimicrobial, chemical, rheological, sensorial properties and probiotic viability of fermented milk beverages

    Directory of Open Access Journals (Sweden)

    Oktay Yerlikaya

    2014-11-01

    Full Text Available In this research, effect of bee pollen supplement on antimicrobial, chemical, rheological, sensorial properties and probiotic viability of fermented milk beverages was studied. Bee pollens were added in the rate of 2.5 mg•mL-1 (B, 5 mg•mL-1 (C, 7.5 mg•mL-1 (D, 10 mg•mL-1 (E, and 20 mg•mL-1 (F. Control sample (A was not supplemented with bee pollen. Control and supplemented milk samples were fermented by a commercial ABT1 starter culture (Chr. Hansen, Hørsholm, Denmark containing Lactobacillus acidophilus La 5, Bifidobacterium animalis subs. lactis Bb 12, and Streptococcus thermophilus. While no antimicrobial impact was observed against L. monocytogenes, S. aureus, P. fluorescens, P. aeruginosa and A. hydrophilia upto 7.5 mg•mL-1 pollen addition, addition between 10 mg•mL-1 to 20 mg•mL-1 resulted in activity, and positive effect only in inhibition rates against bacteria such as S. thyphimurium and E. coli. Bee pollen supplements has shown a positive effect on probiotic viability and occurred on increase apparent viscosity, but their effect on sensorial properties was negative. Furthermore an improvement with increasing concentration of pollen addition that yielded no negative effect on physicochemical properties was detected.

  12. Effect of forest fragmentation on microsporogenesis and pollen viability in Eugenia uniflora, a tree native to the Atlantic Forest.

    Science.gov (United States)

    de Almeida, D J; Faria, M V; da Silva, P R

    2012-12-06

    Habitat fragmentation, caused by the expansion of agriculture in natural areas, may be one of the strongest impacts humans have on the ecosystem. These changes can decrease the number of individuals in a population, leading to endogamy. In allogamous species, endogamy can have a negative effect on reproductive capacity. In this study, we analyzed the effects of forest fragmentation on microsporogenesis and pollen viability in Eugenia uniflora L., a tree species native to the Atlantic Forest. We analyzed 4 populations, 3 of which were connected by forest corridors and 1 of which was isolated by agricultural fields on all sides. For microsporogenesis analysis, 9000 meiocytes representing all stages of meiosis were evaluated. To perform the pollen viability test, we evaluated 152,000 pollen grains. Microsporogenesis was stable in plants from populations that were connected by forest corridors (abnormalities, less than 6%), while microsporogenesis in plants from the isolated population showed a higher level of abnormalities (13-29%). Average pollen viability was found to be more than 93% in the non-isolated populations and 82.62% in the isolated population. The χ(2) test showed that, in the isolated population, the meiotic index was significantly lower than that in the non-isolated populations (P = 0.03). The analysis of variance for the percentage of viable pollen grains confirmed the significant difference between the isolated and non-isolated populations. Our data show that forest fragmentation has a direct effect on microsporogenesis and pollen viability in E. uniflora and can directly influence the reproductive capacity of isolated populations of this species.

  13. 不同贮藏温度下大别山五针松花粉活力的变化%Change in pollen viability of Pinus dabeshanensis at different storage temperatures

    Institute of Scientific and Technical Information of China (English)

    项小燕; 吴甘霖; 段仁燕; 王志高; 张中信; 王广艳

    2016-01-01

    By means of MTT staining method, pollen viability of Pinus dabeshanensis C. Y. Cheng et Y. W. Law stored for 1-170 d under conditions of room temperature (20 ℃-28 ℃), 4 ℃ and-20 ℃ was measured. The result shows that pollen viability of P. dabeshanensis is 95. 97% during pollen flourishing period. When storage for 7 d at different temperatures, pollen viability is still over 90%. Pollen viability decreases to 40. 33% when storage for 75 d at room temperature, while that decreases to 81. 67% and 73. 33% when storage for 75 d at 4 ℃ and -20 ℃, respectively. But when storage for 115 d at different temperatures, pollen viability is lower than 20%. It is indicated that short-term ( one month) storage at room temperature is suitable to keep pollen viability of P. dabeshanensis, but 4 ℃ is more suitable for keeping pollen viability for longer time.

  14. 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.

  15. Pollen viability and meiotic analysis of Solanum commersonii commersonii Dun., Solanum commersonii malmeanum Bitt. and Solanum tuberosum L.

    Directory of Open Access Journals (Sweden)

    Alexandre Alonso Alves

    2007-01-01

    Full Text Available Meiotic abnormalities in potato hamper sexual recombination, due to their influence on pollen production andviability rate. In this study we evaluated pollen viability and meiosis of three clones of Solanum commersonii commersoniiDun. (SCC, two of Solanum commersonii malmeanum Bitt. (SCM and seven clones and four cultivars of Solanum tuberosumL., with the purpose of indicating promising genotypes for genetic breeding of potato. Early chromosome migration atmetaphases I and II and chromosome pairing anomalies were the main causes of pollen inviability in the evaluated genotypes.Clones SCC 07 and SCM 60 are the most suitable for sexual recombination, owing to the high percentage of viable pollengrains and low frequencies of meiotic abnormalities.

  16. Method of Testing Viability of Pollen in Pomegranate%石榴花粉生活力测定方法

    Institute of Scientific and Technical Information of China (English)

    刘程宏; 张芳明; 宋尚伟

    2012-01-01

    Three pomegranate varieties (Tunisia soft seed, Yu large seed and Taishan red) were used as the tested materials, the methods of testing their pollen viability were screened and analyzed. The results showed that; though benzidine staining method obtained slightly higher determination result of pollen viability than glucose solution culture method, it had better correlation. So benzidine staining method is a better method for the determination of pollen viability of pomegranate.%以突尼斯软籽、豫大籽、泰山红3个石榴品种为试验材料,对其花粉活力的测定方法进行了筛选,结果表明:联苯胺染色法较之葡萄糖溶液培养法测定结果略偏高,但相关性良好,因此联苯胺染色法是测定石榴花粉生活力较好的染色方法.

  17. Determination of Pollen Viability of Magnolia sinostellata%景宁木兰花粉生活力测定

    Institute of Scientific and Technical Information of China (English)

    刘饶; 蒋燕锋; 许元科; 毛昌会

    2012-01-01

    Pollen viability of Magnolia sinostellata was determined by TTC, H2O2 dyeing and culturing in vitro methods. The results showed that TTC and H2O2 dyeing could not determine exactly the viability of pollen, and the sucrose concentration and boric acid had great effect on pollen viability. It concluded that it had the highest germination rate with the medium of 5% sucrose and 10 mg/L boric acid. The pollen of M. sinostellata had vitality of 16-20 days at room temperature, but had 26-30 days at low temperature (4t).%以景宁木兰花粉为材料,分别用TTC染色法、离体萌发法和过氧化物酶测定法测定景宁木兰花粉活力,结果表明,TTC染色法和过氧化物酶测定法不能准确表示景宁木兰花粉的生活力;在离体萌发法测定景宁木兰花粉活力时,培养基中添加蔗糖、硼酸对景宁木兰花粉萌发影响较大,添加5%蔗糖和0.01%硼酸比较适合景宁木兰花粉萌发;景宁木兰花粉在室温下其生命力一般保持16 ~ 20d,4℃低温贮藏可使花粉生活力时间延长至26~30 d.

  18. Methods to Test Pollen Viability of Stylosanthes%柱花草花粉活力的测定方法

    Institute of Scientific and Technical Information of China (English)

    贺庆梅; 张华; 吴泽霖; 罗丽娟

    2012-01-01

    利用6种常用花粉活力测定方法对柱花草花粉活力进行测定.并筛选出各方法的最佳配方。结果表明:以离体萌发法为最佳,最适培养基:10%蔗糖、10%PEG-6000(聚乙二醇)、0.01%心B03、0.03%CaCl2·2H2O、0.01%KNO3,pH6.5,柱花草花粉在该培养基上30℃条件下培养10min,萌发率可达84.03%。0.5%12+1.5%KI的碘-碘化钾染色效果好,色差明显,较离体萌发法测定值偏高,但差异不显著,可选作简单快速测定法;FDA(荧光素二醋酸脂)染色法、醋酸洋红染色法、无机酸法、TTC(2,3,5-氯代三苯基四氮唑)法均不适合柱花草花粉活力的检测.%Used 6 commonly methods of pollen viability determination on Stylo pollen viability, and screened out their optimal formula. The results showed that pollen germination in vitro method was the best, and the best medium was 10% sucrose, 10% PEG-6000 (polyethylene glycol), 0.01% HEBO3, 0.03% CaCl2, 2H2O, 0.01% KNO3 and pH 6.5, Stylo pollen germination in this medium at 30℃ for l0 min, and then pollen germination rate were 84.03%. It can be concluded that 0.5% I2 and 1.5% KI components of I-KI staining was the best staining method, because it got no significant difference viability rate to germination in vitro method and can dye fast and clearly. The FDA (fluorescein diacetate) staining, acetocarmine staining, inorganic acid method, TTC (2,3,5-Triphenyltetrazolium chloride ) staining were unsuitable to assay pollen vitality of Stylo.

  19. In vitro viability and preservation of pollen grain of kiwi (Actinidia chinensis var. deliciosa (A. Chev. A. Chev

    Directory of Open Access Journals (Sweden)

    Douglas André Steinmacher

    2011-01-01

    Full Text Available Kiwi is a dioecious plant species, requiring cross pollination for fruit production. The objective of this study was toevaluate the in vitro viability and shelf life of pollen grains of two kiwi varieties. Flowers of the cultivars Matua and Tomuri werecollected and the pollen germinated in vitro, in culture medium containing agar (1 %, sucrose (0, 5, 10, 20 and 40 % and boric acid(0 and 50 mg L-1H3BO3. Pollen grains were stored in a BOD incubator (25.0 °C, refrigerator (4.0 °C, freezer (-18.0 °C and in liquid N2 (-196.0 °C, and evaluated after 0, 40, 120, 240 and 365 days. The culture medium enriched with 12 % sucrose and 50 mgL-1 H3BO3 was the most suitable. Pollen grains can be stored for a short period in the refrigerator or freezer, and cryopreserved for at least one year.

  20. 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....

  1. Parietaria judaica flowering phenology, pollen production, viability and atmospheric circulation, and expansive ability in the urban environment: impacts of environmental factors

    Science.gov (United States)

    Fotiou, Christina; Damialis, Athanasios; Krigas, Nikolaos; Halley, John M.; Vokou, Despoina

    2011-01-01

    Parietaria judaica (Urticaceae) grows abundantly in urban areas of the Mediterranean region. Its pollen is a major allergy source. We studied the species' distribution and abundance in and around Thessaloniki (Greece), pollen production and pollen season. We also examined how urban pollution affects pollen viability. Our ultimate goal was to obtain an estimate of the species' performance and ability to expand under different environmental conditions related to climate change. We mapped P. judaica and the other Urticaceae species. In a north- and a south-facing population, we recorded the progress of P. judaica flowering and estimated the pollen content per flower, shoot and surface unit. We concurrently assessed atmospheric circulation of Urticaceae pollen. We estimated P. judaica pollen viability and Cu, Pb and Zn concentrations in plants collected from sites differing in traffic intensity. P. judaica is the most abundant Urticaceae species in the area; its occurrence has increased dramatically over the last 100 years. Production of flowers is intense in spring and autumn. Flowering started 12 days earlier in the south-facing population in spring, and 3 days later in autumn. Pollen production was higher in spring and in the south-facing population. Flower and pollen production were positively correlated with the size of the plant and the flower, respectively. Copper and lead concentrations in plants were positively correlated with pollen viability, which was higher for plants collected from high-traffic sites. P. judaica has a high phenotypic plasticity; this is a feature that promotes success of expansive and invasive species. It is also well adapted to warm and polluted urban environments. The climatic change forecast for the Mediterranean region could provoke earlier, longer, and more pronounced flowering and, consequently, more P. judaica pollen in the air. In return, this would result in increased severity of Parietaria pollinosis.

  2. Effects of Storage Condition on Jatropha curcas Pollen Viability%贮藏条件对麻疯树花粉生活力的影响

    Institute of Scientific and Technical Information of China (English)

    蒲光兰; 周兰英; 贾其坤; 沈杰

    2011-01-01

    以四年生麻疯树(Jatropha curcas L.)花粉为试验材料,研究不同发育阶段和不同保存条件对花粉生活力的影响,以期为麻疯树的远距离杂交提供一定的理论依据.研究结果表明,麻疯树新鲜花粉的生活力均为100%,随贮藏时间的延长,花粉生活力呈下降趋势;相同保存条件下,发育阶段不同的花粉生活力差异不显著;相同发育阶段的花粉,贮藏方法不同,花粉生活力存在极显著的差异;麻疯树花粉生活力以冷冻(-20℃)贮藏方法处理的最高,冷藏(2℃)处理次之,高温贮藏花粉生活力下降最快.%The experiment was conducted with the pollens of 4-year-old Jatropha curcas L. to study the effects of different developmental stage and storage condition on pollen viability. The results showed that viability of fresh pollen was 100%, and pollen viability declined with the time prolonging. The difference of pollen viability was not significant in different developmental stages, however, it was significant under different storage conditions. Storaging pollen under -20 ℃ was the best tem-preture conditions followed by under 2 ℃ of cold storage. Pollen viability declined quickly under high temperature.

  3. Study on Pollen Viability of Different Tobacco Varieties%不同品种烟草花粉生活力研究

    Institute of Scientific and Technical Information of China (English)

    廖雪芳; 朱列书; 岳伦勇

    2013-01-01

    Pollen is the male-gamete of seed plant,which plays an important role in sexual reproduction.Taking the pollens of 8 different tobacco varieties as the experiment materials,each variety included pollens from both top-flowers and side-flowers.The changes of pollen viability as the extension of storage time was tested by I-KI coloration. The results showed that viability of fresh pollen was 100%,and pollen viability all declined with the time prolonging. However,there also existed differences among those 8 tobacco varieties.%花粉是种子植物的雄配子体,在有性繁殖中发挥着重要的作用。以8个烟草品种的顶花和侧花的花粉为试验材料,通过I-KI染色法测定不同生长部位的烟草花粉随着存放时间的延长花粉生活力的变化情况,结果表明:烟草新鲜花粉的生活力均为100%,随贮藏时间的延长,花粉生活力整体呈下降趋势,但不同品种间表现存在差异。

  4. Morphology and pollen viability of Lolium multiflorum Lam. Morfologia e viabilidade polínica de Lolium multiflorum Lam.

    Directory of Open Access Journals (Sweden)

    Renata de Castro Nunes

    2012-04-01

    Full Text Available Study and characterization of pollen grains are essential for different areas, especially taxonomy, genetic improvement, phylogeny, and paleobotany. As yet, there are no reports on pollen morphology of genotypes of naturalized Lolium multiflorum Lam., introduced cultivars or breeding populations, diploid or polyploid. Ten genotypes of annual ryegrass (L. multiflorum were evaluated for the viability of pollen grains using propionic carmine and Alexander's stains, while morphology was assessed by the acetolysis technique. Measures of polar axis (P, equatorial diameter (E, exine thickness, and analysis of pollen grains were obtained by scanning electron microscopy (SEM. All genotypes showed high rate of pollen viability (> 89% for both stains. There were differences between genotypes in the following quantitative traits: polar axis, equatorial diameter, exine, endexine, ektexine, and P/E ratio. Pollen grains were characterized as small, monoporates, with circular and non-prominent apertures. In addition to helping distinction of pollen grains, morphometric differences can be used later to compare ploidy levels, thus assisting in breeding programs of the species.O estudo e a caracterização do grão de pólen são fundamentais para diferentes áreas, em especial, para a taxonomia, o melhoramento genético, a filogenia e a paleobotânica. Para genótipos de Lolium multiflorum Lam., naturalizados no Brasil, cultivares introduzidas ou populações de melhoramento, diploides e poliploides, não existem relatos sobre a caracterização morfopolínica. Nesse trabalho foram analisados dez gentótipos de azevém anual (L. multiflorum. A viabilidade dos grãos de pólen foi verificada por coloração com os corantes carmim propiônico e Alexander e a morfologia por meio da técnica de acetólise, sendo obtidas medidas do eixo polar (P, do diâmetro equatorial (E, e da espessura da exina, e análise dos grãos de pólen por microscopia eletrônica de

  5. 太子参花粉活力和柱头可授性研究%Pollen Viability and Stigma Receptivity of Pseudostellaria heterophylla

    Institute of Scientific and Technical Information of China (English)

    韩怡; 巢建国; 谷巍; 张莹; 孙亚昕

    2012-01-01

    目的:研究太子参的花粉活力、柱头可授性及花粉贮藏.方法:采用离体萌发法、染色法测定花粉活力,用联苯胺-过氧化氢法测定柱头可授性,并检测不同贮藏条件下花粉的活力.结果:离体萌发法适用于太子参花粉活力测定,最适培养基为0.04%硼酸+15%蔗糖+11%聚乙二醇,萌发率达92.44%;太子参花药开裂期柱头可授性较强;花粉的短期保存以4℃效果较好,长期保存以-80℃效果最佳.结论:在进行杂交授粉时,应选花药开裂期的花粉,对开花第2天的柱头进行人工授粉,本研究为太子参的良种选育及种质资源保护提供了科学依据.%Objective: To study the pollen viability, the stigma receptivity and storage character of Pseudostellaria heterophylla. Methods: The pollen viability was evaluated by the methods of in vitro pollen germination and pollen staining,the stigma receptivity was estimated by benzidine-H2O2 method,and the pollen viability in different storage conditions were detected. Results;In vitro pollen germination method was suitable for the determination of pollen germination of Pseudostellaria heterophylla,the optimal medium was 0. 04% H3BO3 + 15% sucrose + 11% PEG4000 ,in which the pollen germination capacity reached to 92. 44% ;The stigma receptivity of Pseudostellaria heterophylla was higher when the pollen anther opening; The results showed that short-term pollen storage at -4 ℃was the most suitable while the long-term pollen storage was at -80 ℃. Conclusion; The optimum cross pollination times of Pseudostellaria heterophylla was 2 days after blooming and choose the pollen in anther opening. This study provides a foundation for the breeding and germplasm resources protection of Pseudostellaria heterophylla.

  6. 金边瑞香花粉活力和柱头可授性研究%Pollen Viability and Stigma Receptivity of Daphne odora var. marginata

    Institute of Scientific and Technical Information of China (English)

    周华; 余发新; 王碧琴; 刘腾云

    2012-01-01

    [目的]研究金边瑞香花粉活力和柱头可授性.[方法]采用I-KI法、TTC法和固体培养基法测定金边瑞香花粉的活力,并用联苯胺-过氧化氢法测定柱头的可授性.[结果]金边瑞香从初花期至盛花期,I-KI法未对花粉内部染色,使用,TTC法花粉未变红色,离体培养法未见有花粉管萌发,均表明花粉不具生活力.柱头表面有少量气泡产生的,且柱头变色,表明金边瑞香柱头可授性较低.[结论]金边瑞香花粉无活力,柱头可授性低.%[Objective] To study the pollen viability and stigma receptivity of Daphne odora var. marginala. [Method] The pollen viability was detected by the methods of iodine-iodide Kalium(I-KI) , triphenyllrazolium chloride(TTC) and solid medium. The stigma receptivity was estimated by benzidine-H2O2 method. [ Result] The pollen was not stained by I - KI method, and did not become red by TTC method, and there was no germinated pollen tube by the in vitro culture method, indicating that the pollen viability was zero during the whole flowering period of Daphne odora var. marginata. Few bubbles appeared on the stigma surface and the stigma color changed, which meant that stigma receptivity was very low. [Conclusion] Daphne odora var. marginata has no pollen viability and low stigma receptivity.

  7. Meiose e viabilidade polínica na família Araceae Meiosis and pollen viability in Araceae family

    Directory of Open Access Journals (Sweden)

    Maria Goreti Senna Corrêa

    2005-06-01

    Full Text Available O objetivo deste trabalho foi analisar a microsporogênese e a viabilidade dos grãos de pólen em 17 espécies de aráceas coletadas no Rio Grande do Sul, Brasil. Nove espécies foram analisadas quanto à ocorrência de células mãe de pólen (CMP normais e anormais nas fases de metáfase, anáfase e telófase, tanto da meiose I (M I como da meiose II (M II; 10 espécies foram estudadas quanto à presença de tétrades com número normal ou anormal de micrósporos e 17 espécies quanto à viabilidade dos grãos de pólen. As CMP anormais apresentaram, tanto em M I quanto em M II, cromossomos fora da placa metafásica ou cromossomos retardatários em anáfase e/ou telófase. As freqüências de CMP normais/anormais encontradas na microsporogênese salientam a grande variação existente entre as espécies. Ressalta-se a ausência de CMP com anomalias na microsporogênese de Monstera deliciosa Adans., assim como em M I de Anthurium scandens (Aubl Engl. e em M II de Caladium hortulanum Birdsey. O número observado de CMP anômalas, em M I e M II, nas espécies Syngonium podophyllum Schott e Zantedeschia aethiopica Spreng, foi maior que o esperado. A freqüência média de tétrades normais em dez espécies de aráceas, assim como a de grãos de pólen viáveis em 17 espécies, foi significativamente superior à freqüência média de anormais e de inviáveis, respectivamente.The objective of this work was to analyze microsporogenesis and pollen viability in 17 species of the Araceae family collected at Rio Grande do Sul, Brazil. Occurrence of normal and abnormal pollen mother cells (PMC was analyzed in metaphase, anaphase and telophase, in meiosis I (M I and meiosis II (M II of nine species; tetrads with normal or abnormal number of microspores was observed in 10 species, and pollen grain viability, in 17 species. Abnormal PMC presented chromosomes outside the metaphasic plate or laggard chromosomes in anaphase and/or telophase in both M I and M

  8. Study on the Storage of Pollen Viability of Oingcui Plum%青脆李花粉生活力及贮藏性研究

    Institute of Scientific and Technical Information of China (English)

    刘佳; 李靖; 陈栋; 蒋彧

    2014-01-01

    【目的】探索不同因素对青脆李花粉生活力及萌发率的影响。【方法】以青脆李花粉为试材,通过TTC法研究了不同发育阶段、干燥方式、贮藏条件、贮藏时间4个因素对青脆李花粉生活力的影响,并采用培养基萌发法观察花粉萌发过程及植物生长调节剂对花粉萌发的作用。【结果】青脆李盛花期花粉生活力,明显高于初花期和末花期;室内自然阴干的花粉生活力平均高于干燥器干燥的花粉生活力;常温、0、4及-18℃条件下贮藏的花粉平均生活力随温度降低呈升高趋势;花粉生活力随贮藏时间的增长逐渐减弱,-18℃贮藏30 d的花粉生活力可达35.3%;6-BA对花粉萌发有抑制作用,适宜浓度的2,4-D(20 mg/L)可促进花粉萌发。【结论】盛花期花粉自然阴干是花粉的最佳采集方式,而长时间贮藏则以低温保存为宜。%Obj ective]The aim of the study was to investigate effects of different factors on pollen viability and germination rate of Qingcui plum.[Method]The effects of development stage,des-iccating methods,storage condition and time on pollen viability of Qingcui plum were investigated by TTC method.The pollen germination process and effect of growth substance on pollen activity were observed based on medium.[Results]Pollen viability of Qingcui plum in the flowering sea-son was higher compared to the beginning and ending of blooming period.Pollen viability by natu-ral drying was higher than that by drying in desiccator.Pollen viability tended to increase with de-creasing temperature (room temperature,0,4 and -18 ℃).In addition,pollen viability tended to decrease with storage time.The pollen viability in -18 ℃for 30 days was 35. 3%.Pollen ger-mination was inhibited by 6-BA but 20 mg/L of 2 ,4-D stimulated pollen germination.[Conclu-sion]Natural drying during the flowering season was the best method for pollen collection.How-ever,low temperature

  9. 大花百子莲的花粉活力与柱头可授性1)%Pollen Viability and Stigma Receptivity of Agapanthus praecox ssp.orientalis ‘Big Blue

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    We investigated the pollen viability and stigma receptivity of A.praecox ssp.orientalis‘Big Blue’ in Shanghai, Chi-na, and analyzed the influence of pollen viability and stigma receptivity to reproduction.The best composition of medium is 10%sucrose+0.1%H3 BO3+0.2 g・ L-1 Ca(NO3 ) 2 .Pollen viability gradually reduces with the flowering process.Pollen viability is 80%at initial time of florescence and the value is 3%at the end of florescence.Survival time of pollen is seven days in 4℃.The value is five days in 25℃and two days in 35℃.Pollen has the germination ability at the first day of flowering and stigma has receptivity ability at the next day of flowering.Therefore, A.praecox ssp.orientalis‘Big Blue’ is dichogamy.%  以引种植物大花百子莲为对象,对其在引种地的花粉活力、柱头可授性进行了研究,探讨了两者与授粉成功的关系。结果表明:大花百子莲花粉萌发的最佳培养基为10%蔗糖+0.1% H3 BO3+0.2 g・ L-1 Ca(NO3)2;随着开花进程的不断深入,花粉活力不断下降,始花期的花粉活力接近80%,末花期花粉活力只有3%左右;花粉在4℃条件下存活时间约为7 d,25℃条件下存活时间为5 d,而在35℃条件下存活时间只有2 d;大花百子莲花粉在开花当天已具有萌发能力,而柱头在开花第2天具有可授性,因此大花百子莲存在雌雄异熟现象。

  10. Effects of different collecting pollen periods and storage conditions on pollen viability of kiwifruit%采粉期及贮藏条件对猕猴桃花粉生活力的影响

    Institute of Scientific and Technical Information of China (English)

    陈永安; 陈鑫; 刘艳飞

    2012-01-01

    【Objective】 Research about effects of different collecting pollen periods and storage conditions on pollen viability of kiwifruit was conducted for the production of artificial auxiliary pollination and hybrid breeding with favorable basis.【Method】 With Zhonghuaxi 401 as test materials,pollens in flowering before 3,2,1 d big budding period and flowering 6,12,24 h were collected;With soft dates kiwifruit,Qinxiong 201,Zhonghuaxi 401 and Maohua kiwifruit as test materials,pollens in big budding period were collected,and stored under normal temperature(18-26 ℃),low temperature(4 and-15 ℃).Pollen viability of kiwifruit in different collecting pollen periods and storage conditions was compared.【Result】 Kiwifruit pollen viability has only 1.92% in the flowering before 3 d;kiwifruit pollen viability has reached 48.07% and 69.11% in the flowering before 2 d and 1 d;the big budding pollen viability was the highest,reaching 82.31%.In the flowering 6 h,12 h and 24 h,pollen viability was 66.89%,46.03% and 31.40%,and they all were lower than the big budding.Four different kinds of kiwifruit fresh pollen viability was all higher,more than 70%.Under normal conditions,kiwifruit pollen can only be stored for 6-9 d,at 4 ℃ refrigerated condition pollen life would maintain 60-150 d,average storage can be as long as 90 d,and under-15 ℃ frozen conditions pollen viability can keep longer,would reach 360 d.【Conclusion】 It is better to use pollen in big budding;temperature is one of the important factors affecting kiwifruit pollen viability.The lower the temperature is,the better the results of the pollen storage is.%【目的】研究不同采粉期及贮藏条件对猕猴桃花粉生活力的影响,为猕猴桃生产中人工辅助授粉和杂交育种提供依据。【方法】以猕猴桃品种"中华系401"为试材,分别于开花前3,2,1d及大蕾期和开花后6,12,24h采集花粉,比较不同采粉期对猕猴桃花粉生活力的影响;以"

  11. Detection methods of pollen viability of wild Dichondra repens%野生马蹄金花粉生活力检测方法比较

    Institute of Scientific and Technical Information of China (English)

    刘帮龙; 张晓慧; 干友民; 贺啸尘; 莫利

    2011-01-01

    The pollen viability of wild Dichondra repent" ods of I2-KI, 4, 4'-diaminobiphenyl-l-Naphthol, TTC comparison of the four methods indicated that the meth wild Dichondra repens pollen activity. 4,4'-diaminobi (SD200303 and GD200503) was detected by methand pollen germination in vitro, respectively. The ods of I2-KI and TTC were not suitable to evaluate phenyl-l-Naphthol method could detect the pollen viability, but the measured value was higher than that of pollen viability. The method of germination in vitro was the fittest and convenient, in which pollen tube grew well and pollen viability was stable. The optimum culture medium was 10% Sucrose+0.005% HBO3 +0. 015% [Ca(NO3)2 4H20] +0.001% MgSO4 7 H2 O+ 0. 005 % KNO3 + 0.5 % Agar.%以野生马蹄金(Dichondrarepens)材料SD200303和GD200503为对象,分别以碘一碘化钾染色法、联苯胺一甲萘酚染色法、TTC法和离体萌发法测定其花粉活力,比较各检测方法测定效果。结果表明,碘一碘化钾染色法、TTC法染色效果不佳,不适宜野生马蹄金花粉活力测定;联苯胺-一甲萘酚染色法能测定花粉生活力,但测定值偏高;离体萌发法测定野生马蹄金花粉活力,花粉管生长良好,且萌发率基本稳定,便于快速直观统计花粉生活力,适宜野生马蹄金花粉生活力检测,其较适宜的培养基为蔗糖10%+硼酸(HBO。)O.005%+硝酸钙[Ca(NOs)2·4H2O]0.015%+硫酸镁(MgSO。·7H20)0.001%+硝酸钾(KN03)O.005%+0.5%琼脂。

  12. Research on Methods for Pollen Viability Determinationof Water Chestnut%菱花粉生活力测定方法研究

    Institute of Scientific and Technical Information of China (English)

    李双梅; 柯卫东; 彭静; 李峰; 钟兰; 孙亚林

    2014-01-01

    In order to explore suitable methods for pollen viability determination of water chestnut, the pollen viability of cultivar Xiaoganhongling was determined by using the methods of inorganic salt culture, MTT staining and TTC staining. The results showed that the medium supplemented with low concentrations of sucrose and boric acid could promote the germination of pollen, and the optimum medium for pollen germination was 10% sucrose+0.005% boric acid, with the germination rate of 65.9%. The MTT staining and TTC staining methods were not ideal for pollen viability determination of water chestnut, because their dyeing rates were merely 36.9%and 27.1%.%为了探索菱花粉生活力的最佳测定方法,以孝感红菱花粉为试材,利用无机盐培养法、MTT(四甲基噻唑蓝)染色法和TTC(氯化三苯基四氮唑)染色法对花粉生活力进行测定。研究结果表明,培养基中添加低浓度的蔗糖和硼酸对菱花粉的萌发有促进作用,菱花粉萌发的最适培养基为10%蔗糖+0.005%硼酸,萌发率达65.9%;用MTT染色法和TTC染色法测定菱花粉生活力,染色率仅为36.9%和27.1%,效果不理想。

  13. Comparison of Detection Methods of Pollen Viability in Konjac%魔芋花粉生活力检测方法的比较研究

    Institute of Scientific and Technical Information of China (English)

    李勇军; 尹桂芳; 马继琼; 陈建华; 王玲

    2012-01-01

    采用I2-KI染色法、醋酸洋红染色法、过氧化物酶染色法、TTC染色法、无机酸法检测魔芋花粉的生活力,同时以培养基萌发法测定花粉萌发率,并以此为对照研究各方法的测定结果与培养基萌发法测定结果的相关性.结果表明:I2-KI染色法、醋酸洋红染色法、过氧化物酶染色法测定结果极显著高于培养基萌发法,不适于魔芋花粉活力的测定;TTC染色法测定结果极显著高于培养基萌发法,但与培养基萌发法极显著相关,适用于魔芋花粉活力的快速检测;无机酸法测定结果与培养基萌发法差异不显著,且与培养基萌发法极显著相关,适于魔芋花粉活力的准确测定.%The pollen viability of Konjac was detected by methods of iodine-iodide kalium( I2-KI), carmine acetate dyeing (CAD), peroxide enzyme coloration (POX) , triphenyltetrazolium chloride (TTC) and mineralacid (MA). At the same time, the germination in vitro (GIV) rate of pollen was detected by germination in culture medium as control to study the correlation between I2-KI, CAD, POX, TTC, MA and cultured in vitro. The results showed that the pollen viability of Konjac detected with I2 -Kl, CAD and POX was notably higher than that of germination in culture medium, therefore I2 -KI, CAD and POX were inappropriate for pollen viability detection in Konjac. TTC and MA could be used to detect pollen viability effectively and quickly, however, the significant difference of pollen viability between TTC/GIV and MA/GIV were observed.

  14. High-Temperature-Induced Defects in Tomato (Solanum lycopersicum) Anther and Pollen Development Are Associated with Reduced Expression of B-Class Floral Patterning Genes

    Science.gov (United States)

    Kristensen, Lieke; Wolters-Arts, Mieke; de Groot, Peter F. M.; Jansma, Stuart Y.; Mariani, Celestina; Park, Sunghun

    2016-01-01

    Sexual reproduction is a critical process in the life-cycle of plants and very sensitive to environmental perturbations. To better understand the effect of high temperature on plant reproduction, we cultivated tomato (Solanum lycopersicum) plants in continuous mild heat. Under this condition we observed a simultaneous reduction in pollen viability and appearance of anthers with pistil-like structures, while in a more thermotolerant genotype, both traits were improved. Ectopic expression of two pistil-specific genes, TRANSMITTING TISSUE SPECIFIC and TOMATO AGAMOUS LIKE11, in the anthers confirmed that the anthers had gained partial pistil identity. Concomitantly, expression of the B-class genes TOMATO APETALA3, TOMATO MADS BOX GENE6 (TM6) and LePISTILLATA was reduced in anthers under continuous mild heat. Plants in which TM6 was partially silenced reacted hypersensitively to temperature elevation with regard to the frequency of pistilloid anthers, pollen viability and pollen quantity. Taken together, these results suggest that high-temperature-induced down-regulation of tomato B-class genes contributes to anther deformations and reduced male fertility. Improving our understanding of how temperature perturbs the molecular mechanisms of anther and pollen development will be important in the view of maintaining agricultural output under current climate changes. PMID:27936079

  15. High-Temperature-Induced Defects in Tomato (Solanum lycopersicum) Anther and Pollen Development Are Associated with Reduced Expression of B-Class Floral Patterning Genes.

    Science.gov (United States)

    Müller, Florian; Xu, Jiemeng; Kristensen, Lieke; Wolters-Arts, Mieke; de Groot, Peter F M; Jansma, Stuart Y; Mariani, Celestina; Park, Sunghun; Rieu, Ivo

    2016-01-01

    Sexual reproduction is a critical process in the life-cycle of plants and very sensitive to environmental perturbations. To better understand the effect of high temperature on plant reproduction, we cultivated tomato (Solanum lycopersicum) plants in continuous mild heat. Under this condition we observed a simultaneous reduction in pollen viability and appearance of anthers with pistil-like structures, while in a more thermotolerant genotype, both traits were improved. Ectopic expression of two pistil-specific genes, TRANSMITTING TISSUE SPECIFIC and TOMATO AGAMOUS LIKE11, in the anthers confirmed that the anthers had gained partial pistil identity. Concomitantly, expression of the B-class genes TOMATO APETALA3, TOMATO MADS BOX GENE6 (TM6) and LePISTILLATA was reduced in anthers under continuous mild heat. Plants in which TM6 was partially silenced reacted hypersensitively to temperature elevation with regard to the frequency of pistilloid anthers, pollen viability and pollen quantity. Taken together, these results suggest that high-temperature-induced down-regulation of tomato B-class genes contributes to anther deformations and reduced male fertility. Improving our understanding of how temperature perturbs the molecular mechanisms of anther and pollen development will be important in the view of maintaining agricultural output under current climate changes.

  16. Pollen resistance to water in 80 angiosperm species: flower structures protect rain-susceptible pollen.

    Science.gov (United States)

    Mao, Yun-Yun; Huang, Shuang-Quan

    2009-08-01

    Flowers exhibit adaptive responses to biotic and abiotic factors. It remains unclear whether pollen susceptibility to rain damage plays a role in the evolution of floral form. We investigated flower performance in rain and compared pollen longevity in dry conditions, pure water and solutions with different sucrose concentrations in 80 flowering species from 46 families with diverse floral shapes and pollination modes. A pollen viability test showed that pollen longevity in all studied species was greatly reduced by wetting. We found that pollen of species with complete protection by flower structures was susceptible to water damage and a high proportion of resistant pollen occurred in unprotected species. Flowers whose structures expose pollen to rain may also reduce rain damage through temporal patterns of pollen presentation. This prediction was supported by our direct measurement of pollen presentation duration on rainy days. Our observations showed that variation in pollen performance in water was associated with differences in floral forms. Water-resistant pollen and extended pollen presentation duration were favored by selection via rain contact in species in which pollen was not protected from rain. These findings support the functional hypothesis that flower structures protect susceptible pollen from rain, demonstrating that rain acts as a force shaping floral form.

  17. 檫木花粉活力和柱头可授性研究%Pollen Viability and Stigma Receptivity of Sassafras tzumu (Hemsl.) Hemsl

    Institute of Scientific and Technical Information of China (English)

    王馨; 于芬; 季春峰; 龙春玲; 杨光耀

    2013-01-01

    通过野外观察檫木Sassafras tzumu (Hemsl.) Hemsl的开花过程,用联苯胺-过氧化氢法测定其柱头可授性, TTC的方法测定檫木花粉活力。结果表明:柱头具可授性时间为8 d,檫木的花粉活力持续时间为32 h。根据测定时间发现柱头可授期和花粉活力较强期重叠较长,通过后期观察到檫木有结实,说明檫木具有正常的传粉机制和结实能力。%Flowering process of Sassafras tzumu (Hemsl.) Hemsl was observed in the wild, stigma receptivity of sassafras tzumu was evaluated with benzidine-H2O2 method, and pollen viability of sassafras tzumu was evaluated with TTC method. The results showed that stigma can be granted with 8 days, pollen viability of sassafras tzumu has durative 32 hours. According to the measured time to discover stigma receptivity and pollen viability stronger has a longer period of overlap, later period observation showed that sassafras tzumu have fructify, which indicated that sassafras tzumu has normal pollination mechanisms and fructification ability.

  18. Pollen Viability and Stigma Receptivity of Tagetes erecta%万寿菊花粉活力及柱头可授性研究

    Institute of Scientific and Technical Information of China (English)

    赵剑颖; 张华丽; 张西西; 张睿鹂; 关雪莲

    2012-01-01

    为探明造成万寿菊雄性不育系结实率低的原因,对万寿菊花粉活力及柱头可授性进行了研究.采用花粉离体萌发法研究万寿菊自交系V-01花粉萌发适宜温度、花粉活力日变化和适宜贮存条件;用联苯胺-过氧化氢法检测万寿菊雄性不育系S-261、S-17-06-29、S-0191不育株柱头的可授性;水溶性苯胺蓝染色法检测花粉在柱头的萌发情况.结果表明:(1)万寿菊V-01适宜萌发温度介于25~30℃之间;V-01花粉活力日变化趋势为先升高后降低,11-13时采集的花粉萌发率最高;4℃干燥贮存是最适宜的花粉贮存条件.(2)万寿菊柱头形态呈“γ”状时有可授性,可授性可持续3天.(3)万寿菊花粉授粉到柱头上1h内即可萌发,授粉后2h,花粉细胞达到花粉管内.%In order to investigate the difference among different sterile lines of Tagetes erecta, the pollen viability and stigma receptivity of it was studied in this paper. The pollen germination in vitro was used to select the optimum geminating temperature of the pollen, to observe daily variation of pollen viability and to choose optimum storage condition of marigold V-01 (Tagetes erecta L.) pollen. The stigma receptivity was tested with benzidine-H2O2 method. Aniline blue water soluble staining was for detecting the pollen germination on stigma. The results showed that: (1) 25-30℃ was the best temperature for the pollen germination. The pollen viability increased firstly in the morning, reached the maximum at 11 am to 13 pm and then decreased. 4℃ with dry condition was the best pollen storage condition. (2) Stigma with the shape of 'γ' was respectable and could sustain 3 days. (3) Pollen geminated on stigma 1 hour later and pollen cells flew into the pollen tube 2 hours later after the pollination.

  19. Germination Rate and Viability of Manglietia glauca Pollen%灰木莲花粉的萌发率和生活力

    Institute of Scientific and Technical Information of China (English)

    招礼军; 龙永宁; 朱栗琼; 刘威; 莫世宇; 罗叶红

    2014-01-01

    The fresh pollen of Manglietia glauca was used as material to study the effect of mediums with different concentrations of sucrose, boric acid and calcium chloride on in vitro pollen germination . And the pollen viabilities of M. glauca were tested by using 2 , 3 , 5-triphenyltetrazolium chloride staining ( TTC) , iodine-potassium iodide staining ( I-IK) and mineral acid test. The results showed that when the pH was 6. 0, the optimum medium consisting of 150 g/L sucrose, 50 mg/L boric acid, 100 mg/L calci-um chloride and 7 g/L agar was suitable for M. glauca pollen cultured. The in vitro germination rate was 62. 2% and the pollen tube grew well. The mineral acid test was unsuitable for detecting the pollen via-bility. The results tested by TTC and I-IK methods were similar to that of in vitro germination method with pollen viabilities 60. 6% and 64. 1% respectively. However, it was difficult to distinguish the stained pollen grains using the I-IK method. The TTC method was the optimum test method for testing pollen via-bility of M. glauca rapidly.%以灰木莲( Manglietia glauca)的新鲜花粉为材料,研究不同浓度蔗糖、硼酸和氯化钙组合的培养基对灰木莲花粉离体萌发的影响,并用TTC染色法、 I-IK染色法和无机酸法对灰木莲的花粉生活力进行了测定。结果表明:在pH值6.0时,以150 g/L蔗糖+50 mg/L硼酸+100 mg/L氯化钙+7 g/L琼脂的培养基配方最适合灰木莲花粉的培养,离体萌发率达到62.2%,花粉管生长良好;无机酸法不适宜灰木莲花粉生活力的检测;TTC染色法和I-IK染色法的测定结果与离体萌发法的结果较接近,分别为60.6%和64.1%,但I-IK染色法在观察判断上较为困难。因此, TTC染色法是快速检测灰木莲花粉生活力的最佳方法。

  20. Pollen viability and stigma receptivity of Cistanche deserticola%肉苁蓉花粉活力与柱头可授性研究

    Institute of Scientific and Technical Information of China (English)

    徐荣; 朱维成; 陈君; 王霞; 刘同宁

    2011-01-01

    Objective: To study the characteristics of pollen viability and stigma receptivity of C. deserticola and provide theory basis for seed production and breeding of C. deserticola. Method: Different physiological measurement methods were applied to evaluate pollen viability and stigma receptivity. The results of different methods were compared with the seed setting percentage of the cross-pollination in the field test and pollen germination percentage by fluoroscope observation methods. The changes of pollen vitality and stigma receptivity in different conditions were tested using proper methods. Result: The optimum methods on pollen viability and stigma receptivity detection were MTT-test and Benzidine-Hydrogen Peroxide method respectively. Results showed that the mean pollen viability and stigma receptivity were both the highest in inchoate anthesis with pollen germination percentage up to 95%, and can maintain viable for 4-5 d,but at the lower temperature of 4 ℃, the pollen can be stored up to 10 days. Conclusion: The physiological characteristics of pollen and stigma of C. deserticola displayed good ecological adaptation, which are much more adaptive to the large area of cultivation condition.%目的:明确肉苁蓉Cistanche deserticola的花粉活力和寿命以及柱头的可授期,为肉苁蓉种子生产和良种选育提供理论依据.方法:比较不同生理测定方法对肉苁蓉花粉活力与柱头可授性测定的有效性和适用性,并与田间人工授粉结实率和荧光显微观察结果相比较;应用适宜方法测定不同条件下肉苁蓉的花粉和柱头的活力变化.结果:确定肉苁蓉花粉活力和柱头可授性的最佳测定方法分别为MTT法和联苯胺-过氧化氢法,测得肉苁蓉开花3 h后的花粉活力和柱头可授性均为最高水平,此时花粉在柱头的萌发率高达95%以上,活性可保持4~5 d,而低温保存的花粉寿命可保持10 d以上.结论:肉苁蓉花粉与柱头的生理特征具

  1. Field realistic doses of pesticide imidacloprid reduce bumblebee pollen foraging efficiency.

    Science.gov (United States)

    Feltham, Hannah; Park, Kirsty; Goulson, Dave

    2014-04-01

    Bumblebees and other pollinators provide a vital ecosystem service for the agricultural sector. Recent studies however have suggested that exposure to systemic neonicotinoid insecticides in flowering crops has sub-lethal effects on the bumblebee workforce, and hence in reducing queen production. The mechanism behind reduced nest performance, however, remains unclear. Here we use Radio Frequency Identification (RFID) technology to test whether exposure to a low, field realistic dose (0.7 ppb in sugar water and 6 ppb in pollen) of the neonicotinoid imidacloprid, reduces worker foraging efficiency. Whilst the nectar foraging efficiency of bees treated with imidacloprid was not significantly different than that of control bees, treated bees brought back pollen less often than control bees (40 % of trips vs 63 % trips, respectively) and, where pollen was collected, treated bees brought back 31 % less pollen per hour than controls. This study demonstrates that field-realistic doses of these pesticides substantially impacts on foraging ability of bumblebee workers when collecting pollen, and we suggest that this provides a causal mechanism behind reduced queen production in imidacloprid exposed colonies.

  2. 半夏花粉活力检测及杂交研究%Study on Pollen Viability and Hybridization of Pinellia ternate

    Institute of Scientific and Technical Information of China (English)

    王康才; 肖亚雯; 罗庆云; 胡龙娇

    2012-01-01

    To establish a breeding system and provide information for the genetic modification of Pinellia ternata, the combining ability as well as the daily change in pollen viability of 4 Pinellia ternate populations which were collected from Haimen city of Jiangsu province, Xinjiang city of Shanxi province, Taizhou city of Jiangsu province and Willing city of Chongqing were tested. The results showed that the pollen viabilities of all tested 4 populations were the highest in the morning, and the population collected from Xinjiang city of Shanxi province had the highest pollen viability, followed by that from Taizhou city of Jiangsu province, and the pollen viabilities of Pinellia ternate from Haimen city of Jiangsu province and Wuling city of Chongqing were lower. The hybrid compatibility between different populations was obviously different. Based on the above results, the compatibility of pollen and stigma between various populations was the main factor affecting the hybrid setting rate of Pinellia ternata.%为建立半夏杂交育种体系,在利用优化的半夏花粉活力检测体系对江苏海门、山西新绛、江苏泰州、重庆武陵等4个半夏居群的花粉活力日变化情况进行测定的基础上,对各居群间配合力进行了检测.结果显示,4个居群中,以山西新绛半夏的花粉活力最高,其次为江苏泰州半夏,江苏海门半夏及重庆武陵半夏的花粉活力较低;在同一天中,各居群半夏花粉活力在早晨最高;不同居群半夏间杂交亲和力差异显著.上述结果表明,各居群间花粉和柱头亲和性是影响杂交结实率的主要因素.

  3. The Research on the Pollen Viability of Rosa chinensis Varieties and Rosa multiflora with Different Methods%多个月季品种与蔷薇的花粉生活力研究

    Institute of Scientific and Technical Information of China (English)

    杨攀; 王升; 郭风民; 李永华

    2015-01-01

    With a total of 30 Rosa chinensis varieties and Rosa multiflora as test materials,the pollen viability was measured by staining and germination,and the varieties was graded according to the pollen germination. The result showed as follows. The germination was suitable for detecting pollen viability,the measurement with 10%sucrose concentration was suitable for the Rosa chinensis and Rosa multiflora varieties pollen germination.‘Rosa multiflora Thunb.var.platyphylla Thory’‘Darthuizer Orang Fire’‘Rosa cymos’and‘Fen He’had the higher pollen germination rate than other varieties,and the rates respectively were 84.20%,71.60%,59.20%and 54.00%,the pollen viability gradually reduced as the extension of storage time. With the pollen germination as the judgment ,Rosa chinensis and Rosa multiflora varieties were classified three grades:the pollen germination of the first grade was more than 50%,‘Rosa multiflora Thunb.var.platyphylla Thory’‘Darthuizer Orang Fire’;the second grade was between 10% and 50%‘,Pink Peace‘’Monica’;the third grade was less than 10%‘,Spectra‘’ Golden Showers’.%以30个月季品种及蔷薇属植物为试验材料,采用沙尔达考夫染色法、悬滴液发芽法测定其花粉生活力,并根据花粉萌发率对品种进行分级.结果表明:1)悬滴液发芽法更适合花粉生活力的测定,10%蔗糖浓度下适宜月季品种及蔷薇属植物的花粉萌发;2)30个月季品种和蔷薇中,花粉萌发率较高的是‘十姊妹’‘、橘红火焰’‘、小果蔷薇’和‘粉荷’,分别为84.20%、71.60%、59.20%和54.00%,花粉生活力随着时间的延长而降低;3)以花粉萌发率为判断标准,月季品种及蔷薇分为三个等级,一级品种:‘十姊妹’、‘橘红火焰’,萌发率高于50%;二级品种:‘粉和平’、‘摩尼卡’,萌发率在10%~50%;三级品种:‘光谱’、‘金阵雨’,萌发率低于10%.

  4. Pollen Viability and Stigma Receptivity of A rtemisia annua L%青蒿花粉活力及柱头可授性研究

    Institute of Scientific and Technical Information of China (English)

    王卫; 杨水平; 崔广林; 张雪; 刘芸; 陈阳

    2015-01-01

    以野生青蒿中形态差异较为明显的绿秆(品系Y03)和紫红秆(品系Y07)为材料,分别以碘碘化钾染色法、T TC染色法、联苯胺甲萘酚染色法和离体萌发法测定其花粉活力,并从中选取较适宜的检测方法研究其贮藏特性,采用联苯胺过氧化氢法测定其柱头的可授性.结果表明,碘碘化钾和 TTC染色法不适宜青蒿的花粉活力检测,联苯胺甲萘酚染色法可以用于快速测定青蒿花粉活力,但测定值偏高,离体萌发法能准确可靠地反应花粉活力;两个品系的新鲜花粉在室温条件下只能贮藏2d,4℃,-19℃条件下可以贮藏3d,干燥处理显著加快了花粉活力的丧失;联苯胺过氧化氢法测得两个品系青蒿柱头可授期为8~10 d ,边缘雌花可授性比中央两性花的强,且其可授期比中央两性花长1~2d.%The pollen viability of two accessions of wild A rtemisia annua L. ,Y03 with green stem stem and Y07 with purple‐red ,was tested with the methods of I2‐KI (iodine‐potassium iodide dyeing method) , TTC (triphenyl tetrazolium chloride staining) ,benzidine‐α‐naphthol coloring and pollen germination in vitro ,respectively ,and suitable detection methods were selected from them for determining the storage characteristics of pollen .Then stigma receptivity of the species was evaluated with the benzidine‐H2 O2 method .The results indicated that I2‐KI and TTC were unsuitable for the test of pollen viability of A. an‐nua ;benzidine‐α‐naphthol coloring could be used to measure pollen viability ,but the measured value was a bit too high ;the method of germination in vitro proved to be most desirable ,and it could accurately and reliably reflect pollen viability .The appropriate storage time of the pollen was 2 days at room temperature , and 3 days at 4 ℃ or at -19 ℃ .Drying treatment significantly accelerated the loss of pollen vitality .De‐termined with the

  5. 3种油茶植物花粉贮藏及生活力的研究%Studies on the pollen storage and viability of 3 oil-tea species

    Institute of Scientific and Technical Information of China (English)

    黄永芳; 吴雪辉; 何美儿; 丁健; 安星

    2011-01-01

    对普通油茶、越南油茶和广宁红花油茶3种油茶植物花粉的贮藏条件、萌发培养基、培养温度以及不同贮藏条件和不同贮藏时间对花粉生活力的影响进行研究.结果表明,不同油茶植物在不同贮藏条件下,花粉生活力差异较大,随贮藏时间的延长,花粉生活力呈明显的下降趋势.在低温和冷冻干燥条件下贮藏的花粉生活力下降缓慢,其中以冷冻干燥贮藏的下降速度最慢;在室内自然温度下贮藏的花粉生活力下降很快,大部分花粉生活力在贮藏10 d后基本丧失.不同油茶植物的花粉适宜培养温度为20 ℃,萌发的适宜培养基为0.01%硼酸+0.03%硝酸钙+0.02%硫酸镁+0.01%硝酸钾+15%蔗糖+1%琼脂.%Three oil-tea species including: Camellia oleifera, C. vietnamenisis, C. semiserrata were selected for the studies on the best conditions of pollen storage, suitable culture medium, culture temperature for pollen germination, and the effects of different conditions and different time for pollen storage on pollen viability. The results were summarized as follows: the difference in oil-tea pollen viability under different storage conditions was significant, the longer the storage time, the lower the pollen viability. The pollen viability changed with the storage conditions and time in a different way. The pollen viability in the frozen ( - 20 ℃ ) conditions decreased slowest, which kept a high level of viability after three month. The pollen viability under natural conditions decreased rapidly fast, which reached 0 after 10 days. The most suitable germination temperature for pollen was 20 ℃, and the most suitable culture medium was 0.01% HBO3 +0.03% Ca( NO3 ) 2 · 4H2O +0.02% MgSO4 · 7H2O +0.01% KNO3 + 15% sucrose + 1% agar.

  6. 大叶相思花粉离体萌发适宜条件及活力检测方法%Conditions for in vitro Germination and Testing Method for Pollen Viability of Acacia auriculiformis

    Institute of Scientific and Technical Information of China (English)

    詹妮; 黄烈健

    2016-01-01

    Objective]This study was aimed to studying the suitable conditions of in vitro pollen germination and the methods of pollen viability test for Acacia auriculiformis in order to provide a basis for hybrid breeding of A. auriculiformis and creating new breeding material by artificial pollination.[Methods]Pollen of A. auriculiformis was collected after 10:00 am on the next day of collection of flower clusters using the brush method. The pollen was germinated in vitro in conditions with different temperatures,the different concentrations of sucrose and boric acid,and suitable conditions for in vitro pollen germination of A. auriculiformis were chosen. Peroxidase method,I2-KI method and in vitro pollen germination method were used to detect the pollen viability of A. auriculiformis,and the effectiveness of these methods was assessed.[Results]When the pollen was cultured at 28 ℃,germination rate was 71. 99%,the average length of pollen tubes was 5. 3 D (1D=the length of pollen grain),the average number of pollen tubes was 6. 2,which were significantly higher than those of the other culture temperatures. When the culture medium contained 200 g · L -1 sucrose,the pollen germination rate was 84. 96%,the average length of pollen tubes was 5. 8 D,the average number of pollen tubes was 6. 2, which were significantly higher than those of the other sucrose concentrations. When the culture medium contained 300 mg ·L -1 boric acid,the pollen germination rate was 75. 32%,the average length of pollen tubes could reach 4. 8 D,the average number of pollen tube was 5. 4,which were significantly higher than those of the other boric acid concentrations. A. auriculiformis pollen in the culture medium at 30 ℃ culture temperature with 200 g·L -1 sucrose and 300 mg·L -1 boric acid had a germination rate of 98 . 26%,and the length of pollen tubes could be up to 10 times of the composite pollen length,and 10 pollen tubes could be produced at most,significantly higher than other

  7. Progress on Test Methods of Pollen Viability in Fruit Trees%果树花粉生活力检测研究进展

    Institute of Scientific and Technical Information of China (English)

    刘程宏; 宋尚伟; 张芳明

    2011-01-01

    Testing the viability of fruit tree pollen contained dyeing, germination, pollination and some other methods. Dyeing method often includes diaminobiphenyl dyeing, TTC dyeing, I2-KI dyeing,FCR dyeing,etc. Germination method includes germination in vitro and germination in vivo. This paper summarized the various methods of testing fruit tree pollen viability and their application, and compared the detection results of each method.%果树花粉生活力检测的方法有染色法、萌发法、授粉结实检测法及其他一些方法,常用的染色法有联苯胺染色法、TTC染色法、I2 - KI染色法、FCR染色法等,萌发法又包括离体萌发法和活体萌发法.掌握花粉生活力检测方法对于提高杂交育种效率具有较高的实际应用价值,为此,对上述各种方法及其应用研究进展进行了综述,并对各方法的检测效果进行了评价和比较.

  8. 黄毛草莓花粉活力及柱头可授性测定%Pollen Viability and Stigma Receptivity of Fragaria nilgerrensis

    Institute of Scientific and Technical Information of China (English)

    明晓; 吴璇; 汉由之; 涂蔷; 郑彦超

    2012-01-01

    In order to study the biological characteristics of flowering of Fragaria nilgerrensis,pollen-shedding rule and breeding system of Fragaria nilgerrensis were observed.Buds of different periods were used as test materials to determine the pollen germination rate and stigma receptivity with different methods.The result showed that the single flower season of Fragaria nilgerrensis lasted for 2 days,9∶30~17∶00 each day was considered to be pollen-releasing period and it peaked from 12∶00~14∶00.The pollen viability reached the top during the flowering stage,but in other periods were lower or were not viable.Stigma receptivity peaked at early flowering period and mid-full bloom stage.It had a certain degree of receptivity till the end of flowering season.%为了研究黄毛草莓的开花生物学特性,观测黄毛草莓的散粉规律和繁育系统,并以不同时期的花蕾为试材,用不同方法测定花粉的萌发率和柱头可授性。结果表明:黄毛草莓的单朵花期为2d,散粉时间为每天9∶30~17∶00,在12∶00~14∶00达到顶峰。黄毛草莓的花粉在开花盛期活力最大,其它时期均较低或没有活力。柱头可授性在开花初期和盛花中期达到顶峰,持续到末花期仍具有一定的可授性。

  9. Mutants of the major ryegrass pollen allergen, Lol p 5, with reduced IgE-binding capacity: candidates for grass pollen-specific immunotherapy.

    Science.gov (United States)

    Swoboda, Ines; De Weerd, Nicole; Bhalla, Prem L; Niederberger, Verena; Sperr, W R; Valent, Peter; Kahlert, Helga; Fiebig, Helmut; Verdino, Petra; Keller, Walter; Ebner, Christof; Spitzauer, Susanne; Valenta, Rudolf; Singh, Mohan B

    2002-01-01

    More than 400 million individuals are sensitized to grass pollen allergens. Group 5 allergens represent the most potent grass pollen allergens recognized by more than 80 % of grass pollen allergic patients. The aim of our study was to reduce the allergenic activity of group 5 allergens for specific immunotherapy of grass pollen allergy. Based on B- and T-cell epitope mapping studies and on sequence comparison of group 5 allergens from different grasses, point mutations were introduced by site-directed mutagenesis in highly conserved sequence domains of Lol p 5, the group 5 allergen from ryegrass. We obtained Lol p 5 mutants with low IgE-binding capacity and reduced allergenic activity as determined by basophil histamine release and by skin prick testing in allergic patients. Circular dichroism analysis showed that these mutants exhibited an overall structural fold similar to the recombinant Lol p 5 wild-type allergen. In addition, Lol p 5 mutants retained the ability to induce proliferation of group 5 allergen-specific T cell lines and clones. Our results demonstrate that a few point mutations in the Lol p 5 sequence yield mutants with reduced allergenic activity that represent potential vaccine candidates for immunotherapy of grass pollen allergy.

  10. Meiose e viabilidade polínica em acessos de Capsicum annuum e Capsicum baccatum Meiosis and pollen viability in accessions of Capsicum annuum and Capsicum baccatum

    Directory of Open Access Journals (Sweden)

    Kellen Coutinho Martins

    2010-08-01

    Full Text Available O objetivo deste trabalho foi estudar o comportamento meiótico e a viabilidade polínica em quatro acessos das espécies Capsicum annuum e Capsicum baccatum. Em todos os acessos, foram observados 12 bivalentes, confirmando o número e nível de ploidia relatados na literatura para essas espécies. Os resultados mostraram uma divisão celular normal, porém algumas anormalidades foram detectadas, tais como migração precoce dos cromossomos em metáfases I e II, cromossomos retardatários em anáfase I e divisão assincrônica. Os acessos estudados apresentaram um índice meiótico variando de 75,6 a 93,6%, e a viabilidade polínica em todos os acessos foi superior a 90%, demonstrando que as irregularidades meióticas observadas não comprometeram a viabilidade destes.The objective of this research was to study the meiotic behavior and pollen viability in four accessions of species Capsicum annuum and Capsicum baccatum. In all accessions, twelve bivalents were observed, confirming the number and ploidy level reported in the literature for these species. The results showed a normal cell division although some abnormalities had been detected, as early chromosome migration at metaphases I and II, later chromosomes at anaphase I and asynchronous division. The studied accessions presented a meiotic index (MI that varied from 75.6 to 93.6% and the pollen viability in all accessions was higher than 90%, demonstrating that the meiotic irregularities observed didn't affect their viability.

  11. 羊蹄甲属5个树种花粉生活力测定%Measurement on Pollen Viability of Five Species from Bauhinia

    Institute of Scientific and Technical Information of China (English)

    王裕霞; 梁梦琳; 魏丹; 唐洪辉

    2016-01-01

    采用 MTT 法和离体萌发法对红花羊蹄甲(Bauhinia blakeana)等5个羊蹄甲属树种花粉生活力进行测定,结果表明,红花羊蹄甲、黄花羊蹄甲(B. tomentosa)、宫粉羊蹄甲(B. variegata)、橙红羊蹄甲(B. galpinii)和羊蹄甲(B. purpurea)花粉 MTT 染色率分别为40.3%、79.8%、93.6%、95.7%、100%,羊蹄甲、宫粉羊蹄甲、橙红羊蹄甲花粉细胞生活力较其他两个树种要高;离体萌发试验测得以上5个树种的花粉萌发率差异很大,红花羊蹄甲、黄花羊蹄甲、宫粉羊蹄甲、橙红羊蹄甲和羊蹄甲花粉的最高萌发率分别为0、23.0%、92.1%、50.0%、80.3%,其中宫粉羊蹄甲花粉萌发率最高,羊蹄甲花粉次之,红花羊蹄甲花粉不萌发。以上5个树种中宫粉羊蹄甲及羊蹄甲的盛花期花粉可以作为人工授粉进行杂交育种较为理想的花粉来源。宫粉羊蹄甲花粉最适离体萌发培养基配方为蔗糖220 g/L+硼酸20 mg/L。%The pollen viability of the five species of Bauhinia was studied by MTT and invitro germination method. The result showed that the MTT staining rates of Bauhinia blakeana, B. tomentosa, B. variegata, B. galpinii and B. purpurea were 40.3%, 79.8%, 93.6%, 95.7% and 100%, respectively. The viability of pollen cell of B. purpurea, B. variegata and B. galpinii were higher than other two species. There were great differences in 5 tree species in the invitro germination test result, and the highest germination rate of B. blakeana, B. tomentosa, B. variegata, B. galpinii and B. purpurea were 0、23.0%、92.1%、50.0%、80.3%, respectively. The B. variegata pollen germination rate was the highest, followed by B. purpurea, and the pollen of B. blakeana was not germinated. In the five species, the flowering period pollen of B. variegata and B. galpinii can be an ideal pollen source for artificial breeding. The optimum medium for the invitro germination of B. variegata pollen was sucrose

  12. The influence of storage temperature and humidity on carrot pollen viability%贮藏温度和湿度对胡萝卜花粉生活力的影响

    Institute of Scientific and Technical Information of China (English)

    宋红霞; 侯璐芬; 武喆; 张光星

    2011-01-01

    采用液体培养基萌发法测定贮藏于室温、冷藏和冷冻条件下干燥与否的胡萝卜花粉生活力.结果表明:胡萝卜花粉的生活力在相同贮藏条件下随时间的延长逐渐降低,贮藏温度越低,生活力下降速度越慢;干燥贮藏花粉生活力高于非干燥贮藏花粉.本试验条件下,冰箱冷冻干燥贮藏最有利于保持胡萝卜花粉的生活力.%The effects of storage temperature and humidity on carrot pollen viability were studied by germinating tests in liquid medium.The results showed that the pollen viability gradually decreased with the storage time lasting,and the lower the storage temperature,the slower the viability descending rate; The pollen viability was higher in dry storage than in non-dry storage,and freeze-drying storage was the best in keeping the pollen viability.

  13. Halosulfuron reduced purple nutsedge (Cyperus rotundus) tuber production and viability

    Science.gov (United States)

    Weeds persist and cause economic losses in agricultural systems because they exploit an underutilized portion of that system. Reducing the impact of weeds on agroecosystems begins with minimizing the number of propagules (e.g, seeds and tubers) that are produced and returned to the soil. Purple nu...

  14. 芭蕉芋的花粉活力和柱头的可授性研究%Study on Pollen Viability and Stigma Receptivity of Canna edulis

    Institute of Scientific and Technical Information of China (English)

    周明强; 欧珍贵; 班秀文; 李志芳; 黎青

    2013-01-01

    In order to explore the possibility of hybrid breeding for Canna edulis, the author studied the pollen viability and stigma receptivity of three Canna edulis varieties planted in Guizhou by the methods of TTC staining and benzidine -H2 O2 .The re-sults showed that the pollen viability of Canna edulis was generally lower than that of other crops .Under the isolated condition for o-ver 36 hours, the pollen of Canna edulis was basically of no viability , and its short lifetime affected the seed setting rate .The stigma receptivity changed with time history , it showed a rising trend from 19:00 on that day to 10:30 on the next day , and then began to decline.From 4:30 to 10:30 on the next day, the stigma receptivity was the strongest .As a result, as long as we choice the right time and supplement artificial pollination , the objective of enhancing the fertilized rate of Canna edulis will be attained , and the breeding and improvement of new varieties will be realized successfully .%为探讨芭蕉芋杂交育种的可能性,采用TTC染色法和联苯胺-过氧化氢法对贵州种植的3个品种(材料)的花粉活力和柱头可授性进行了研究,结果表明:芭蕉芋花粉活力普遍低于其他作物,在离体条件下,36 h后,基本没有活力,寿命较短,影响了芭蕉芋种子结实率;柱头可授性随时间的变化而变化,从当日19:00到次日10:30均呈上升趋势,随后开始下降,次日4:30~10:30是柱头可授性最强的时间,只要选择合适的时期辅以人工授粉,则可达到提高芭蕉芋授粉受精目的,从而进行新品种选育及改良。

  15. Study on pollen viability of olive%油橄榄花粉生活力研究

    Institute of Scientific and Technical Information of China (English)

    马和; 陈炜青; 姜成英; 吴文俊

    2012-01-01

      油橄榄栽培过程中,合理配置授粉树是提高油橄榄坐果率的有效措施之一,而且花粉的产量及其质量直接影响到育种的成败,因此花粉生活力测定方法及测定标准一直是育种家关注的问题。选择恰当的花粉活力测定方法对其花粉活力的变化规律进行研究,对提高油橄榄繁殖效率具有重要意义。%  In the process of olive cultivation, configuring pollination trees is one of the effective measures to improve the olive fruit set-ting rate. Pollen output and its quality directly affect the success or failure of the breeding, so it is important to improve the efficiency of the olive breeding by choosing appropriate method for the determination of the pollen vigor pollen energy and study the change rule.

  16. 七叶树花粉活力和柱头可授性变化的研究%Pollen viability and stigma receptivity of Aesculus chinensis

    Institute of Scientific and Technical Information of China (English)

    李莺; 陈鹏涛; 樊静静

    2012-01-01

    采用花粉离体萌发法研究不同蔗糖浓度、硼酸浓度和不同温度对七叶树花粉萌发的影响及花粉活力测定,用联苯胺-过氧化氢法测定柱头可授性.结果表明:七叶树花粉萌发的最佳培养基是12%蔗糖+30 mg/L硼酸,花粉萌发的最适温度为25℃.雄花在开花当天花粉活力最高达75.69%,并在开花当天的上午10:00时,花粉活力最强,10:00~16:00花粉活力保持较高活力,是最佳授粉时段.两性花的柱头可授期持续时间较长,为8~9 d,开花3d达到最强,开花1~4 d柱头可授性保持较高水平,为授粉的最佳时间段.因此,从七叶树的花部特征、花粉活力与柱头可授性及花粉萌发的条件看,在长期的自然选择下七叶树在花部结构和开花生理上都是相配合的,以保障生殖成功.%In vitro pollen-germinating method was used to study the effects of different sucrose and boric acid concentrations, and temperatures on pollen germination and vitality of Aesculus Chinese. Benzidine-hydrogen peroxide method was used to assay stigma receptive. The results showed that the best sucrose and boric acid concentration for pollen germination was 12% and 30 mg/L,respectively,and the optimized temperature was 25℃. The pollen viability of male flowers maintained at higher levels from 10:00 to 16:00 and the highest (75. 69%) at 10:00 during the flowering day. As a result,the best time for pollination was at 10:00. The stigma receptivity of perfect flowers lasted about 8 - 9 d,the stigma receptivity maintained at high levels 1 -4 d after flowering and was the strongest 3 d after flowering. As a result,the best time for pollination was at 1- 4 d after flowering. According to the floral character,pollen viability,stigma receptivity and pollen germination of A. Chinensis, during long terms of natural selection, the floral structure was matched with flowering physiology of A. Chinensis in order to guarantee successful reproduction.

  17. Pectic arabinan side chains are essential for pollen cell wall integrity during pollen development

    DEFF Research Database (Denmark)

    Cankar, Katarina; Kortstee, Anne; Toonen, Marcel A.J.

    2014-01-01

    transgenes were not transmitted to the next generation when these lines were used as a pollen donor, suggesting male sterility. Viability of mature pollen was severely decreased in potato lines with reduced pectic arabinan, but not in lines with altered galactan side chains. Anthers and pollen of different...... developmental stages were microscopically examined to study the phenotype in more detail. Scanning electron microscopy of flowers showed collapsed pollen grains in mature anthers and in earlier stages cytoplasmic protrusions at the site of the of kin pore, eventually leading to bursting of the pollen grain...... and leaking of the cytoplasm. This phenomenon is only observed after the microspores are released and the tapetum starts to degenerate. Timing of the phenotype indicates a role for pectic arabinan side chains during remodelling of the cell wall when the pollen grain is maturing and dehydrating....

  18. 三七及屏边三七花粉不同贮藏条件生活力测定%Determination of Pollen Viability ofPanax Notoginseng and Panax Stipuleanatus on Different Store Conditions

    Institute of Scientific and Technical Information of China (English)

    孙玉琴; 黄天卫; 杨莉; 韦美丽; 王朝粱; 陈中坚

    2012-01-01

    采用MTT染色法测定栽培三七及屏边三七在不同贮藏条件下花粉生活力维持时间,结果表明,三七花粉在冰冻条件下,花粉从有活力至活力完全丧失约80d,保鲜条件下二年生三七花粉活力维持时间约45d,三年生三七花粉活力维持时间约60d。屏边三七花粉在保鲜条件下从有活力至活力完全丧失约60d,而冰冻条件下仅为35d。%The paper determines pollen viability of Panax notoginseng and Panax Stipuleanatus on Different store conditions by MMT staining method and discovers that pollen viability lasts about 80 days under the freezing condition, two-year-old pollen 45 days, and three-year-old pollen 60 days. Pollen viability of Panax Stipuleanatus lasts 60 days under the fresh-keeping condition, but only 35 days under the freezing condition.

  19. Meiose e viabilidade polínica em linhagens avançadas de pimenta Meiosis and pollen viability in advanced lines of pepper

    Directory of Open Access Journals (Sweden)

    Marisa T Pozzobon

    2011-06-01

    Full Text Available Doze linhagens de pimenta, incluindo exemplares do tipo Jalapeño (CNPH 2862, CNPH 2864, Dedo-de-Moça (CNPH 1397, CNPH 0039, CNPH 0053, Cambuci (CNPH 0283, Peixe-Boi (CNPH 0434, Falsa Cumari (CNPH 3761, Bode Vermelha (CNPH 3773, Biquinho Doce (CNPH 3870, Tabasco (CNPH 3000 e Malagueta (CNPH 2869 tiveram o comportamento meiótico e a estimativa da viabilidade do pólen analisados, com o objetivo de indicar materiais potencialmente férteis para o programa de melhoramento de Capsicum da Embrapa. A análise convencional, por coloração, revelou um comportamento relativamente normal, durante a microsporogênese, para a maioria das linhagens, com índice meiótico (IM e percentual médio de viabilidade polínica acima de 90%. As principais anormalidades observadas foram aderências cromossômicas, cromossomos não orientados, retardatários, pontes, micronúcleos, micrócitos e citomixia. Três linhagens, CNPH 0283, CNPH 3000 e CNPH 3773 mostraram menor percentual de pólens viáveis, respectivamente 77, 66 e 58%. Somente para CNPH 0283 a baixa fertilidade do pólen esteve associada à maior frequência de irregularidades e, consequentemente, ao baixo IM (77%. Os resultados do presente trabalho confirmam a importância da análise citológica como ferramenta auxiliar na seleção de linhagens meioticamente estáveis e potencialmente férteis o que possibilita o planejamento de programas de produção de sementes das cultivares em vias de lançamento.Twelve lines of pepper, from different groups {Jalapeño (CNPH 2862, CNPH 2864, Dedo-de-Moça (CNPH 1397, CNPH 0039, CNPH 0053, Cambuci (CNPH 0283, Peixe-Boi (CNPH 0434, Falsa Cumari (CNPH 3761, Bode Vermelha (CNPH 3773, Biquinho Doce (CNPH 3870, Tabasco (CNPH 3000 and Malagueta (CNPH 2869 had their meiotic behavior and the estimation of pollen viability analyzed with the aim of indicating potentially fertile material for the Capsicum breeding program. Conventional analysis by staining revealed a

  20. 映山红开花习性与花粉生活力研究%Study on the Flowering Habit and Pollen Viability of R. arborescens Planch

    Institute of Scientific and Technical Information of China (English)

    卜志国; 杜绍华; 张晓曼

    2011-01-01

    [目的]探讨映山红的开花习性及花粉生活力.[方法]以映山红(Rhododendron arborescens)为试验材料.观察映山红(R.simisiiPlanch)开花的习性;采用离体培养基萌发测定法,以及培养基中蔗糖的浓度、培养温度、硼酸、钙离子等因素对花粉萌发和花粉管伸长的影响.[结果]映山红花期4~6月,单花期3~5 d;花紫色,2~6朵簇生于枝端;花萼5裂,长2~4 mm;花冠宽漏斗状,长4~5 cm,5裂;雄蕊7~10,花药紫色;柱头头状.蔗糖浓度为5%时映山红花粉萌发最好;光照条件下25℃时萌发率最高,达70%以上;培养基为20mg/L硼酸+10mg/L氯化钙+5%蔗糖+0.5 g琼脂,萌发率最高达87%;在一定浓度(0~20 mg/L)范围内,钙离子对映山红花粉的萌发率影响不大,主要影响花粉管长度;对花粉萌发率的影响比较明显,浓度间差异均达显著水平,在一定硼酸浓度(0~20 mg/L)范围内,随着硼酸浓度的增加花粉的萌发率上升.[结论]该研究可为今后利用映山红开展人工育种奠定基础.%[ Objective ] To investigate the flowering habit and pollen viability of R. arborescens Planch. [ Method ] R. arborescens Planch as test material, effects of sucrose concentrations, culture temperature, boric acid and Ca2+ on the pollen germination and tube growth were studied through in vitro culture method. [ Result ] The flower season of R. arborescens Planch lasts 4 to 6 months with single flowering phase of 3 - 5 d;purple, 2 -6 flowers cluster in the end of branches; calyx 5-lobed, 2-4 mm in length; funnel-form corolla, 4 -5 cm in length, 5-lobed; 7 -10 stamens, purple anther; capitate stigmas. 5% sucrose was proved to be the best for the germination of pollen, and the germination rate was the highest at 25 ℃ in daylight ( more than 70% ); the optimum combination for the germination of pollen was 20 mg/L boric acid + 10 mg/L CaCl2 +5% sucrose +0.5% agar, under this condition, the germination rate reached as high as

  1. 甜瓜雄花采摘时间及贮藏温度对花粉生活力的影响%Effect of Different Male-flower Picking Time and Storage Temperature on Melon Pollen Viability

    Institute of Scientific and Technical Information of China (English)

    张永平; 杨少军; 陈幼源

    2011-01-01

    Taking 3 stable inbred-lines of melon ( Cucumis melon L. ) as experimental material, we studied the effects of different male-flower picking time and storage temperature on their pollen viabilities.The results indicated that the pollen viabilities of 3 melon cultivars were the best at 8:00 am and then decreased gradually as time extended. Under low temperature of 4 ℃, the pollen viability could maintain in good condition and as time flew, it also drop down. But pollen viabilities and retaining times of different melon cultivars were different.%以3个甜瓜品系的稳定自交系为试材,研究了甜瓜鲜雄花不同采摘时间及贮藏温度对花粉生活力的影响.结果表明:3个甜瓜品系在早晨8:00花粉生活力最佳,随着时间的推移,花粉生活力下降;在4℃条件下,花粉生活力保持最好,随着温度的升高和时间的延长,花粉生活力逐渐下降,但不同甜瓜品系的花粉生活力及保持时间不同.

  2. Interactive effect of reduced pollen availability and Varroa destructor infestation limits growth and protein content of young honey bees.

    Science.gov (United States)

    van Dooremalen, C; Stam, E; Gerritsen, L; Cornelissen, B; van der Steen, J; van Langevelde, F; Blacquière, T

    2013-04-01

    Varroa destructor in combination with one or more stressors, such as low food availability or chemical exposure, is considered to be one of the main causes for honey bee colony losses. We examined the interactive effect of pollen availability on the protein content and body weight of young bees that emerged with and without V. destructor infestation. With reduced pollen availability, and the coherent reduced nutritional protein, we expected that V. destructor infestation during the pupal stage would have a larger negative effect on bee development than without infestation. Moreover, when raised with ample pollen available after emergence, infested pupae were expected not to be able to compensate for early losses due to V. destructor. We found that both V. destructor infestation and reduced pollen availability reduced body weight, abdominal protein level, and increased the head to abdomen protein ratio. The availability of pollen did indeed not result in compensation for reduced mass and protein content caused by V. destructor infestation in young bees after 1 week of their adult life. Both V. destructor and nutrition are top concerns for those studying honey bee health and this study demonstrates that both have substantial effects on young bees and that ample available pollen cannot compensate for reduced mass and protein content caused by V. destructor parasitism.

  3. Specific immunotherapy with mugwort pollen allergoid reduce bradykinin release into the nasal fluid

    Science.gov (United States)

    Grzanka, Alicja; Jawor, Barbara; Czecior, Eugeniusz

    2016-01-01

    Introduction A pathomechanism of allergic rhinitis is complex. A neurogenic mechanism seems to play a significant role in this phenomenon. Aim The evaluation of influence of specific immunotherapy of mugwort pollen allergic patients on the bradykinin concentration in the nasal lavage fluid. Material and methods The study included 22 seasonal allergic rhinitis patients. Thirty persons with monovalent allergy to mugwort pollen, confirmed with skin prick tests and allergen-specific immunoglobulin E, underwent a 3-year-long allergen immunotherapy with the mugwort extract (Allergovit, Allergopharma, Germany). The control group was composed of 9 persons with polyvalent sensitivity to pollen, who were treated with pharmacotherapy. Before the allergen-specific immunotherapy (AIT) and in subsequent years before the pollen seasons, a provocation allergen test with the mugwort extract was performed, together with collection of nasal fluids, where bradykinin concentration was determined according to Proud method. Results There were similar levels of bradykinin in both groups at baseline prior to therapy (AIT group: 584.0 ±87.2 vs. controls 606.3 ±106.5 pg/ml) and changes after allergen challenge 1112.4 ±334.8 vs. 1013.3 ±305.9 pg/ml as well. The bradykinin concentration in nasal lavage fluid after mugwort challenge in 1 year was lower in the AIT group (824.1 ±184.2 pg/ml vs. 1000.4 ±411.5 pg/l; p < 005) with a further significant decrease after the 2nd and 3rd year of specific immunotherapy. Significant reduction of symptoms and medications use was observed in hyposensitized patients. Conclusions A decreased level of bradykinin as a result of AIT suggests that some of the symptomatic benefits of AIT may be related to the reduced release of bradykinin into nasal secretions. These values correlate with clinical improvement within the course of treatment. PMID:27605897

  4. GA3、2,4-D、B和蔗糖对梨花粉生活力及花粉生长速度的影响%Pollen Viability of Asian Pear and Effect of PGR,B and Sucrose on Germination and Pollen Tube Development

    Institute of Scientific and Technical Information of China (English)

    谢深喜; 罗先实; 吴月嫦; Lovatt CJ

    2004-01-01

    以5个亚洲梨品种为试材,通过离体培养研究了花穗中花的着生部位,不同浓度的GAs、2,4-D和蔗糖对花粉生活力、花粉管生长速度的影响.结果表明,不同品种的花粉生活力差异明显,黄花花粉萌发快;新世纪花粉生活力强,花粉管生长迅速.花的着生位置及花器官的发育程度对花粉生活力有明显影响,边花的生活力比中心花强.不同浓度的B、2,4-D、GA3对花粉萌发及花粉管生长均有不同程度的影响,高浓度的GA3、2,4-D抑制花粉管的生长,但浓度较高的蔗糖能促进花粉粒的萌发和生长,且两者呈正相关(R2=0983).%The pollen viability of 5 cultivars of Asian pear, the influence of flower position in a cluster and the effect of GA3, 2,4-D, B and sucrose on its germination and tube development were studied in vitro. The difference of viability among 5 cultivars was significant. The pollen of Huanghua germinated fast. Both germination rate and pollen tube length of Shinseiki were much higher and longer. Nijisseiki had the poorest performances on germination. Huanqing showed a low capability on pollen tube development; the length was the shortest within the 5 varieties. The flower position in a cluster and developmental stage influenced pollen viability;the viability of pollen grain from outer flowers of a cluster was greater than those from central flowers. Mediate concentration of B,GA3 and 2,4-D increased germination and pollen tube growth. The germination rate and pollen tube length on the medium that contained 15 mg/L of boron were greater than those of other treatments. There were negative relationship trend between pollen viability and the content of GA3 and 2,4-D. High content of sucrose on the medium benefited germination and pollen tube development. There was a linear regression relationship between germination rate and content of sucrose in the medium (R2=0.983).

  5. Model-Based Analysis on the Pollen Viabilities of Transgenic Rice B2 at Different Temperatures%转基因水稻B2花粉活力的温度模型

    Institute of Scientific and Technical Information of China (English)

    刘寿东; 史佩剑; 江晓东; 姚克敏; 胡凝

    2011-01-01

    The pollen viability of a genetically-modified japonica rice, B2, containing bar gene with herbicide Basta resistance was investigated under nine temperatures(5℃, 10℃, 15℃, 20℃, 25℃, 30℃, 35℃, 40℃, and 45℃ ) by 2,3,5-triphenyl tetrazolium chloride (TTC) method in vitro after 0, 1, 2, 3, 4, 5, 6, 8, 12, and 14 min from anther. The result showed that the pollen viability decreased with the passing time in vitro, like as "S curve", which could be accurately described by the Logistic equation. In vitro pollen viability first increased and then decreased with the rising temperature. The optimal temperature for pollen viability ranged from 20℃ to 30℃, and 25℃ was the most optimum temperature. High temperature stress on the pollen viability was more obvious than low temperature. Two equations, an exponential one and a Logistic one, could give the satisfied predicts of the pollen viability duration and pollen longevity, helping to estimate the risk of transgenic flow.%以含bar基因的抗Basta转基因粳稻B2为材料,分别在5℃、10℃、15℃、20℃、25℃、30℃、35℃、40℃、45℃下进行处理,用2,3,5-氯化三苯基四氮唑(TTC)染色法测定了不同温度处理下转基冈水稻B2花粉离体0、1、2、3、4、5、6、8、12、14 min 后的活力.B2花粉离体后活力呈现"S"型下降,用Logistic模型可精确模拟两者的关系;其次,B2花粉离体后活力随着温度先升后降,花粉活力的最适温度范围足20℃~30℃,25℃时活力最强,高温对花粉活力的胁迫作用更大.采用指数方程和Logistic方程分段函数,建立B2花粉活力的温度模型,可精确预测花粉存活时间和寿命,为进一步准确估算转基因水稻基因飘移距离提供依据.

  6. Comparação entre métodos para testar a viabilidade de pólen de pessegueiro Comparison among methods for testing pollen viability

    Directory of Open Access Journals (Sweden)

    Patrícia Milech Einhardt

    2006-04-01

    that the pollen used in controlled hibridization has a high germination percentage. There are different ways to test pollen viability: 1. by staining 2-in vitro pollen germination; 3- in vivo germination test; 4-fruit set, obtained by using the pollen to be tested. In the present work, performed in 2004, a comparison was made among the three first methods above. Pollen samples of five cultivars , Esmeralda, Eldorado, Granada, Maciel and Vanguarda ,collected in 2003, were used in the experiment. The culture medium for in vitro germination tests was constituted by 10g of sucrose and 1g of agar dissolved in 100ml of distilled water. Twigs with flowers on balloon stage were collected and taken to the laboratory where they were placed in recipients containing water. The procedure used was the one described for light microscopy using differential dye, in order to observe the pollen tubes on the stigma or in the pistil. Propionic carmin was used as a dye for the staining method of pollen viability evaluation. Variance analysis showed differences among cultivars, among methods and a highly significant interaction between cultivar and method. The staining method using propionic carmin as a dye gave higher percentage of viability than in vivo germination for all the tested cultivars. In vitro germination was statistically equal to in vivo germination , except for cultivars Esmeralda and Granada for which gave higher germination percentages. However, the largest differences between the two methods was 10.03% in cv. Esmeralda, which in spite of being statistically significant, practically would be acceptable for routine tests. It was concluded that in vitro tests using the culture medium is representative of the in vivo situation while the staining procedure was not reliable.

  7. Horse chestnut pollen quality

    Directory of Open Access Journals (Sweden)

    Ćalić Dušica

    2017-01-01

    Full Text Available Pollen quality of horse chestnut, expressed as pollen productivity, viability and germination was studied. Anthers of horse chestnut genotypes had pollen production from 3.66 to 5.06 x 103 pollen grains per anther, depending of genotype. Also, pollen of horse chestnut Ah1-Ah4 genotypes showed different viability (from 56 to 68%, after staining with fluorescein diacetate. Pollen germination of Ah1-Ah4 genotypes varied from 50-66% on basic medium. Inclusion of polyethylene glycol-PEG from 10%, 15% and 20% v/w increased pollen germination. The best results were achieved on medium with the largest PEG concentration. On these medium 76-91% pollen grains were germinated, depending of genotype. The best pollen quality, for all tested parameters, had genotype Ah2. Knowledge about morphology, production, viability, in vitro germination, tube growth as well as pollen: ovule ratio can be of great importance for future pollen biology studies. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. 173015

  8. 冷蒿的开花动态与花粉活力及柱头可授性研究%Observation on the Flowering Dynamic, Pollen Viability and Stigma Receptivity in Artemisia frigida Willd.

    Institute of Scientific and Technical Information of China (English)

    张雅荣; 宛涛; 蔡萍; 伊卫东

    2012-01-01

    Flowering dynamic was observed in test field, pollen viability of Artemisia frigida Willd. Was evaluated with TTC method, and stigma receptivity of Artemisia frigida Willd. Was evaluated with benzidine-H2O2 method. The results showed that flowers in inflorescence of Artemisia frigida Willd. Bloomed from up to down and outer florets bloomed before others, then middle florets bloomed later. The pollen viability of Artemisia frigida Willd. Was lower at initial stage, higher on the 2nd or 3rd day after flowering, and then reduced evidently, but a few pollen viability still existed until inflorescence withered. The life-span of pollen was about 20 days. The stigma receptivity of outer female flowers appeared on the first flowering day, and lasted longer, the highest on the 2nd or 3rd day after flowering. The stigma receptivity of middle flowers appeared latter than the outer female flowers, but the stigma receptivity were highest on the 2nd or 3rd day after flowering and lasted longer. The best stage of stigma receptivity and pollination was on the 2nd or 3rd day after flowering.%在试验地观察了冷蒿的开花动态,用TTC法测定了冷蒿花序花粉的活力,采用联苯胺—过氧化氢法测定了其柱头的可授性.结果表明,冷蒿花序的开花顺序是自上而下的,小花的开放是自外轮至中央小花.冷蒿的花粉活力在盛花期开花之初很低,第2~3d花粉活力较高,随后活力明显下降,但直至其花序枯萎,少量的花粉仍具有部分活力.花粉寿命较长,约为20d.冷蒿边缘雌花柱头的可授性在开花当天就具有,并且持续时间较长,在第2~3d可授性最强.中央两性小花柱头可授性要稍晚于边缘小花,但是在开花后第2~3d可授性也达到最高,其可授性时间也较长.柱头可授性的最佳时期为开花后第2~3d.冷蒿的最佳授粉期在开花后2~3d左右.

  9. Viabilidade do pólen de laranjas doces em diferentes condições de armazenamento Viability of citrus pollen in different storage conditions

    Directory of Open Access Journals (Sweden)

    Leila Aparecida Salles Pio

    2007-02-01

    Full Text Available O presente trabalho foi realizado visando avaliar a viabilidade de grãos de pólen armazenados das cultivares copas cítricas Natal, Pêra e Valência. O pólen foi submetido a 3 temperaturas de armazenamento: -10ºC (freezer, 4ºC ( refrigerador e temperatura ambiente; 2 ambientes (com e sem dessecador e na presença e ausência de sílica-gel. A avaliação do índice de germinação foi feita com o pólen fresco e a cada 7 dias, durante 9 semanas. Para avaliar a germinação foi utilizado meio constituído de 1% de ágar e 10% de sacarose, 800 mg L-1 de nitrato de cálcio (Ca(NO32 4H2O, 200 mg L-1 de Ácido Bórico (H3BO3 e pH corrigido para 6,5. Os grãos de pólen foram incubados à temperatura de 25 ± 2ºC por 12 horas. As avaliações foram realizadas através da porcentagem de grãos de pólen germinados. Constatou-se que os grãos de pólen possuem redução na viabilidade com o aumento do tempo de armazenamento; o armazenamento em freezer (-10ºC foi mais eficiente do que em refrigerador (4ºC e à temperatura ambiente. Melhores resultados foram alcançados com os tratamentos em freezer com sílica-gel dentro de dessecador e em freezer sem sílica-gel dentro de dessecador. A cultivar Valência apresentou-se superior às demais em todos os tratamentos.The present work was accomplished to evaluate the effects of storage on the viability of pollen grains from Natal, Pêra and Valência cultivars of sweet oranges. The grains were stored at 3 temperatures: -10ºC (freezer, 4ºC (refrigerator, and room temperature; 2 environments (with or without desiccator and in the presence or absence of silica-gel. The germination was evaluated every 7 days, during 9 weeks. To evaluate the germination, a medium consisting of 1% and sucrose 10%, 800 mg L-1 calcium nitrate (Ca(NO32 4H2O, 200 mg L-1 boric acid (H3BO3 and pH 6,5 was used. The pollen was incubated at 25 ± 2ºC temperature for 12 hours. The evaluation was performed using the percentage of

  10. Pollen Quantity and Viability of Five Rabbiteye Blueberry Varieties%5个兔眼蓝莓品种的花粉量与花粉活力测定

    Institute of Scientific and Technical Information of China (English)

    杨芩; 廖优江; 任永权; 田栋伟; 蔡陈; 刘宗朝; 李性苑; 张文华

    2013-01-01

    为了给兔眼蓝莓品种栽培搭配合适授粉树及开展人工辅助授粉提供科学依据,以我国南方地区主栽的5个兔眼蓝莓品种为材料,对其花粉量和花粉活力进行测定.结果表明,5个兔眼蓝莓品种的花粉量和花粉活力均有显著差异,其中杰兔的花粉量与花粉活力分别为600.34粒和79.84%,均显著高于其他4个品种,同时梯扶蓝和巴尔德温两品种的花粉量均高于450粒,花粉活力均高于65%.因此,杰兔、梯扶蓝和巴尔德温可作为兔眼蓝莓的栽培授粉品种,并可与其他相互亲和品种搭配建园;而S13的花粉量(324.32粒)最少,花粉活力(22.66%)最低,不宜作为授粉树.%The pollen quantity and pollen viability of five main rabbiteye blueberry varieties were determined to provide the scientific basis for selecting appropriate pollinizers and artificial supplementary pollination in cultivation of rabbiteye blueberry.The results showed that there were significant differences in pollen quantity and pollen viability between five varieties,the pollen quantity and pollen viability of Premier variety was 600.34 and 79.84%,significantly higher than other four varieties respectively and the pollen quantity and pollen viability of Tifblue and Baldwin varieties both was over 450 and 65%,which indicates that Premier,Tifblue and Baldwin varieties can be used as pollination varieties for cultivation of rabbiteye blueberry.

  11. Analysis on Pollen Morphology and Variation of Viability of Lilium Asiatic Hybrids with Different Ploidy%不同倍性亚洲百合的花粉形态与活力变化规律分析

    Institute of Scientific and Technical Information of China (English)

    崔光芬; 杜文文; 段青; 贾文杰; 王祥宁

    2015-01-01

    为研究亚洲百合的花粉活力变化规律及形态在倍性水平上的差异,以8个亚洲百合品种为材料,采用混合染料染色法和萌发法测定花粉活力,并以电子显微镜观察花粉形态。结果显示,3种倍性亚洲百合的花粉最高活力时段均在开花第1天,三倍体品种为上午10:30,二倍体和四倍体品种为中午12:30,花粉活力的总体变化趋势为先升高后降低。花粉大小与倍性呈正相关,极轴值范围为96.47~137.91μm,赤道轴值40.68~56.55μm,四倍体品种的P ×E值最大,其次为三倍体和二倍体。花粉中部网眼大小的范围为3.93~8.57μm,随品种倍性增加而增大,形态参数聚类显示倍性相同的品种之间花粉相似性更高。研究表明,不同倍性亚洲百合的花粉活力持久性差异较大,杂交育种时可根据倍性选择花粉活力最高时段进行授粉。%In order to investigate differences of pollen morphology and variation of viability of Lilium Asiatic hybrids in ploidy level,with 8 Asiatic lily cultivars as materials,pollen viability was measured by the methods of mixed dye staining and germination.Meanwhile,pollen morphology was observed with an electron microscope.The results showed that the highest pollen viability of three kinds of ploidy Asiatic lily appeared in the first day of the flowering period,which of the triploid varieties were at 10:30 AM,diploid and tetraploid cultivars were at 12:30 PM.Trends of pollen viability in 8 lily cultivars increased first and then decreased.There was a positive correlation between pollen size and ploidy.The polar axis ranged in 96.47 -137.91 μm and the equatorial axis value were 40.68 -56.55 μm.P ×E value of tetraploid pollen was the largest,followed by triploid and diploid.The pollen cen-tral mesh size range 3.93 to 8.57 μm,which increased with increasing ploidy of varieties.Morphological parameters cluster displayed higher pollen

  12. Morphological observation and analyses of viability and germination rate of Daphne genkwa pollen%芫花的花粉形态观察及生活力和萌发率分析

    Institute of Scientific and Technical Information of China (English)

    刘芳; 汪甜; 王杨; 沈永宝

    2011-01-01

    @@ 芫花(Daphne genkwa Sieb.et Zucc.)别名南芫花、芫花条、药鱼草等,为瑞香科( Thymelaeaceae)瑞香属(Daphne L.)的多年生落叶小灌木.芫花的干燥花蕾是著名的中药材,具有利尿、镇咳、祛痰、抑菌、引产、抗肿瘤等功效[1];另外,芫花花色艳丽、花团锦簇,具有良好的观赏性[2].目前,关于芫花的研究主要集中在化学成分和药理作用方面[1,3-6],也有少量关于其组织培养[7]、遗传多样性[8]、病虫害防治[9]等方面的研究报道,但对芫花的花粉形态及牛理特性方面的研究尚未见报道.作者采用扫描电镜观察了芫花的花粉形态,并检测了其花粉生活力和萌发率,以期为芫花种质资源的利用和保护提供一定的实验基础.%Pollen morphology of Daphne genkwa Sieb. et Zucc. was observed by scanning electron microscope (SEM), and its viability and germination rate were measured by TTC and sucrose in vitro culture methods. The results show that pollen is stenopalynous type with a diameter of 15.6-21.6 μm. Per pollen has 10-16 apertures which is irregular circular with a diameter of 1.4-2.0 μm. Surface ornamentation of pollen is rough reticulate pattern which is circular polygon ( tetragonheptagon, mostly pentagon-hexagon). Pollen viability is 51% by TTC. Sucrose of different concentrations has a significant effect on pollen germination rate during pollen culture. And pollen germination rate is the highest with a percentage of 27.0% in medium containing 50 g·L-1 sucrose, while pollen could not germinate in medium containing sucrose over 250 g · L-1. Otherwise, there is the phenomenon of "multi-aperture germination" during pollen germinating.

  13. 贮藏条件对薄壳山核桃4个品系花粉活力影响%Effect of different storage condition on pollen viability of four varieties of Carya illinoensis

    Institute of Scientific and Technical Information of China (English)

    李雪; 徐迎春; 李永荣; 李晓储

    2011-01-01

    通过TTC染色法测定4个薄壳山核桃品系Mahan(‘马汉')、Western(‘威斯登')、Shoshoni(‘肖肖尼')、‘钟山25'的花粉分别在室温、4℃和-20℃等不同贮藏条件下活力的变化.研究结果表明,-20℃条件下花粉活力贮藏时间最长,到140天时花粉活力仍在50%左右.以花粉活力保持在50%为标准,室温条件下Western和‘钟山25'贮藏时间最长(8天);4℃下Western花粉贮藏时间最长(21天);-20℃下,4个品系贮藏天数都在84天以上,其中Western、'钟山25'贮藏时间最长,达140天.%The dynamics of pollen viability under different storage condition of four Carya illinoensis varieties were assayed by TIC so as to provide technical support for the artificial pollination. The dynamics of pollen viability under room temperature, 4℃and -20℃ storage condition of four varieties were assayed. Results showed that with the storage prolonging, pollen viability gradually decreased. -20℃ storage had the longest pollen viability, which could reach 50% at 140th day. With the pollen viability at 50% as a standard, under room temperature, Western and ' Zhongshan 25' had longest storage time of 8 days; Under 4℃ pollen storage time Western was the longest storage time of 21 days; When storage under -20℃, the storage time of the 4 viabilities were mere than 84 days, in which Western, ‘Zhongshan 25' had longest storage time, up to 140 days.

  14. Study on the Pollen Viability and Stigma Receptivity of Four Plants in Hedychium%4种姜花属植物花粉活力和柱头可授性研究

    Institute of Scientific and Technical Information of China (English)

    熊友华; 闫建勋; 刘念

    2011-01-01

    [目的]为姜花属植物种间有性杂交育种提供理论依据.[方法]采用TIC法、联苯胺-过氧化氢法测定4种姜花属植物白姜花、圆瓣姜花、红姜花和金姜花的花粉活力和柱头可授性.[结果]4种植物花粉活力在89.7%~97.8%,其中红姜花的花粉活力最高,然后依次为:白姜花、圆瓣姜花和金姜花:4种植物的柱头可授性在91.3%-98.7%,其大小依次为:白姜花、圆瓣姜花、红姜花和金姜花.[结论]4种姜花属植物都具有较高的花粉活力和柱头可授性,其中白姜花的花粉活力和柱头可授性均最高.%[ Objective ] The basis of the sexual hybridization breeding among the species from Hedychium was provided. [ Method] In order to evaluated The pollen viability and stigma receptivity of four Hedychium plants: H. coronarium, H. coccineum, H. gardnerianum, and H. forrestii were measured with the method of TTC and Benzidine-H2O2. [ Results] The results showed that the pollen viability of four plants were in the range from 89.7% to 97.8%, among which, the pollen viability of H. gardnerianum was highest and then the order of pollen viability was H. coronarium > H. coccineum > H. forrestii. The stigma receptivity was in the range from 91.3% to 98.7% and the order of the stigma receptivity was H. coronarium > H. coccineum > H. gardnerianum > H. forrestii. [ Conclusion] All the four plants had high pollen viability and stigma receptivity, among which, the pollen viability and stigma receptivity of H. coronarium were highest.

  15. Optimization of Culture Medium for Testing Apricot Pollen Viability and Study of the Storability of the Fruit%杏花粉活力测定培养基筛选及耐贮性研究

    Institute of Scientific and Technical Information of China (English)

    安晓芹; 王玲丽; 逯东阳; 孙慧瑛; 廖康

    2011-01-01

    [ Objective and Method]The pollen viability of Dahuangxing cultured in vitro on agar medium supplemented with different concentrations of sucrose and boric acid were compared, and the optimum medium was used to test the pollen vitality which was stored at three different temperatures. [ Result ] The results showed that the medium with 15% sucrose, 0.01% boric acid and 1% agar is the best for germination, and besides, stored in dry and closed condition, the pollen vigor at three different temperatures from high to low always was; - 18℃, 4-5℃, room temperature, while the decrease amplitude of the pollen viability was just the opposite. [Conclusion]The pollen viability stored at - 18℃: still could reach to 30.00% one year later, while stored at 4 - 5℃ the pollen viability would be lost after storage for eleven months, and the room temperature kept the pollen vigor only for 3 months.%[目的]以固体琼脂培养基离体培养‘大黄杏’品种花粉,比较不同浓度蔗糖、硼酸对花粉离体萌发的影响.[方法]用筛选出的最适培养基测定三种贮藏温度条件下花粉活力变化.[结果]‘大黄杏’品种最适萌发培养基为:l5%蔗糖+0.01%硼酸+1%琼脂;干燥密闭条件下,为期1年贮藏于三种温度条件下花粉活力大小依次均为:-18℃>4~5℃>室温,活力下降幅度由大到小则依次均为:室温>4 ~5℃>- 18℃.[结论]花粉于-18℃贮藏后1年活力仍达30.00%,4~5℃在贮后第11个月丧失活力,而在室温下贮藏3个月花粉即失去活力.

  16. 不同贮藏方式对4种桉树花粉活力影响的研究%Study on Effects of Different StorageMethods on Pollen Viability of 4 Eucalyptus

    Institute of Scientific and Technical Information of China (English)

    王伟; 徐建民; 陆钊华; 李光友; 黄宏健; 谭沛涛; 叶棠

    2009-01-01

    [Objective] The aim was to research the effects of different storageMethods on pollen viability of 4 eucalyptus, and explore the suitable low temperature condition and storageMethodfor pollen 9torage of eucalyptus. [Method] Taking the pollens of E. urophylla S. T. Blake, E. urophylla S. T. Blake × E. grandis W. Hill exmaiden, E. grandis W. Hill exmaiden and E. dunnii Maiden as test material, the pollens were preserved in room temperature, low temperature, low temperature freezing and ultra low temperature freezing. The pollen viabilities during different storage time were determined. [Result] The best medium for eucalyptus pollen germination was 20% sucrose + 6% agar + 0. 1 ‰ boric acid. StorageMethods and time had significant effect on pollen viability. After 30 days, the pollen germination rate of E. urophylla and E. dunnii declined to 10% , after 50 days, the pollen germination rate of E. urophylla S. T. Blake × E. grandis W. Hill exmaiden and E. dunnii Maiden declined to 10% in room temperature. The pollen was preserved in low temperature freezing and ultra low temperature freezing for one years, the pollen germination rate was still more than 35%. Pollen germination rate was also affected by different thawingMethods, and 38 ℃ water bath for 3 minutes was the bestMethod. [Conclusion] Selecting low temperature freezingMethodto preserve pollen in practical work, it can obtain economic and efficient benefit.%[目的]研究不同贮藏方式对4种桉树花粉活力的影响,探索出适宜桉树花粉贮藏的低温条件和贮藏方式.[方法]以尾叶桉、尾叶桉×巨桉、巨桉和邓恩桉花粉为试验材料,对其进行常温、低温、低温冷冻和超低温冷冻贮藏,并对不同贮藏时间内的花粉活力进行检测.[结果]适合桉树花粉萌发的最佳培养基为20%蔗糖+6%琼脂+0.1‰硼酸;贮藏方式和贮藏时间对花粉活力有显著影响,常温真空贮藏,尾叶桉和巨桉花粉贮藏30 d后,萌发率降至10%以

  17. Relationship of Flower Age to Stigma Receptivity and Pollen Viability in Blueberry%花龄对蓝莓柱头可授性及花粉活力的影响

    Institute of Scientific and Technical Information of China (English)

    杨芩; 任永权; 廖优江; 蔡陈; 田栋伟; 赵俊; 李性苑

    2012-01-01

    The relationship of flower age to stigma receptivity and pollen viability of 'Lanyv' blueberry was investigated. Results showed that the development of male and female organs is synchronous, which favors pollination and fruit set. Pollen viability reaches a relatively high level 1~5 days after flower opening. The peak pollen viability period is from 2d to 4d after flowering when more than 50% of the pollens are capable of germination. This period should be the best time to collect pollen. Similarly the stigma receptivity reaches the highest point 2d to 4d after flower opening on which it should be the best time to do artificial pollination,%以南高丛蓝莓“蓝雨”(Vaccinium australe)为试材,研究了花龄对柱头可授性和花粉活力的影响.结果表明,蓝雨蓝莓雌雄性器官的育性具有同步性.从花后第1~5天花粉活力都较高,特别是花后第2~4天,花粉活力保持在50%以上,是人工辅助授粉收集花粉的良好时期;花后第2~4天柱头分泌黏液较多,此期柱头具有较强可授性,是开展人工辅助授粉的最佳时期.

  18. 川白芷与祁白芷花粉活力及柱头可授性测定%Pollen viability and stigma receptivity of Angelica dahurica from Sichuan and Hebei province

    Institute of Scientific and Technical Information of China (English)

    陈郡雯; 吴卫; 侯凯; 徐应文; 邵金凤; 李静夜

    2011-01-01

    目的:研究川白芷与祁白芷花粉活力、寿命及柱头可授性,为良种选育提供依据.方法:采用TTC法测定花粉活力及寿命,用联苯胺-过氧化氢法测定柱头可授性.结果:川白芷与祁白芷花蕾期花粉已具有较高活力,随着雄蕊发育,二者活力逐渐增强,花药开裂盛期花粉活力均达85%以上,且花粉活力均随散粉时间延长而逐渐降低.川白芷不同分枝花序的花粉活力差异较小,均维持在85%左右;祁白芷的花粉活力表现为主茎花序<一级分枝花序<二级分枝花序,整体来看,空间位置对花粉活力的影响较小.川白芷与祁白芷花粉在室温储藏条件下,开花后第5天花粉活力仍保持约50%,其中川白芷下降幅度大于祁白芷;-20℃条件下可适当延长花粉活力.柱头于开花后第4天逐渐具有可授性,第6天最强,随后逐渐萎蔫变褐,开花后第10天不具可授性.结论:在进行人工授粉时,应选花药开裂盛期的花粉对开花第6天的柱头进行授粉.%Objective: To provide theoretical basis for artificial cross breeding of Angelica dahurica from Sichuan and Hebei Province, the characteristics of stigma receptivity and the viability and life-span of pollen were studied. Method: The viability and life-span of pollen were evaluated by TTC (2,3, 5-triphenyl tetrazliura chloride) test, and the stigma receptivity was estimated by benzi-dine-H2O2method. Result: The pollen viability of A. dahurica from Sichuan and Hebei provinces was increased gradually since the bud stage, but those levels had since subsided after the pollen release from craze antheral. There was a little difference in the pollen viability of A. dahurica from Sichuan at different branches. While the order of the pollen viability of A. dahurica from Hebei was main stem < first-order branching < second-order branching. At room temperature, the pollen viability of both decreased during time of anthers dehiscing but also above 50

  19. 我国几个主要椰子品种花粉生活力研究%Study on Pollen Viability of Several Major Coconut (Cocos nucifera) Varieties in China

    Institute of Scientific and Technical Information of China (English)

    李和帅; 王承民; 王波超; 范海阔

    2013-01-01

    The pollen viability of six coconut ( Cocos nucifera L.) varieties was determined by using five methods ( sucrose-based germination, aceto-carmine dyeing, TTC dyeing, I2 -KI dyeing, and red ink dyeing) respectively, and the advantages and disadvantages of these five methods were compared .The test results showed that the former four methods were better than the last one.Among six varieties, hybrid Wenye 78F1 had the maximum pollen viability , and the pollen viability of Hainan Tall was higher than that of other four varieties .%采用蔗糖萌发、醋酸洋红染色、TTC染色、I2-KI染色、红墨水染色法,分别测定了6个椰子( Cocos nucifera L.)品种的花粉活力,并比较了各方法的优、缺点。试验结果表明:前4种方法的测定效果较好;在6个品种中,杂交种文椰78F1的花粉活力最高,海南高种的花粉活力较高。

  20. Viabilidade de pólen in vivo e in vitro em genótipos de açaizeiro In vivo and in vitro pollen viability of açaí palm genotypes

    Directory of Open Access Journals (Sweden)

    Maria do Socorro Padilha de Oliveira

    2001-04-01

    Full Text Available Determinou-se a viabilidade de pólen in vivo e in vitro em 20 genótipos de açaizeiro, da coleção de germoplasma da Embrapa Amazônia Oriental. Os grãos de pólen in vivo foram retirados de botão floral (BF e de flor recém-aberta (FA e os in vitro de ampolas armazenadas em freezer (-10ºC, com período de armazenamento (PA de um (PA1, três (PA3, seis (PA6 e doze (PA12 meses. Utilizou-se a solução de Baker, sendo foi retirada uma amostra para cada estádio. Calculou-se a taxa de viabilidade pela contagem de, aproximadamente, 500 grãos de pólen. Pólen in vivo, na maioria dos genótipos exibiram alta viabilidade com médias de 84,8% para botões e 93,2% para flores recém-abertas, sendo as melhores taxas registradas nos genótipos 3 e 19. Para pólen in vitro, os genótipos apresentaram redução na viabilidade com o aumento do período de armazenamento (PA1: 79,6%, PA3: 77,4%, PA6: 74,1% e PA12: 61,3% mas o armazenamento não foi prejudicial, pois grande parte dos genótipos alcançaram valores acima de 50%, destacando-se os genótipos 3 e 9 com as maiores percentagens. Portanto, pode-se considerar que, nos genótipos testados, pólen in vivo têm alta viabilidade e os in vitro devem ser usados em polinizações controladas sem prejuízos na fecundação, em até doze meses de conservação.The rate of in vivo and in vitro pollen viability, in 20 açai palm (Euterpe oleracea Mart. genotypes, belonging to the germplasm collection of Embrapa Eastern Amazon, was determined. The in vivo pollen grains were extracted from floral buds (FB and recently opened flowers (ROF. The in vitro pollen grains were obtained from flasks stored in the freezer under -10ºC,with storage period (SP of one (SP1, three (SP3, six (SP6 and twelve (SP12 months of storage. The pollen viability was accessed utilizing the Baker's procedure. The viability rate was achieved by counting up to 500 grains per slide. Most of the genotypes showed high viability for in vivo

  1. Pollen morphological characteristics, viability test and storage of endangered medicinal plant Atractylodes lancea%濒危药用植物茅苍术花粉形态、活力测定及贮存研究

    Institute of Scientific and Technical Information of China (English)

    李琳; 谷巍; 巢建国; 高杰; 周娟娟; 申修源

    2012-01-01

    Objective: To study the pollen morphological characteristics, viability test and storage character of the endangered plant Atractybdes lancea. Method: Pollen grains morphologies of A. lancea were observed by scanning electron microscope. The optimum culture medium and viability determination methods were screened out by liquid culture and dyeing methods, and then the pollen germination capacities in different storage conditions were detected. Result: The pollen grains are quasi-spherical, with tricrdpate and spinous sculpture. The optimal culture medium was ME, + 16% PEG4000 + 10% sucrose, in which the pollen germination capacity reached to 62. 1% , while the other three dyeing methods were not able to be applied to detecting the pollen viability of A. lancea. The low storage temperature could significantly prolong the storage time of pollen of A. lancea. A1 -80℃, pollen viability could be maintained for 60 days. Conclusion: liquid culture method is suitable for the determination of pollen germination of A. lancea, and the rate of pollen germination is closely related to the storage time and temperature. At hist, this study provides a foundation for the artificial pollination and cultivating in wildness of A. lancea.%目的:研究濒危药用植物茅苍术花粉形态、活力测定及贮存.方法:采用扫描电镜观察茅苍术花粉形态,用液体培养及染色法筛选花粉萌发最适培养基及活力测定方法,并检测不同贮存条件下花粉的活力.结果:茅苍术花粉粒呈类球形,具3萌发沟,外壁表面具刺状雕纹;在ME3+16%PEG4000+10%蔗糖液体培养基上花粉萌发率最高,达62.1%,而其他3种染色法均不宜用于茅苍术花粉活力的检测;低温可明显延长茅苍术花粉的贮存时间,在-80℃低温下可贮存60d.结论:液体培养法适于茅苍术花粉粒活力的测定,花粉萌发率与贮存温度及时间密切相关,本研究为茅苍术人工辅助授粉及野生抚育研究提供了科学的依据.

  2. Research on Pollen Viability and Its Storage Conditions of 32 Lily Genotypes%百合32个基因型的花粉生活力及其贮藏条件的研究

    Institute of Scientific and Technical Information of China (English)

    张艺萍; 吴丽芳; 王祥宁; 瞿素萍; 崔光芬; 夏晶; 张世梅; 郭树华; 王继华

    2013-01-01

    花粉生活力是评估花粉细胞活性的依据之一,其活力测定结果的准确性决定细胞学试验和杂交育种的成败。本研究以32个百合品种的花粉为试验材料,采用染色法和花粉离体萌发法,探讨了不同百合品种新鲜花粉生活力、萌发率的差异,不同贮藏条件下同品种花粉生活力的差异。结果表明:离体萌发法的测定结果更能反映花粉活力,Casa Blanca的萌发率最高,为87.33%,Yelloween的萌发率最低,为1.33%。对于相同的贮藏条件即室温贮藏来说,因品种和贮藏时间的不同花粉生活力变化有明显差异,总的趋势为随贮藏时间延长,萌发率下降,但不同基因型间下降速度不同。在冷藏条件下,花粉萌发率随贮藏时间的推移总体也呈下降趋势,但下降速度比室温贮藏的明显缓慢,且不同品种的变化亦有所差别。%Pollen viability is to assess the activity of one of the basis of pollen cells ,The activity assay results of cytological experiments and determine the accuracy of breeding success or failure .In this study ,32 lily cultivars as experimental materials ,comparison of different varieties of fresh lily pollen viability ,germination rate differences , and different storage conditions hereinafter pollen viability differences by staining method and in vitro pollen germi-nation method .The results showed that:It is more accurate to pollen viability of in vitro pollen germination method . Germination rate of Casa Blanca is highest namely 87.33%,Yelloween is lowest namely 1.33%.To uniform storage dry condition in room ,pollen viability of different lily cultivars is obvious different by different storage time .Germina-tion rate decrease as extension as storage times ,but rate of descend is different by different cultivars .Pollen germina-tion rate decrease as extension as storage times in cold storage ,but rate of descend is slower than in room storage .

  3. Pollen performance, cell number, and physiological state in the early-divergent angiosperm Annona cherimola Mill. (Annonaceae) are related to environmental conditions during the final stages of pollen development.

    Science.gov (United States)

    Lora, J; Herrero, M; Hormaza, J I

    2012-09-01

    Pollen performance is an important determinant for fertilization success, but high variability in pollen behavior both between and within species occurs in different years and under varying environmental conditions. Annona cherimola, an early-divergent angiosperm, is a species that releases a variable ratio of bicellular and tricellular hydrated pollen at anther dehiscence depending on temperature. The presence of both bi- and tricellular types of pollen is an uncommon characteristic in angiosperms and makes Annona cherimola an interesting model to study the effect of varying environmental conditions on subsequent pollen performance during the final stages of pollen development. In this work, we study the influence of changes in temperature and humidity during the final stages of pollen development on subsequent pollen performance, evaluating pollen germination, presence of carbohydrates, number of nuclei, and water content. At 25 °C, which is the average field temperature during the flowering period of this species, pollen had a viability of 60-70 %, starch hydrolyzed just prior to shedding, and pollen mitosis II was taking place, resulting in a mixture of bi- and tricellular pollen. This activity may be related to the pollen retaining 70 % water content at shedding. Temperatures above 30 °C resulted in a decrease in pollen germination, whereas lower temperatures did not have a clear influence on pollen germination, although they did have a clear effect on starch hydrolysis. On the other hand, slightly higher dehydration accelerated mitosis II, whereas strong dehydration arrested starch hydrolysis and reduced pollen germination. These results show a significant influence of environmental conditions on myriad pollen characteristics during the final stages of pollen development modifying subsequent pollen behavior and contributing to our understanding of the variability observed in pollen tube performance.

  4. 玉竹开花习性及花粉生活力测定方法的比较研究%A comparative study on flowering habits of Polygonatum odoratum and pollen viability determination method

    Institute of Scientific and Technical Information of China (English)

    宫丽婷; 孟庆龙; 吕东明; 王天媛; 任跃英; 骆长林; 封安新; 康岩

    2015-01-01

    以玉竹为试验材料,研究其开花习性及花粉生活力快速有效的测定方法. 选取正常生长的玉竹植株进行定株,观察玉竹花朵并对其朵花期、序花期、株花期、盛花期进行观察并记录;采用I2-KI染色法、TTC染色法、亚甲基蓝染色法、改良石炭酸染色法检测花粉生活力,以悬滴培养法进行对照.结果表明玉竹花期为4月末到5月中下旬,持续约25d左右. 玉竹朵花期从现蕾到凋谢时长12~17d,每一花序开花持续时间为2~4d,盛花期在见花的9~15d,占整个花期的58.34%. I2-KI和TTC染色法对玉竹花粉的染色效果不理想,不适于观测其花粉活力,改良石炭酸染色法使花粉生活力的测定值偏高,亚甲基蓝染色法使花粉细胞出现蓝色、浅蓝色反应,利于分辨花粉生活力的有无. 本文旨在对玉竹的开花习性及不同染色法测定花粉生活力的筛选的研究,进一步了解玉竹开花生物学特性,为研究玉竹的有性繁殖特征积累资料,进一步为玉竹的育种研究工作提供参考依据.%ObjectiveIn Polygonatum odoratum as test material,studying on its flowering habits and rapid and effective method for measuring pollen viability.[Methods]Selecting the normal growth of the plants of Polygonatum odoratum and given strain,observation Polygonatum odoratum flowers and flowers flowering, flowering sequence, flowering plants, flowering ,as well as recorded;Using the I2-KI staining, TTC staining, methylene blue staining, modified carbolic acid staining pollen viability,and hanging drop culture method were compared.Rsesults Polygonatum odoratum flowering in late April to mid-May to late,continue about 25d.Polygonatum odoratum flowering flowers from bud to wither long 12~17d,Each inflorescence flowering duration of 2~4d, see the flowers in full bloom at 9 ~15d, accounting for 58.34 percent of total flowering.I2 -KI and TTC staining pollen Polygonatum odoratum dyeing effect is not ideal, is not

  5. Study on Stigma Viability and the Effects of Preserving Methods on Host Pollen Viability of Upland Cotton in Hainan%海南陆地棉柱头活力和保存方式对宿主花粉活力的影响

    Institute of Scientific and Technical Information of China (English)

    雷亚柯; 贾朝阳; 张海之; 刘德征; 张景峰; 齐振宇

    2011-01-01

    Taking Zhoumian 6 as material, an upland cotton cultivar bred by ourselves, we studied the stigma viability, host pollen viability and the difference between preserving host pollen viability by LD and RD. The stigma viability of upland cotton which was emasculated could last for a long time, its boll probability was still above 84% during the following period of 17h to 46 h, and the best time for stigma to be pollinated was in 17-42 h after the flower being emasculated. To preserve host pollen viability, the way by LD was much superior to the way by RD, and the difference between the two methods became significant when the host pollen was preserved for 26.5 h. The best pollination time for pollen kept by RD was within 24.5 h after the flower was picked, even the pollen was kept for 28.5 h, and its boll probability was still at a high level, which was about 80%. The pollen viability preserved by LD didn't decrease significantly in the following 28. 5 h after the flower was picked, and its boll probability was always above 90% during the following 28.5h. Winter breeding in Hainan, if we need the boll probability of upland cotton to be around 80%, two methods can be taken. One is to let the stigma pollinated with fresh pollen in the following 17-46 h after being emasculated; the other is to let the fresh stigma pollinated with pollen preserved no more than 28.5h, no matter the way keeping pollen is by LD or by RD.%以自育陆地棉品种周棉6号为材料,研究雌蕊柱头活力、宿主花粉活力持续时间及宿主花粉活力在低温避光(LD)和常温避光(RD)处理下的差异.结果表明,陆地棉去雄后柱头活力持续时间较长,17~46 h成铃率可维持在84%以上,去雄后柱头最佳授粉时期是17~42 h;ID处理对维持宿主花粉活力的效果远优于RD处理,2种处理存在显著差异的时间是处理后26.5 h;RD处理的最佳授粉时间是处理24.5 h内,但28.5 h还具有约80%的较高成铃率,低温避光

  6. Ingestion of Bt rice pollen does not reduce the survival or hypopharyngeal gland development of Apis mellifera adults.

    Science.gov (United States)

    Wang, Yuanyuan; Dai, Pingli; Chen, Xiuping; Romeis, Jörg; Shi, Jianrong; Peng, Yufa; Li, Yunhe

    2016-10-07

    Because of its ecological and economic importance, the honey bee Apis mellifera is commonly used to assess the environmental risk of insect-resistant, genetically modified plants. In the current laboratory study, feeding-exposure experiments were used to determine whether pollen from transgenic rice harms A. mellifera worker bee. In one experiment, the survival and mean acinus diameter of hypopharyngeal glands of adult bees were similar when bees were fed on pollen from Bt rice lines or from a non-Bt rice line, but bee survival was significantly reduced when they received pollen that was mixed with potassium arsenate as a positive control. In a second experiment, bee survival and hypopharyngeal gland development were not reduced when adult bees were fed on non-Bt pollen and a sucrose solution supplemented with Cry2A at 400 µg/g, Cry1C at 50 µg/g, or bovine serum albumin (BSA) at 400 µg/g diet, but bee survival and hypopharyngeal gland development were reduced when the diet was supplemented with soybean trypsin inhibitor (SBTI) as a positive control. In both experiments, the uptake of Cry proteins by adult bees was confirmed. Overall, the results indicate that the planting of Bt rice lines expressing Cry2A or Cry1C protein poses a negligible risk to A. mellifera worker bees. This article is protected by copyright. All rights reserved.

  7. 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.

  8. 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.

  9. Correlações entre viabilidade de pólen e características de frutos em mutantes de laranjeira 'Pêra' Correlations between pollen grain viability and fruit characteristics in 'Pêra' sweet orange mutants

    Directory of Open Access Journals (Sweden)

    Rodrigo Rocha Latado

    2004-10-01

    Full Text Available O objetivo deste trabalho foi avaliar, durante dois anos, a viabilidade de grãos de pólen e as correlações entre essa viabilidade e as características de frutos de plantas mutantes de laranjeira 'Pêra'. As plantas mutantes foram obtidas a partir de tratamento de borbulhas com raios-gama e selecionadas após três propagações vegetativas. A viabilidade dos grãos de pólen foi avaliada pelo método de coloração com carmin acético. Não houve diferenças entre anos na viabilidade de grãos de pólen e no número de sementes por fruto, indicando que estes caracteres não foram afetados pelas alterações ambientais anuais. Correlações positivas e significativas foram observadas entre a viabilidade média dos grãos de pólen e o número médio de sementes por fruto e, também, com o teor de sólidos solúveis totais do suco dos frutos. Uma das razões para a existência de mutantes com menor número de sementes por fruto é a baixa porcentagem de grãos de pólen viáveis.The objective of this work was to evaluate the pollen grain viability of 'Pêra' sweet orange mutant plants and to estimate its correlation with fruit characteristics. Mutant plants were obtained from shoot treatment with gamma-rays and selected after three vegetative propagations. Pollen grain viability was evaluated using carmine-acetic staining method. No difference was found between years for pollen grain viability and for number of seeds per fruit, indicating that these characters were not affected by the yearly environmental alterations. Positive correlations were found between pollen grain viability and mean number of seeds per fruit, and with the total soluble solid content in juice. Therefore, one of the reasons for the smaller number of seeds per fruit in these mutants is the low percentage of viable pollen grain.

  10. Research Progress of Pollen Collection,Preservation and Viability Testing in Trees%林木花粉采集、保存及活力检测的研究进展

    Institute of Scientific and Technical Information of China (English)

    黄烈健; 詹妮

    2014-01-01

    According to the research reports on pollen of trees in recently years,this paper mainly reviewed pollen collection,preservation and viability testing of many trees.It provided a basal theory for artificial pollination and cross breeding of trees in the future.%文章综述近年来有关林木花粉研究的相关报道,主要从花粉采集、保存以及活力测定等方面的研究内容进行阐述并提出建议,旨在为今后开展林木花粉研究提供理论参考,为人工授粉、杂交育种等提供重要的理论依据与技术支撑。

  11. Rising atmospheric CO2 is reducing the protein concentration of a floral pollen source essential for North American bees.

    Science.gov (United States)

    Ziska, Lewis H; Pettis, Jeffery S; Edwards, Joan; Hancock, Jillian E; Tomecek, Martha B; Clark, Andrew; Dukes, Jeffrey S; Loladze, Irakli; Polley, H Wayne

    2016-04-13

    At present, there is substantive evidence that the nutritional content of agriculturally important food crops will decrease in response to rising levels of atmospheric carbon dioxide, Ca However, whether Ca-induced declines in nutritional quality are also occurring for pollinator food sources is unknown. Flowering late in the season, goldenrod (Solidago spp.) pollen is a widely available autumnal food source commonly acknowledged by apiarists to be essential to native bee (e.g. Bombus spp.) and honeybee (Apis mellifera) health and winter survival. Using floral collections obtained from the Smithsonian Natural History Museum, we quantified Ca-induced temporal changes in pollen protein concentration of Canada goldenrod (Solidago canadensis), the most wide spread Solidago taxon, from hundreds of samples collected throughout the USA and southern Canada over the period 1842-2014 (i.e. a Ca from approx. 280 to 398 ppm). In addition, we conducted a 2 year in situtrial of S. Canadensis populations grown along a continuous Ca gradient from approximately 280 to 500 ppm. The historical data indicated a strong significant correlation between recent increases in Ca and reductions in pollen protein concentration (r(2)= 0.81). Experimental data confirmed this decrease in pollen protein concentration, and indicated that it would be ongoing as Ca continues to rise in the near term, i.e. to 500 ppm (r(2)= 0.88). While additional data are needed to quantify the subsequent effects of reduced protein concentration for Canada goldenrod on bee health and population stability, these results are the first to indicate that increasing Ca can reduce protein content of a floral pollen source widely used by North American bees.

  12. 金沙江干热河谷扭黄茅花粉微形态及活力研究%Study on the Pollen Micro-morphological Characters and Viability of Heteropogon contortus from Jinshajiang Dry-hot Valley

    Institute of Scientific and Technical Information of China (English)

    谢勇; 毕玉芬; 浦卫琼; 王海宁

    2012-01-01

    [目的]为丰富抗旱耐热的育种材料来源提供依据.[方法]对来自金沙江干热河谷不同地区的扭黄茅花粉形态进行了电镜扫描观察,并采用碘-碘化钾(I-KI)染色法进行活力测定.[结果]扭黄茅花粉粒为中等大小花粉粒,花粉形态为近球型,花粉壁纹饰为粗糙型,萌发孔为单一萌发孔,萌发孔有孔环,表明扭黄茅具有进化性状,但是进化程度较低,仍属于原始状态,与扭黄茅为野生状态相一致.金沙江沿岸永胜、攀枝花、元谋扭黄茅的花粉活力为80.00% ~ 87.10%,差异不显著(P>0.05).永胜地区扭黄茅花粉活力为82.19%~87.00%,不同扭黄茅材料间的花粉活力差异也不显著(P>0.05).[结论]金沙江沿岸各地区的扭黄茅花粉形态与结构基本一致,表明其是一个自然类群.%[Objective] The research aimed to provide basis for enriching the breeding materials with heat-resistance and drought-resistance. [ Method ] The pollen morphology of Heteropogon contortus from different areas of Jinshajiang dry-hot valley was observed by using electron microscope scanning. And the pollen viability was measured by using iodine-iodine kalium staining method. [ Result] The pollen grains were medium size, spheroidal shape, with rough type extine sculpture and single germinal aperture and annular ring. This indicated that H. contortus had the typical evolutionary character, with low evolutionary level, belonging to the original state, which was accordant with the wild strain of//. contortus. The pollen viability of H. contortus from Yongsheng, Panzhihua and Yuanmou along Jinshajiang River was 80. 00% - 87. 10% , without significant difference(P >0. 05). The pollen viability of H, contortus from Yongsheng area was 82. 19% -87.00% , and the difference of pollen viability among different materials of H. contortus was not significant P > 0. 05 ) . [ Conclusion ] The pollen grains micro-morphological characters and its viability of H

  13. The Variation of the Pollen Viabilities of Transgenic Rice B68-1 at Different Temperatures and Humidity%B68-1转基因水稻花粉活力的温湿响应规律

    Institute of Scientific and Technical Information of China (English)

    潘永地; 朱世杨; 胡凝; 张小玲

    2014-01-01

    为了研究转基因水稻花粉活力在各种气象条件下的变化规律,以含bar基因的抗Basta转基因籼稻B68-1为材料,分别在温度20℃、25℃、30℃、35℃及相对湿度30%、50%、70%、90%的不同温湿组合条件下进行处理,用2,3,5-氯化三苯基四氮唑(TTC)染色法测定了这些组合条件处理下B68-1转基因水稻花粉离体0、1、2、3、4、5、6、8、10、12、14 min后的活力。试验结果表明,B68-1花粉离体后活力变化在各种条件下呈现为“S”型或“S”型的一段;B68-1花粉离体后活力在一定湿度条件下随着温度先升后降,各湿度条件下花粉在25℃时活力最强,高温对花粉活力的胁迫作用更大;B68-1花粉离体后活力在一定的温度条件下随着湿度也是先升后降,各温度条件下花粉在相对湿度70%时活力最强,高湿对花粉活力的胁迫作用更大。通过指数形式的生长曲线(Logistic方程)分段函数,拟合构建了B68-1花粉活力在不同湿度下的温度模型,可精确预测花粉存活时间和寿命,为进一步准确估算转基因水稻基因飘移距离提供基础数据。%The pollen viability of a transgenic rice, B68-1 containing bargene with herbicide Basta resistance, was investigated under four temperatures (20℃, 25℃, 30℃, 35℃) and four kinds of humidity (30%, 50%, 70%, 90%) by 2,3,5-triphenyl tetrazolium chloride (TTC) method in vitro after 0, 1, 2, 3, 4, 5, 6, 8, 10, 12, 14 min from anther. The test showed that B68-1 pollen viability decreased with passing time in vitro under various conditions, like“S curve”or its section, which could accurately described by the Logistic equation. In vitro, pollen viability first increased and then decreased with the rising temperature, and showed the same with humidity. 25℃ was the most optimum temperature in any determined humidity, and 70% humidity was the most optimum humidity in any determined temperature. High

  14. Determination of Iris tectorum Pollen Viability and Its Storage Method%鸢尾花粉生活力测定及贮藏特性研究

    Institute of Scientific and Technical Information of China (English)

    贾文庆; 尤扬; 刘会超; 李玮

    2012-01-01

    Aimed at effective breeding of Iris tectorum, fresh pollen of Iris was served as experiment material to evaluate the influence of sucrose, boric acid, and storage conditions on Iris pollen germination. The results showed that boric acid and sucrose had significant effect on Iris pollen germination, the most suitable medium for the pollen culture is sucrose 145 g/L + boric acid 0. 045 g/L; vitality of pollen were gradually descend as lasting of store time. The best environmental temperature to keep I-ris tectorum pollen vitality was at —196℃. There was a correlation between pollen morphology and pollen germination.%为有效开展鸢尾育种工作,以鸢尾花粉为试材,研究蔗糖、硼酸等不同贮藏条件和时间对鸢尾花粉萌发的影响.结果表明,硼酸、蔗糖两者对鸢尾花粉萌发有显著影响,最适宜的花粉培养基为蔗糖145 g/L+硼酸0.045 g/L;花粉生活力随贮藏时间的延长而下降,不同的贮藏条件对鸢尾花粉生活力有显著的影响,最佳贮藏方法为-196℃干燥,耐贮藏时间可达400 d以上.花粉形态与其萌发之间有相关性.

  15. 肉果秤锤树花粉活力测定方法%Study on Detection Methods for Pollen Viability of Sinoj ac k ia s ac oc arp a L.Q.Luo

    Institute of Scientific and Technical Information of China (English)

    伏秦超; 王娟; 张西玉; 刘超; 刘芳

    2015-01-01

    本研究以离体培养萌发法为参照,从TTC法、I2-KI法、过氧化物酶沉淀法和醋酸洋红法4种方法中筛选出适宜快速测定肉果秤锤树(Sinojackia sarcocarpa L.Q.Luo)花粉活力的方法。结果表明:肉果秤锤树花粉离体培养萌发的最适条件为23℃培养下15%蔗糖、0.01 mg/mL硼酸,萌发率达84.85%;过氧化物酶沉淀法、TTC法、I2-KI法和醋酸洋红法测定的萌发率分别为78.45%、0、100%和37.01%。过氧化物酶沉淀法测定结果与离体培养萌发法的测定结果最接近(p<0.01),是简单快速测定肉果秤锤树花粉活力的最适方法。本研究筛选出的花粉离体培养萌发条件和花粉活力快速测定方法,可为进一步开展肉果秤锤树育种工作提供理论依据与技术支持。%We firstly investigated the optimum condition of Sinojackia sacocarpa L.Q.Luo's pollen germination under in v itro culture condition, and then recruited four different methods to detect the pollen viability, such as triphenyltetrazolium chloride (TTC), iodine-iodide kalium (I2-KI), peroxide enzyme and acidcarmine method, in comparison with in vitro pollen germination method. Our results showed that a culture medium containing 15%sucrose and 0.01 mg/mL boric acid had the best effect on in vitro pollen germination at 23℃, and the pollen germination rate was up to 84.85%. Furthermore, we found the detection of pollen viability using peroxide enzyme, TTC, I2-KI and acidcarmine method was 78.45%, 0, 100% and 37.01%, respectively; These data suggested that peroxide enzyme method provided a quicker and more convenient means compared to other three methods, because its result was close to true viability ratio and dyeing was fast and clear. This study selected the optional condition for the pollen germination in vitro culture and identified a fast method for detecting the pollen vitality, which should provide the theoretic foundation for breeding work.

  16. Actin-myosin contractility is responsible for the reduced viability of dissociated human embryonic stem cells.

    Science.gov (United States)

    Chen, Guokai; Hou, Zhonggang; Gulbranson, Daniel R; Thomson, James A

    2010-08-06

    Human ESCs are the pluripotent precursor of the three embryonic germ layers. Human ESCs exhibit basal-apical polarity, junctional complexes, integrin-dependent matrix adhesion, and E-cadherin-dependent cell-cell adhesion, all characteristics shared by the epiblast epithelium of the intact mammalian embryo. After disruption of epithelial structures, programmed cell death is commonly observed. If individualized human ESCs are prevented from reattaching and forming colonies, their viability is significantly reduced. Here, we show that actin-myosin contraction is a critical effector of the cell death response to human ESC dissociation. Inhibition of myosin heavy chain ATPase, downregulation of myosin heavy chain, and downregulation of myosin light chain all increase survival and cloning efficiency of individualized human ESCs. ROCK inhibition decreases phosphorylation of myosin light chain, suggesting that inhibition of actin-myosin contraction is also the mechanism through which ROCK inhibitors increase cloning efficiency of human ESCs.

  17. Viabilidade dos grãos de pólen de flores de pinheira (Annona squamosa em diferentes horários Viability of the sugar apple (Annona squamosa pollen grains at different hours of the day

    Directory of Open Access Journals (Sweden)

    Silvia Nietsche

    2009-04-01

    Full Text Available No manejo do cultivo da pinha (Annona squamosa, a polinização artificial é uma prática preconizada para, obter maior pegamento dos frutos bem como uniformização do formato dos mesmos. Nesse sentido, conduziu-se este trabalho, com o objetivo de avaliar a viabilidade dos grãos de pólen de flores de pinheira em diferentes horários de coleta. O pólen foi obtido a partir de flores no estádio funcionalmente estaminada. Foram avaliados oito horários de coleta de pólen: zero hora, 1 hora, 2 horas, 3 horas, 4 horas, 5 horas, 6 horas e 7 horas da manhã. Foi utilizado meio de cultura padrão para germinação de pólen, com concentração de 10% de sacarose. As flores foram coletadas nos horários estabelecidos e os grãos de pólen foram retirados das anteras com auxílio de um pincel número 2 e em seguida inoculados em placas de Petri contendo o meio de cultura. O delineamento experimental foi inteiramente casualizado com quatro repetições, sendo cada parcela experimental constituída por duas placas Petri. Foram contados 100 grãos de pólen por placa. Após 6 horas de inoculação, os grãos de pólen foram visualizados sob lupa. Foram considerados germinados os grãos de pólen que possuíam tubo polínico com tamanho igual ou superior ao diâmetro do próprio pólen. Não foram observadas diferenças significativas entre o horário de coleta dos grãos de pólen. A percentagem média da germinação variou de 46,75% a 53,62% dos grãos de pólen germinados.In the management of the sugar apple (Annona squamosa crop, the artificial pollination is a preconized practice to obtain higher establishment of the fruits as well as their standardization. This study was carried out to evaluate the viability of sugar apple pollen grains at different collecting times. The pollens were obtained from the flowers at the functional staminate stage. The pollen grains were collected every hour, starting from 00:00am and ending at 07:00am, totalizing 8

  18. Modo de reprodução e viabilidade de pólen de três espécies de jabuticabeira Reproductive mode and pollen viability of three jabuticaba tree species

    Directory of Open Access Journals (Sweden)

    Moeses Andrigo Danner

    2011-06-01

    Full Text Available O objetivo deste trabalho foi determinar o modo de reprodução e as condições para testes de viabilidade in vitro de pólen de três espécies de jabuticabeira (Plinia cauliflora, P. trunciflora e P. jaboticaba. Avaliaram-se a frutificação efetiva em ramos ensacados e não ensacados, e aspectos da morfologia floral. A viabilidade de pólen foi avaliada em meio de cultura com e sem ácido bórico, com pólen coletado em diferentes períodos após antese. A germinação de pólen de seis genótipos foi quantificada antes e após armazenamento. P. trunciflora e P. jaboticaba são autocompatíveis, porém os polinizadores aumentam a frutificação. A espécie Plinia cauliflora necessita de agentes polinizadores para frutificar, pois apresenta flores com maior distância estigma-anteras que as outras duas espécies, o que impede a autofecundação passiva. A adição de ácido bórico no meio de cultura aumenta a germinação in vitro de pólen de jabuticabeira. A viabilidade do pólen é máxima após seis horas da antese. É possível a conservação do pólen por até 90 dias em congelador (-18ºC, desde que apresente alta germinação inicial (maior que 80%. Esses resultados auxiliam no planejamento de cruzamentos em jabuticabeira.The objective of this study was to determine the reproductive mode and the conditions for in vitro pollen viability testing of three jabuticaba tree species (Plinia cauliflora, P. trunciflora and P. jaboticaba. Observed fruit set in bagged and not bagged branches and aspects of floral morphology. Pollen viability was evaluated in culture medium with and without boric acid with pollen collected at different times after anthesis. Pollen germination of six genotypes was quantified before and after storage. P. trunciflora and P. jaboticaba are self-compatible, however the polinizer increase fruiting. The P. cauliflora requires polinizers for fruiting, because it has flowers with greater stigma-anther distance than the

  19. Morfologia e viabilidade de grãos de pólen de acessos silvestres de abacaxi Morphology and viability of pollen grains from wild varieties of pineapple

    Directory of Open Access Journals (Sweden)

    Taliane Leila Soares

    2011-10-01

    Full Text Available O objetivo do trabalho foi avaliar a viabilidade de grãos de pólen de acessos silvestres de abacaxi mediante a percentagem de germinação in vitro, crescimento do tubo polínico em duas temperaturas de incubação e uso de carmim acético. Além disso, o trabalho busca reconhecer os padrões da morfologia polínica de algumas variedades de abacaxi. Foram utilizadas amostras de pólen coletadas de seis acessos de abacaxi: Silvestre-25, I-26/803 (Ananas macrodontes, Igor (A. comosus var. erectifolius, Ananás Santo Amaro, FRF-22 e FRF-32 (A. comosus var. bracteatus. Os grãos de pólen foram inoculados em meio de cultura contendo 10% de sacarose, 0,01% H3BO3, 0,01% KNO3, 0,03% Ca(NO32.4H2O, solidificado com 1% de ágar e pH ajustado para 6,5. Foram testadas as temperaturas de incubação de 25°C e 30°C. A viabilidade do pólen foi avaliada pela coloração com carmim acético a 2%. Todas as variedades de A. comosus apresentaram grãos de pólen de tamanho médio, simetria radial, âmbito ovalado a esferoidal, 2-porados, subprolatos, exina eutectada, reticulada, heterobrocada, lumens variando de arredondados a poligonais, sem granulações, com exceção dos dois acessos de A. macrodontes que apresentaram tamanho grande. Melhores taxas de germinação foram obtidas para A. macrodontes em comparação com o erectifolius e bracteatus. A maioria dos acessos apresentou viabilidade com carmim acético acima de 76%.The aim of this research was to evaluate the pollen grains viability from accessions of wild pineapple using in vitro pollen germination and the growth of the polinic tube in two different temperatures and acetic carmine. In addition, the study aimed to recognize the pattern of pollen morphology of some pineapple varieties. Samples from six pineapple's accessions: Silvestre-25, I-26/803 (Ananas macrodontes, Igor (A. comosus var. erectifolius, Ananás Santo Amaro, FRF-22 and FRF-32 (A. comosus var. bracteatus were used. The pollen grains

  20. Caracterização citogenética, viabilidade de pólen e hibridação artificial em gérbera Chromosome number, pollen viability and gerbera hybridization

    Directory of Open Access Journals (Sweden)

    Raquel DL Cardoso

    2009-03-01

    Full Text Available Este trabalho foi conduzido com o objetivo de confirmar o número de cromossomos em cultivares de Gerbera hybrida Hort., determinar o número de cromossomos em acessos não comerciais de Gerbera sp., avaliar a viabilidade de pólen e a possibilidade de cruzamentos entre cultivares e acessos não comerciais. Foram coletados ápices de raízes e pólen de seis cultivares e de sete acessos não comerciais. O material coletado foi corado com carmim acético a 45%. A contagem dos cromossomos foi realizada em células metafásicas intactas e a estimativa de viabilidade de pólen realizada por meio da contagem do número de grãos de pólen viáveis e não viáveis. A possibilidade de cruzamento entre as cultivares e entre as cultivares e acessos não comerciais foi avaliada por meio da hibridação entre os genitores femininos, cv. Terra Fame e acesso A8, e masculinos, cvs. Cariba e Azteca. Todos os acessos contiveram cinqüenta cromossomos, indicando que a variação morfológica nos capítulos (simples, semidobrado e dobrado não é devida a mutações cromossômicas numéricas ou a poliploidia. A viabilidade do pólen variou de 87,67% a 99,27%. A formação de sementes foi de 4,46% nos cruzamentos entre cultivares, e de 50% entre o A8 e as cultivares. A compatibilidade genômica entre os acessos, a alta viabilidade do pólen e o sucesso na obtenção de sementes entre acessos comercias e não comerciais, revela a possibilidade de produção de híbridos com novas combinações alélicas e transferência de caracteres desejáveis dos acessos não comerciais para os comerciaisThis work was conducted to confirm the chromosomes number of Gerbera hybrida Hort. cultivars, to determine the chromosomes number in the non commercial accessions of Gerbera sp., and to estimate the pollen viability and the possibility of crossings among different accessions. Root-tip and pollen were collected from six cultivars and seven non commercial accessions. The collected

  1. Pollen Viability and Stigmatic Receptivity of Peasant Varieties Jatropha curcas in Guizhou Province%贵州小桐子农家品种的花粉活力和柱头可授性

    Institute of Scientific and Technical Information of China (English)

    曾亚军; 周凤娇

    2012-01-01

    Pollen viability and stigmatic receptivity of J. curcas grown in Luodian, Wangmo, Ceheng and Zhenfeng were studied to preferably develop and utilize germplasm resources of J. curcas in Guizhou, and fully develop their actions as bioenergy. The results showed that in the years of 2007 - 2011, the pollen viability and stigmatic receptivity of J. curcas grown in Qiaoma Forest Farm of Ceheng County were higher than other areas.%为更好地开发和利用贵州小桐子种质资源,以充分发挥其生物能源的作用,对贵州省罗甸县、望谟县、册亨县和贞丰县4个地方的小桐子花粉活力和柱头可授性进行了比较.结果表明,2007 2011年5年中,册亨县巧马采育林场种植的小桐子农家品种的花粉活力和柱头可授性均高于其他3个地方的品种.

  2. Comparison of Anther Yield and Pollen Viability between Different Efficient Pollination Trees to Apple%不同品系苹果高效授粉树花药产出率及花粉生活力比较

    Institute of Scientific and Technical Information of China (English)

    董彦; 韩甜甜; 吴曼; 沈向

    2012-01-01

    The anther yield and pollen viability of different new bred crabapple lines were compared in this paper. The results showed that the efficient lines 1379, 1681, 5309, 7098, 7538, 7551, 7560, 7653, 7654, 7660 and 7672 had higher anther yield and pollen viability with the blooming period similar to Red Fuji apple tree and long duration, so they were better for pollination to apple.%以新选育的苹果高效授粉树不同品系为试材,研究各品系的花药产出率及花粉活力,结果表明,苹果高效授粉树优系1379、1681、5309、7098、7538、7551、7560、7653、7654、7660及7672花药产出率大,花粉生活力高,花期与红富士苹果相近、持续时间长,可满足苹果授粉需要.

  3. Study on the Flowering Dynamics Pollen Viability and Stigma Receptivity of Amomum villosum%阳春砂的开花动态及花粉活力和柱头可授性研究

    Institute of Scientific and Technical Information of China (English)

    彭建明; 李荣英; 李戈; 王艳芳

    2011-01-01

    目的:研究阳春砂花粉活力和柱头可授性在开花散粉后的动态变化规律,为提高阳春砂仁坐果率提供基础资料.方法:在景洪市基诺族乡、景哈哈尼族乡和药植所云南分所园内选取10 ~ 30个花序,观察其的开花动态,并用悬滴法检测花粉活力(每次用3朵花),用MTT法测定柱头的可授性(用标记的10 ~30个花序的柱头).结果:阳春砂一个花序自第一朵开放到最后一朵开完需要3 ~ 9d.单花花期一般为1d;花粉在上午11:00以前均保持较高地萌发率,到中午11:00以后花粉活力下降,18:00仍有萌发能力;不同地区柱头可授性差异明显,花序上部小花柱头可授性比下部小花的高,不同花期柱头可授性变化不大.结论:景哈乡阳春砂柱头可授性比基诺乡的高,云南分所园内橡胶树下为最低.%Objective; Testing the dynamic changes of pollen viability and stigma receptivity after flowering, to provide a basis information on increasing fruit set of Amomum villosum. Method; Selecting 10-30 flowers In an inflorescence in Jingha village, Jinuo village and under robber - forest of Yunnan Branch, Institute of midic-inal Plant, observed floral dynamic, detected pollen viability with the hanging drop method ( three flowers each time) and stigma receptivity with the MTT method (10 -30 Stigmas each time) . Result; The Inflorescence flowering since the first flower opening to the last one in an inflorescence of Amomum villosum takes 3 to 9 days, the life span of a flower is generallyl day; Pollen viability in the morning before 11: 00 am maintain a high germination rate , then the pollen viability decrease after 11: 00 am, the pollen viability still has some germination rate till 6: 00 pm; Stigma receptivity of different regions is significantly different, flower stigma receptivity of the upper Inflorescence is higher than the lower part of Inflorescence, stigma receptivity has no change in different flowering period

  4. Morphological Observation and Pollen Viability of Dwarf Peony%矮牡丹花粉形态观察与萌发特性研究

    Institute of Scientific and Technical Information of China (English)

    贾文庆; 尤扬; 刘会超; 刘美玲

    2012-01-01

    Pollen morphology of dwarf peony and the effects of different cultural media on pollen germination and pollen tube elongation were evaluated. The results indicated that the pollen germinating percentage was consistent with the proportion of prolate pollens. Culture media with different concentrations of sucrose and boric had good effects on the pollen germination. The pollen germinating percentage reached the highest after incubated on the media supplemented with 9% sucrose and 0. 045% boric acid. Low concentrations (1× 10-5 — 1×10-3 mol/L) of Ca2+ had good effect on pollen tube elongation, while high concentrations (IX 10~2 — 1 X 10"1 mol/L) inhibited them. The most suitable concentration of Ca2+ to promote pollen tube elongation was 1 X 10~3 mol/L in the culture medium. Low concentration (0. 1 X 10-3 mol/L) Mg2+ had good effect on pollen tube elongation, while high concentration (0. 2X10-3 —1. 8X1CT3 mol/L) Mg2+ exhibited inhibited effects. The most suitable concentration of Mg2+ to promote pollen tube elongation was 0. 1X10-3 mol/L in the culture medium.%以矮牡丹花粉为材料,研究花粉的形态及不同培养基对矮牡丹花粉萌发及花粉管伸长的影响.结果表明,花粉萌发率与长球形花粉占花粉总数的百分率一致;适合矮牡丹花粉萌发的培养基为9%蔗糖+0.004 5%硼酸;低浓度(1×10-5~1×10-3 mol/L)的Ca2+促进了花粉管的伸长,高浓度(1×10-2~1×10-1 mol/L)的Ca2+抑制了花粉管的伸长,适合花粉管伸长的Ca2+浓度为1×10-3 mol/L;低浓度(0.1×10-3 mol/L)的Mg2+促进了花粉管的伸长,高浓度(0.2×10-3~1.8×10-3mol/L)的Mg2+抑制了花粉管的伸长,适合花粉管伸长的浓度为Mg2+0.1×10-3 mol/L.

  5. 甘草花粉超微鉴定及花粉活力、柱头可受性荧光显微镜观察%Identification of Pollen Ultrastructure and Fluorescence Microscope Observation of Pollen Viability and Stigma Activity of Liquorice

    Institute of Scientific and Technical Information of China (English)

    马春英; 屈平; 王文全

    2011-01-01

    The ultrastructure of the pollen in the Glycyrrhiza uralensis Fisch. , G. glabra L. and G. inflata Batal.were observed by the scanning electron microscope(SEM). Pollination way, pollen viability stigma activity and the fertilization time ascertainment after pollination were observed by the fluorescence microscope. The results showed that the study on the ultrastructure of pollen offered certain morphology basis for the discrimination of the liquorice.The pollination way of the liquorice was cleistogamy. The pollen viability was the highest at 12:00 on daytime,and the stigma had no ability to accept the pollen exceeding four days after artificial emasculation. The pollen tube entered into the ovule to fertilize 6h after pollination when the fixed pistils were observed different time after pollination. In order to establish the correct strategy of seed selection and breeding of the liquorice in the future, the sexual reproduction properties of the liquorice was also studied.%对甘草的有性生殖特性进行了研究,利用扫描电子显微镜对乌拉尔甘草、光果甘草和胀果甘草花粉的超微结构进行观察,利用荧光显微镜确定乌拉尔甘草的授粉方式、花粉生活力和柱头活性以及授粉后受精时间.结果表明,花粉超微结构为甘草的鉴别提供了一定的形态学依据;甘草的授粉方式属于闭花受精;花粉生活力在每天12:00时最强,去雄后超过4d的柱头已经不具备接受花粉的能力;对授粉后不同时间的雌蕊进行研究得出授粉后6h花粉管进入胚珠进行受精.

  6. 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.

  7. 紫玉兰花粉的生活力测定及贮藏方法%The Determination of Magnolia liliiflora Pollen Viability and lts Storage Method

    Institute of Scientific and Technical Information of China (English)

    刘会超; 贾文庆; 郭艳艳

    2011-01-01

    In order to explore appropriate storage method and optimum determination method and study the relationship between the pollen life and the storage environment, isolated culture, carmine acetate dyeing、I-KI staining and TTC staining methods were used to determine the fresh pollen ability of Magnolia liliiflora. The results showed that culture media with different concentration of sucrose and boric had good effects on the pollen germination. The pollen germinating percentage reached the highest (90.05%) after incubated on the media supplemented with 2% sucrose and 0. 001% boric acid. The best conditions to keep vitality of pollen is in not dry environment at -80C, the storage ability lasted for more than 5 d.%为了探明紫玉兰花粉生活力测定方法以及适宜的贮藏方法,采用离体培养法、醋酸洋红染色法、碘-碘化钾染色法和TTC氯化三苯基四氮唑)染色法等方法研究了花粉寿命长短与环境条件的关系.结果表明:4种测定方法中只有离体培养法适用于紫玉兰花粉生活力测定;培养基中添加不同浓度的蔗糖和硼酸对花粉的萌发有促进作用,紫玉兰花粉萌发的最适培养基为2%蔗糖+ 0.001%硼酸,萌发率达90.57%;在贮藏5d的情况下,花粉最适宜的贮藏条件为-80 ℃,不干燥.

  8. Loss of the Arabidopsis thaliana P4-ATPase ALA3 Reduces Adaptability to Temperature Stresses and Impairs Vegetative, Pollen, and Ovule Development

    DEFF Research Database (Denmark)

    McDowell, Stephen C.; Lopez Marques, Rosa Laura; Poulsen, Lisbeth Rosager

    2013-01-01

    , a P4-ATPase associated with the trans-Golgi network (ALA3) was previously reported to be important for vegetative growth and reproductive success. Here we show that multiple phenotypes for ala3 knockouts are sensitive to growth conditions. For example, ala3 rosette size was observed to be dependent...... upon both temperature and soil, and varied between 40% and 80% that of wild-type under different conditions. We also demonstrate that ala3 mutants have reduced fecundity resulting from a combination of decreased ovule production and pollen tube growth defects. In-vitro pollen tube growth assays showed...... that ala3 pollen germinated ~2 h slower than wild-type and had approximately 2-fold reductions in both maximal growth rate and overall length. In genetic crosses under conditions of hot days and cold nights, pollen fitness was reduced by at least 90-fold; from ~18% transmission efficiency (unstressed...

  9. Reduced cell viability and apoptosis induction in human thyroid carcinoma and mesothelioma cells exposed to cidofovir.

    Science.gov (United States)

    Catalani, Simona; Palma, Francesco; Battistelli, Serafina; Nuvoli, Barbara; Galati, Rossella; Benedetti, Serena

    2017-02-20

    Besides its well-recognized antiviral activity, Cidofovir (CDV) has been shown to exert anticancer properties both within in vitro and in vivo models. The aim of this study was to evaluate the effects of CDV on still unexplored cultured cancer cells from human mesothelioma as well as breast, colon, liver, lung, prostate, and thyroid carcinomas. Overall, a dose- and time-dependent inhibition of cell viability was observed after CDV exposure. To clarify the mechanisms underlying CDV action, apoptotic cell death was investigated in two infected cell lines [Ist-Mes1 and Ist-Mes2 mesothelioma cells (SV40+)] and in two uninfected cell lines (NCI-H2425 mesothelioma cells and FTC-133 thyroid cancer cells), which resulted the most sensitive to CDV treatment. Reduced expression of procaspase-3 and increased expression of PARP p85 fragment were observed in both infected and uninfected mesothelioma cells, indicating apoptosis induction by CDV in a virus-independent manner. Similarly, the increase of the pro-apoptotic proteins p53, cytochrome c and caspase-3, the decrease of the survival protein Bcl-x, and the increment of Bax/Bcl-2 ratio revealed the occurrence of apoptosis in CDV-treated FTC-133. The presence of nuclear DNA fragmentation confirmed apoptotic cell death by CDV. Overall, our findings warrant further investigations to explore the therapeutic potential of CDV for human mesothelioma and follicular thyroid carcinoma.

  10. Embryo-larval exposure to atrazine reduces viability and alters oxidative stress parameters in Drosophila melanogaster.

    Science.gov (United States)

    Figueira, Fernanda Hernandes; Aguiar, Lais Mattos de; Rosa, Carlos Eduardo da

    2017-01-01

    The herbicide atrazine has been used worldwide with subsequent residual contamination of water and food, which may cause adverse effects on non-target organisms. Animal exposure to this herbicide may affect development, reproduction and energy metabolism. Here, the effects of atrazine regarding survival and redox metabolism were assessed in the fruit fly D. melanogaster exposed during embryonic and larval development. The embryos (newly fertilized eggs) were exposed to different atrazine concentrations (10μM and 100μM) in the diet until the adult fly emerged. Pupation and emergence rates, developmental time and sex ratio were determined as well as oxidative stress parameters and gene expression of the antioxidant defence system were evaluated in newly emerged male and female flies. Atrazine exposure reduced pupation and emergence rates in fruit flies without alterations to developmental time and sex ratio. Different redox imbalance patterns were observed between males and females exposed to atrazine. Atrazine caused an increase in oxidative damage, reactive oxygen species generation and antioxidant capacity and decreased thiol-containing molecules. Further, atrazine exposure altered the mRNA expression of antioxidant genes (keap1, sod, sod2, cat, irc, gss, gclm, gclc, trxt, trxr-1 and trxr-2). Reductions in fruit fly larval and pupal viability observed here are likely consequences of the oxidative stress induced by atrazine exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. A study on pollen germination and viability in different varieties of Carya illinoensis%不同美国山核桃品种花粉萌发与活力研究

    Institute of Scientific and Technical Information of China (English)

    朱雪晨; 王改萍; 彭方仁; 吕昕

    2015-01-01

    In order to analyze effects of different culture conditions on pollen vitality , influences of culture time,culture temperature, pH value of culture medium,sugar,boric acid and PEG-4000 concentration on pollen germination were studied by in vitro culture of four different Carya illinoensis cultivars.The results showed that culture time had extremely significant effect on the pollen germination and the pollen length of C. illinoensis. The suitable culture time was 24 h. The culture temperature,pH value,sugar boric acid and PEG-4000 concentrations in liquid medium had obvious influence on pollen viability of the four varieties.The optimum culture temperature for all varieties was 25-30℃. The weak acidic en⁃vironment was favorable for germination and growth of pollens, and the suitable pH value of liquid medium was 5.6.The pollen germination rate and pollen tube length reached their peaks when the sugar concentration was 20%-25%, the concentration of boric acid was over 0.03%;and the concentration of PEG-4000 was over 15%.%为了分析不同培养条件对美国山核桃花粉生活力的影响,以4个不同品种美国山核桃花粉为试验材料,研究了培养时间、培养温度、培养基pH、蔗糖、硼酸和PEG-4000浓度等对花粉离体萌发的影响。结果表明:不同培养时间对美国山核桃花粉的生活力有显著影响,适宜的培养时间为24 h;适宜的培养温度为25~30℃,温度过高或者过低均会抑制花粉萌发和花粉管生长;适宜的液体培养基pH为5.5,超过此范围均表现为抑制萌发。在一定浓度范围内,蔗糖、硼酸和PEG-4000对美国山核桃4个品种的花粉萌发和花粉管生长起促进作用,而超过阈值后起抑制作用;培养基组分中以含20%~25%的蔗糖、0.03%的硼酸和15%的PEG-4000为宜。

  12. Pectic arabinan side chains are essential for pollen cell wall integrity during pollen development.

    Science.gov (United States)

    Cankar, Katarina; Kortstee, Anne; Toonen, Marcel A J; Wolters-Arts, Mieke; Houbein, Rudolf; Mariani, Celestina; Ulvskov, Peter; Jorgensen, Bodil; Schols, Henk A; Visser, Richard G F; Trindade, Luisa M

    2014-05-01

    Pectin is a complex polysaccharide and an integral part of the primary plant cell wall and middle lamella, contributing to cell wall mechanical strength and cell adhesion. To understand the structure-function relationships of pectin in the cell wall, a set of transgenic potato lines with altered pectin composition was analysed. The expression of genes encoding enzymes involved in pectin acetylation, degradation of the rhamnogalacturonan backbone and type and length of neutral side chains, arabinan and galactan in particular, has been altered. Upon crossing of different transgenic lines, some transgenes were not transmitted to the next generation when these lines were used as a pollen donor, suggesting male sterility. Viability of mature pollen was severely decreased in potato lines with reduced pectic arabinan, but not in lines with altered galactan side chains. Anthers and pollen of different developmental stages were microscopically examined to study the phenotype in more detail. Scanning electron microscopy of flowers showed collapsed pollen grains in mature anthers and in earlier stages cytoplasmic protrusions at the site of the of kin pore, eventually leading to bursting of the pollen grain and leaking of the cytoplasm. This phenomenon is only observed after the microspores are released and the tapetum starts to degenerate. Timing of the phenotype indicates a role for pectic arabinan side chains during remodelling of the cell wall when the pollen grain is maturing and dehydrating.

  13. The pollen of No. 5 , No. 27 and No. 35 of clones of Carya illinoensis was chosen as the experimental material to study the pollen viability and pollen morphology with SEM in different processing modes, plucking time and powder numbers. The results indica%3个薄壳山核桃无性系花粉活力与显微结构比较研究

    Institute of Scientific and Technical Information of China (English)

    李川; 辜夕容; 姚小华; 王开良; 常君; 余裕龙

    2012-01-01

    The pollen of No. 5 , No. 27 and No. 35 of clones of Carya illinoensis was chosen as the experimental material to study the pollen viability and pollen morphology with SEM in different processing modes, plucking time and powder numbers. The results indicated that there are significant differences in the pollen viability in different processing modes, plucking time and powder numbers, also in the Polar axis and equatorial axis of the pollen of these three clones. The form of pollen is ellipsoid and has three apertures which are evenly disposed on the equatorial plane. The equatorial plane of the pollen of these three clones is oval in shape, while the polar planes of clones No. 5 and No. 27 are nearly round and that of No. 35 nearly triangular. There are indifferent granular veins on the surface of the pollen with granular risings equally distributed. This paper provides palynology basis for the origin, evolution and phylogenetic relationship of Carya illinoensis, and foundation of the selection and breeding of new varieties, and cross-hybrid breeding.%以薄壳山核桃无性系5号、27号、35号花粉为试验材料,测定了不同处理方式、不同采摘时期和不同出粉次数下的花粉活力,同时利用扫描电子显微镜对其花粉形态进行了观测.结果表明,不同处理方式、不同采摘时间和不同出粉次数下收集的同一薄壳山核桃无性系花粉,其活力存在显著性差异(P<0.05).3个无性系花粉极轴长(P)和赤道轴长(E)存在显著性差异(P<0.05),花粉粒形状均为扁球形,具有3个萌发孔,均匀分布在赤道面上;3个无性系花粉赤道面观均呈椭圆形,无性系5号和27号极面观呈近圆形,而无性系35号极面观呈近三角形;3个无性系花粉表面呈颗粒状纹饰,均匀分布着颗粒状的突起,表面纹饰差异不明显.通过研究薄壳山核桃花粉的超显微结构,可为薄壳山核桃品种的起源、演化以及种类间亲缘关系等提供孢粉

  14. Low nutrient availability reduces high-irradiance–induced viability loss inoceanic phytoplankton

    NARCIS (Netherlands)

    Kulk, G.; van de Poll, W.H.; Visser, R.J.W.; Buma, A.G.J.

    2013-01-01

    In situ viability of oceanic phytoplankton may be relatively low in open oceans. This is assumed to be related to the high-irradiance and low-nutrient conditions typical for oligotrophic regions. However, experimental evidence for this phenomenon was not yet available. In the present study, the impo

  15. Study on the Pollen Viability and Stigma Receptivity of Chrysanthemum morifolium ‘Fubaiju’%福白菊花粉活力和柱头可授性研究

    Institute of Scientific and Technical Information of China (English)

    徐雷; 刘常丽; 王慧弟; 陈科力

    2012-01-01

    Objective:To study the blooming habits,pollen viability and stigma receptivity of Chrysanthemum morifolium and provide theoretical basis for its breeding.Methods:Explored the blooming habits by dynamic observation on the process of blossom,evaluated the pollen viability by germination in vitro culture method and estimated stigma receptivity by benzidine-hydrogen peroxide method.Results: About the pollen viability,there were no significant differences between the flowers which in the same round of the capitulum; Tubular flowers in the center of a capitulum were significantly higher than that on the edge; In the morning pollen vitality gradually raised,during 11:00 ~ 14:00 maintained the highest,and then gradually decreased; Tubular flower began to loose powder on the third day,during 4th ~6th day the pollen viability was highest,respectively was 35.12% ,39.89% ,38.12% ,then gradually decreased,on the 15th day was only 7.41 % ,finally turned into wither.Regard to the stigma receptivity,the center of a capitulum were significantly higher than that on the edge,outer edge ligulate flower had no receptivity; Revealed the strongest during 13:00 ~ 14:00 in one day; During the 5th ~7th day was the strongest after flowering.The regulation of the stigma secreted mucus existed great consistency with the stigma receptivity,namely the stigma receptivity usually was strong when it secreted large number mucus.Conclusion:Understand the blossom habits of Chrysanthemun morifolium,as well as the dynamic changes regulation of pollen viability and stigma receptivity during its blossom,which could be used to select the flowers in a capitulum which are on the more suitable period and position for artificial pollination and hybridization breeding research.%目的:明确福白菊(Chrysanthemum morifolium‘ Fubaiju’)开花习性、花粉活力以及柱头可授性,以期为药用菊花良种选育提供理论依据.方法:对开花过程进行动态观察了解开花习性,采用

  16. Hypericum perforatum plant cells reduce Agrobacterium viability during co-cultivation.

    Science.gov (United States)

    Franklin, G; Conceição, L F R; Kombrink, E; Dias, A C P

    2008-05-01

    Plant recalcitrance is the major barrier in developing Agrobacterium-mediated transformation protocols for several important plant species. Despite the substantial knowledge of T-DNA transfer process, very little is known about the factors leading to the plant recalcitrance. Here, we analyzed the basis of Hypericum perforatum L. (HP) recalcitrance to Agrobacterium-mediated transformation using cell suspension culture. When challenged with Agrobacterium, HP cells swiftly produced an intense oxidative burst, a typical reaction of plant defense. Agrobacterium viability started to decline and reached 99% mortality within 12 h, while the plant cells did not suffer apoptotic process. This is the first evidence showing that the reduction of Agrobacterium viability during co-cultivation with recalcitrant plant cells can affect transformation.

  17. Gallic acid reduces cell viability, proliferation, invasion and angiogenesis in human cervical cancer cells

    OpenAIRE

    Zhao, Bing; HU, MENGCAI

    2013-01-01

    Gallic acid is a trihydroxybenzoic acid, also known as 3,4,5-trihydroxybenzoic acid, which is present in plants worldwide, including Chinese medicinal herbs. Gallic acid has been shown to have cytotoxic effects in certain cancer cells, without damaging normal cells. The objective of the present study was to determine whether gallic acid is able to inhibit human cervical cancer cell viability, proliferation and invasion and suppress cervical cancer cell-mediated angiogenesis. Treatment of HeLa...

  18. Bee Pollen

    Science.gov (United States)

    ... It can also include some nectar and bee saliva. Pollens come from many plants, so the contents ... rash. You may hear claims that bee pollen enzymes (chemical compounds that assist in chemical reactions) provide ...

  19. Gallic acid reduces cell viability, proliferation, invasion and angiogenesis in human cervical cancer cells.

    Science.gov (United States)

    Zhao, Bing; Hu, Mengcai

    2013-12-01

    Gallic acid is a trihydroxybenzoic acid, also known as 3,4,5-trihydroxybenzoic acid, which is present in plants worldwide, including Chinese medicinal herbs. Gallic acid has been shown to have cytotoxic effects in certain cancer cells, without damaging normal cells. The objective of the present study was to determine whether gallic acid is able to inhibit human cervical cancer cell viability, proliferation and invasion and suppress cervical cancer cell-mediated angiogenesis. Treatment of HeLa and HTB-35 human cancer cells with gallic acid decreased cell viability in a dose-dependent manner. BrdU proliferation and tube formation assays indicated that gallic acid significantly decreased human cervical cancer cell proliferation and tube formation in human umbilical vein endothelial cells, respectively. Additionally, gallic acid decreased HeLa and HTB-35 cell invasion in vitro. Western blot analysis demonstrated that the expression of ADAM17, EGFR, p-Akt and p-Erk was suppressed by gallic acid in the HeLa and HTB-35 cell lines. These data indicate that the suppression of ADAM17 and the downregulation of the EGFR, Akt/p-Akt and Erk/p-Erk signaling pathways may contribute to the suppression of cancer progression by Gallic acid. Gallic acid may be a valuable candidate for the treatment of cervical cancer.

  20. Exogenous calcium improves viability of biocontrol yeasts under heat stress by reducing ROS accumulation and oxidative damage of cellular protein.

    Science.gov (United States)

    An, Bang; Li, Boqiang; Qin, Guozheng; Tian, Shiping

    2012-08-01

    In this article, we investigated the effect of exogenous calcium on improving viability of Debaryomyces hansenii and Pichia membranaefaciens under heat stress, and evaluated the role of calcium in reducing oxidant damage of proteins in the yeast cells. The results indicated that high concentration of exogenous calcium in culture medium was beneficial for enhancing the tolerance of the biocontrol yeasts to heat stress. The possible mechanism of calcium improving the viability of yeasts was attributed to enhancement of antioxidant enzyme activities, decrease in ROS accumulation and reduction of oxidative damage of intracellular protein in yeast cells under heat stress. D. hansenii is more sensitive to calcium as compared to P. membranaefaciens. Our results suggest that application of exogenous calcium combined with biocontrol yeasts is a practical approach for the control of postharvest disease in fruit.

  1. Do trichothecenes reduce viability of circulating blood cells and modify haemostasis parameters?

    Science.gov (United States)

    Froquet, R; Arnold, F; Batina, P; Parent-Massin, D

    2003-01-01

    This manuscript describes the results of experiments conducted using human blood cells to determine the ability of T-2 toxin and DON to cause changes in clotting time, platelet aggregation, red blood cell haemolysis, RBC glucose content, lactate release, glutathione depletion, as well as white blood cell viability. In vitro results showed that haemostasis parameters and erythrocytes were not affected at concentrations able to induce inhibition of haematopoietic progenitor proliferation. In the presence of 10(-8) M and 10(-6) M T-2, the leucocyte number decreased at 24 h by 30% and 50% respectively. A 50% decrease in leucocyte number was observed for 10(-5) M DON. Results were compared with haematopoietic progenitor sensitivities. Due to the differences in sensitivities between mature blood cells and haematopoietic progenitors, haematological problems associated with trichothecene intoxication could be attributed to haematopoiesis inhibition.

  2. Loss of the Arabidopsis thaliana P₄-ATPase ALA3 reduces adaptability to temperature stresses and impairs vegetative, pollen, and ovule development.

    Directory of Open Access Journals (Sweden)

    Stephen C McDowell

    Full Text Available Members of the P4 subfamily of P-type ATPases are thought to help create asymmetry in lipid bilayers by flipping specific lipids between the leaflets of a membrane. This asymmetry is believed to be central to the formation of vesicles in the secretory and endocytic pathways. In Arabidopsis thaliana, a P4-ATPase associated with the trans-Golgi network (ALA3 was previously reported to be important for vegetative growth and reproductive success. Here we show that multiple phenotypes for ala3 knockouts are sensitive to growth conditions. For example, ala3 rosette size was observed to be dependent upon both temperature and soil, and varied between 40% and 80% that of wild-type under different conditions. We also demonstrate that ala3 mutants have reduced fecundity resulting from a combination of decreased ovule production and pollen tube growth defects. In-vitro pollen tube growth assays showed that ala3 pollen germinated ∼2 h slower than wild-type and had approximately 2-fold reductions in both maximal growth rate and overall length. In genetic crosses under conditions of hot days and cold nights, pollen fitness was reduced by at least 90-fold; from ∼18% transmission efficiency (unstressed to less than 0.2% (stressed. Together, these results support a model in which ALA3 functions to modify endomembranes in multiple cell types, enabling structural changes, or signaling functions that are critical in plants for normal development and adaptation to varied growth environments.

  3. 榛子花粉生活力和柱头可授性与结实特征研究%Pollen viability, stigma receptivity and fruiting characteristics of hazelnut.

    Institute of Scientific and Technical Information of China (English)

    刘剑锋; 颜堃; 程云清; 王占武; 邹振峰

    2012-01-01

    . Pollen grains attached on stigma reached the maximum on 4th day after anthesis under natural pollination conditions, and the pollen amounts of pollen grains of C. heterophylla and Dawei were 40.6 and 84.6 respectively, after that the amount of pollen grains reduced sharply ; and after being bagged, the amounts were 58.1 and 78.5 on 30th day after anthesis. 4) Pollen tubes of C. heterophylla and Dawei could stretch to the end of stigma within 24 hours. 5)Receptive stigma percentages of C. heterophylla and Dawei were 87.3% and 92.1% respectively after stigma being bagged for 30 days. 6) Non-edible nut part of C. heterophylla was more than 50% , and blank nut was the major reason leading to non-edible nut. Non-edible nut part of Dawei was less than 15%. Flower drop ratio of the two hazelnut cuhivars decreased by cross-pollination, while cross-pollination had no effects on non-edible nut ratio.

  4. Quercetin Stimulates Insulin Secretion and Reduces the Viability of Rat INS-1 Beta-Cells.

    Science.gov (United States)

    Kittl, Michael; Beyreis, Marlena; Tumurkhuu, Munkhtuya; Fürst, Johannes; Helm, Katharina; Pitschmann, Anna; Gaisberger, Martin; Glasl, Sabine; Ritter, Markus; Jakab, Martin

    2016-01-01

    Previously we described insulinotropic effects of Leonurus sibiricus L. plant extracts used for diabetes mellitus treatment in Traditional Mongolian Medicine. The flavonoid quercetin and its glycoside rutin, which exert anti-diabetic properties in vivo by interfering with insulin signaling in peripheral target tissues, are constituents of these extracts. This study was performed to better understand short- and long-term effects of quercetin and rutin on beta-cells. Cell viability, apoptosis, phospho-protein abundance and insulin release were determined using resazurin, annexin-V binding assays, Western blot and ELISA, respectively. Membrane potentials (Vmem), whole-cell Ca2+ (ICa)- and ATP-sensitive K+ (IKATP) currents were measured by patch clamp. Intracellular Ca2+ (Cai) levels were measured by time-lapse imaging using the ratiometric Ca2+ indicator Fura-2. Rutin, quercetin and the phosphoinositide-3-kinase (PI3K) inhibitor LY294002 caused a dose-dependent reduction in cell viability with IC50 values of ∼75 µM, ∼25 µM and ∼3.5 µM, respectively. Quercetin (50 µM) significantly increased the percentage of Annexin-V+ cells within 48 hrs. The mean cell volume (MCV) of quercetin-treated cells was significantly lower. Within 2 hrs, quercetin significantly decreased basal- and insulin-stimulated Akt(T308) phosphorylation and increased Erk1/2 phosphorylation, without affecting P-Akt(S473) abundance. Basal- and glucose-stimulated insulin release were significantly stimulated by quercetin. Quercetin significantly depolarized Vmem by ∼25 mV which was prevented by the KATP-channel opener diazoxide, but not by the L-type ICa inhibitor nifedipine. Quercetin significantly stimulated ICa and caused a 50% inhibition of IKATP. The effects on Vmem, ICa and IKATP rapidly reached peak values and then gradually diminished to control values within ∼1 minute. With a similar time-response quercetin induced an elevation in Cai which was completely abolished in the absence of

  5. Quercetin Stimulates Insulin Secretion and Reduces the Viability of Rat INS-1 Beta-Cells

    Directory of Open Access Journals (Sweden)

    Michael Kittl

    2016-06-01

    Full Text Available Background/Aims: Previously we described insulinotropic effects of Leonurus sibiricus L. plant extracts used for diabetes mellitus treatment in Traditional Mongolian Medicine. The flavonoid quercetin and its glycoside rutin, which exert anti-diabetic properties in vivo by interfering with insulin signaling in peripheral target tissues, are constituents of these extracts. This study was performed to better understand short- and long-term effects of quercetin and rutin on beta-cells. Methods: Cell viability, apoptosis, phospho-protein abundance and insulin release were determined using resazurin, annexin-V binding assays, Western blot and ELISA, respectively. Membrane potentials (Vmem, whole-cell Ca2+ (ICa- and ATP-sensitive K+ (IKATP currents were measured by patch clamp. Intracellular Ca2+ (Cai levels were measured by time-lapse imaging using the ratiometric Ca2+ indicator Fura-2. Results: Rutin, quercetin and the phosphoinositide-3-kinase (PI3K inhibitor LY294002 caused a dose-dependent reduction in cell viability with IC50 values of ∼75 µM, ∼25 µM and ∼3.5 µM, respectively. Quercetin (50 µM significantly increased the percentage of Annexin-V+ cells within 48 hrs. The mean cell volume (MCV of quercetin-treated cells was significantly lower. Within 2 hrs, quercetin significantly decreased basal- and insulin-stimulated Akt(T308 phosphorylation and increased Erk1/2 phosphorylation, without affecting P-Akt(S473 abundance. Basal- and glucose-stimulated insulin release were significantly stimulated by quercetin. Quercetin significantly depolarized Vmem by ∼25 mV which was prevented by the KATP-channel opener diazoxide, but not by the L-type ICa inhibitor nifedipine. Quercetin significantly stimulated ICa and caused a 50% inhibition of IKATP. The effects on Vmem, ICa and IKATP rapidly reached peak values and then gradually diminished to control values within ∼1 minute. With a similar time-response quercetin induced an elevation in Cai

  6. Pollen immunotherapy reduces the development of asthma in children with seasonal rhinoconjunctivitis (the PAT-study)

    DEFF Research Database (Denmark)

    Möller, Christian; Dreborg, Sten; Ferdousi, Hosne A

    2002-01-01

    BACKGROUND: Children with allergic rhinitis are likely to develop asthma. OBJECTIVE: The purpose of this investigation was to determine whether specific immunotherapy can prevent the development of asthma and reduce bronchial hyperresponsiveness in children with seasonal allergic rhinoconjunctivi...

  7. Effectiveness of common household cleaning agents in reducing the viability of human influenza A/H1N1.

    Science.gov (United States)

    Greatorex, Jane S; Page, Rosanna F; Curran, Martin D; Digard, Paul; Enstone, Joanne E; Wreghitt, Tim; Powell, Penny P; Sexton, Darren W; Vivancos, Roberto; Nguyen-Van-Tam, Jonathan S

    2010-02-01

    In the event of an influenza pandemic, the majority of people infected will be nursed at home. It is therefore important to determine simple methods for limiting the spread of the virus within the home. The purpose of this work was to test a representative range of common household cleaning agents for their effectiveness at killing or reducing the viability of influenza A virus. Plaque assays provided a robust and reproducible method for determining virus viability after disinfection, while a National Standard influenza virus RT-PCR assay (VSOP 25, www.hpa-standardmethods.org.uk) was adapted to detect viral genome, and a British Standard (BS:EN 14476:2005) was modified to determine virus killing. Active ingredients in a number of the cleaning agents, wipes, and tissues tested were able to rapidly render influenza virus nonviable, as determined by plaque assay. Commercially available wipes with a claimed antiviral or antibacterial effect killed or reduced virus infectivity, while nonmicrobiocidal wipes and those containing only low concentrations (<5%) of surfactants showed lower anti-influenza activity. Importantly, however, our findings indicate that it is possible to use common, low-technology agents such as 1% bleach, 10% malt vinegar, or 0.01% washing-up liquid to rapidly and completely inactivate influenza virus. Thus, in the context of the ongoing pandemic, and especially in low-resource settings, the public does not need to source specialized cleaning products, but can rapidly disinfect potentially contaminated surfaces with agents readily available in most homes.

  8. 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...

  9. Flowering, pollen characteristics and insect foraging on Campanula bononiensis (Campanulaceae, a protected species in Poland

    Directory of Open Access Journals (Sweden)

    Bożena Denisow

    2014-07-01

    Full Text Available This study investigated the floral biology and pollen quantity and quality of Campanula bononiensis L. (Campanulaceae, a protected species in Poland. Observations and measurements were made during the years 2007–2009 in natural phytocoenoses from the Festuco-Brometea class situated within the Lublin area, SE Poland. A considerable decrease (approx. 87% in population density was observed. Significant variations both in the amount of pollen (18.5%–34.8% of pollen in the total anther dry weight, i.e. 0.5–1.5 mg per 10 anthers and in pollen viability (38.8–97.0% were noted. Both a low amount of pollen and low pollen viability may reduce the reproductive success of individuals. The most frequent visiting insects were bees (Apoidea, including solitary bees 45.7%, honeybees 20.4%, and bumblebees 11.4%. Dipterans, coleopterans (weevils, lepidopterans and ants were also recorded, implying a strong impact of C. bononiensis on insect biodiversity within grasslands.

  10. Effectiveness of common household cleaning agents in reducing the viability of human influenza A/H1N1.

    Directory of Open Access Journals (Sweden)

    Jane S Greatorex

    Full Text Available BACKGROUND: In the event of an influenza pandemic, the majority of people infected will be nursed at home. It is therefore important to determine simple methods for limiting the spread of the virus within the home. The purpose of this work was to test a representative range of common household cleaning agents for their effectiveness at killing or reducing the viability of influenza A virus. METHODOLOGY/PRINCIPAL FINDINGS: Plaque assays provided a robust and reproducible method for determining virus viability after disinfection, while a National Standard influenza virus RT-PCR assay (VSOP 25, www.hpa-standardmethods.org.uk was adapted to detect viral genome, and a British Standard (BS:EN 14476:2005 was modified to determine virus killing. CONCLUSIONS/SIGNIFICANCE: Active ingredients in a number of the cleaning agents, wipes, and tissues tested were able to rapidly render influenza virus nonviable, as determined by plaque assay. Commercially available wipes with a claimed antiviral or antibacterial effect killed or reduced virus infectivity, while nonmicrobiocidal wipes and those containing only low concentrations (<5% of surfactants showed lower anti-influenza activity. Importantly, however, our findings indicate that it is possible to use common, low-technology agents such as 1% bleach, 10% malt vinegar, or 0.01% washing-up liquid to rapidly and completely inactivate influenza virus. Thus, in the context of the ongoing pandemic, and especially in low-resource settings, the public does not need to source specialized cleaning products, but can rapidly disinfect potentially contaminated surfaces with agents readily available in most homes.

  11. Inactivation of two newly identified tobacco heavy metal ATPases leads to reduced Zn and Cd accumulation in shoots and reduced pollen germination

    Science.gov (United States)

    Hermand, Victor; Julio, Emilie; Dorlhac de Borne, François; Punshon, Tracy; Ricachenevsky, Felipe K; Bellec, Arnaud; Gosti, Françoise; Berthomieu, Pierre

    2015-01-01

    Cadmium (Cd) is a non-essential heavy metal, which is classified as a “known human carcinogen” by the International Agency for Research on Cancer (IARC). Understanding the mechanisms controlling Cd distribution in planta is essential to develop phytoremediation approaches as well as for food safety. Unlike most other plants, tobacco (Nicotiana tabacum) plants translocate most of the Cd taken up from the soil, out of the roots and into the shoots, leading to high Cd accumulation in tobacco shoots. Two orthologs to the Arabidopsis thaliana HMA2 and HMA4 Zn and Cd ATPases that are responsible for zinc (Zn) and Cd translocation from roots to shoots were identified in tobacco and sequenced. These genes, named NtHMAα and NtHMAβ, were more highly expressed in roots than in shoots. NtHMAα was expressed in the vascular tissues of both roots and leaves as well as in anthers. No visual difference was observed between wild-type plants and plants in which the NtHMAα and NtHMAβ genes were either mutated or silenced. These mutants showed reduced Zn and Cd accumulation in shoots as well as increased Cd tolerance. When both NtHMA genes were silenced, plant development was altered and pollen germination was severely impaired due to Zn deficiency. Interestingly, seeds from these lines also showed decreased Zn concentration but increased iron (Fe) concentration. PMID:24760325

  12. Viabilidade do grão de pólen de acessos de capim-elefante, milheto - DOI: 10.4025/actascibiolsci.v28i1.1052 Pollen viability in elephantgrass, pearl millet and interspecific hybrids - DOI: 10.4025/actascibiolsci.v28i1.1052

    Directory of Open Access Journals (Sweden)

    Antônio Vander Pereira

    2006-03-01

    Full Text Available O objetivo deste trabalho foi estimar a viabilidade do pólen em acessos de capim-elefante, milheto e híbridos interespecíficos por meio de germinação in vitro e coloração com carmim propiônico, orceína acética e corante de Alexander. Os testes de germinação foram realizados com grãos de pólen frescos e armazenados por 30 dias. Os acessos de capim-elefante e de milheto apresentaram alta viabilidade de pólen. Apenas um deles, quando avaliado com o corante de Alexander, mostrou baixa fertilidade. Para os híbridos, observou-se alta taxa de pólens funcionais com os corantes nucleares. Entretanto, o corante de Alexander confirmou a completa esterilidade desses acessos. Os acessos de capim-elefante e milheto apresentaram baixa porcentagem de pólens viáveis quando induzidos à germinação em meio de cultura. Nos híbridos foi constatada completa esterilidade do grão de pólen, condizente com as anormalidades meióticas relatadas na literatura. Quanto ao armazenamento, os grãos de pólen de todos os acessos perderam completamente o poder germinativoThe aim of this work was to estimate the pollen viability in elephantgrass, pearl millet and interspecific hybrids accessions through in vitro germination and staining with propionic carmine, acetic orcein and Alexander’s stain. The germination tests were accomplished with fresh pollen grains and stored for 30 days. The elephantgrass and peare millet accessions presented a high pollen viability. Just one of the accessions, when evaluated with Alexander's stain, showed low fertility. For the hybrid, a high rate of functional pollen was observed with the nuclear stain. However, Alexander's stain confirmed the complete sterility of those accessions. Elephantgrass and pearl millet accessions presented a low percentage of viable pollen grain, when induced to germination in culture medium. Complete sterility of the pollen grain was verified in the hybrid, agreeing with the meiotic

  13. Interactive effect of reduced pollen availability and Varroa destructor infestation limits growth and protein content of young honey bees

    NARCIS (Netherlands)

    Dooremalen, van C.; Stam, E.; Gerritsen, L.J.M.; Cornelissen, B.; Steen, van der J.J.M.; Langevelde, van F.; Blacquiere, T.

    2013-01-01

    Varroa destructor in combination with one or more stressors, such as low food availability or chemical exposure, is considered to be one of the main causes for honey bee colony losses. We examined the inter-active effect of pollen availability on the protein content and body weight of young bees tha

  14. 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.

  15. Taraxacum officinale pollen depresses seed set of montane wildflowers through pollen allelopathy

    Directory of Open Access Journals (Sweden)

    Deirdre Loughnan

    2014-08-01

    Full Text Available Plant species that share pollinators can suffer from interspecific pollen deposition. Male reproductive success is inevitably reduced by the loss of pollen to flowers of another species. Female reproductive success can be affected by reduced stigmatic area or, more strongly, through allelopathic effects by which the admixture of some foreign pollen reduces seed or fruit set. We tested for allelopathic effects of Taraxacum officinale (Asteracaeae pollen on the seed set of montane wildflowers Erythronium grandiflorum (Liliaceae and Erysimum capitatum (Brassicaceae, by hand-pollinating plants with pollen mixtures. Taraxacum is a common invasive species, which produces allelopathic chemicals in its root and vegetative tissue, making it a likely candidate for pollen allelopathy. Flowers of both species produced fewer well-developed seeds when pollinated with pollen mixtures containing Taraxacum pollen. The pollen-allelopathic potential of weedy dandelion may add to its ability to disrupt communities that it invades.

  16. Inhibiting pollen reduced nicotinamide adenine dinucleotide phosphate oxidase–induced signal by intrapulmonary administration of antioxidants blocks allergic airway inflammation

    Science.gov (United States)

    Dharajiya, Nilesh; Choudhury, Barun K.; Bacsi, Attila; Boldogh, Istvan; Alam, Rafeul; Sur, Sanjiv

    2011-01-01

    Background Ragweed extract (RWE) contains NADPH oxidases that induce oxidative stress in the airways independent of adaptive immunity (signal 1) and augment antigen (signal 2)–induced allergic airway inflammation. Objective To test whether inhibiting signal 1 by administering antioxidants inhibits allergic airway inflammation in mice. Methods The ability of ascorbic acid (AA), N-acetyl cystenine (NAC), and tocopherol to scavenge pollen NADPH oxidase–generated reactive oxygen species (ROS) was measured. These antioxidants were administered locally to inhibit signal 1 in the airways of RWE-sensitized mice. Recruitment of inflammatory cells, mucin production, calcium-activated chloride channel 3, IL-4, and IL-13 mRNA expression was quantified in the lungs. Results Antioxidants inhibited ROS generation by pollen NADPH oxidases and intracellular ROS generation in cultured epithelial cells. AA in combination with NAC or Tocopherol decreased RWE-induced ROS levels in cultured bronchial epithelial cells. Coadministration of antioxidants with RWE challenge inhibited 4-hydroxynonenal adduct formation, upregulation of Clca3 and IL-4 in lungs, mucin production, recruitment of eosinophils, and total inflammatory cells into the airways. Administration of antioxidants with a second RWE challenge also inhibited airway inflammation. However, administration of AA+NAC 4 or 24 hours after RWE challenge failed to inhibit allergic inflammation. Conclusion Signal 1 plays a proinflammatory role during repeated exposure to pollen extract. We propose that inhibiting signal 1 by increasing antioxidant potential in the airways may be a novel therapeutic strategy to attenuate pollen-induced allergic airway inflammation. Clinical implications Administration of antioxidants in the airways may constitute a novel therapeutic strategy to prevent pollen induced allergic airway inflammation. PMID:17336614

  17. Flowering and the Pollen Fertility in Iranian Garlic Clones

    Directory of Open Access Journals (Sweden)

    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.

  18. Detection condition optimization of pollen viability of Taxus media ‘Hicksii' and analysis on its suitable storage temperature%曼地亚红豆杉‘Hicksii’花粉活力检测条件优化和适宜诸藏温度分析

    Institute of Scientific and Technical Information of China (English)

    王呈伟; 郑玉红; 李莹; 陆波; 彭峰; 陈晓萱

    2012-01-01

    By single-factor experiment design, experimental conditions of TTC staining and in vitro culture methods suitable for pollen viability detection of Taxus media ' Hicksii' were selected, and changes of ' Hicksii' pollen viability stored at conditions from 25℃ to -196 ℃ for thirteen weeks were detected by optimal conditions. The results show that the detection result of pollen viability by TTC staining method is higher than that by in vitro culture method. Among three influence factors (staining solution pH, TTC concentration and staining temperature) of TTC staining method, staining solution pH has an extremely significant influence on detection result, while staining temperature and TTC concentration have no significant influence but the former has an effect on staining speed. Among three influence factors (sucrose addition, concentrations of H3 BO3 and Ca(NO3)2 in medium and culture temperature) of in vitro culture method, sucrose addition has an extremely significant influence on detection result. The pollen viability is the highest in medium containing 15% ( mass-volume ratio) sucrose, while all of pollens can not germinate in media containing 20% or 25% (mass-volume ratio) sucrose. Addition of 200 mg·L-1 Ca(NO3)2 in media containing 100 or 200 mg·L-1 H3 BO3 can obviously improve pollen viability, and culture temperature has an effect on pollen germination speed but no obvious effect on pollen viability. The optimal detection condition of TTC staining method is taking 5.0 g·L-1 TTC solution (pH 7.0), dyeing at 35℃ for 2. 0 h. The optimal detection condition of in vitro culture method is using culture medium containing 15% (mass-volume ratio) sucrose, 100 mg·L-1 H3 BO3 and 200 mgg·L-1 Ca( NO3) 2, taking dark culture for 4 d. Stored at 25 ℃, 4 ℃ , 0℃, -20℃, -80℃ and -196℃ for thirteen weeks, pollen viability of 'Hicksii'and its retain time have significant differences. In which, pollens lost viability stored at -80℃ or -196℃ for 3 d

  19. ECHIDNA protein impacts on male fertility in Arabidopsis by mediating trans-Golgi network secretory trafficking during anther and pollen development.

    Science.gov (United States)

    Fan, Xinping; Yang, Caiyun; Klisch, Doris; Ferguson, Alison; Bhaellero, Rishi P; Niu, Xiwu; Wilson, Zoe A

    2014-03-01

    The trans-Golgi network (TGN) plays a central role in cellular secretion and has been implicated in sorting cargo destined for the plasma membrane. Previously, the Arabidopsis (Arabidopsis thaliana) echidna (ech) mutant was shown to exhibit a dwarf phenotype due to impaired cell expansion. However, ech also has a previously uncharacterized phenotype of reduced male fertility. This semisterility is due to decreased anther size and reduced amounts of pollen but also to decreased pollen viability, impaired anther opening, and pollen tube growth. An ECH translational fusion (ECHPro:ECH-yellow fluorescent protein) revealed developmentally regulated tissue-specific expression, with expression in the tapetum during early anther development and microspore release and subsequent expression in the pollen, pollen tube, and stylar tissues. Pollen viability and production, along with germination and pollen tube growth, were all impaired. The ech anther endothecium secondary wall thickening also appeared reduced and disorganized, resulting in incomplete anther opening. This did not appear to be due to anther secondary thickening regulatory genes but perhaps to altered secretion of wall materials through the TGN as a consequence of the absence of the ECH protein. ECH expression is critical for a variety of aspects of male reproduction, including the production of functional pollen grains, their effective release, germination, and tube formation. These stages of pollen development are fundamentally influenced by TGN trafficking of hormones and wall components. Overall, this suggests that the fertility defect is multifaceted, with the TGN trafficking playing a significant role in the process of both pollen formation and subsequent fertilization.

  20. Impedance Flow Cytometry: A Novel Technique in Pollen Analysis.

    Science.gov (United States)

    Heidmann, Iris; Schade-Kampmann, Grit; Lambalk, Joep; Ottiger, Marcel; Di Berardino, Marco

    2016-01-01

    An efficient and reliable method to estimate plant cell viability, especially of pollen, is important for plant breeding research and plant production processes. Pollen quality is determined by classical methods, like staining techniques or in vitro pollen germination, each having disadvantages with respect to reliability, analysis speed, and species dependency. Analysing single cells based on their dielectric properties by impedance flow cytometry (IFC) has developed into a common method for cellular characterisation in microbiology and medicine during the last decade. The aim of this study is to demonstrate the potential of IFC in plant cell analysis with the focus on pollen. Developing and mature pollen grains were analysed during their passage through a microfluidic chip to which radio frequencies of 0.5 to 12 MHz were applied. The acquired data provided information about the developmental stage, viability, and germination capacity. The biological relevance of the acquired IFC data was confirmed by classical staining methods, inactivation controls, as well as pollen germination assays. Different stages of developing pollen, dead, viable and germinating pollen populations could be detected and quantified by IFC. Pollen viability analysis by classical FDA staining showed a high correlation with IFC data. In parallel, pollen with active germination potential could be discriminated from the dead and the viable but non-germinating population. The presented data demonstrate that IFC is an efficient, label-free, reliable and non-destructive technique to analyse pollen quality in a species-independent manner.

  1. Particulate Bioglass reduces the viability of bacterial biofilms formed on its surface in an in vitro model.

    Science.gov (United States)

    Allan, Iain; Newman, Hubert; Wilson, Michael

    2002-02-01

    45S5 Bioglass is a bioactive implant material which, in its particulate form, is used in the repair of periodontal defects. The surface reactions undergone by this material in an aqueous environment may exert an antibacterial effect that would be beneficial to periodontal surgical treatment. Biofilms of Streptococcus sanguis, an early plaque former, and mixed species biofilms from a salivary inoculum grown under conditions similar to those associated with periodontal implants, were grown on particulate Bioglass in a constant depth film fermenter (CDFF). Control biofilms were grown on inert glass particulates. At sample times of 3, 24 and 48 hours the viability of biofilms of S. sanguis grown on Bioglass was significantly lower than for those grown on inert glass. In the experiments with subgingivally-modelled mixed species biofilms, the total anaerobic counts were significantly lower on Bioglass after 24 and 48 hours, but not 96 or 168 hours, compared to inert glass. Thus, particulate Bioglass has the potential to reduce bacterial colonisation of its surface in vivo, a feature relevant to post-surgical periodontal wound healing.

  2. 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. ...

  3. Cluster Analysis for the Pollen Quantity and Viability of 27 Euphorbia pulcherrima Cultivars and Comparison of Testing Methods%一品红27个品种花粉量、花粉活力及3种测定方法的比较

    Institute of Scientific and Technical Information of China (English)

    李畅; 苏家乐; 刘晓青; 陈尚平; 何丽斯

    2012-01-01

    Variation analysis for the quantity and germination characteristics of pollens was carried out in vitro on 27 Euphorbia pulcherrima cultivars. ' Cam Red' and ' Prestige Red' , ' Premium Red' and ' Capri White' were chosen as the experimental materials for determining their different pollen viability. Comparison of three testing methods, including TTC coloration, I - KI coloration, peroxide enzyme coloration, were used. The result showed that significant variations in the pollen quantity, germination rate and length of the pollen tubes were observed among the different cultivars, which were estimated to be 817 -3867 grains per anther, 18.04% -82.07% and 0. 20 - 1. 52 mm respectively. There was significant positive correlation among the pollen quantity, germination rate and length of the pollen tubes. Further investigation on the pollination value of different E. pulcherrima cultivars was performed based on cluster analysis on the above data. The population of the cultivars with low germinated pollen quantity and shorter pollen tube length was relatively larger, accounting 40. 74% of the total tested cultivars. The statistic data from peroxide enzyme coloration differed little from the germination rate testing method, so it is believed this method may be the better one for testing E. pulcherrima pollen viability.%以一品红27个品种为试材,探讨其单药花粉量及其花粉离体萌发特性差异;并从中选择花粉相对活力低、高组4个品种(“双喜”和“威望”、“金奖”和“金多利”)的花粉,以花粉离体萌发法为对照,对Ⅰ-KⅠ染色法、TTC染色法、过氧化物酶染色法3种染色测定花粉活力法进行比较筛选.结果表明:测试品种单药花粉量变化范围为817 ~3 867粒,花粉萌发率18.04% ~ 82.07%,花粉管长度0.20~1.52 mm;品种间存在明显差异.花粉量、花粉萌发率、花粉管长度3指标间极显著正相关.对上述各因子聚类分析表明供试品种中可萌

  4. 不同贮藏温度对桔梗花粉生活力及授粉结实能力的影响%Effect of Storage Temperature on Pollen Viability and Seeds Setting of Platycodon grandiflorum

    Institute of Scientific and Technical Information of China (English)

    刘自刚

    2011-01-01

    以ME3+BK+100 g/L蔗糖+150 g/L PEG4000作为培养基,把桔梗新鲜花粉在不同的温度下进行培养,结果表明,30℃培养1.5 h为花粉萌发和花粉管生长的最佳培养条件.把桔梗花粉贮藏在不同的温度下,结果显示:低温贮藏可明显延长花粉的寿命,常温下花粉仅能贮藏4d左右,但在10、4、-20℃下贮藏,花粉寿命可分别达60、90、150d以上;随着贮藏时间的延长,花粉的授粉结实率均呈下降趋势,但低温贮藏可明显减缓结实率下降的速度.%Pollens of Platycodon grandiflorum were cultured in the culture medium of ME3+BK+10% sucrose+150 g/L PEG (pH5.8). The results showed that the pollen germination were best at 30℃ for 1.5 h. Pollens of Platycodon grandiflorum were stored under different temperatures. The result showed that life of pollen at being stored under low temperature was prolonged significantly. The life span on pollen stored at 10 ℃, 4℃ and -20℃ in icebox was 60 d, 90 d and 150 d, respectively, while that for ambient temperature was about 4 d. Seeds setting of pollen after stored under different temperature was decreased with the storagetime extended, and seeds setting of pollen under ambient temperature storage was lower than those under low storage temperature.

  5. A synthetic combination of mutations, including fs(1)pyrSu(b), rSu(b) and b, causes female sterility and reduces embryonic viability in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Piskur, Jure; Gojkovic, Zoran; Bahn, E.

    1999-01-01

    A Drosophila melangaster mutant, fs(1)pyr(Su(b)), carrying a mutation that maps to the tip of the X chromosome, has been isolated. The mutation, when present alone, does not confer a detectable phenotype. However, this mutation causes female sterility and reduces embryonic viability when combined...

  6. Polyamines in Pollen: From Microsporogenesis to Fertilization.

    Science.gov (United States)

    Aloisi, Iris; Cai, Giampiero; Serafini-Fracassini, Donatella; Del Duca, Stefano

    2016-01-01

    The entire pollen life span is driven by polyamine (PA) homeostasis, achieved through fine regulation of their biosynthesis, oxidation, conjugation, compartmentalization, uptake, and release. The critical role of PAs, from microsporogenesis to pollen-pistil interaction during fertilization, is suggested by high and dynamic transcript levels of PA biosynthetic genes, as well as by the activities of the corresponding enzymes. Moreover, exogenous supply of PAs strongly affects pollen maturation and pollen tube elongation. A reduction of endogenous free PAs impacts pollen viability both in the early stages of pollen development and during fertilization. A number of studies have demonstrated that PAs largely function by modulating transcription, by structuring pollen cell wall, by modulating protein (mainly cytoskeletal) assembly as well as by modulating the level of reactive oxygen species. Both free low-molecular weight aliphatic PAs, and PAs conjugated to proteins and hydroxyl-cinnamic acids take part in these complex processes. Here, we review both historical and recent evidence regarding molecular events underlying the role of PAs during pollen development. In the concluding remarks, the outstanding issues and directions for future research that will further clarify our understanding of PA involvement during pollen life are outlined.

  7. Effects of Different Storage Factors on Pollen Viability of Watermelon Variety‘Zaojia’%不同保存因子对早佳西瓜花粉活力的影响

    Institute of Scientific and Technical Information of China (English)

    林燚; 杨瑜斌; 王驰; 杨景华; 张明方

    2013-01-01

    The paper studied watermelon〔Citrullus lanatus(Thunb.)Matsum. et Nakai〕pollen cryopreservation methods and pollination technique.The result indicated that pollens of ‘Zaojia’ water-melon can be stored at -18 ℃ or -25 ℃under vacuum condition for 186 to 223 days with over 50% ac-tivity. Pollen activity can be varied under different storage conditions,of which -25 ℃ can have longer storage time than -18 ℃,and the pollen vitality is higher.The stored pollens should be activated at 25 ℃ for 30 min before usage,so as to achieve higher fruit setting rate.The application of stored pollen will not influence the quality of watermelon.%研究了西瓜花粉低温保存及授粉技术,结果表明:早佳西瓜花粉在-18℃或-25℃的温度下,真空保存186~223 d仍有50%以上的活力。花粉活力因花粉保存条件不同有较大差异,-25℃比-18℃保存的时间长、活力高。保存花粉使用前应在25℃条件下放置30 min激活活力,以取得较高的坐果率。使用保存花粉授粉不影响西瓜品质。

  8. Pollen Grain and Hybridization Studies in the Genus Capsicum

    Directory of Open Access Journals (Sweden)

    Tomi Lois OLATUNJI

    2016-03-01

    Full Text Available The current study aimed to evaluate the pollen viability of the commonly cultivated varieties of Capsicum species and assessed the potentials for gene exchange among the genotypes through hybridization studies. Capsicum annuum var. abbreviatum, C. annuum var. acuminatum, C. annuum var. grossum and C. frutescens var. baccatum were the species and varieties used in this study. The present findings indicated that the percentage of pollen viability varied in the studied Capsicum genotypes. The highest pollen viability was obtained in C. annuum var. abbreviatum (96.3%, followed by C. annuum var. grossum (95%, and C. annuum var. acuminatum (91.1%. The lowest pollen viability was recorded in C. frutescens var. baccatum (86.2%. The pollen viability was high in most varieties indicating that meiosis is normal, resulting in viable pollen grains. Several intraspecific and interspecific crosses were performed among the Capsicum genotypes and three putative hybrid fruits were produced. Percentage successes obtained in the crosses were low and comparable in both intra and inter-specific crosses. In the entire crosses pattern, pollination success of 10% was recorded for C. frutescens var. baccatum and C. annuum var. acuminatum. Knowing the nature and viability of pollen grains may help in predicting the success rate of hybridization and the successful crosses between C. frutescens var. baccatum and C. annuum var. acuminatum suggest that these two varieties are the closest genetically.

  9. An investigation of the effects of stage of ensilage on Nassella neesiana seeds, for reducing seed viability and injury to livestock

    Science.gov (United States)

    Weller, S. L.; Florentine, S. K.; Sillitoe, J. F.; Grech, C. J.; McLaren, D. A.

    2016-03-01

    The noxious weed Nassella neesiana is established on a wide range of productive land throughout southeastern Australia. N. neesiana seeds, when mature, are sharp, causing injury to livestock, thus posing a problem in fodder bales. To reduce infestations of agricultural weeds in situ, production of silage from weed-infested pastures is practised as part of integrated weed management (IWM). However, there is little data to demonstrate whether this process is useful to reduce infestations or the harmful properties of N. neesiana. Therefore, the minimum duration of ensilage required to reduce the viability of N. neesiana seeds was investigated, both with and without addition of ensilage inoculants in this process. Also, the decreasing propensity of the seeds to injure livestock, after various times and conditions of ensilage, was assessed. Ensilage inoculant reduced seed germination probability to zero after 35 days. When no inoculant was added, zero viability was achieved after 42 days. A qualitative assessment of the hardness of ensilaged seeds found seed husks were softer (and therefore safer) after 42 days, whether inoculant was used or not. Therefore, we suggest that both the viability of N. neesiana seeds and hardness of seed casings are significantly reduced after 42 days, thereby reducing the risks of seed dispersal and injury to livestock.

  10. Pollen competition between two sympatric Orchis species (Orchidaceae): the overtaking of conspecific of heterospecific pollen as a reproductive barrier.

    Science.gov (United States)

    Luca, A; Palermo, A M; Bellusci, F; Pellegrino, G

    2015-01-01

    The frequency of hybrid formation in angiosperms depends on how and when heterospecific pollen is transferred to the stigma, and on the success of that heterospecific pollen at fertilising ovules. We applied pollen mixtures to stigmas to determine how pollen interactions affect siring success and the frequency of hybrid formation between two species of Mediterranean deceptive orchid. Plants of Orchis italica and O. anthropophora were pollinated with conspecific and heterospecific pollen (first conspecific pollen then heterospecific pollen and vice versa) and molecular analysis was used to check the paternity of the seeds produced. In this pair of Mediterranean orchids, competition between conspecific and heterospecific pollen functions as a post-pollination pre-zygotic barrier limiting the frequency of the formation of hybrids in nature. Flowers pollinated with heterospecific pollen can remain receptive for the arrival of conspecific pollen for a long time. There is always an advantage of conspecific pollen for fruit formation, whether it comes before or after heterospecific pollen, because it overtakes the heterospecific pollen. The conspecific pollen advantage exhibited in O. italica and O. anthropophora is likely to result from the reduced germination of heterospecific pollen or retarded growth of heterospecific pollen tubes in the stigma and ovary. Overall, the results indicate that our hybrid zone represents a phenomenon of little evolutionary consequence, and the conspecific pollen advantage maintains the genetic integrity of the parental species.

  11. Viabilidade do grão de pólen de acessos de capim-elefante, milheto e híbridos interespecíficos (capim-elefante x milheto = Pollen viability in elephantgrass, pearl millet and interspecific hybrids (elephantgrass x pearl millet acessions

    Directory of Open Access Journals (Sweden)

    Antônio Vander Pereira

    2006-01-01

    Full Text Available O objetivo deste trabalho foi estimar a viabilidade do pólen em acessos de capim-elefante, milheto e híbridos interespecíficos por meio de germinação in vitro e coloração com carmim propiônico, orceína acética e corante de Alexander. Os testes de germinação foram realizados com grãos de pólen frescos e armazenados por 30 dias. Osacessos de capim-elefante e de milheto apresentaram alta viabilidade de pólen. Apenas um deles, quando avaliado com o corante de Alexander, mostrou baixa fertilidade. Para os híbridos, observou-se alta taxa de pólens funcionais com os corantes nucleares. Entretanto,o corante de Alexander confirmou a completa esterilidade desses acessos. Os acessos de capim-elefante e milheto apresentaram baixa porcentagem de pólens viáveis quando induzidos à germinação em meio de cultura. Nos híbridos foi constatada completa esterilidade do grão de pólen, condizente com as anormalidades meióticas relatadas naliteratura. Quanto ao armazenamento, os grãos de pólen de todos os acessos perderam completamente o poder germinativo.The aim of this work was to estimate the pollen viability in elephantgrass, pearl millet and interspecific hybrids accessionsthrough in vitro germination and staining with propionic carmine, acetic orcein and Alexander’s stain. The germination tests were accomplished with fresh pollen grains and stored for 30 days. The elephantgrass and peare millet accessions presented a high pollenviability. Just one of the accessions, when evaluated with Alexander's stain, showed low fertility. For the hybrid, a high rate of functional pollen was observed with the nuclear stain. However, Alexander's stain confirmed the complete sterility of those accessions. Elephantgrass and pearl millet accessions presented a low percentage of viable pollen grain, when induced to germination in culture medium. Complete sterility of the pollen grain was verified in the hybrid, agreeing with the meiotic abnormalities

  12. 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.

  13. Viability Theory

    CERN Document Server

    Aubin, Jean-Pierre; Saint-Pierre, Patrick

    2011-01-01

    Viability theory designs and develops mathematical and algorithmic methods for investigating the adaptation to viability constraints of evolutions governed by complex systems under uncertainty that are found in many domains involving living beings, from biological evolution to economics, from environmental sciences to financial markets, from control theory and robotics to cognitive sciences. It involves interdisciplinary investigations spanning fields that have traditionally developed in isolation. The purpose of this book is to present an initiation to applications of viability theory, explai

  14. Impedance Flow Cytometry: A Novel Technique in Pollen Analysis

    OpenAIRE

    Heidmann, Iris; Schade-Kampmann, Grit; Lambalk, Joep; Ottiger, Marcel; Di Berardino, Marco

    2016-01-01

    Introduction An efficient and reliable method to estimate plant cell viability, especially of pollen, is important for plant breeding research and plant production processes. Pollen quality is determined by classical methods, like staining techniques or in vitro pollen germination, each having disadvantages with respect to reliability, analysis speed, and species dependency. Analysing single cells based on their dielectric properties by impedance flow cytometry (IFC) has developed into a comm...

  15. 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.

  16. Forced Trefoil Factor Family Peptide 3 (TFF3) Expression Reduces Growth, Viability, and Tumorigenicity of Human Retinoblastoma Cell Lines.

    Science.gov (United States)

    Große-Kreul, Jan; Busch, Maike; Winter, Claudia; Pikos, Stefanie; Stephan, Harald; Dünker, Nicole

    2016-01-01

    Trefoil factor family (TFF) peptides have been shown to effect cell proliferation, apoptosis, migration and invasion of normal cells and various cancer cell lines. In the literature TFF peptides are controversially discussed as tumor suppressors and potential tumor progression factors. In the study presented, we investigated the effect of TFF3 overexpression on growth, viability, migration and tumorigenicity of the human retinoblastoma cell lines Y-79, WERI-Rb1, RBL-13 and RBL-15. As revealed by WST-1 and TUNEL assays as well as DAPI and BrdU cell counts, recombinant human TFF3 significantly lowers retinoblastoma cell viability and increases apoptosis levels. Transient TFF3 overexpression likewise significantly increases RB cell apoptosis. Stable, lentiviral TFF3 overexpression lowers retinoblastoma cell viability, proliferation and growth and significantly increases cell death in retinoblastoma cells. Blockage experiments using a broad-spectrum caspase inhibitor and capase-3 immunocytochemistry revealed the involvement of caspases in general and of caspase-3 in particular in TFF3 induced apoptosis in retinoblastoma cell lines. Soft agarose and in ovo chicken chorioallantoic membrane (CAM) assays revealed that TFF3 overexpression influences anchorage independent growth and significantly decreases the size of tumors forming from retinoblastoma cells. Our study demonstrates that forced TFF3 expression exerts a significant pro-apoptotic, anti-proliferative, and tumor suppressive effect in retinoblastoma cells, setting a starting point for new additive chemotherapeutic approaches in the treatment of retinoblastoma.

  17. Forced Trefoil Factor Family Peptide 3 (TFF3) Expression Reduces Growth, Viability, and Tumorigenicity of Human Retinoblastoma Cell Lines

    Science.gov (United States)

    Winter, Claudia; Pikos, Stefanie; Stephan, Harald; Dünker, Nicole

    2016-01-01

    Trefoil factor family (TFF) peptides have been shown to effect cell proliferation, apoptosis, migration and invasion of normal cells and various cancer cell lines. In the literature TFF peptides are controversially discussed as tumor suppressors and potential tumor progression factors. In the study presented, we investigated the effect of TFF3 overexpression on growth, viability, migration and tumorigenicity of the human retinoblastoma cell lines Y-79, WERI-Rb1, RBL-13 and RBL-15. As revealed by WST-1 and TUNEL assays as well as DAPI and BrdU cell counts, recombinant human TFF3 significantly lowers retinoblastoma cell viability and increases apoptosis levels. Transient TFF3 overexpression likewise significantly increases RB cell apoptosis. Stable, lentiviral TFF3 overexpression lowers retinoblastoma cell viability, proliferation and growth and significantly increases cell death in retinoblastoma cells. Blockage experiments using a broad-spectrum caspase inhibitor and capase-3 immunocytochemistry revealed the involvement of caspases in general and of caspase-3 in particular in TFF3 induced apoptosis in retinoblastoma cell lines. Soft agarose and in ovo chicken chorioallantoic membrane (CAM) assays revealed that TFF3 overexpression influences anchorage independent growth and significantly decreases the size of tumors forming from retinoblastoma cells. Our study demonstrates that forced TFF3 expression exerts a significant pro-apoptotic, anti-proliferative, and tumor suppressive effect in retinoblastoma cells, setting a starting point for new additive chemotherapeutic approaches in the treatment of retinoblastoma. PMID:27626280

  18. City scale pollen concentration variability

    Science.gov (United States)

    van der Molen, Michiel; van Vliet, Arnold; Krol, Maarten

    2016-04-01

    Pollen are emitted in the atmosphere both in the country-side and in cities. Yet the majority of the population is exposed to pollen in cities. Allergic reactions may be induced by short-term exposure to pollen. This raises the question how variable pollen concentration in cities are in temporally and spatially, and how much of the pollen in cities are actually produced in the urban region itself. We built a high resolution (1 × 1 km) pollen dispersion model based on WRF-Chem to study a city's pollen budget and the spatial and temporal variability in concentration. It shows that the concentrations are highly variable, as a result of source distribution, wind direction and boundary layer mixing, as well as the release rate as a function of temperature, turbulence intensity and humidity. Hay Fever Forecasts based on such high resolution emission and physical dispersion modelling surpass traditional hay fever warning methods based on temperature sum methods. The model gives new insights in concentration variability, personal and community level exposure and prevention. The model will be developped into a new forecast tool to serve allergic people to minimize their exposure and reduce nuisance, coast of medication and sick leave. This is an innovative approach in hay fever warning systems.

  19. Polyamines in Pollen: From Microsporogenesis to Fertilization

    Science.gov (United States)

    Aloisi, Iris; Cai, Giampiero; Serafini-Fracassini, Donatella; Del Duca, Stefano

    2016-01-01

    The entire pollen life span is driven by polyamine (PA) homeostasis, achieved through fine regulation of their biosynthesis, oxidation, conjugation, compartmentalization, uptake, and release. The critical role of PAs, from microsporogenesis to pollen–pistil interaction during fertilization, is suggested by high and dynamic transcript levels of PA biosynthetic genes, as well as by the activities of the corresponding enzymes. Moreover, exogenous supply of PAs strongly affects pollen maturation and pollen tube elongation. A reduction of endogenous free PAs impacts pollen viability both in the early stages of pollen development and during fertilization. A number of studies have demonstrated that PAs largely function by modulating transcription, by structuring pollen cell wall, by modulating protein (mainly cytoskeletal) assembly as well as by modulating the level of reactive oxygen species. Both free low-molecular weight aliphatic PAs, and PAs conjugated to proteins and hydroxyl-cinnamic acids take part in these complex processes. Here, we review both historical and recent evidence regarding molecular events underlying the role of PAs during pollen development. In the concluding remarks, the outstanding issues and directions for future research that will further clarify our understanding of PA involvement during pollen life are outlined. PMID:26925074

  20. Fusion proteins of flagellin and the major birch pollen allergen Bet v 1 show enhanced immunogenicity, reduced allergenicity, and intrinsic adjuvanticity.

    Science.gov (United States)

    Kitzmüller, Claudia; Kalser, Julia; Mutschlechner, Sonja; Hauser, Michael; Zlabinger, Gerhard J; Ferreira, Fatima; Bohle, Barbara

    2017-04-26

    Recombinant fusion proteins of flagellin and antigens have been demonstrated to induce strong innate and adaptive immune responses. Such fusion proteins can enhance the efficacy of allergen-specific immunotherapy. We sought to characterize different fusion proteins of flagellin and the major birch pollen allergen Bet v 1 for suitability as allergy vaccines. A truncated version of flagellin (NtCFlg) was genetically fused to the N- or C-terminus of Bet v 1. Toll-like receptor (TLR) 5 binding was assessed with HEK293 cells expressing TLR5. Upregulation of CD40, CD80, CD83, and CD86 on monocyte-derived dendritic cells from allergic patients was analyzed by using flow cytometry. The T cell-stimulatory capacity of the fusion proteins was assessed with naive and Bet v 1-specific T cells. IgE binding was tested in inhibition ELISAs and basophil activation tests. Mice were immunized with the fusion proteins in the absence and presence of aluminum hydroxide. Cellular and antibody responses were monitored. Murine antibodies were tested for blocking capacity in basophil activation tests. Both fusion proteins matured monocyte-derived dendritic cells through TLR5. Compared with Bet v 1, the fusion proteins showed stronger T cell-stimulatory and reduced IgE-binding capacity and induced murine Bet v 1-specific antibodies in the absence of aluminum hydroxide. However, only antibodies induced by means of immunization with NtCFlg fused to the C-terminus of Bet v 1 inhibited binding of patients' IgE antibodies to Bet v 1. Bet v 1-flagellin fusion proteins show enhanced immunogenicity, reduced allergenicity, and intrinsic adjuvanticity and thus represent promising vaccines for birch pollen allergen-specific immunotherapy. However, the sequential order of allergen and adjuvant within a fusion protein determines its immunologic characteristics. Copyright © 2017 American Academy of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  1. Pollen Viability,Pistil Receptivity and Embryogenesis in the Cross between Dendranthema indicum and D.grandiflorum%野菊与菊花杂交中花粉活力和柱头可授性及胚胎发育研究

    Institute of Scientific and Technical Information of China (English)

    孙春青; 陈发棣; 房伟民; 刘兆磊; 侯喜林; 滕年军

    2009-01-01

    应用石蜡制片、活体压片、光学显微镜及扫描电子显微镜观察等方法,研究了四倍体河南云台山野菊(Dendranthema indicum)与栽培菊花'钟山金山'(D.grandiflorum 'Zhongshanjinshan')种间杂交中父本花粉活力、花粉在柱头萌发、花粉管生长及胚胎发育情况等.结果发现,父本云台山野菊的花粉活力在授粉时为12%左右.人工授粉后的不同时间,在柱头上都观察到正常萌发的花粉粒,且花粉管都能进入柱头,其中,在授粉后0.5 h时,平均每柱头有5.9粒花粉萌发;12 h时,为59.9粒;而24和48 h时,则分别降为47.1和35.7粒.此外,在授粉后8、10、12和15 d时,分别在49.1%、40.8%、39.7%和38.5%子房内观察到正常发育的胚胎,最终杂交结实率为44.8%,而母本自然开放结实率为52.3%.研究表明,授粉前其多数母本雌蕊发育良好、授粉后多数花粉能在柱头正常萌发和花粉管正常生长,在受精后大部分胚胎发育正常是野菊与栽培菊种间杂交较高结实率的重要保证,而授粉前父本较低的花粉活力对杂交结实率影响不大.%Pollen viability of male parent,pollen germination and pollen tube growth on the stigmas,and embryogenesis were investigated in the cross between Dendranthema indicum and D.grandiflorum using technique of paraffin section,temporary mount method,light microscopy,and scanning electron microscopy as well.It was found that pollen viability was approximately 12% just before pollination,and many pollen grains germinated and pollen tubes penetrated stigmas normally during different time after pollination.There was an average of 5.9 germinated pollen grains on each stigma at 0.5 h after pollination and the number reached the highest value,59.9 at 12 h after pollination.Then the number was decreased to 47.1 and 35.7 at 24 and 48 h after pollination,respectively.In addition,normal embryos were observed in 49.1%,40.8%,39.7% and 38.5% ovaries at 8,10,12 and 15 d after

  2. Caffeic Acid Reduces the Viability and Migration Rate of Oral Carcinoma Cells (SCC-25 Exposed to Low Concentrations of Ethanol

    Directory of Open Access Journals (Sweden)

    Arkadiusz Dziedzic

    2014-10-01

    Full Text Available Alcohol increases the risk of carcinoma originated from oral epithelium, but the biological effects of ultra-low doses of ethanol on existing carcinoma cells in combination with natural substances are still unclear. A role for ethanol (EtOH, taken in small amounts as an ingredient of some beverages or mouthwashes to change the growth behavior of established squamous cell carcinoma, has still not been examined sufficiently. We designed an in vitro study to determine the effect of caffeic acid (CFA on viability and migration ability of malignant oral epithelial keratinocytes, exposed to ultra-low concentrations (maximum 100 mmol/L EtOH. MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-dimethyltetrazolium bromide and LDH (lactate dehydrogenase assays were used to assess the cytotoxic effect of EtOH/CFA and the viability of squamous carcinoma SCC-25 cells (ATCC CRL-1628, mobile part of the tongue. Tested EtOH concentrations were: 2.5, 5, 10, 25, 50, and 100 mmol/L, along with an equal CFA concentration of 50 μmol/L. Carcinoma cells’ migration was investigated by monolayer “wound” healing assay. We demonstrated that very low concentrations of EtOH ranging between 2.5 and 10 mmol/L may induce the viability of oral squamous cell carcinoma cells, while the results following addition of CFA reveal an antagonistic effect, attenuating pro-proliferative EtOH activity. The migration rate of oral squamous carcinoma cells can be significantly inhibited by the biological activity of caffeic acid.

  3. Seed set, pollen morphology and pollen surface composition response to heat stress in field pea.

    Science.gov (United States)

    Jiang, Yunfei; Lahlali, Rachid; Karunakaran, Chithra; Kumar, Saroj; Davis, Arthur R; Bueckert, Rosalind A

    2015-11-01

    Pea (Pisum sativum L.) is a major legume crop grown in a semi-arid climate in Western Canada, where heat stress affects pollination, seed set and yield. Seed set and pod growth characteristics, along with in vitro percentage pollen germination, pollen tube growth and pollen surface composition, were measured in two pea cultivars (CDC Golden and CDC Sage) subjected to five maximum temperature regimes ranging from 24 to 36 °C. Heat stress reduced percentage pollen germination, pollen tube length, pod length, seed number per pod, and the seed-ovule ratio. Percentage pollen germination of CDC Sage was greater than CDC Golden at 36 °C. No visible morphological differences in pollen grains or the pollen surface were observed between the heat and control-treated pea. However, pollen wall (intine) thickness increased due to heat stress. Mid-infrared attenuated total reflectance (MIR-ATR) spectra revealed that the chemical composition (lipid, proteins and carbohydrates) of each cultivar's pollen grains responded differently to heat stress. The lipid region of the pollen coat and exine of CDC Sage was more stable compared with CDC Golden at 36 °C. Secondary derivatives of ATR spectra indicated the presence of two lipid types, with different amounts present in pollen grains from each cultivar.

  4. Total reflection X-ray fluorescence analysis of pollen as an indicator for atmospheric pollution*1

    Science.gov (United States)

    Pepponi, G.; Lazzeri, P.; Coghe, N.; Bersani, M.; Gottardini, E.; Cristofolini, F.; Clauser, G.; Torboli, A.

    2004-08-01

    The viability of pollen is affected by environmental pollution and its use as a bio-indicator is proposed. Such effects can be observed and quantified by biological tests. However, a more accurate identification of the agents affecting the viability is required in order to validate the biological assay for environmental monitoring. The chemical analysis of pollen is meant to ascertain the existence of a correlation between its reduced biological functions and the presence of pollutants. Moreover, such biological systems act as accumulators and allow the detection and quantification of species present in the environment at low concentrations. Total reflection X-ray fluorescence analysis (TXRF) has been chosen for the investigation due to its high sensitivity, multielement capability and wide dynamic range. Corylus avellana L. (hazel) pollen has been collected in areas with different anthropic impact in the province of Trento, Italy. For the TXRF measurements, a liquid sample is needed, especially if a quantitative analysis is required. In the present work, the analysis after a microwave digestion has been compared with the analysis of a suspension of the pollen samples. In both cases, an internal standard has been used for the quantification. The concentrations of 17 elements ranging from Al to Pb have been determined in 13 samples. Analysis of the suspensions showed to be comparable to that of digested samples in terms of spectral quality, but the latter preparation method gave better reproducibility. Sub-ppm lowest limits of detection were obtained for iron and heavier elements detected.

  5. Genetic engineering of the major timothy grass pollen allergen, Phl p 6, to reduce allergenic activity and preserve immunogenicity.

    Science.gov (United States)

    Vrtala, Susanne; Focke, Margarete; Kopec, Jolanta; Verdino, Petra; Hartl, Arnulf; Sperr, Wolfgang R; Fedorov, Alexander A; Ball, Tanja; Almo, Steve; Valent, Peter; Thalhamer, Josef; Keller, Walter; Valenta, Rudolf

    2007-08-01

    On the basis of IgE epitope mapping data, we have produced three allergen fragments comprising aa 1-33, 1-57, and 31-110 of the major timothy grass pollen allergen Phl p 6 aa 1-110 by expression in Escherichia coli and chemical synthesis. Circular dichroism analysis showed that the purified fragments lack the typical alpha-helical fold of the complete allergen. Superposition of the sequences of the fragments onto the three-dimensional allergen structure indicated that the removal of only one of the four helices had led to the destabilization of the alpha helical structure of Phl p 6. The lack of structural fold was accompanied by a strong reduction of IgE reactivity and allergenic activity of the three fragments as determined by basophil histamine release in allergic patients. Each of the three Phl p 6 fragments adsorbed to CFA induced Phl p 6-specific IgG Abs in rabbits. However, immunization of mice with fragments adsorbed to an adjuvant allowed for human use (AluGel-S) showed that only the Phl p 6 aa 31-110 induced Phl p 6-specific IgG Abs. Anti-Phl p 6 IgG Abs induced by vaccination with Phl p 6 aa 31-110 inhibited patients' IgE reactivity to the wild-type allergen as well as Phl p 6-induced basophil degranulation. Our results are of importance for the design of hypoallergenic allergy vaccines. They show that it has to be demonstrated that the hypoallergenic derivative induces a robust IgG response in a formulation that can be used in allergic patients.

  6. Experiments of pollinationg and pollen viability and stigma receptivity of ‘Weixuan1'%‘围选1号’授粉试验及花粉生活力和柱头可授性的测定

    Institute of Scientific and Technical Information of China (English)

    高金锋; 张超; 李玲; 王萍; 李彦慧

    2012-01-01

    In this paper, pollination experiments and the effects of pollination tree on fruiting rate and seed-setting rate of Prunus armeniaca were studied by choosing grafting 'Weixuanl' as female parent and 4 different apricot tree as male parent. After the choosing suitable method. Pollen viability of 'Weixuanl' was evaluated by pollen germination test in vitro. It is feasibility to test stigma receptivity by the benzidine-H2O2 also. The conclusion is drawn as follows: The self pollination results showed that the self-pollination rate for 'Weixuanl' was 0. 84%(<6%) and * Weixuanl' were suggested to be a self-incompatible cultivar, The result indicated that most it need pollinating variety. Prunus armeniaca L. Cv. Katy is the best one a-mong them, The fructification ratio of cross pollination is 25. 88%; The viable pollen ratios of four test species were more than 70% and they could pollinate each other under natural condition, The pollen viability was 84.31% for 'Weixuanl', but pollen germination rate is low; The sucrose concentration has some effect on pollen germiration, which has a highest germina-tion rate at 10%; The stigma receptivity began enhancing in the time 3 h after anthesis. The stigma receptivity of 'Weixuanl' was around 4 days. Optimal pollination period lasted around 2 days.%以嫁接的2年生‘围选1号’为授粉母树,分别以‘围选1号’、‘优一’、‘凯特’、‘金太阳’4个不同的杏品种作为父本,进行授粉试验,研究不同授粉树对‘围选1号’结实率和坐果率的影响.同时,用花粉离体培养法测定其花粉生活力,并用苯胺一过氧化氢法测定了其柱头可授性.结果表明:‘围选1号’自花授粉坐果率为0.84%(<6%),是自交不亲和品种;‘围选1号'以‘凯特'作为的授粉树效果最好,坐果率为25.88%;供试品种的花粉生活力都在70%以上.‘围选1号’的花粉生活力高达84.31%,但花粉的萌发力相对较低;不同蔗糖浓度

  7. Badania biologii pyłku wytwarzanego przez kwiaty wiśni zakwitajace w różnych fazach kwitnienia [Studies of the biology of pollen formed by sour cherry flowers flowering in different stages of the blooming period

    Directory of Open Access Journals (Sweden)

    Stanisław Wociór

    2015-06-01

    Full Text Available During four years (1971-1974, five sour cherry cultivars were examined for the pollen viability, germination and pollen tube growth. Pollen which was taken from the earliest and the last blooming stages had the smaller viability, germination and the shorter pollen tube then the pollen from the flowers at full bloom. Substancial differences of the pollen characters between cultivars and the years of investigations were found.

  8. Drugs with anti-oxidant properties can interfere with cell viability measurements by assays that rely on the reducing property of viable cells.

    Science.gov (United States)

    Shenoy, Niraj; Stenson, Mary; Lawson, Joshua; Abeykoon, Jithma; Patnaik, Mrinal; Wu, Xiaosheng; Witzig, Thomas

    2017-02-27

    Cell viability assays such as Cell Titer Blue and Alamar Blue rely on the reducing property of viable cells to reduce the reagent dye to a product which gives a fluorescent signal. The current manufacture-recommended protocols do not take into account the possibility of the reagent substrate being reduced directly to the fluorescent product by drugs with an anti-oxidant property. After suspecting spurious results while determining the cytotoxic potential of a drug of interest (DOI) with known anti-oxidant property against a renal cell cancer (RCC) cell line, we aimed to establish that drugs with anti-oxidant property can indeed cause false-negative results with the current protocols of these assays by direct reduction of the reagent substrate. We also aimed to counter the same with a simple modification added to the protocol. Through our experiments, we conclusively demonstrate that drugs with anti-oxidant properties can indeed interfere with cell viability measurements by assays that rely on the reducing property of viable cells. A simple modification in the protocol, as elaborated in the manuscript, can prevent spurious results with these otherwise convenient assays.Laboratory Investigation advance online publication, 27 February 2017; doi:10.1038/labinvest.2017.18.

  9. CONTRIBUTIONS TO THE MORPHOLOGY OF POLLEN FROM SOME VARIETIES OF MALUS DOMESTICA, PYRUS COMMUNIS, PRUNUS DOMESTICA, PRUNUS PERSICA AND PRUNUS ARMENIACA

    Directory of Open Access Journals (Sweden)

    Nicoleta IANOVICI

    2010-01-01

    Full Text Available The objective of this study was to compare Rosaceae genotypes from for their pollen viability and morphology. The pollen of some varieties of Malus domestica, Pyrus communis, Prunus domestica, Prunus persica and Prunus armeniaca was identified. Pollen from mature anthers was collected. Pollen grains of all genera of Rosaceae surveyed occur as radially symmetric isopolar monads. The main aspect studied were the shape of pollen in the polar view (polar perimeter and polar area of pollen. Shape of pollen is triangular-obtuse-convex in polar view. The pollen class is trizonocolpate-obtus-triangular while the sculpturing of exine surface is striate. The number of colpi is three while the spines are absent. Apart from fully developed pollen grains, also much smaller, not completely developed pollen were found in the samples of the examined species. The viability of the pollen was determined on 1% 2,3,5-triphenyl tetrazolium chloride (TTC. Viable, semi-viable and dead pollen numbers and their percentages were determined. This stain test may be used to determine pollen viability in these species to provide only a rough estimate of viability. The results presented here are important for improving our understanding of Rosaceae reproduction biology. Knowledge of reproduction biology, particularly pollen viability and quality, is critical for the newly-developed cultivars.

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

    Directory of Open Access Journals (Sweden)

    Renata Śnieżko

    2014-02-01

    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.

  11. A first test of elemental allelopathy via heterospecific pollen receipt.

    Science.gov (United States)

    Wipf, Heidi M-L; Meindl, George A; Ashman, Tia-Lynn

    2016-03-01

    Coflowering plants often share pollinators and may receive mixed species pollen loads. Although detrimental effects of heterospecific pollen receipt have been documented, trait-based modifiers of interactions on the stigma remain largely unknown. Chemicals that mediate interactions between sporophytes could also influence pollen-pollen or pollen-style interactions. We test for the first time whether nickel (Ni) accumulation in pollen can lead to "elemental allelopathy" and intensify the fitness consequences of heterospecific pollen receipt. We grew Ni-hyperaccumulator Streptanthus polygaloides in soils augmented with three concentrations of Ni, measured pollen Ni concentration, and hand-pollinated non-Ni hyperaccumulator Mimulus guttatus. We assayed pollen germination, tube growth and seeds of M. guttatus after pure and mixed species pollinations. Streptanthus polygaloides pollen accumulated Ni in proportion to soil availability and at levels significantly greater than M. guttatus pollen. Although receipt of S. polygaloides pollen increased M. guttatus pollen germination, it decreased the proportion of pollen tubes reaching the ovary and seed number. Increased Ni in pollen, however, did not significantly intensify the effect of S. polygaloides pollen receipt on M. guttatus seed production. Different levels of Ni in the pollen of S. polygaloides achieved in the greenhouse did not significantly reduce the fitness of M. guttatus. Stigma tolerance to Ni may also have contributed to the lack of response to increased Ni in heterospecific pollen. This study paves the way for additional tests in other metal hyperaccumulators and recipients, and to identify mechanisms of interactions on the stigma. © 2016 Botanical Society of America.

  12. Impedance Flow Cytometry as a Tool to Analyze Microspore and Pollen Quality.

    Science.gov (United States)

    Heidmann, Iris; Di Berardino, Marco

    2017-01-01

    Analyzing pollen quality in an efficient and reliable manner is of great importance to the industries involved in seed and fruit production, plant breeding, and plant research. Pollen quality parameters, viability and germination capacity, are analyzed by various staining methods or by in vitro germination assays, respectively. These methods are time-consuming, species-dependent, and require a lab environment. Furthermore, the obtained viability data are often poorly related to in vivo pollen germination and seed set. Here, we describe a quick, label-free method to analyze pollen using microfluidic chips inserted into an impedance flow cytometer (IFC). Using this approach, pollen quality parameters are determined by a single measurement in a species-independent manner. The advantage of this protocol is that pollen viability and germination can be analyzed quickly by a reliable and standardized method.

  13. Effects of fructooligosaccharide and whey protein concentrate on the viability of starter culture in reduced-fat probiotic yogurt during storage.

    Science.gov (United States)

    Akalin, A S; Gönç, S; Unal, G; Fenderya, S

    2007-09-01

    Viability of yogurt starter cultures and Bifidobacterium animalis was assessed during 28 d storage in reduced-fat yogurts containing 1.5% milk fat supplemented with 1.5% fructooligosaccharide or whey protein concentrate. These properties were examined in comparison with control yogurts containing 1.5% and 3% milk fat and no supplement. Although fructooligosaccharide improved the viability of Streptococcus thermophilus, Lactobacillus delbrueckii subs. bulgaricus, and Bifidobacterium animalis, the highest growth was obtained when milk was supplemented with whey protein concentrate in reduced-fat yogurt (P yogurt increased the viable counts of S. thermophilus, L. delbrueckii subs. bulgaricus, and B. animalis by 1 log cycle in the 1st week of storage when compared to control sample. Similar improvement in the growth of both yogurt bacteria and B. animalis was also obtained in the full-fat yogurt containing 3% milk fat and no supplement. Addition of whey protein concentrate also resulted in the highest content of lactic and acetic acids (P < 0.05). A gradual increase was obtained in organic acid contents during the storage.

  14. The nuclear factor (erythroid-derived 2)-like 2 (NRF2) antioxidant response promotes melanocyte viability and reduces toxicity of the vitiligo-inducing phenol monobenzone.

    Science.gov (United States)

    Arowojolu, Omotayo A; Orlow, Seth J; Elbuluk, Nada; Manga, Prashiela

    2017-07-01

    Vitiligo, characterised by progressive melanocyte death, can be initiated by exposure to vitiligo-inducing phenols (VIPs). VIPs generate oxidative stress in melanocytes and activate the master antioxidant regulator NRF2. While NRF2-regulated antioxidants are reported to protect melanocytes from oxidative stress, the role of NRF2 in the melanocyte response to monobenzone, a clinically relevant VIP, has not been characterised. We hypothesised that activation of NRF2 may protect melanocytes from monobenzone-induced toxicity. We observed that knockdown of NRF2 or NRF2-regulated antioxidants NQO1 and PRDX6 reduced melanocyte viability, but not viability of keratinocytes and fibroblasts, suggesting that melanocytes were preferentially dependent upon NRF2 activity for growth compared to other cutaneous cells. Furthermore, melanocytes activated the NRF2 response following monobenzone exposure and constitutive NRF2 activation reduced monobenzone toxicity, supporting NRF2's role in the melanocyte stress response. In contrast, melanocytes from individuals with vitiligo (vitiligo melanocytes) did not activate the NRF2 response as efficiently. Dimethyl fumarate-mediated NRF2 activation protected normal and vitiligo melanocytes against monobenzone-induced toxicity. Given the contribution of oxidant-antioxidant imbalance in vitiligo, modulation of this pathway may be of therapeutic interest. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  15. Pollen grain traits of oil species from the Novi Sad collection

    Directory of Open Access Journals (Sweden)

    Atlagić Jovanka

    2009-01-01

    Full Text Available The collection of oil species in Novi Sad contains 12 species represented with 1-4 cultivars or landraces. In the continuous work on this collection in the sense of breeding of some of those species and their usage as a source of 'desirable genes' we analyzed pollen grain morphology (shape and size, as well as pollen viability. To determine mentioned pollen traits we used Axiovert 40C microscope together with a software package (AxioVision LE; Rel.4.3. for measurement of pollen length and width. Pollen viability was determined using a staining method (ALEXANDER, 1969. The results showed that species differ by pollen grain shape (round, egg-shaped, triangular and rod as well as by shape of exine (thick and spiky, thick to thin. In some species there was a specific number of apertures present (1-11. The size of viable pollen grains ranged from 29,10/12,58μ (coriander to 176,63/169,94μ (oil gourd, while non-viable pollen grains were always smaller (27,27/10,97μ to 119,62/100,86μ at the same plant species. Pollen viability of most species was around 80%. Lowest pollen viability was found in white flax (56,98%, and the highest in oil pumpkin (91,43%.

  16. 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.

  17. 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.

  18. Ultrastructure and germination of Vitis vinifera cv. Loureiro pollen.

    Science.gov (United States)

    Abreu, I; Costa, I; Oliveira, M; Cunha, M; de Castro, R

    2006-08-01

    The cultivar Loureiro of Vitis vinifera is one of the most economically important, recommended in almost the totality of the Região Demarcada dos Vinhos Verdes. In vineyards, the grape productivity of this cultivar is normal while in others it is extremely low. The aim of this work was to study the morphology and germination of Vitis vinifera cv. Loureiro pollen with high and low productivity. The pollen grain was examined under light, transmission and scanning electron microscopy. Typically V. vinifera pollen present three furrows but in the cultivar Loureiro we found tricolporated and acolporated (without furrows or pores) pollen grains. Both pollen types present generative and vegetative cells with the usual aspect and a dense cytoplasm rich in organelles. In the acolporated pollen a continuous exine layer and an irregular intine layer were observed. Differences were found in the starch accumulation, since only in tricolporated pollen abundant plastids filled with numerous starch granules were observed. To determine the causes of the low productivity of this cultivar we tested pollen viability by the fluorochromatic reaction and pollen germinability by in vitro assays. We observed that the acolporated pollen grain is viable, but no germination was recorded.

  19. The catastrophic decline of the Sumatran rhino (Dicerorhinus sumatrensis harrissoni in Sabah: Historic exploitation, reduced female reproductive performance and population viability

    Directory of Open Access Journals (Sweden)

    P. Kretzschmar

    2016-04-01

    Full Text Available The reasons for catastrophic declines of Sumatran rhinos are far from clear and data necessary to improve decisions for conservation management are often lacking. We reviewed literature and assembled a comprehensive data set on surveys of the Sumatran rhino subspecies (Dicerorhinus sumatrensis harrissoni in the Malaysian state of Sabah on Borneo to chart the historical development of the population in Sabah and its exploitation until the present day. We fitted resource selection functions to identify habitat features preferred by a remnant population of rhinos living in the Tabin Wildlife Reserve in Sabah, and ran a series of population viability analyses (PVAs to extract the key demographic parameters most likely to affect population dynamics. We show that as preferred habitat, the individuals in the reserve were most likely encountered in elevated areas away from roads, in close distance to mud-volcanoes, with a low presence of human trespassers and a wallow on site, and within a neighbourhood of dense forest and grassland patches preferably on Fluvisols and Acrisols. Our population viability analyses identified the percentage of breeding females and female lifetime reproductive period as the crucial parameters driving population dynamics, in combination with total protection even moderate improvements could elevate population viability substantially. The analysis also indicates that unrestrained hunting between 1930 and 1950 drastically reduced the historical rhino population in Sabah and that the remnant population could be rescued by combining the effort of total protection and stimulation of breeding activity. Based on our results, we recommend to translocate isolated reproductively healthy individuals to protected locations and to undertake measures to maximise conceptions, or running state-of-the-art reproductive management with assisted reproduction techniques. Our study demonstrates that a judicious combination of techniques can do

  20. Reduced Subendocardial Viability Ratio Is Associated With Unfavorable Cardiovascular Risk Profile in Women With Short Duration of Type 2 Diabetes

    DEFF Research Database (Denmark)

    Laugesen, Esben; Høyem, Pernille; Fleischer, Jesper;

    2016-01-01

    .2-5.0) years) and 86 sex- and age-matched control subjects in a cross-sectional study. SEVR was noninvasively assessed by tonometry and markers of cardiovascular risk by carotid-femoral pulse wave velocity (PWV), homeostasis model assessment of insulin resistance (HOMA2-IR), C-reactive protein, urinary albumin......: SEVR is reduced in women with short duration of T2DM and associated with cardiovascular risk markers. The latter association seems to be at least partly mediated via heart rate. We hypothesize that reduced SEVR may contribute to the unfavorable cardiovascular prognosis in women with diabetes....

  1. Allergenic pollen and pollen allergy in Europe.

    Science.gov (United States)

    D'Amato, G; Cecchi, L; Bonini, S; Nunes, C; Annesi-Maesano, I; Behrendt, H; Liccardi, G; Popov, T; van Cauwenberge, P

    2007-09-01

    The allergenic content of the atmosphere varies according to climate, geography and vegetation. Data on the presence and prevalence of allergenic airborne pollens, obtained from both aerobiological studies and allergological investigations, make it possible to design pollen calendars with the approximate flowering period of the plants in the sampling area. In this way, even though pollen production and dispersal from year to year depend on the patterns of preseason weather and on the conditions prevailing at the time of anthesis, it is usually possible to forecast the chances of encountering high atmospheric allergenic pollen concentrations in different areas. Aerobiological and allergological studies show that the pollen map of Europe is changing also as a result of cultural factors (for example, importation of plants such as birch and cypress for urban parklands), greater international travel (e.g. colonization by ragweed in France, northern Italy, Austria, Hungary etc.) and climate change. In this regard, the higher frequency of weather extremes, like thunderstorms, and increasing episodes of long range transport of allergenic pollen represent new challenges for researchers. Furthermore, in the last few years, experimental data on pollen and subpollen-particles structure, the pathogenetic role of pollen and the interaction between pollen and air pollutants, gave new insights into the mechanisms of respiratory allergic diseases.

  2. Carbohydrate metabolism before and after dehiscence in the recalcitrant pollen of pumpkin (Cucurbita pepo L.).

    Science.gov (United States)

    Carrizo García, C; Guarnieri, M; Pacini, E

    2015-05-01

    Pumpkin (Cucurbita pepo L.) pollen is starchy, sucrose-poor and recalcitrant, features opposite to those of several model species; therefore, some differences in carbohydrate metabolism could be expected in this species. By studying pumpkin recalcitrant pollen, the objective was to provide new biochemical evidence to improve understanding of how carbohydrate metabolism might be involved in pollen functioning in advanced stages. Four stages were analysed: immature pollen from 1 day before anthesis, mature pollen, mature pollen exposed to the environment for 7 h, and pollen rehydrated in a culture medium. Pollen viability, water and carbohydrate content and activity of enzymes involved in carbohydrate metabolism were quantified in each stage. Pollen viability and water content dropped quickly after dehiscence, as expected. The slight changes in carbohydrate concentration and enzyme activity during pollen maturation contrast with major changes recorded with ageing and rehydration. Pumpkin pollen seems highly active and closely related to its surrounding environment in all the stages analysed; the latter is particularly evident among insoluble sucrolytic enzymes, mainly wall-bound acid invertase, which would be the most relevant for sucrose cleavage. Each stage was characterised by a particular metabolic/enzymatic profile; some particular features, such as the minor changes during maturation, fast sucrolysis upon rehydration or sharp decrease in insoluble sucrolytic activity with ageing seem to be related to the lack of dormancy and recalcitrant nature of pumpkin pollen.

  3. Glutathione synthesis is essential for pollen germination in vitro

    Science.gov (United States)

    2011-01-01

    Background The antioxidant glutathione fulfills many important roles during plant development, growth and defense in the sporophyte, however the role of this important molecule in the gametophyte generation is largely unclear. Bioinformatic data indicate that critical control enzymes are negligibly transcribed in pollen and sperm cells. Therefore, we decided to investigate the role of glutathione synthesis for pollen germination in vitro in Arabidopsis thaliana accession Col-0 and in the glutathione deficient mutant pad2-1 and link it with glutathione status on the subcellular level. Results The depletion of glutathione by buthionine sulfoximine (BSO), an inhibitor of glutathione synthesis, reduced pollen germination rates to 2-5% compared to 71% germination in wildtype controls. The application of reduced glutathione (GSH), together with BSO, restored pollen germination and glutathione contents to control values, demonstrating that inhibition of glutathione synthesis is responsible for the decrease of pollen germination in vitro. The addition of indole-3-acetic acid (IAA) to media containing BSO restored pollen germination to control values, which demonstrated that glutathione depletion in pollen grains triggered disturbances in auxin metabolism which led to inhibition of pollen germination. Conclusions This study demonstrates that glutathione synthesis is essential for pollen germination in vitro and that glutathione depletion and auxin metabolism are linked in pollen germination and early elongation of the pollen tube, as IAA addition rescues glutathione deficient pollen. PMID:21439079

  4. Plant genetics. Pollen clusters.

    Science.gov (United States)

    Smyth, D R

    1994-09-01

    New Arabidopsis mutations that result in all four products of meiosis being held together as a tetrad of fused pollen grains may facilitate genetic mapping and lead to new insights into pollen biology.

  5. Reducing Viability Bias in Analysis of Gut Microbiota in Preterm Infants at Risk of NEC and Sepsis

    Directory of Open Access Journals (Sweden)

    Gregory R. Young

    2017-06-01

    Full Text Available Necrotising enterocolitis (NEC and sepsis are serious diseases of preterm infants that can result in feeding intolerance, the need for bowel resection, impaired physiological and neurological development, and high mortality rates. Neonatal healthcare improvements have allowed greater survival rates in preterm infants leading to increased numbers at risk of developing NEC and sepsis. Gut bacteria play a role in protection from or propensity to these conditions and have therefore, been studied extensively using targeted 16S rRNA gene sequencing methods. However, exact epidemiology of these conditions remain unknown and the role of the gut microbiota in NEC remains enigmatic. Many studies have confounding variables such as differing clinical intervention strategies or major methodological issues such as the inability of 16S rRNA gene sequencing methods to determine viable from non-viable taxa. Identification of viable community members is important to identify links between the microbiota and disease in the highly unstable preterm infant gut. This is especially important as remnant DNA is robust and persists in the sampling environment following cell death. Chelation of such DNA prevents downstream amplification and inclusion in microbiota characterisation. This study validates use of propidium monoazide (PMA, a DNA chelating agent that is excluded by an undamaged bacterial membrane, to reduce bias associated with 16S rRNA gene analysis of clinical stool samples. We aim to improve identification of the viable microbiota in order to increase the accuracy of clinical inferences made regarding the impact of the preterm gut microbiota on health and disease. Gut microbiota analysis was completed on stools from matched twins (n = 16 that received probiotics. Samples were treated with PMA, prior to bacterial DNA extraction. Meta-analysis highlighted a significant reduction in bacterial diversity in 68.8% of PMA treated samples as well as significantly

  6. Citrus flavonoid naringenin reduces mammary tumor cell viability, adipose mass, and adipose inflammation in obese ovariectomized mice.

    Science.gov (United States)

    Ke, Jia-Yu; Banh, Taylor; Hsiao, Yung-Hsuan; Cole, Rachel M; Straka, Shana R; Yee, Lisa D; Belury, Martha A

    2017-09-01

    Obesity-related metabolic dysregulation may be a link between obesity and postmenopausal breast cancer. Naringenin, a flavonoid abundant in grapefruits, displays beneficial effects on metabolic health and tumorigenesis. Here, we assessed the effects of naringenin on mammary tumor cell growth in vitro and in obese ovariectomized mice. Naringenin inhibited cell growth, increased phosphorylation of AMP-activated protein kinase (AMPK), down-regulated CyclinD1 expression, and induced cell death in E0771 mammary tumor cells. Obese ovariectomized mice were fed a high-fat (HF), high-fat diet with low naringenin (LN; 1% naringenin) or high-fat diet with high naringenin (HN; 3% naringenin) for 2 weeks and then implanted with E0771 cells in mammary adipose tissue. Three weeks after tumor cell implantation, naringenin accumulation in tumor was higher than that in mammary adipose tissue in HN mice. HN decreased body weight, adipose mass, adipocyte size, α-smooth muscle actin mRNA in mammary adipose tissue, and mRNA of inflammatory cytokines in both mammary and perigonadal adipose tissues. Compared with mice fed HF diet, HN delayed growth of tumors early but did not alter final tumor weight. Naringenin reduces adiposity and ameliorates adipose tissue inflammation, with a moderate inhibitory effect on tumor growth in obese ovariectomized mice. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Fisetin Reduces Cell Viability Through Up-Regulation of Phosphorylation of ERK1/2 in Cholangiocarcinoma Cells.

    Science.gov (United States)

    Kim, Nayoung; Lee, Sang Hyub; Son, Jun Hyuk; Lee, Jae Min; Kang, Min-Jung; Kim, Bo Hye; Lee, Jung-Su; Ryu, Ji Kon; Kim, Yong-Tae

    2016-11-01

    Cholangiocarcinoma (CCA) is a malignancy with poor prognosis and limited therapeutic options. Effective prevention and treatment of CCA require developing novel anticancer agents and improved therapeutic regimens. As natural products are concidered a rich source of potential anticancer agents, we investigated the anticancer effect of fisetin in combination with gemcitabine. Cytotoxic effect of fisetin and gemcitabine on a human CCA cell line SNU-308 was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and apoptosis assay using propidium iodine and annexin V. Molecular mechanisms of fisetin action in CCA were investigated by western blotting. Fisetin was found to inhibit survival of CCA cells, through strongly phosphorylating ERK. It also induced cellular apoptosis additively in combination with gemcitabine. Expression of cellular proliferative markers, such as phospho-p65 and myelocytomatosis (MYC), were reduced by fisetin. These results suggest fisetin in combination with gemcitabine as a candidate for use in improved anticancer regimens. Copyright© 2016 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

  8. Capping biological quantum dots with the peptide CLPFFD to increase stability and to reduce effects on cell viability

    Science.gov (United States)

    Riveros, A. L.; Astudillo, J.; Vásquez, C. C.; Jara, Danilo H.; Guerrero, Ariel R.; Guzman, F.; Osorio-Roman, I. O.; Kogan, M. J.

    2016-08-01

    Highly fluorescent nanoparticles, or quantum dots, have multiple applications in biology and biomedicine; however, in most cases, it is necessary to functionalize them to enhance their biocompatibility and selectivity. Generally, functionalization is performed after nanoparticle synthesis and involves the use of molecules or macromolecules having two important traits: specific biological activity and functional groups that facilitate nanoparticle capping (i.e. atom-atom interaction). For this reason, we carried out a simple protocol for the chemical synthesis of cadmium telluride quantum dots capped with glutathione, and we then functionalized these nanoparticles with the amphipathic peptide CLPFFD. This peptide attaches selectively to β-Amyloid fibres, which are involved in Alzheimer's disease. Our results show that the optical properties of the quantum dots are not affected by functionalization with this peptide. Infrared spectra showed that cadmium telluride quantum dots were functionalized with the peptide CLPFFD. In addition, no significant differences were observed between the surface charge of the quantum dots with or without CLPFFD and the nanocrystal size calculated for HR-TEM was 4.2 nm. Finally, our results show that quantum dots with CLPFFD are stable and that they resulted in a significantly reduced cytotoxicity with respect to that induced by quantum dots not conjugated with the peptide. Moreover, the results show that the CLPFFD-functionalized nanoparticles bind to β-Amyloid fibres.

  9. Ecological implications of reduced pollen supply in the alpine: a case study using a dominant cushion plant species [v2; ref status: indexed, http://f1000r.es/3xc

    Directory of Open Access Journals (Sweden)

    Anya Reid

    2014-08-01

    Full Text Available The reproductive assurance hypothesis states that self-incompatible female plants must produce twice the number of seeds relative to their self-compatible hermaphroditic counterparts to persist in gynodioecious populations. This is a viable life-history strategy, provided that pollination rates are sufficiently high. However, reduced pollination rates in alpine plants are likely due to climate induced plant-pollinator mismatches and general declines in pollinators. Using a gynodioecious population of the dominant plant Silene acaulis (Caryophyllaceae, we tested the reproductive assurance hypothesis and also the stress gradient hypothesis with a series of pollinator exclusion trials and extensive measurements of subsequent reproductive output (gender ratio, plant size, percent fruit-set, fruit weight, seeds per fruit, total seeds, seed weight, and seed germination. The reproductive assurance hypothesis was supported with female plants being more sensitive to and less likely to be viable under reductions in pollination rates. These findings are the first to show that the stress gradient hypothesis is also supported under a gradient of pollen supply instead of environmental limitations. Beneficiary abundance was negatively correlated to percent fruit-set under current pollen supply, but became positive under reduced pollen supply suggesting that there are important plant-plant-pollinator interactions related to reproduction in these alpine plant species.

  10. Ecological implications of reduced pollen deposition in alpine plants: a case study using a dominant cushion plant species [v1; ref status: indexed, http://f1000r.es/3mb

    Directory of Open Access Journals (Sweden)

    Anya Reid

    2014-06-01

    Full Text Available The reproductive assurance hypothesis states that self-incompatible female plants must produce twice the number of seeds relative to their self-compatible hermaphroditic counterparts to persist in gynodioecious populations. This is a viable life-history strategy, provided that pollination rates are sufficiently high. However, reduced pollination rates in alpine plants are likely due to climate induced plant-pollinator mismatches and general declines in pollinators. Using a gynodioecious population of the dominant plant Silene acaulis (Caryophyllaceae, we tested the reproductive assurance hypothesis and also the stress gradient hypothesis with a series of pollinator exclusion trials and extensive measurements of subsequent reproductive output (gender ratio, plant size, percent fruit-set, fruit weight, seeds per fruit, total seeds, seed weight, and seed germination. The reproductive assurance hypothesis was supported with female plants being more sensitive to and less likely to be viable under reductions in pollination rates. These findings are the first to show that the stress gradient hypothesis is also supported under a gradient of pollen supply instead of environmental limitations. Beneficiary abundance was negatively correlated to percent fruit-set under current pollen supply, but became positive under reduced pollen supply suggesting that there are important plant-plant-pollinator interactions related to reproduction in these alpine plant species.

  11. Chemical and plant tests to assess the viability of amendments to reduce metal availability in mine soils and tailings.

    Science.gov (United States)

    Rodríguez, Luis; Gómez, Rocío; Sánchez, Virtudes; Alonso-Azcárate, Jacinto

    2016-04-01

    The goal of this research was to assess the potential of several industrial wastes to immobilise metals in two polluted soils deriving from an old Pb/Zn mine. Two different approaches were used to assess the performance of different amendments: a chemical one, using extraction by ethylenediaminetetraacetic acid (EDTA), and a biological one, using Lupinus albus as a bio-indicator. Four amendments were used: inorganic sugar production waste (named 'sugar foam', SF), sludge from a drinking water treatment sludge (DWS), organic waste from olive mill waste (OMW) and paper mill sludge (PMS). Amendment to soil ratios ranged from 0.1 to 0.3 (w/w). All the amendments were capable of significantly decreasing (p soils used, with decreases in ranges 21-100, 25-100 and 2-100 % for Pb, Zn and Cu, respectively. The amendments tested were also effective in reducing the bioavailability of Pb and Zn for L. albus, which gave rise to a decrease in shoot metal accumulation by the lupine plants compared to that found in the control soil. That decrease reached up to 5.6 and 2.8 times for Pb and Zn, respectively, being statistically significant in most cases. Moreover, application of the OMW, DWS and SF amendments led to higher average values of plant biomass (up to 71%) than those obtained in the control soil. The results obtained showed the technology put forward to be a viable means of remediating mine soils as it led to a decrease in the availability and toxicity of metals and, thus, facilitated the growth of a vegetation layer.

  12. 番茄花粉保存与生活力测定%Preservation Methods and Determination of Tomato Pollen Vitality

    Institute of Scientific and Technical Information of China (English)

    李自娟; 黄文; 应芳卿; 赵建设; 万秀娟; 胡京昂

    2014-01-01

    With the pollens of tomato cultivar Shicheng 116 as material, we observed the quantity and viability of mature pollen grains by using the Alexander staining method, and we stored the tomato pollens at room temperature (25℃), 4℃and-17℃, aiming to find out the best storage temperature and the longest storage time. In addition, we preserved a group of flower buds in Carnoy's fluid. The results showed that, as the storage time prolonged, the pollen viability and germination number were decreased. Stored at room temperature, the pollen viability was the strongest on the first day, and the pollen activity was reduced to 68.60% after three days. Stored at 4℃ in refrigerator, the pollen viability was reduced to 57.00%after the preservation of eight days, and the total amount of pollen was decreased after eighty days' preservation, but the ratio of viable pollens was 58.14%. Stored at -17℃ refrigerator, the pollen vitality was the highest of 83.10% on the first preservation day, and the pollen vitality was reduced to 48.79% after the preservation of twenty eight days, while the the pollen vitality was increased to 59.38% after eighty days' preservation. The pollen vitality was 70.55% after being preserved in the Carnoy's fluid for eighty days.%以番茄品种世诚116的花粉为材料,采用亚历山大染色法测定成熟花粉粒的数量和活力。将番茄花粉分别贮藏在室温(25℃),4℃和-17℃条件下,测定其活力最强的贮藏温度和贮藏时间。试验结果表明,随着贮藏时间的延长,花粉活力和总萌发数呈下降趋势,室温保存当天的花粉活力最强,贮藏3 d花粉活力降为68.60%;4℃冰箱保存8 d后,花粉活力降为57.00%,保存80 d,花粉总量减少,但其有活力的花粉占花粉总量的58.14%;-17℃冰箱保存1 d的花粉活力最高,为83.10%,保存28 d时,其花粉活力降为48.79%,保存80 d时,其活力在59.38%。而在卡诺依氏固定液中保存80 d的

  13. Usefulness and limitations of pollen characters in environmental studies based on Viola L. species (sect. Melanium Ging.

    Directory of Open Access Journals (Sweden)

    A. Słomka

    2014-04-01

    Full Text Available The aim of these studies was to determine the effect of environmental pollution on pollen development. Pollen heteromorphism (the presence of pollen morphs differing in aperture number in one flower of a plant, pollen viability (stainability and pollen grain size in European metallophytes from sect. Melanium Ging. (Viola L., Violaceae were analyzed by SEM and histochemical staining. Plants’ tolerance to heavy metals is positively correlated with their pollen viability, which should be termed stainability as it depends on the staining method applied and is not correlated with pollen germination. Abortive pollen can be produced as an effect of heavy metals but also may result from hybridization, a very common phenomenon in pansies. Pollen stainability in hybrids can be high (even exceeding 70% or low (barely above 20%, and stainable pollen grains can differ greatly in size (from very small to giant, indicating a cytological imbalance resulting from disturbed meiosis. The number of pollen apertures is an adaptive character in facultative metallophytes. Plants from a metallicolous population produced a wider range of aperture number (3, 4, 5 than plants from a non-metallicolous population, which developed only 4- and 5-aperturate pollen. Three-aperturate longer-lived pollen are favored in the harsh conditions of a metal-polluted environment.

  14. The morphology of pollen presenter and polymorphism of pollen grains Taraxacum officinale F. H. Wigg.

    Directory of Open Access Journals (Sweden)

    Elżbieta Weryszko-Chmielewska

    2012-12-01

    Full Text Available The study of the structure of the pollen presenter of Taraxacum officinale and morphology of pollen grains was conducted based on plant material sampled from three different sites. One of them was a forest meadow situated away from the city, and the other two were located in the city centre of Lublin. Light and electron scanning microscopy were used in the study. The pollen presenter in Taraxacum officinale occurs at the upper part of the style situated over the androecium and on the outer part of the stigma. Numerous unicellular trichomes are found on the entire surface of the epidermis of the presenter. The function of the presenter consists in transferring pollen grains above the androecium and corolla petals. Its activity does not stop after pollen release from anthers. Taraxacum pollen grains represent the Crepis - type. Most frequently, they are tricolporate, radially symmetric and isopolar. In terms of the size, they are included in medium-sized grains. In the material examined, many deformed and asymmetric grains were observed, though they were marked by high viability at the level of 96.5-99%. Grains with the largest average lengths of the equatorial and polar axes were found in plants sampled from the meadow situated out of town. In the plant material from all sites, grains with disturbances of the external structure occurred.

  15. Coculture of Staphylococcus aureus with Pseudomonas aeruginosa Drives S. aureus towards Fermentative Metabolism and Reduced Viability in a Cystic Fibrosis Model.

    Science.gov (United States)

    Filkins, Laura M; Graber, Jyoti A; Olson, Daniel G; Dolben, Emily L; Lynd, Lee R; Bhuju, Sabin; O'Toole, George A

    2015-07-01

    The airways of patients with cystic fibrosis are colonized with diverse bacterial communities that change dynamically during pediatric years and early adulthood. Staphylococcus aureus is the most prevalent pathogen during early childhood, but during late teens and early adulthood, a shift in microbial composition occurs leading to Pseudomonas aeruginosa community predominance in ∼50% of adults. We developed a robust dual-bacterial in vitro coculture system of P. aeruginosa and S. aureus on monolayers of human bronchial epithelial cells homozygous for the ΔF508 cystic fibrosis transmembrane conductance regulator (CFTR) mutation to better model the mechanisms of this interaction. We show that P. aeruginosa drives the S. aureus expression profile from that of aerobic respiration to fermentation. This shift is dependent on the production of both 2-heptyl-4-hydroxyquinoline N-oxide (HQNO) and siderophores by P. aeruginosa. Furthermore, S. aureus-produced lactate is a carbon source that P. aeruginosa preferentially consumes over medium-supplied glucose. We find that initially S. aureus and P. aeruginosa coexist; however, over extended coculture P. aeruginosa reduces S. aureus viability, also in an HQNO- and P. aeruginosa siderophore-dependent manner. Interestingly, S. aureus small-colony-variant (SCV) genetic mutant strains, which have defects in their electron transport chain, experience reduced killing by P. aeruginosa compared to their wild-type parent strains; thus, SCVs may provide a mechanism for persistence of S. aureus in the presence of P. aeruginosa. We propose that the mechanism of P. aeruginosa-mediated killing of S. aureus is multifactorial, requiring HQNO and P. aeruginosa siderophores as well as additional genetic, environmental, and nutritional factors. In individuals with cystic fibrosis, Staphylococcus aureus is the primary respiratory pathogen during childhood. During adulthood, Pseudomonas aeruginosa predominates and correlates with worse patient

  16. 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.

  17. Cotton flowers: Pollen and petal humidity sensitivities determine reproductive competitiveness in diverse environments

    Science.gov (United States)

    This study investigated the abiotic stress tolerance of mature cotton [Gossypium hirsutum (L.)] pollen and identified genetic variability among the six cotton lines studied. Genetic diversity in pollen viability was observed following a 6.5 h exposure to 25% relative humidity (RH). NM67, DP565, and...

  18. Effect of Implantation Machine Parameters on N+ ion Implantation for Upland Cotton (Gossypium hirsutum L.) Pollen

    Institute of Scientific and Technical Information of China (English)

    YUE Jieyu; YU Lixiang; WU Yuejin; TANG Canming

    2008-01-01

    Effect of parameters of ion implantation machine,including ion energy,total dose,dose rate,impulse energy and implantation interval on the pollen grains of upland cotton implanted with nitrogen ion beam were studied.The best parameters were screened out.The results also showed that the vacuum condition before the nitrogen ion implantation does not affect the pollen viability.

  19. Apomixis does not affect visitation to flowers of Melastomataceae, but pollen sterility does.

    Science.gov (United States)

    Maia, F R; Varassin, I G; Goldenberg, R

    2016-01-01

    Apomixis is an asexual seed reproduction mechanism thorough which embryos are originated from material tissues inside the ovules, without precedent fertilisation. It allows plants to colonise new habitats, even in places where flower visitors are scarce or where plants are isolate. Apomixis seems to be related to pollen sterility and, in species with flowers that offer pollen as a reward for pollinators, the amount or quality of the pollen offered by these species may influence the amount of the visits and specific composition of the visitors. In order to test this hypothesis, we studied breeding systems of 16 species of Melastomataceae and their flower visitors, evaluating composition and abundance of the visits to apomictic and sexual species. Apomictic plants with no viable pollen or with pollen with low viability did not receive visits from pollinators, and consequently probably produce strictly apomictic fruits. On the other hand, apomictic and sexual plants with high pollen viability do receive visits; in this case, apomictic plants may produce fruits and seeds through both sexual and apomictic methods. The species composition of insects visiting Melastomataceae with high pollen viability was similar, regardless of whether the plants were apomictic or not. It seems that pollen viability levels are important to determine visits to the flowers irrespective of breeding system.

  20. Flavonoids, alkali earth and rare earth elements affect germination of pecan pollen

    Science.gov (United States)

    The factors regulating pecan [Carya illinoinensis (Wangenh.) K. Koch] pollen grain germination on receptive stigmatic flower surfaces in vivo or in vitro in pollen viability assays are poorly understood. While there are many potential regulating factors, there is evidence for involvement of flavonol...

  1. Evaluation of Holocene pollen records from the Romanian Plain.

    Science.gov (United States)

    Tomescu

    2000-05-01

    This study is a critical review of pollen analyses carried out on Holocene sequences from 15 sites in and near the Romanian Plain. Three sites come from natural sediments, 10 sites are from anthropogenic deposits and two are from both anthropogenic and natural settings. The general reconstruction is of a steppe-forest-steppe vegetation through the Holocene. The nature of the deposits, however, casts doubts on this reconstruction. Deposits of archaeological sites generally yield pollen spectra that are influenced by human activities and thus unsuitable for vegetation reconstructions. Loess deposits are also unfavorable for pollen preservation because of high pH and porosity. Consequently, pollen spectra from loess deposits are strongly biased by selective pollen destruction. Research and experiments carried out by several authors suggest that spectra dominated by Asteraceae, Poaceae, Chenopodiaceae or Pinus pollen in soils and loess are a result of selective pollen destruction, especially if low pollen concentrations, progressive pollen deterioration or high frequencies of deteriorated or unidentifiable pollen are evidenced. The fact that pollen records from the Romanian Plain come from loess, alkaline peat or archaeological sites reduces their reliability for reconstructions of vegetation. The vegetation history of similar regions in Hungary, Bulgaria and Turkey suggests that early Holocene steppe vegetation was gradually replaced by forest or forest-steppe vegetation in the late Holocene. Records from lake sediments are required to find out whether the Holocene vegetation history of the Romanian Plain was similar.

  2. Overexpression of fatty acid synthase in human gliomas correlates with the WHO tumor grade and inhibition with Orlistat reduces cell viability and triggers apoptosis.

    Science.gov (United States)

    Grube, Susanne; Dünisch, Pedro; Freitag, Diana; Klausnitzer, Maren; Sakr, Yasser; Walter, Jan; Kalff, Rolf; Ewald, Christian

    2014-06-01

    Fatty acid synthase (FASN), catalyzing the de novo synthesis of fatty acids, is known to be deregulated in several cancers. Inhibition of this enzyme reduces tumor cell proliferation. Unfortunately, adverse effects and chemical instability prevent the in vivo use of the best-known inhibitors, Cerulenin and C75. Orlistat, a drug used for obesity treatment, is also considered as a potential FASN inhibitor, but its impact on glioma cell biology has not yet been described. In this study, we analyzed FASN expression in human glioma samples and primary glioblastoma cell cultures and the effects of FASN inhibition with Orlistat, Cerulenin and C75. Immunohistochemistry followed by densitometric analysis of 20 glioma samples revealed overexpression of FASN that correlated with the WHO tumor grade. Treatment of glioblastoma cells with these inhibitors resulted in a significant, dose-dependent reduction in tumor cell viability and fatty acid synthesis. Compared to Cerulenin and C75, Orlistat was a more potent inhibitor in cell cultures and cell lines. In LN229, cell-growth was reduced by 63.9 ± 8.7 % after 48 h and 200 µM Orlistat compared to controls; in LT68, the reduction in cell growth was 76.3 ± 23.7 %. Nuclear fragmentation assay and Western blotting analysis after targeting FASN with Orlistat demonstrated autophagy and apoptosis. Organotypic slice cultures treated with Orlistat showed reduced proliferation after Ki67 staining and increased caspase-3 cleavage. Our results suggest that FASN may be a therapeutic target in malignant gliomas and identify Orlistat as a possible anti-tumor drug in this setting.

  3. Pollen structure and function in caesalpinioid legumes.

    Science.gov (United States)

    Banks, Hannah; Rudall, Paula J

    2016-03-01

    A diverse range of pollen morphologies occurs within the large, paraphyletic legume subfamily Caesalpinioideae, especially among early-branching lineages. Previous studies have hypothesized an association between surface ornamentation and pollination syndrome or other aspects of pollen function such as desiccation tolerance and adaptations to accommodate volume changes. We reviewed caesalpinioid pollen morphology using light microscopy, scanning and transmission electron microscopy, in combination with a literature survey of pollination vectors. Pollen structural diversity is greatest in the early-branching tribes Cercideae and Detarieae, whereas Cassieae and Caesalpinieae are relatively low in pollen diversity. Functional structures to counter desiccation include opercula (lids) covering apertures and reduced aperture size. Structures preventing wall rupture during dehydration and rehydration include different forms of colpi (syncolpi, parasyncolpi, pseudocolpi), striate supratectal ornamentation, and columellate or granular wall structures that resist tensile or compressive forces respectively. Specialized aperture structures (Zwischenkörper) may be advantageous for efficient germination of the pollen tube. In Detarieae and Cercideae in particular, there is potential to utilize pollen characters to estimate pollination systems where these are unknown. Supratectal verrucae and gemmae have apparently evolved iteratively in Cercideae and Detarieae. At the species level, there is a potential correlation between striate/verrucate patterns and vertebrate pollination. © 2016 Botanical Society of America.

  4. CdO-NPs; synthesis from 1D new nano Cd coordination polymer, characterization and application as anti-cancer drug for reducing the viability of cancer cells

    Science.gov (United States)

    Afzalian Mend, Behnaz; Delavar, Mahmoud; Darroudi, Majid

    2017-04-01

    The hexagonal CdO nano-particles (CdO-NPs) was prepared using new nano Cd coordination polymer, [Cd(NO3)(bipy)(pzca)]n (1) as a precursor, through direct calcination process at 500 °C. The precursor (1) was synthesized by sonochemical method. The new nano compound (1) was characterized by IR spectroscopy, elemental analyses, X-ray powder diffraction (XRD), transmission electron microscopy (TEM) and thermal gravimetric analyses. The structure of nano coordination polymer was determined by comparing the XRD pattern of nano and single-crystal of compound (1). The nano CdO was characterized by scanning electron microscopy (SEM) and X-ray powder diffraction (XRD). In addition, the activity and efficiency of nano CdO as an anti-cancer drug was studied on cancer cells with different concentration. The results shows that the viability of cancer cells reduced above 2 μg/mL of CdO-NPs concentration.

  5. Hypoxia in high glucose followed by reoxygenation in normal glucose reduces the viability of cortical astrocytes through increased permeability of connexin 43 hemichannels

    Science.gov (United States)

    Orellana, Juan A.; Hernández, Diego E.; Ezan, Pascal; Velarde, Victoria; Bennett, Michael V. L.; Giaume, Christian; Sáez, Juan C.

    2009-01-01

    Brain ischemia causes more extensive injury in hyperglycemic than normoglycemic subjects, and the increased damage is to astroglia as well as neurons. In the present work, we found that in cortical astrocytes from rat or mouse, reoxygenation after hypoxia in a medium mimicking interstitial fluid during ischemia increases hemichannel activity and decreases cell-cell communication via gap junctions as indicated by dye uptake and dye coupling, respectively. These effects were potentiated by high glucose during the hypoxia in a concentration-dependent manner (and by zero glucose) and were not observed in connexin 43−/− astrocytes. The responses were transient or persistent after short and long periods of hypoxia, respectively. The persistent responses were associated with a progressive reduction in cell viability that was prevented by La3+ or peptides that block connexin 43 (Cx43) hemichannels or by inhibition of p38 MAP kinase prior to hypoxia-reoxygenation but not by treatments that block pannexin hemichannels. Block of Cx43 hemichannels did not affect the reduction in gap junction mediated dye coupling observed during reoxygenation. Cx43 hemichannels may be a novel therapeutic target to reduce cell death following stroke, particularly in hyperglycemic conditions. PMID:19705457

  6. LATERAL ORGAN BOUNDARIES DOMAIN (LBD)10 interacts with SIDECAR POLLEN/LBD27 to control pollen development in Arabidopsis.

    Science.gov (United States)

    Kim, Min-Jung; Kim, Mirim; Lee, Mi Rha; Park, Soon Ki; Kim, Jungmook

    2015-03-01

    During male gametophyte development in Arabidopsis thaliana, the microspores undergo an asymmetric division to produce a vegetative cell and a generative cell, which undergoes a second division to give rise to two sperm cells. SIDECAR POLLEN/LATERAL ORGAN BOUNDARIES DOMAIN (LBD) 27 plays a key role in the asymmetric division of microspores. Here we provide molecular genetic evidence that a combinatorial role of LBD10 with LBD27 is crucial for male gametophyte development in Arabidopsis. Expression analysis, genetic transmission and pollen viability assays, and pollen development analysis demonstrated that LBD10 plays a role in the male gametophyte function primarily at germ cell mitosis. In the mature pollen of lbd10 and lbd10 expressing a dominant negative version of LBD10, LBD10:SRDX, aberrant microspores such as bicellular and smaller tricellular pollen appeared at a ratio of 10-15% with a correspondingly decreased ratio of normal tricellular pollen, whereas in lbd27 mutants, 70% of the pollen was aborted. All pollen in the lbd10 lbd27 double mutants was aborted and severely shrivelled compared with that of the single mutants, indicating that LBD10 and LBD27 are essential for pollen development. Gene expression and subcellular localization analyses of LBD10:GFP and LBD27:RFP during pollen development indicated that posttranscriptional and/or posttranslational controls are involved in differential accumulation and subcellular localization of LBD10 and LBD27 during pollen development, which may contribute in part to combinatorial and distinct roles of LBD10 with LBD27 in microspore development. In addition, we showed that LBD10 and LBD27 interact to form a heterodimer for nuclear localization.

  7. 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.

  8. An improved pollen collection and cryopreservation method for highly recalcitrant tropical fruit species of mango (Mangifera indica L.) and litchi (Litchi chinensis Sonn.).

    Science.gov (United States)

    Chaudhury, Rekha; Malik, S K; Rajan, S

    2010-01-01

    An improved method for pollen collection from freshly dehiscing anthers of mango (Mangifera indica L.) and litchi (Litchi chinensis Sonn.) using the organic solvent cyclohexane has been devised. Using this method pollen quantity sufficient for large scale pollinations could be collected and stored for future use. Transport of pollen in viable conditions over long distances, from site of collection (field genebank) to cryolab was successfully devised for both these fruit species. Cryopreservation was successfully applied to achieve long-term pollen storage over periods of up to four years. Pollen viability was tested using in vitro germination, the fluorochromatic reaction (FCR) method and by fruit set following field pollination. On retesting, four year cryostored pollen of different mango and litchi varieties showed high percentage viability as good as fresh control pollens. Pollens of more than 180 cultivars of mango and 19 cultivars of litchi have been stored in the cryogenebank using the technology developed, thus facilitating breeding programmes over the long-term.

  9. Chemotaxonomy as a tool for interpreting the cryptic diversity of Poaceae pollen

    NARCIS (Netherlands)

    Julier, A.C.M.; Jardine, P.E.; Coe, A.L.; Gosling, W.D.; Lomax, B.H.; Fraser, W.T.

    2016-01-01

    The uniform morphology of different species of Poaceae (grass) pollen means that identification to below family level using light microscopy is extremely challenging. Poor taxonomic resolution reduces recoverable information from the grass pollen record, for example, species diversity and

  10. 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.

  11. 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.

  12. JNK1/2 Activation by an Extract from the Roots of Morus alba L. Reduces the Viability of Multidrug-Resistant MCF-7/Dox Cells by Inhibiting YB-1-Dependent MDR1 Expression

    Directory of Open Access Journals (Sweden)

    Youn Kyung Choi

    2013-01-01

    Full Text Available Cancer cells acquire anticancer drug resistance during chemotherapy, which aggravates cancer disease. MDR1 encoded from multidrug resistance gene 1 mainly causes multidrug resistance phenotypes of different cancer cells. In this study, we demonstrate that JNK1/2 activation by an extract from the root of Morus alba L. (White mulberry reduces doxorubicin-resistant MCF-7/Dox cell viability by inhibiting YB-1 regulation of MDR1 gene expression. When MCF-7 or MCF-7/Dox cells, where MDR1 is highly expressed were treated with an extract from roots or leaves of Morus alba L., respectively, the root extract from the mulberry (REM but not the leaf extract (LEM reduced cell viabilities of both MCF-7 and MCF-7/Dox cells, which was enhanced by cotreatment with doxorubicin. REM but not LEM further inhibited YB-1 nuclear translocation and its regulation of MDR1 gene expression. Moreover, REM promoted phosphorylation of c-Jun NH2-terminal kinase 1/2 (JNK1/2 and JNK1/2 inhibitor, SP600125 and rescued REM inhibition of both MDR1 expression and viabilities in MCF-7/Dox cells. Consistently, overexpression of JNK1, c-Jun, or c-Fos inhibited YB-1-dependent MDR1 expression and reduced viabilities in MCF-7/Dox cells. In conclusion, our data indicate that REM-activated JNK-cJun/c-Fos pathway decreases the viability of MCF-7/Dox cells by inhibiting YB-1-dependent MDR1 gene expression. Thus, we suggest that REM may be useful for treating multidrug-resistant cancer cells.

  13. Liquid Nitrogen (-196°C effect under pollen of some cultured or ornamental species

    Directory of Open Access Journals (Sweden)

    Sabina GLIGOR

    2006-05-01

    Full Text Available The criopreservation involve the stock of the vegetal material at low temperatures (-196°C in liquid nitrogen, in thermal conditions in which the division of cells and metabolic processes slow down, thus that the samplings may be conserved for long periods without suffering any genetic modifications. This stock technique is applied till present only on 80 vegetal species, keeping their seeds and vitrocultures preponderantly; researches were made regarding the maintenance of pollen in liquid nitrogen.The mature pollen, able to resist a higher degree of desiccation, may be conserved at low temperatures, without criopreservation. It was made researches on criopreservation of rise, maize, wheat, roses, sun flower and soy pollen. Our study purpose was to follow the impact of liquid nitrogen (-196°C about on viability of some cultured and ornamental species. The designed time of criopreservation it was 30 minutes and 7 days, using the TTC (tripheniltetrazole chloride method which allows testing the viability of vegetal material based on dehydrogenase activity.It was observed at Petunia hybrida species, that the pollen viability was low - in relevance with the witness represented from the pollen which was not resigned to the nitrogen liquid treatment - between percentage limits of 3.5-8%, in the case when the vegetal material was submersed 30 minutes in liquid nitrogen and 7.5-14.5% 7 days at (-196°C. The submersing of Nicotiana alata var. grandiflora species at 7 days, determined a low viability with 11.53%. The following two studied species Cucurbita and Hosta were proved to be the most resistant at submersing and maintenance in liquid nitrogen. The most affected pollen was Campsis radicans species. At Datura stramonium species was observed 2.59% a low viability of pollen, after 30 minutes of liquid nitrogen treatment, was 19.56%, after 7 days of submersing, the most pollen granules losing completely their viability.

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

    African Journals Online (AJOL)

    AJL

    2013-11-13

    Nov 13, 2013 ... 2Key Laboratory of Horticultural Plant Biology, Laboratory of Silivculture and Tree Breeding, College of Horticulture and ... by field artificial pollination were analyzed in this study. .... columnar or slightly-bent about 30° at the front end, light ... The relationship between cultivar, growth day of stigma and stigma.

  15. In vitro flowering and pollen viability of cucumber

    Science.gov (United States)

    Flowers were produced on sterile cucumber (Cucumis sativus L.) plants grown in vitro from seed or from micropropagated shoots from stem fragments. Highest numbers of flowers on plants from both sources were produced on hormone-free MS medium as well as with 6 µM of kinetin (MSK). Plants cultured on ...

  16. Phenotypic Correlations among Pollen Quality and Morphological Traits of Saintpaulia

    Directory of Open Access Journals (Sweden)

    Erzsebet BUTA

    2015-06-01

    Full Text Available In order to estimate the correlation between pollen viability, germination and the morphological traits, 15 Saintpaulia genotypes were analysed. Pollen viability was obtained by staining with potassium iodide (25% and germination was estimated using solid nutrient medium (15% sucrose, 85% humidity, 22 °C temperature. Several morphological traits such as number of flowers, diameter of leaves rosette, number of leaves, length and width of leaves and petiole length were evaluated to determine growth indices. The results obtained indicated that ‘Hot Pink Bell’ genotype achieved the highest number of flowers and the largest diameter of leaves rosette. Genotypes ‘Tomahawks’ and S. grotei recorded the highest number of leaves. Higher width of leaves values was obtained in ‘Aloha Orchid’, while genotype ‘Park Avenue Blue’ was noted for a high length of leaves. Positive correlations were recorded among viability and germination in S. jonantha, S. rupicola and S. grotei. Significant positive correlation was registered between pollen viability and the number of flowers, but also between germination and the number of flowers per plant. The results indicated a possible correlation between viability, germination capacity and the morphological traits in most genotypes studied.

  17. Effect of Implantation Machine Parameters on N+ ion Implantation for Upland Cotton(Gossypium hirsutum L.) Pollen

    Science.gov (United States)

    Yue, Jieyu; Yu, Lixiang; Wu, Yuejin; Tang, Canming

    2008-10-01

    Effect of parameters of ion implantation machine, including ion energy, total dose, dose rate, impulse energy and implantation interval on the pollen grains of upland cotton implanted with nitrogen ion beam were studied. The best parameters were screened out. The results also showed that the vacuum condition before the nitrogen ion implantation does not affect the pollen viability.

  18. A 12,000-Yr Pollen Record off Cape Hatteras: Pollen Sources and Mechanisms of Pollen Dispersion

    Science.gov (United States)

    Naughton, F.; Keigwin, L.; Peteet, D.; Costas, S.; Desprat, S.; Oliveira, D.; de Vernal, A.; Voelker, A.; Abrantes, F.

    2015-01-01

    Integrating both marine and terrestrial signals from the same sediment core is one of the primary challenges for understanding the role of ocean-atmosphere coupling throughout past climate changes. It is therefore vital to understand how the pollen signal of a given marine record reflects the vegetation changes of the neighboring continent. The comparison between the pollen record of marine core JPC32 (KNR178JPC32) and available terrestrial pollen sequences from eastern North America over the last 12,170 years indicates that the pollen signature off Cape Hatteras gives an integrated image of the regional vegetation encompassing the Pee Dee river, Chesapeake and Delaware hydrographic basins and is reliable in reconstructing the past climate of the adjacent continent. Extremely high quantities of pollen grains included in the marine sediments off Cape Hatteras were transferred from the continent to the sea, at intervals 10,100-8800 cal yr BP, 8300-7500 cal yr BP, 5800- 4300 cal yr BP and 2100-730 cal yr BP, during storm events favored by episodes of rapid sea-level rise in the eastern coast of US. In contrast, pollen grains export was reduced during 12,170-10,150 cal yr BP and 4200- 2200 cal yr BP, during episodes of intense continental dryness and slow sea level rise episodes or lowstands in the eastern coast of US. The near absence of reworked pollen grains in core JPC32 contrasts with the high quantity of reworked material in nearby but deeper located marine sites, suggesting that the JPC32 recordwas not affected by the DeepWestern Boundary Current (DWBC) since the end of the Younger Dryas and should be considered a key site for studying past climate changes in the western North Atlantic.

  19. A 12,000-Yr Pollen Record off Cape Hatteras: Pollen Sources and Mechanisms of Pollen Dispersion

    Science.gov (United States)

    Naughton, F.; Keigwin, L.; Peteet, D.; Costas, S.; Desprat, S.; Oliveira, D.; de Vernal, A.; Voelker, A.; Abrantes, F.

    2015-01-01

    Integrating both marine and terrestrial signals from the same sediment core is one of the primary challenges for understanding the role of ocean-atmosphere coupling throughout past climate changes. It is therefore vital to understand how the pollen signal of a given marine record reflects the vegetation changes of the neighboring continent. The comparison between the pollen record of marine core JPC32 (KNR178JPC32) and available terrestrial pollen sequences from eastern North America over the last 12,170 years indicates that the pollen signature off Cape Hatteras gives an integrated image of the regional vegetation encompassing the Pee Dee river, Chesapeake and Delaware hydrographic basins and is reliable in reconstructing the past climate of the adjacent continent. Extremely high quantities of pollen grains included in the marine sediments off Cape Hatteras were transferred from the continent to the sea, at intervals 10,100-8800 cal yr BP, 8300-7500 cal yr BP, 5800- 4300 cal yr BP and 2100-730 cal yr BP, during storm events favored by episodes of rapid sea-level rise in the eastern coast of US. In contrast, pollen grains export was reduced during 12,170-10,150 cal yr BP and 4200- 2200 cal yr BP, during episodes of intense continental dryness and slow sea level rise episodes or lowstands in the eastern coast of US. The near absence of reworked pollen grains in core JPC32 contrasts with the high quantity of reworked material in nearby but deeper located marine sites, suggesting that the JPC32 recordwas not affected by the DeepWestern Boundary Current (DWBC) since the end of the Younger Dryas and should be considered a key site for studying past climate changes in the western North Atlantic.

  20. Correlation between pollen morphology and pollination mechanisms in the Hydrocharitaceae.

    Science.gov (United States)

    Tanaka, Norio; Uehara, Koichi; Murata, Jin

    2004-08-01

    The pollen morphology of 11 genera and 11 species of the Hydrocharitaceae and one species of the Najadaceae was studied using scanning and transmission electron microscopies, and the exine structures and sculptures are discussed in relation to pollination mechanisms and the molecular phylogeny. The pollen grains of the Hydrocharitaceae are spherical, inaperturate, and form monads or tetrads, while those of the Najadaceae are elliptical, inaperturate, and form monads. The entomophilous genera Egeria, Blyxa, Ottelia, Stratiotes, and Hydrocharis share pollen grains that have projections like spines or bacula. The anemophilous genus Limnobium has reticulate pollen grains. The hypohydrophilous genera Thalassia and Najas are characterized by pollen grains with reduced exine structures. The pollen-epihydrophilous genera Elodea and Hydrilla have tightly arranged small spinous pollen grains, and the male flower-epihydrophilous genera Enhalus and Vallisneria have reduced reticulate or gemmate exines. Character state reconstruction of the exine structures and sculptures using a molecular phylogenetic tree suggests that variation in the exine is generally correlated with the pollination mechanism; the selective pressures acting on the pollination mechanisms have reduced the exine structure in hypohydrophilous plants and resulted in various exine sculptures that are adapted to the different pollination mechanisms in entomophilous, anemophilous, and pollen-epihydrophilous plants.

  1. Nucleofection of Rat Pheochromocytoma PC-12 Cells with Human Mutated Beta-Amyloid Precursor Protein Gene (APP-sw) Leads to Reduced Viability, Autophagy-Like Process, and Increased Expression and Secretion of Beta Amyloid

    OpenAIRE

    Beata Pająk; Elżbieta Kania; Arkadiusz Orzechowski

    2015-01-01

    Pheochromocytoma PC-12 cells are immune to physiological stimuli directed to evoke programmed cell death. Besides, metabolic inhibitors are incapable of sensitizing PC-12 cells to extrinsic or intrinsic apoptosis unless they are used in toxic concentrations. Surprisingly, these cells become receptive to cell deletion after human APP-sw gene expression. We observed reduced cell viability in GFP vector + APP-sw-nucleofected cells (drop by 36%) but not in GFP vector − or GFP vector + APP-wt-nucl...

  2. 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.

  3. Cytoskeleton in Pollen and Pollen Tubes of Ginkgo biloba L.

    Institute of Scientific and Technical Information of China (English)

    Jun-Mei LIU; Hong ZHANG; Yan LI

    2005-01-01

    The distribution of F-actin and microtubules was investigated in pollen and pollen tubes of Ginkgo biloba L. using a confocal laser scanning microscope after fluorescence and immunofluorescence labeling. A dense F-actin network was found in hydrated Ginkgo pollen. When Ginkgo pollen was germinating,F-actin mesh was found under the plasma membrane from which the pollen tube would emerge. After pollen germination, F-actin bundles were distributed axially in long pollen tubes of G. biloba. Thick F-actin bundles and network were found in the tip of the Ginkgo pollen tube, which is opposite to the results reported for the pollen tubes of some angiosperms and conifers. In addition, a few circular F-actin bundles were found in Ginkgo pollen tubes. Using immunofluorescence labeling, a dense microtubule network was found in hydrated Ginkgo pollen under confocal microscope. In the Ginkgo pollen tube, the microtubules were distributed along the longitudinal axis and extended to the tip. These results suggest that the cytoskeleton may have an essential role in the germination of Ginkgo pollen and tube growth.

  4. Subtropical grass pollen allergens are important for allergic respiratory diseases in subtropical regions

    Directory of Open Access Journals (Sweden)

    Davies Janet

    2012-03-01

    Full Text Available Abstract Background Grass pollen allergens are a major cause of allergic respiratory disease but traditionally prescribing practice for grass pollen allergen-specific immunotherapy has favoured pollen extracts of temperate grasses. Here we aim to compare allergy to subtropical and temperate grass pollens in patients with allergic rhinitis from a subtropical region of Australia. Methods Sensitization to pollen extracts of the subtropical Bahia grass (Paspalum notatum, Johnson grass (Sorghum halepense and Bermuda grass (Cynodon dactylon as well as the temperate Ryegrass (Lolium perenne were measured by skin prick in 233 subjects from Brisbane. Grass pollen-specific IgE reactivity was tested by ELISA and cross-inhibition ELISA. Results Patients with grass pollen allergy from a subtropical region showed higher skin prick diameters with subtropical Bahia grass and Bermuda grass pollens than with Johnson grass and Ryegrass pollens. IgE reactivity was higher with pollen of Bahia grass than Bermuda grass, Johnson grass and Ryegrass. Patients showed asymmetric cross-inhibition of IgE reactivity with subtropical grass pollens that was not blocked by temperate grass pollen allergens indicating the presence of species-specific IgE binding sites of subtropical grass pollen allergens that are not represented in temperate grass pollens. Conclusions Subtropical grass pollens are more important allergen sources than temperate grass pollens for patients from a subtropical region. Targeting allergen-specific immunotherapy to subtropical grass pollen allergens in patients with allergic rhinitis in subtropical regions could improve treatment efficacy thereby reducing the burden of allergic rhinitis and asthma.

  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.

  6. The Arabidopsis KINβγ Subunit of the SnRK1 Complex Regulates Pollen Hydration on the Stigma by Mediating the Level of Reactive Oxygen Species in Pollen.

    Science.gov (United States)

    Gao, Xin-Qi; Liu, Chang Zhen; Li, Dan Dan; Zhao, Ting Ting; Li, Fei; Jia, Xiao Na; Zhao, Xin-Ying; Zhang, Xian Sheng

    2016-07-01

    Pollen-stigma interactions are essential for pollen germination. The highly regulated process of pollen germination includes pollen adhesion, hydration, and germination on the stigma. However, the internal signaling of pollen that regulates pollen-stigma interactions is poorly understood. KINβγ is a plant-specific subunit of the SNF1-related protein kinase 1 complex which plays important roles in the regulation of plant development. Here, we showed that KINβγ was a cytoplasm- and nucleus-localized protein in the vegetative cells of pollen grains in Arabidopsis. The pollen of the Arabidopsis kinβγ mutant could not germinate on stigma, although it germinated normally in vitro. Further analysis revealed the hydration of kinβγ mutant pollen on the stigma was compromised. However, adding water to the stigma promoted the germination of the mutant pollen in vivo, suggesting that the compromised hydration of the mutant pollen led to its defective germination. In kinβγ mutant pollen, the structure of the mitochondria and peroxisomes was destroyed, and their numbers were significantly reduced compared with those in the wild type. Furthermore, we found that the kinβγ mutant exhibited reduced levels of reactive oxygen species (ROS) in pollen. The addition of H2O2 in vitro partially compensated for the reduced water absorption of the mutant pollen, and reducing ROS levels in pollen by overexpressing Arabidopsis CATALASE 3 resulted in compromised hydration of pollen on the stigma. These results indicate that Arabidopsis KINβγ is critical for the regulation of ROS levels by mediating the biogenesis of mitochondria and peroxisomes in pollen, which is required for pollen-stigma interactions during pollination.

  7. From pollen actin to crop male sterility

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Actin plays an important role in the life activity of animal and plant cells. Pollen cells have plenty of actin whose structure and characteristics are very similar to the animal actin. The nucleotide sequence and amino acid sequence of plant actin gene are very similar to those of the animal gene. The content of pollen actin from male sterile plants is much more lower than that from its maintainer plants. The expression of actin gene is organ-specific during the plant development. The expression quantity of actin gene in pollen is much more higher than those from root, stem and leaf. The expression plasmid of the anti-sense actin gene was constructed, transferred to the protoplasts of wheat and tomato to inhibit the expression of actin gene in pollen and thus the male sterile plants of wheat and tomato were obtained. The actin in pollens from the transgenic plants was reduced significantly, whereas the pistil was not affected. This study might pave a new way to breeding male sterile lines for the application of hybrid vigor of wheat and tomato.

  8. Mating system and early viability resistance to habitat fragmentation in a bird-pollinated eucalypt.

    Science.gov (United States)

    Breed, M F; Ottewell, K M; Gardner, M G; Marklund, M H K; Stead, M G; Harris, J B C; Lowe, A J

    2015-08-01

    Habitat fragmentation has been shown to disrupt ecosystem processes such as plant-pollinator mutualisms. Consequently, mating patterns in remnant tree populations are expected to shift towards increased inbreeding and reduced pollen diversity, with fitness consequences for future generations. However, mating patterns and phenotypic assessments of open-pollinated progeny have rarely been combined in a single study. Here, we collected seeds from 37 Eucalyptus incrassata trees from contrasting stand densities following recent clearance in a single South Australian population (intact woodland=12.6 trees ha(-1); isolated pasture=1.7 trees ha(-1); population area=10 km(2)). 649 progeny from these trees were genotyped at eight microsatellite loci. We estimated genetic diversity, spatial genetic structure, indirect contemporary pollen flow and mating patterns for adults older than the clearance events and open-pollinated progeny sired post-clearance. A proxy of early stage progeny viability was assessed in a common garden experiment. Density had no impact on mating patterns, adult and progeny genetic diversity or progeny growth, but was associated with increased mean pollen dispersal. Weak spatial genetic structure among adults suggests high historical gene flow. We observed preliminary evidence for inbreeding depression related to stress caused by fungal infection, but which was not associated with density. Higher observed heterozygosities in adults compared with progeny may relate to weak selection on progeny and lifetime-accumulated mortality of inbred adults. E. incrassata appears to be resistant to the negative mating pattern and fitness changes expected within fragmented landscapes. This pattern is likely explained by strong outcrossing and regular long-distance pollen flow.

  9. Extensive pollen flow but few pollen donors and high reproductive variance in an extremely fragmented landscape.

    Directory of Open Access Journals (Sweden)

    Rafael G Albaladejo

    Full Text Available Analysing pollen movement is a key to understanding the reproductive system of plant species and how it is influenced by the spatial distribution of potential mating partners in fragmented populations. Here we infer parameters related to levels of pollen movement and diversity of the effective pollen cloud for the wind-pollinated shrub Pistacia lentiscus across a highly disturbed landscape using microsatellite loci. Paternity analysis and the indirect KinDist and Mixed Effect Mating models were used to assess mating patterns, the pollen dispersal kernel, the effective number of males (N(ep and their relative individual fertility, as well as the existence of fine-scale spatial genetic structure in adult plants. All methods showed extensive pollen movement, with high rates of pollen flow from outside the study site (up to 73-93%, fat-tailed dispersal kernels and large average pollination distances (δ = 229-412 m. However, they also agreed in detecting very few pollen donors (N(ep = 4.3-10.2 and a large variance in their reproductive success: 70% of males did not sire any offspring among the studied female plants and 5.5% of males were responsible for 50% of pollinations. Although we did not find reduced levels of genetic diversity, the adult population showed high levels of biparental inbreeding (14% and strong spatial genetic structure (S(p = 0.012, probably due to restricted seed dispersal and scarce safe sites for recruitment. Overall, limited seed dispersal and the scarcity of successful pollen donors can be contributing to generate local pedigrees and to increase inbreeding, the prelude of genetic impoverishment.

  10. Establishing lunar resource viability

    Science.gov (United States)

    Carpenter, J.; Fisackerly, R.; Houdou, B.

    2016-11-01

    Recent research has highlighted the potential of lunar resources as an important element of space exploration but their viability has not been demonstrated. Establishing whether or not they can be considered in future plans is a multidisciplinary effort, requiring scientific expertise and delivering scientific results. To this end various space agencies and private entities are looking to lunar resources, extracted and processed in situ, as a potentially game changing element in future space architectures, with the potential to increase scale and reduce cost. However, before any decisions can be made on the inclusion of resources in exploration roadmaps or future scenarios some big questions need to be answered about the viability of different resource deposits and the processes for extraction and utilisation. The missions and measurements that will be required to answer these questions, and which are being prepared by agencies and others, can only be performed through the engagement and support of the science community. In answering questions about resources, data and knowledge will be generated that is of fundamental scientific importance. In supporting resource prospecting missions the science community will de facto generate new scientific knowledge. Science enables exploration and exploration enables science.

  11. Pollen irradiation and possible gene transfer in Nicotiana species

    DEFF Research Database (Denmark)

    Engvild, Kjeld Christensen

    1985-01-01

    Progeny from crosses of Nicotiana langsdorffii with gamma irradiated pollen of Nicotiana alata ‘Crimson Bedder’ showed skewed segregation in the F2 favoring the maternal parent. This is probably not gene transfer in a strict sense, rather just an extreme case of reduced transmission of irradiated...... chromosomes, leading to massive overrepresentation of maternal genes. Gene transfer or mutational loss may explain some anomalous F1 plants. Segregation in the F2 progeny showed the presence of several genes from the irradiated pollen. Crosses of Nicotiana sylvestris, N. plumbaginifolia N. paniculata......, 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...

  12. 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 withou

  13. 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...

  14. Pollen morphology of the Stemonaceae

    NARCIS (Netherlands)

    Ham, van der R.W.J.M.

    1991-01-01

    A pollen-morphological survey of all four genera of the Stemonaceae at the light and electron microscope level is presented. Stemonaceae is a eurypalynous family. Stichoneuron pollen, up to now described as monosulcate, appears to be inaperturate. Pentastemona pollen is most deviating in Stemonaceae

  15. Fucoidan from Sargassum sp. and Fucus vesiculosus reduces cell viability of lung carcinoma and melanoma cells in vitro and activates natural killer cells in mice in vivo

    DEFF Research Database (Denmark)

    Ale, Marcel Tutor; Maruyama, Hiroko; Tamauchi, Hidekazu

    2011-01-01

    Fucoidan is known to exhibit crucial biological activities, including anti-tumor activity. In this study, we examined the influence of crude fucoidan extracted from Sargassum sp. (MTA) and Fucus vesiculosus (SIG) on Lewis lung carcinoma cells (LCC) and melanoma B16 cells (MC). In vitro studies were...... performed using cell viability analysis and showed that SIG and MTA fucoidans significantly decreased the viable number of LCC and MC cells in a dose–response fashion. Histochemical staining showed morphological changes of melanoma B16 cells after exposure to fucoidan. The observed changes were indicative...... of crude fucoidan induced apoptosis. Male C57BL/6JJCL mice were subjected to daily i.p. injections over 4 days with either SIG or MTA fucoidan (50 mg/kg body wt.). The cytolytic activity of natural killer (NK) cells was enhanced by crude fucoidan in a dose-dependent manner as indicated by 51Cr labeled YAC...

  16. COMPARATIVE STUDY OF POLLEN AND PISTIL IN CROCUS SATIVUS L. (IRIDACEAE AND ALLIED SPECIES

    Directory of Open Access Journals (Sweden)

    M. GRILLI CAIOLA

    2000-04-01

    Full Text Available Crocus sativus L. is mainly known for the production of the drug saffron. Because of its sterility, it is propagated vegetatively by means of corms. To gain information on the reproductive biology of saffron and allied species, a comparative study on pollen and pistil of Crocus sativus L., C. cartwrightianus Herb., C. thomasii Ten. and C. hadriaticus Herb. was carried out. Pollen and pistils gathered at anthesis were examined by light (LM and scanning electron microscopy (SEM. Pollen shape and size, anomalous pollen grain percentage, pollen viability, pollen germination in vitro and on self-, and cross-pollinated stigmas were examined. Pistils at different developmental stages were examined by light microscopy. C. hadriaticus had the smallest pollen; C. sativus showed a higher percentage of anomalous and aborted grains and a lower percentage of viable grains. Pollen germination in vitro as well as on differently pollinated stigmas was lowest in C. sativus. Pistil organization was similar in all the species, but ovule number and integuments varied. Embryo sacs mature early, and female gametophyte development is regular for some days after flower anthesis. Capsules with seeds were obtained from all diploid species as well as in saffron after free- and cross-pollination. Results confirm that sterility in C. sativus is mainly confined to pollen.

  17. COMPARATIVE STUDY OF POLLEN AND PISTIL IN CROCUS SATIVUS L. (IRIDACEAE AND ALLIED SPECIES

    Directory of Open Access Journals (Sweden)

    P. LAURETTI

    2000-01-01

    Full Text Available Crocus sativus L. is mainly known for the production of the drug saffron. Because of its sterility, it is propagated vegetatively by means of corms. To gain information on the reproductive biology of saffron and allied species, a comparative study on pollen and pistil of Crocus sativus L., C. cartwrightianus Herb., C. thomasii Ten. and C. hadriaticus Herb. was carried out. Pollen and pistils gathered at anthesis were examined by light (LM and scanning electron microscopy (SEM. Pollen shape and size, anomalous pollen grain percentage, pollen viability, pollen germination in vitro and on self-, and cross-pollinated stigmas were examined. Pistils at different developmental stages were examined by light microscopy. C. hadriaticus had the smallest pollen; C. sativus showed a higher percentage of anomalous and aborted grains and a lower percentage of viable grains. Pollen germination in vitro as well as on differently pollinated stigmas was lowest in C. sativus. Pistil organization was similar in all the species, but ovule number and integuments varied. Embryo sacs mature early, and female gametophyte development is regular for some days after flower anthesis. Capsules with seeds were obtained from all diploid species as well as in saffron after free- and cross-pollination. Results confirm that sterility in C. sativus is mainly confined to pollen.

  18. 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.

  19. Expression of Foreign Genes Demonstrates the Effectiveness of Pollen-Mediated Transformation in Zea mays

    Science.gov (United States)

    Yang, Liyan; Cui, Guimei; Wang, Yixue; Hao, Yaoshan; Du, Jianzhong; Zhang, Hongmei; Wang, Changbiao; Zhang, Huanhuan; Wu, Shu-Biao; Sun, Yi

    2017-01-01

    Plant genetic transformation has arguably been the core of plant improvement in recent decades. Efforts have been made to develop in planta transformation systems due to the limitations present in the tissue-culture-based methods. Herein, we report an improved in planta transformation system, and provide the evidence of reporter gene expression in pollen tube, embryos and stable transgenicity of the plants following pollen-mediated plant transformation with optimized sonication treatment of pollen. The results showed that the aeration at 4°C treatment of pollen grains in sucrose prior to sonication significantly improved the pollen viability leading to improved kernel set and transformation efficiency. Scanning electron microscopy observation revealed that the removal of operculum covering pollen pore by ultrasonication might be one of the reasons for the pollen grains to become competent for transformation. Evidences have shown that the eGfp gene was expressed in the pollen tube and embryos, and the Cry1Ac gene was detected in the subsequent T1 and T2 progenies, suggesting the successful transfer of the foreign genes to the recipient plants. The Southern blot analysis of Cry1Ac gene in T2 progenies and PCR-identified Apr gene segregation in T2 seedlings confirmed the stable inheritance of the transgene. The outcome illustrated that the pollen-mediated genetic transformation system can be widely applied in the plant improvement programs with apparent advantages over tissue-culture-based transformation methods. PMID:28377783

  20. 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

  1. The relationship between sperm viability and DNA fragmentation rates

    OpenAIRE

    Mary K. Samplaski; Dimitromanolakis, Apostolos; Lo, Kirk C; Grober, Ethan D.; Mullen, Brendan; Garbens, Alaina; Jarvi, Keith A

    2015-01-01

    Background In humans, sperm DNA fragmentation rates have been correlated with sperm viability rates. Reduced sperm viability is associated with high sperm DNA fragmentation, while conversely high sperm viability is associated with low rates of sperm DNA fragmentation. Both elevated DNA fragmentation rates and poor viability are correlated with impaired male fertility, with a DNA fragmentation rate of > 30% indicating subfertility. We postulated that in some men, the sperm viability assay coul...

  2. Initial invasion of gametophytic self-incompatibility alleles in the absence of tight linkage between pollen and pistil S alleles.

    Science.gov (United States)

    Sakai, Satoki; Wakoh, Haluka

    2014-08-01

    In homomorphic self-incompatibility (SI) systems of plants, the loci controlling the pollen and pistil types are tightly linked, and this prevents the generation of compatible combinations of alleles expressing pollen and pistil types, which would result in self-fertilization. We modeled the initial invasion of the first pollen and pistil alleles in gametophytic SI to determine whether these alleles can stably coexist in a population without tight linkage. We assume pollen and pistil loci each carry an incompatibility allele S and an allele without an incompatibility function N. We assume that pollen with an S allele are incompatible with pistils carrying S alleles, whereas other crosses are compatible. Ovules in pistils carrying an S allele suffer viability costs because recognition consumes resources. We found that the cost of carrying a pistil S allele allows pollen and pistil S alleles to coexist in a stable equilibrium if linkage is partial. This occurs because parents that carry pistil S alleles but are homozygous for pollen N alleles cannot avoid self-fertilization; however, they suffer viability costs. Hence, pollen N alleles are selected again. When pollen and pistil S alleles can coexist in a polymorphic equilibrium, selection will favor tighter linkage.

  3. Fucoidan from Sargassum sp. and Fucus vesiculosus reduces cell viability of lung carcinoma and melanoma cells in vitro and activates natural killer cells in mice in vivo.

    Science.gov (United States)

    Ale, Marcel Tutor; Maruyama, Hiroko; Tamauchi, Hidekazu; Mikkelsen, Jørn D; Meyer, Anne S

    2011-10-01

    Fucoidan is known to exhibit crucial biological activities, including anti-tumor activity. In this study, we examined the influence of crude fucoidan extracted from Sargassum sp. (MTA) and Fucus vesiculosus (SIG) on Lewis lung carcinoma cells (LCC) and melanoma B16 cells (MC). In vitro studies were performed using cell viability analysis and showed that SIG and MTA fucoidans significantly decreased the viable number of LCC and MC cells in a dose-response fashion. Histochemical staining showed morphological changes of melanoma B16 cells after exposure to fucoidan. The observed changes were indicative of crude fucoidan induced apoptosis. Male C57BL/6JJCL mice were subjected to daily i.p. injections over 4 days with either SIG or MTA fucoidan (50mg/kg body wt.). The cytolytic activity of natural killer (NK) cells was enhanced by crude fucoidan in a dose-dependent manner as indicated by (51)Cr labeled YAC-1 target cell release. This study provides substantial indications that crude fucoidan exerts bioactive effects on lung and skin cancer model cells in vitro and induces enhanced natural killer cell activity in mice in vivo.

  4. Establishment of growth medium and quantification of pollen grains of olive cultivars in Brazil's subtropical areas

    Directory of Open Access Journals (Sweden)

    Luiz Fernando de Oliveira da Silva

    2015-01-01

    Full Text Available ABSTRACT Pollen grain germination in vitro indicates viability and consequently provides information related to fruit set. It also assists in the development of hybrids. Along with a suitable species, a standard culture medium is essential for evaluating pollen viability. It should contain a gelling agent consisting of carbohydrates and enhancer elements as well as have the correct pH, temperature, and incubation time. The objective of this study was to optimise the culture medium, determine the pollen germination capacity, and quantify the number of pollen grains per flower of certain olive tree cultivars. A basic sequential culture medium for pollen grain germination was determined, always utilizing the best result from the previous experiment to continue the sequence.The factorial treatment arrangement was: 1 agar versus boric acid; 2 pH versus sucrose; 3 calcium nitrate versus magnesium sulfate. After determining the culture medium components, two experiments were conducted evaluating temperature and incubation time. Another experiment evaluated both the germination percentage and the number of flower pollen grains of 28 cultivars. The culture medium should be composed of 4 g∙L-1 of agar, 90 g∙L-1 of sucrose, and 400 mg∙L-1 of boric acid with a pH adjusted to 5.79 and an incubation time of 60 h at 28 °C. The Manzanilla 215 cultivar had the highest germination rate while Ascolano 315 presented the highest number of pollen grains per flower.

  5. Hydration, sporoderm breaking and germination of Cupressus arizonica pollen.

    Science.gov (United States)

    Chichiriccò, G; Spanò, L; Torraca, G; Tartarini, A

    2009-05-01

    In vitro and in vivo rehydration and germination in Cupressus arizonica pollen were examined using light and scanning electron microscopy. Shed pollen has 12.6% water content, which reduced to 8.2% after dispersal, and this latter pollen survived for some months at room temperature and for years at -10 degrees C. Rehydration requires breaking of the sporoderm walls and depends on the composition and pH of the rehydration medium. Acidity restrains the breakage, while alkalinity promotes it. Pollen division follows exine shedding and requires the persistence of the mucilaginous layer; hence, pH values countering these outcomes prevent division. Division results in a large and a small cell separated by a callosic wall. A pollen tube develops from the innermost intine of the large cell, which is callosic, and extends into the mucilaginous middle intine. The percentage germination never exceeded 17% in all tested media. In vivo, pollen rehydrates and casts off the exine in the micropylar drop. Drop withdrawal brings pollen to the apical nucellar cells that degenerate in the meantime, and it leaves a deposit on the surface of the micropylar canal. After contaction of the nucellar cells, the pollen flattens and its mucilaginous layer shrinks and disappears. This occurs simultaneously with sealing of the micropylar canal. During this time, pollen divides asymmetrically without the callosic wall, and the larger cell develops a tube in the interface with the nucellus. Only some pollen grains accomplish adhesion to the nucellus and germinate. The in vitro and in vivo developmental stages are discussed.

  6. Comparative Proteomic Analysis of Arabidopsis Mature Pollen and Germinated Pollen

    Institute of Scientific and Technical Information of China (English)

    Junjie Zou; Lianfen Song; Wenzheng Zhang; Yi Wang; Songlin Ruan; Wei-Hua Wu

    2009-01-01

    Proteomic analysis was applied to generating the map of Arabidopsis mature pollen proteins and analyzing the differentially expressed proteins that are potentially involved in the regulation of Arabidopsis pollen germination. By applying 2-D electrophoresis and silver staining, we resolved 499 and 494 protein spots from protein samples extracted from pollen grains and pollen tubes, respectively. Using the matrix-assisted laser desorption ionization time-of-flight mass spectrometry method, we identified 189 distinct proteins from 213 protein spots expressed in mature pollen or pollen tubes, and 75 new identified proteins that had not been reported before in research into the Arabidopsis pollen proteome. Comparative analysis revealed that 40 protein spots exhibit reproducible significant changes between mature pollen and pollen tubes. And 21 proteins from 17 downregulated and six upregulated protein spots were identified. Functional category analysis indicated that these differentially expressed proteins mainly involved in signaling, cellular structure, transport, defense/stress responses, transcription, metabolism, and energy production. The patterns of changes at protein level suggested the important roles for energy metabolism-related proteins in pollen tube growth, accompanied by the activation of the stress response pathway and modifications to the cell wall.

  7. Hybrid Viability and Fertility in Co-occuring Plant Species

    Science.gov (United States)

    Hernandez, E.; Garcia, C.; Yost, J.

    2012-12-01

    Similar species of plants can co-exist due to reproductive barriers that keep them from hybridizing. In the case of Lasthenia gracilis and L. californica, certain reproductive barriers allow them to co-exist at Jasper Ridge without hybridization. The two species are locally adapted to different regions of the same hillside, and have slight differences in flowering time but hybrids can be created at low rate in the green house. We tested the viability and fertility of green house produced hybrids to quantify post-zygotic reproductive isolation at Jasper Ridge. We planted 10 hybrid seeds and 10 control seeds from 11 different families. We measured the percent germination, survival to flowering and pollen fertility of the seeds. We expect lower germination, lower survival to flowering, and lower pollen viability of hybrid seeds as compared to control seeds.

  8. Treatment with gemcitabine and TRA-8 anti-death receptor-5 mAb reduces pancreatic adenocarcinoma cell viability in vitro and growth in vivo.

    Science.gov (United States)

    DeRosier, Leo Christopher; Huang, Zhi-Qiang; Sellers, Jeffrey C; Buchsbaum, Donald J; Vickers, Selwyn M

    2006-11-01

    Gemcitabine is a first line agent for pancreatic cancer, but yields minimal survival benefit. This study evaluated in vitro and in vivo effects of a monoclonal antibody (TRA-8) to human death receptor 5, combined with gemcitabine, using two human pancreatic cancer cell lines, S2VP10 and MIA PaCa-2. A subcutaneous model of pancreatic cancer was employed to test in vivo efficacy. S2VP10 and MIA PaCa-2 cells were treated with varying doses of gemcitabine and TRA-8. Cell viability and apoptosis were determined with an adenosine triphosphate assay and annexin V staining, respectively. Mitochondrial membrane destabilization was evaluated with fluorescence-activated cell sorting analysis of JC-1 stained cells. Caspase activation was evaluated by Western blot analysis. MIA PaCa-2 subcutaneous xenografts in athymic nude mice were evaluated for response to treatment with 200 mug of TRA-8 (intraperitoneal on days 9, 13, 16, 20, 23, and 27 postimplant) and 120 mg/kg gemcitabine (I.P. on days 10, 17, and 24). Tumor growth was measured with calipers. MIA PaCa-2 and S2VP10 cells receiving combination treatment with TRA-8 and gemcitabine demonstrated enhanced cytotoxicity, annexin V staining, and mitochondrial destabilization compared to either agent alone. Combination treatment produced enhanced caspase-3 and -8 activation in both cell lines compared with either agent alone. In vivo studies demonstrated mean subcutaneous tumor surface area (produce of two largest diameters) doubling times of 38 days untreated, 32 days gemcitabine, 49 days TRA-8, and 64 days combination treatment. TRA-8 is an apoptosis-inducing agonistic monoclonal antibody that produced synergistic cytotoxicity in combination with gemcitabine in vitro through enhanced caspase activation. These findings, with substantial inhibition of tumor growth in a mouse pancreatic cancer xenograft model receiving combination therapy, are encouraging for anti-death receptor therapy in the treatment of pancreatic cancer.

  9. Theobroma cacao increases cells viability and reduces IL-6 and sVCAM-1 level in endothelial cells induced by plasma from preeclamptic patients.

    Science.gov (United States)

    Rahayu, Budi; Baktiyani, Siti Candra Windu; Nurdiana, Nurdiana

    2016-01-01

    This study aims to investigate whether an ethanolic extract of Theobroma cacao bean is able to increase cell viability and decrease IL-6 and sVCAM-1 in endothelial cells induced by plasma from preeclamptic patients. Endothelial cells were obtained from human umbilical vascular endothelial cells. At confluency, endothelial cells were divided into six groups, which included control (untreated), endothelial cells exposed to plasma from normal pregnancy, endothelial cells exposed to 2% plasma from preeclamptic patients (PP), endothelial cells exposed to PP in the presence of ethanolic extract of T. cacao (PP+TC) at the following three doses: 25, 50, and 100 ppm. The analysis was performed in silico using the Hex 8.0, LigPlus and LigandScout 3.1 software. Analysis on IL-6 and sVCAM-1 levels were done by enzyme linked immunosorbent assay (ELISA). We found that seven of them could bind to the protein NFκB (catechin, leucoanthocyanidin, niacin, phenylethylamine, theobromine, theophylline, and thiamin). This increase in IL-6 was significantly (Pcacao extract. Plasma from PP significantly increased sVCAM-1 levels compared to untreated cells. This increase in sVCAM-1 was significantly attenuated by all doses of the extract. In conclusion, T. cacao extract prohibits the increase in IL-6 and sVCAM-1 in endothelial cells induced by plasma from preeclamptic patients. Therefore this may provide a herbal therapy for attenuating the endothelial dysfunction found in preeclampsia. Copyright © 2016 International Society for the Study of Hypertension in Pregnancy. Published by Elsevier B.V. All rights reserved.

  10. Pollen indicators of human activity

    Institute of Scientific and Technical Information of China (English)

    LI YiYin; ZHOU LiPing; CUI HaiTing

    2008-01-01

    The study of past human activities and their environmental effect is high in the agenda of global change research. A record of pollen assemblages is one of the most common proxies employed for detecting the impact of human activities on the landscape. In this review, we provide a summary and discussion on the recent progress on the use of pollen as indicators of human activity. For most of the studies related to human impact, the following features have been focused on: (1) decline of certain tree pollen; (2) flourishing of pioneer plant pollen; (3) concomitant occurrence of cereal-type pollen and cropland weed pollen; (4) abrupt changes in pollen concentration and richness; and (5) occurrence of nitrophilous plants and pastoral weed. Pollen of anthropogenic plants (weeds and cereal-type plants) is ideal indicators of human activities. Different types of human activities will result in different pollen assem-blages. Patterns of human-impacted pollen spectra would vary between forested areas and grassland. In the study of human impact with pollen data, high resolution in both time and space must be consid-ered. High resolution in space will help to inform the complexity of the landscape. More importantly, it can help to reveal the interference of human activities on the landscape, hence avoiding the bias cre-ated by the limited data points. Fine resolution in time will make accurate recording of short-lived events possible, hence avoiding the exclusion of events related to human activities. The combination of palynology with other proxies will help to decipher more accurately landscape changes through time. Charcoal is a particularly useful proxy for recording the disturbance of humans on vegetation. Its peak values usually occur with pronounced drop of tree pollen and significant rise of anthropogenic pollen.

  11. Floral emasculation reveals pollen quality limitation of seed output in Bulbine bulbosa (Asphodelaceae)1.

    Science.gov (United States)

    Vaughton, Glenda; Ramsey, Mike

    2010-01-01

    Pollen commonly limits seed output in natural plant populations, but the relative contributions of pollen quantity and quality to pollen limitation remain largely unexplored. Estimates of these contributions are needed to promote better understanding of the ecological and evolutionary consequences of pollen limitation. We assessed pollen limitation and distinguished how pollen quantity and quality contributed to seed output in the predominantly outcrossing herb Bulbine bulbosa. We compared seed output of emasculated and cross-pollinated plants that could not self-pollinate with that of intact plants. Seed output was similar in emasculated and cross-pollinated plants, but it was about 50% less in intact plants. These findings indicate that the quantity of cross-pollen deposited by pollinators did not limit seed output. However, pollinators also deposited self-pollen, which reduced seed output because selfing disabled ovules, rendering them unavailable for cross-fertilization. We conclude that pollen quality rather than quantity can limit seed output under natural conditions, which supports recent proposals for greater consideration of pollen quality in the study of pollen limitation.

  12. Allergy to cypress pollen.

    Science.gov (United States)

    Charpin, D; Calleja, M; Lahoz, C; Pichot, C; Waisel, Y

    2005-03-01

    Although Cupressus sempervirens has been spread over southern Europe since antiquity, cypress pollen allergy has not been reported until 1945. In France, the very first case reports were published in 1962. Since then, the prevalence of cypress pollinosis seems to demonstrate an upward trend, concomitantly with the increased use of cypress trees as ornamental plants, as wind breaks and as hedges. Hyposensitization, using improved pollen extracts, is increasingly prescribed. Besides, prevention measures begin to be implemented. Such measures include avoidance of planting new cypress trees, especially near human populations' centres, trimming of cypress hedges before the pollination season and agronomical research for hypoallergenic trees. Altogether, such new developments in cypress allergy deserve an update review.

  13. 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.

  14. Specialized and Generalized Pollen-Collection Strategies in an Ancient Bee Lineage.

    Science.gov (United States)

    Wappler, Torsten; Labandeira, Conrad C; Engel, Michael S; Zetter, Reinhard; Grímsson, Friðgeir

    2015-12-01

    Iconic examples of insect pollination have emphasized narrowly specialized pollinator mutualisms such as figs and fig wasps and yuccas and yucca moths. However, recent attention by pollination ecologists has focused on the broad spectra of pollinated plants by generalist pollinators such as bees. Bees have great impact for formulating hypotheses regarding specialization versus generalization in pollination mutualisms. We report the pollination biology of six northern European species of an extinct tribe of pollen-basket-bearing apine bees, Electrapini, of early-middle Eocene age, examined from two deposits of 48 and 44 million years in age. These bees exhibit a pattern of generalized, incidental pollen occurring randomly on their heads, thoraces, and abdomens, obtained from diverse, nectar-bearing plants. By contrast, a more restricted suite of pollen was acquired for metatibial pollen baskets (corbiculae) of the same bee taxa from a taxonomically much narrower suite of arborescent, evergreen hosts with uniform flower structure. The stereotyped plant sources of the specialist strategy of pollen collection consisted of pentamerous, radially symmetrical flowers with a conspicuous gynoecium surrounded by prominent nectar reward, organized in structurally similar compound inflorescences. Pollen specialization in bees occurs not for efficient pollination but rather in the corbiculate Electrapini as food for bee larvae (brood) and involves packing corbiculae with moistened pollen that rapidly loses viability with age. This specialist strategy was a well-developed preference by the early Eocene, providing a geochronologic midpoint assessment of bee pollen-collection strategies.

  15. Reactive oxygen species are involved in regulation of pollen wall cytomechanics.

    Science.gov (United States)

    Smirnova, A V; Matveyeva, N P; Yermakov, I P

    2014-01-01

    Production and scavenging of reactive oxygen species (ROS) in somatic plant cells is developmentally regulated and plays an important role in the modification of cell wall mechanical properties. Here we show that H2O2 and the hydroxyl radical ((•)OH) can regulate germination of tobacco pollen by modifying the mechanical properties of the pollen intine (inner layer of the pollen wall). Pollen germination was affected by addition of exogenous H2O2, (•)OH, and by antioxidants scavenging endogenous ROS: superoxide dismutase, superoxide dismutase/catalase mimic Mn-5,10,15,20-tetrakis(1-methyl-4-pyridyl)21H, 23H-porphin, or a spin-trap α-(4-pyridyl-1-oxide)-N-tert-butylnitrone, which eliminates (•)OH. The inhibiting concentrations of exogenous H2O2 and (•)OH did not decrease pollen viability, but influenced the mechanical properties of the wall. The latter were estimated by studying the resistance of pollen to hypo-osmotic shock. (•)OH caused excess loosening of the intine all over the surface of the pollen grain, disrupting polar growth induction. In contrast, H2O2, as well as partial removal of endogenous (•)OH, over-tightened the wall, impeding pollen tube emergence. Feruloyl esterase (FAE) was used as a tool to examine whether H2O2-inducible inter-polymer cross-linking is involved in the intine tightening. FAE treatment caused loosening of the intine and stimulated pollen germination and pollen tube growth, revealing ferulate cross-links in the intine. Taken together, the data suggest that pollen intine properties can be regulated differentially by ROS. (•)OH is involved in local loosening of the intine in the germination pore region, while H2O2 is necessary for intine strengthening in the rest of the wall through oxidative coupling of feruloyl polysaccharides.

  16. Nucleofection of rat pheochromocytoma PC-12 cells with human mutated beta-amyloid precursor protein gene (APP-sw) leads to reduced viability, autophagy-like process, and increased expression and secretion of beta amyloid.

    Science.gov (United States)

    Pająk, Beata; Kania, Elżbieta; Orzechowski, Arkadiusz

    2015-01-01

    Pheochromocytoma PC-12 cells are immune to physiological stimuli directed to evoke programmed cell death. Besides, metabolic inhibitors are incapable of sensitizing PC-12 cells to extrinsic or intrinsic apoptosis unless they are used in toxic concentrations. Surprisingly, these cells become receptive to cell deletion after human APP-sw gene expression. We observed reduced cell viability in GFP vector + APP-sw-nucleofected cells (drop by 36%) but not in GFP vector - or GFP vector + APP-wt-nucleofected cells. Lower viability was accompanied by higher expression of Aβ 1-16 and elevated secretion of Aβ 1-40 (in average 53.58 pg/mL). At the ultrastructural level autophagy-like process was demonstrated to occur in APP-sw-nucleofected cells with numerous autophagosomes and multivesicular bodies but without autolysosomes. Human APP-sw gene is harmful to PC-12 cells and cells are additionally driven to incomplete autophagy-like process. When stimulated by TRAIL or nystatin, CLU protein expression accompanies early phase of autophagy.

  17. Nucleofection of Rat Pheochromocytoma PC-12 Cells with Human Mutated Beta-Amyloid Precursor Protein Gene (APP-sw Leads to Reduced Viability, Autophagy-Like Process, and Increased Expression and Secretion of Beta Amyloid

    Directory of Open Access Journals (Sweden)

    Beata Pająk

    2015-01-01

    Full Text Available Pheochromocytoma PC-12 cells are immune to physiological stimuli directed to evoke programmed cell death. Besides, metabolic inhibitors are incapable of sensitizing PC-12 cells to extrinsic or intrinsic apoptosis unless they are used in toxic concentrations. Surprisingly, these cells become receptive to cell deletion after human APP-sw gene expression. We observed reduced cell viability in GFP vector + APP-sw-nucleofected cells (drop by 36% but not in GFP vector − or GFP vector + APP-wt-nucleofected cells. Lower viability was accompanied by higher expression of Aβ 1-16 and elevated secretion of Aβ 1-40 (in average 53.58 pg/mL. At the ultrastructural level autophagy-like process was demonstrated to occur in APP-sw-nucleofected cells with numerous autophagosomes and multivesicular bodies but without autolysosomes. Human APP-sw gene is harmful to PC-12 cells and cells are additionally driven to incomplete autophagy-like process. When stimulated by TRAIL or nystatin, CLU protein expression accompanies early phase of autophagy.

  18. Scintigraphic Assessment of Myocardial Viability

    Energy Technology Data Exchange (ETDEWEB)

    Bom, Hee Seung [Chonnam University Hospital, Kwangju (Korea, Republic of)

    1993-07-15

    The identification of viable myocardium in patients with coronary artery disease and left ventricular dysfunction is an issue of increasing clinical relevance in the current era of myocardial revascularization. There are at least two forms of reversible myocardial dysfunction. Early reperfusion does not always lead to immediate functional improvement; rather, the return of contractility in tissue salvaged by reperfusion is delayed for hours, days or even weeks, a phenomenon that has been termed {sup s}tunned myocardium{sup .} Some patients with coronary artery disease show myocardial dysfunction ar rest which are associated with reduced perfusion, and which disappear after revascularization; this phenomenon has been termed {sup h}ibernating myocardium{sup .} Recently, cardiac imaging techniques that evaluate myocardial viability on the basis of perfusion contraction mismatch and inotropic reserve have gained substantial popularity and clinical success. This review focus on the application of {sup 201}T1 and {sup 99m}Tc-MIBI to address myocardial viability in patients with hibernating and stunned myocardium. It is clear that 4-hour redistribution images of {sup 201}T1 underestimate ischemia and overestimate scar. Delayed imaging and reinjection imaging have been developed for the assessment of viability. Among many protocols suggested, stress-redistribution-reinjection imaging gained most popularity. Although {sup 99m}Tc- MIBI could identify myocardial viability, {sup 201}T1 reinjection technique was regarded as superior to it. In conclusion, {sup 201}T1 stress, 4-hr rest redistribution, and reinjection imaging technique may be the most preferable method for evaluation of myocardial viability.

  19. Division of labour within flowers: heteranthery, a floral strategy to reconcile contrasting pollen fates.

    Science.gov (United States)

    Vallejo-Marín, M; Manson, J S; Thomson, J D; Barrett, S C H

    2009-04-01

    In many nectarless flowering plants, pollen serves as both the carrier of male gametes and as food for pollinators. This can generate an evolutionary conflict if the use of pollen as food by pollinators reduces the number of gametes available for cross-fertilization. Heteranthery, the production of two or more stamen types by individual flowers reduces this conflict by allowing different stamens to specialize in 'pollinating' and 'feeding' functions. We used experimental studies of Solanum rostratum (Solanaceae) and theoretical models to investigate this 'division of labour' hypothesis. Flight cage experiments with pollinating bumble bees (Bombus impatiens) demonstrated that although feeding anthers are preferentially manipulated by bees, pollinating anthers export more pollen to other flowers. Evolutionary stability analysis of a model of pollination by pollen consumers indicated that heteranthery evolves when bees consume more pollen than should optimally be exchanged for visitation services, particularly when pollinators adjust their visitation according to the amount of pollen collected.

  20. Stingless bees (Melipona subnitida) adjust brood production rather than foraging activity in response to changes in pollen stores.

    Science.gov (United States)

    Maia-Silva, Camila; Hrncir, Michael; Imperatriz-Fonseca, Vera Lucia; Schorkopf, Dirk Louis P

    2016-10-01

    Highly eusocial bees (honey bees and stingless bees) sustain their colonies through periods of resource scarcity by food stored within the nest. The protein supply necessary for successful brood production is ensured through adjustments of the colonies' pollen foraging according to the availability of this resource in the environment. In honey bees Apis mellifera, in addition, pollen foraging is regulated through the broods' demand for this resource. Here, we investigated the influence of the colony's pollen store level on pollen foraging and brood production in stingless bees (Melipona subnitida). When pollen was added to the nests, colonies increased their brood production and reduced their pollen foraging within 24 h. On the other hand, when pollen reserves were removed, colonies significantly reduced their brood production. In strong contrast to A. mellifera; however, M. subnitida did not significantly increase its pollen foraging activity under poor pollen store conditions. This difference concerning the regulation of pollen foraging may be due to differences regarding the mechanism of brood provisioning. Honey bees progressively feed young larvae and, consequently, require a constant pollen supply. Stingless bees, by contrast, mass-provision their brood cells and temporary absence of pollen storage will not immediately result in substantial brood loss.

  1. Honey bee gut microbial communities are robust to the fungicide Pristine® consumed in pollen

    Science.gov (United States)

    Honeybees that consume pollen with sublethal levels of the fungicide Pristine® can have reduced pollen digestion, lower ATP synthesis and in many ways resemble malnourished bees. Reduced nutrient acquisition in bees exposed to Pristine® might be because this fungicide affects the composition of gut ...

  2. Study on Floral and Pollen Characters of Tetraploid Rice

    Institute of Scientific and Technical Information of China (English)

    LIU Jian-xin; CHEN Jian-guo; CHEN Dong-ling; SONG Zhao-jian; DAI Bing-cheng; CAI De-tian

    2009-01-01

    Polyploidization is the evolution trend of many crops, and the yield increased obviously after polyploidization. The polyploidization of rice often brings "gigas" of both vegetative organs and seeds. Howevere, in rice breeding, it is required for restoring lines to have not only big anthers but also abundant pollens. People often doubt that the enlargement of the floral organ may just be enlargement of cell size in polyploid rice. So, it is of significance to study characteristics of floral organs and pollens of several tetraploid rice varieties or lines. Floral organ and pollen characteristics of Sg99012 and HN2026 were studied comparatively by stages and different ploidy levels, with the materials 9311, HD9802S, and PA64S as the control. The results showed that chromosome doubling had much more influence on floral characteristics of every lines than seeding by stages, and the tetraploids of every lines displayed "gigas". In correlation analysis, spikelet length, spikelet width, and anther length had significant correlation; spikelet width and anther width had significant correlation, too. Both seeding by stages and chromosome doubling made the correlations of characters between every floral organ changed to some extent. Seeding by stages had little effect on pollen diameter and fertility of HN2026-4X and Sg99012-4X. But chromosome doubling increased pollen size of every lines remarkably, and also increased the pollen quantity of PMeS (polyploid meiosis stability) restoring line HN2026-4X and gene map restoring line 9311-4X remarkably, whereas only had little effect on that of sterile lines. Moreover, chromosome doubling changed pollen fertility and made the number of fertility pollen of 9311 reduced significantly, but the pollen fertility of HN2026 (PMeS restoring line) and PA64S (sterile line) almost had no change after chromosome doubling. The results showed that tetraploid restoring lines had advantage of abundant and big size pollens, and tetraploid sterile

  3. Effects of acidity on tree pollen germination and tube growth

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, J.S.; Van Rye, D.M.; Lassoie, J.P.

    1985-01-01

    Several studies have indicated that pollen germination and tube growth are adversely affected by air pollutants. Pollutants may inhibit the function of pollen by reducing the number of pollen grains which germinate, by reducing the maximum length to which the pollen tubes grow, or by interfering with the formation of the generative cell. The paper reports on studies that are attempting to determine the effects acid rain may have on these crucial stages in the life histories of northeastern tree species. The first stage of this work assessed the effects of acidity in the growth medium on in vitro pollen germination for four deciduous forest species common to central New York State, Betula lutea (yellow birch), B. lenta (black birch), Acer saccharum (sugar maple), and Cornus florida (flowering dogwood). Measurements were taken at the end of the growth period to determine the percentage of grains which had germinated, and to estimate the average tube length. To determine the effects of pollen on the growth medium, the pH of the germination drop was measured at the end of the growth period.

  4. Chemotaxonomy as a tool for interpreting the cryptic diversity of Poaceae pollen

    OpenAIRE

    Julier, Adele C.M.; Jardine, Phillip E.; Coe, Angela L.; William D Gosling; Lomax, Barry H.; Fraser, Wesley T.

    2016-01-01

    The uniform morphology of different species of Poaceae (grass) pollen means that identification to below family level using light microscopy is extremely challenging. Poor taxonomic resolution reduces recoverable information from the grass pollen record, for example, species diversity and environmental preferences cannot be extracted. Recent research suggests Fourier Transform Infra-red Spectroscopy (FTIR) can be used to identify pollen grains based on their chemical composition. Here, we pre...

  5. Inbreeding in Mimulus guttatus reduces visitation by bumble bee pollinators.

    Directory of Open Access Journals (Sweden)

    David E Carr

    Full Text Available Inbreeding in plants typically reduces individual fitness but may also alter ecological interactions. This study examined the effect of inbreeding in the mixed-mating annual Mimulus guttatus on visitation by pollinators (Bombus impatiens in greenhouse experiments. Previous studies of M. guttatus have shown that inbreeding reduced corolla size, flower number, and pollen quantity and quality. Using controlled crosses, we produced inbred and outbred families from three different M. guttatus populations. We recorded the plant genotypes that bees visited and the number of flowers probed per visit. In our first experiment, bees were 31% more likely to visit outbred plants than those selfed for one generation and 43% more likely to visit outbred plants than those selfed for two generations. Inbreeding had only a small effect on the number of flowers probed once bees arrived at a genotype. These differences were explained partially by differences in mean floral display and mean flower size, but even when these variables were controlled statistically, the effect of inbreeding remained large and significant. In a second experiment we quantified pollen viability from inbred and self plants. Bees were 37-54% more likely to visit outbred plants, depending on the population, even when controlling for floral display size. Pollen viability proved to be as important as floral display in predicting pollinator visitation in one population, but the overall explanatory power of a multiple regression model was weak. Our data suggested that bees use cues in addition to display size, flower size, and pollen reward quality in their discrimination of inbred plants. Discrimination against inbred plants could have effects on plant fitness and thereby reinforce selection for outcrossing. Inbreeding in plant populations could also reduce resource quality for pollinators, potentially resulting in negative effects on pollinator populations.

  6. [Cypress pollen allergy].

    Science.gov (United States)

    Charpin, D; Calleja, M; Pichot, C; Penel, V; Hugues, B; Poncet, P

    2013-12-01

    Cypress belongs to the Cupressaceae family, which includes 140 species with non-deciduous foliage. The most important genera in allergic diseases are Cupressus sempervirens or Green cypress, Cupressus arizonica or Blue cypress, Juniperus oxycedrus, Juniperus communis and Thuya. Because J. oxycedrus pollinates in October, C. sempervirens in January and February, C. arizonica in February and March, J. communis in April, the symptomatic period is long-lasting. Because of global warming, the pollination period is tending to last longer and Cupressaceae species are becoming established further the north. In Mediterranean countries, cypress is by far the most important pollinating species, accounting for half of the total pollination. The major allergens belong to group 1. The other allergens from cypress and Juniper share 75 to 97 % structural homology with group 1 major allergens. The prevalence of cypress allergy in the general population ranges from 5 % to 13 %, according to exposure to the pollen. Among outpatients consulting an allergist, between 9 and 35 %, according to different studies, are sensitized to cypress pollen. Repeated cross-sectional studies performed at different time intervals have demonstrated a threefold increase in the percentage of cypress allergy. Risk factors include a genetic predisposition and/or a strong exposure to pollen, but air pollutants could play a synergistic role. The study of the natural history of cypress allergy allows the identification of a subgroup of patients who have no personal or family history of atopy, whose disease began later in life, with low total IgE and often monosensitization to cypress pollen. In these patients, the disease is allergic than rather atopic. In the clinical picture, rhinitis is the most prevalent symptom but conjunctivitis the most disabling. A cross-reactivity between cypress and peach allergy has been demonstrated. The pharmacological treatment of cypress allergy is not different from

  7. Green tea catechin, epigallocatechin-3-gallate, attenuates the cell viability of human non-small-cell lung cancer A549 cells via reducing Bcl-xL expression.

    Science.gov (United States)

    Sonoda, Jun-Ichiro; Ikeda, Ryuji; Baba, Yasutaka; Narumi, Keiko; Kawachi, Akio; Tomishige, Erisa; Nishihara, Kazuya; Takeda, Yasuo; Yamada, Katsushi; Sato, Keizo; Motoya, Toshiro

    2014-07-01

    Clinical and epidemiological studies have indicated that the consumption of green tea has a number of beneficial effects on health. Epigallocatechin-3-gallate (EGCg), the major polyphenolic compound present in green tea, has received much attention as an active ingredient. Among the numerous promising profiles of EGCg, the present study focused on the anticancer effects. Apoptosis induced by EGCg and subsequent cell growth suppression have been demonstrated in a number of cell culture studies. However, the underlying mechanism of apoptotic cell death remains unclear. Thus, the aim of the present study was to identify the major molecule that mediates proapoptotic cell death by EGCg. The effect of EGCg on cell proliferation and the induction of mRNA that modulates apoptotic cell death was evaluated in the A549 human non-small-cell lung cancer cell line. In addition, morphological changes were assessed by microscopy in A549 cells that had been treated with 100 μM EGCg for 24 h. The MTT assay revealed that cell proliferation was significantly reduced by EGCg in a dose-dependent manner (3-100 μM). The mRNA expression level of B-cell lymphoma-extra large (Bcl-xL) was decreased in A549 cells following 24 h incubation with 100 μM EGCg. Therefore, the results indicated that the inhibition of cell proliferation by EGCg may be achieved via suppressing the expression of the cell death-inhibiting gene, Bcl-xL.

  8. Pollen-Specific Aquaporins NIP4;1 and NIP4;2 Are Required for Pollen Development and Pollination in Arabidopsis thaliana.

    Science.gov (United States)

    Di Giorgio, Juliana Andrea Pérez; Bienert, Gerd Patrick; Ayub, Nicolás Daniel; Yaneff, Agustín; Barberini, María Laura; Mecchia, Martín Alejandro; Amodeo, Gabriela; Soto, Gabriela Cynthia; Muschietti, Jorge Prometeo

    2016-05-01

    In flowers with dry stigmas, pollen development, pollination, and pollen tube growth require spatial and temporal regulation of water and nutrient transport. To better understand the molecular mechanisms involved in reproductive processes, we characterized NIP4;1 and NIP4;2, two pollen-specific aquaporins of Arabidopsis thaliana. NIP4;1 and NIP4;2 are paralogs found exclusively in the angiosperm lineage. Although they have 84% amino acid identity, they displayed different expression patterns. NIP4;1 has low expression levels in mature pollen, while NIP4;2 expression peaks during pollen tube growth. Additionally, NIP4;1pro:GUS flowers showed GUS activity in mature pollen and pollen tubes, whereas NIP4;2pro:GUS flowers only in pollen tubes. Single T-DNA mutants and double artificial microRNA knockdowns had fewer seeds per silique and reduced pollen germination and pollen tube length. Transport assays in oocytes showed NIP4;1 and NIP4;2 function as water and nonionic channels. We also found that NIP4;1 and NIP4;2 C termini are phosphorylated by a pollen-specific CPK that modifies their water permeability. Survival assays in yeast indicated that NIP4;1 also transports ammonia, urea, boric acid, and H2O2 Thus, we propose that aquaporins NIP4;1 and NIP4;2 are exclusive components of the reproductive apparatus of angiosperms with partially redundant roles in pollen development and pollination.

  9. Differential selection on pollen and pistil traits in relation to pollen competition in the context of a sexual conflict over timing of stigma receptivity

    Science.gov (United States)

    Lankinen, Åsa; Strandh, Maria

    2016-01-01

    Sexual conflict and its evolutionary consequences are understudied in plants, but the theory of sexual conflict may help explain how selection generates and maintains variability. Here, we investigated selection on pollen and pistil traits when pollen arrives sequentially to partially receptive pistils in relation to pollen competition and a sexual conflict over timing of stigma receptivity in the mixed-mating annual Collinsia heterophylla (Plantaginaceae). In this species the conflict is generated by early fertilizing pollen that reduces seed production, which is counteracted by delaying receptivity in the recipient. We performed sequential two-donor pollinations at early floral developmental stages involving two pollen deposition schedules (with or without a time lag of 1 day), using only outcross or self and outcross pollen. We investigated pollen and pistil traits in relation to siring success (male fitness) and seed production (female fitness). In contrast to previous findings in receptive pistils in C. heterophylla and in other species, last arriving pollen donors showed highest siring success in partially receptive pistils. The last male advantage was weaker when self pollen was the first arriving donor. Two measures of germination rate (early and late) and pollen tube growth rate of first arriving donors were important for siring success in crosses with a time lag, while only late germination rate had an effect in contemporary crosses. Curiously, late stigma receptivity was negatively related to seed production in our contemporary crosses, which was opposite to expectation. Our results in combination with previous studies suggest that pollen and pistil traits in C. heterophylla are differentially advantageous depending on stage of floral development and varying pollen deposition schedules. Variation in success of these traits over floral development time may result from sexually antagonistic selection. PMID:27562796

  10. Pollen extracts and constituent sugars increase growth of a trypanosomatid parasite of bumble bees.

    Science.gov (United States)

    Palmer-Young, Evan C; Thursfield, Lucy

    2017-01-01

    Phytochemicals produced by plants, including at flowers, function in protection against plant diseases, and have a long history of use against trypanosomatid infection. Floral nectar and pollen, the sole food sources for many species of insect pollinators, contain phytochemicals that have been shown to reduce trypanosomatid infection in bumble and honey bees when fed as isolated compounds. Nectar and pollen, however, consist of phytochemical mixtures, which can have greater antimicrobial activity than do single compounds. This study tested the hypothesis that pollen extracts would inhibit parasite growth. Extracts of six different pollens were tested for direct inhibitory activity against cell cultures of the bumble bee trypanosomatid gut parasite Crithidia bombi. Surprisingly, pollen extracts increased parasite growth rather than inhibiting it. Pollen extracts contained high concentrations of sugars, mainly the monosaccharides glucose and fructose. Experimental manipulations of growth media showed that supplemental monosaccharides (glucose and fructose) increased maximum cell density, while a common floral phytochemical (caffeic acid) with inhibitory activity against other trypanosomatids had only weak inhibitory effects on Crithidia bombi. These results indicate that, although pollen is essential for bees and other pollinators, pollen may promote growth of intestinal parasites that are uninhibited by pollen phytochemicals and, as a result, can benefit from the nutrients that pollen provides.

  11. Chromosome numbers, meiotic behavior and pollen fertility in a collection of Paspalum nicorae Parodi accessions

    Directory of Open Access Journals (Sweden)

    Camila Aparecida de Oliveira dos Reis

    2008-01-01

    Full Text Available Chromosome number, meiotic behavior and pollen viability were evaluated in a collection of 53 Paspalumnicorae Parodi accessions, which are part of a breeding project of the species. All accessions are tetraploid, with 2n=4x=40.Despite the invariable chromosome numbers, there was variation among accessions in the frequencies of different chromosomeconfigurations at diakinesis and metaphase I, such as univalents, trivalents and quadrivalents. Other abnormalities asbridges and laggards were also observed at anaphase and telophase I. Meiotic indexes ranged from 82.00 to 99.50% andpollen viability from 88.99 to 95.06%. As the species is pseudogamous apomictic, fertile pollen is necessary for endospermformation. Results show that all plants are meiotically stable and have enough fertile pollen to be used as male parents incontrolled crosses.

  12. Laminin-111 protein therapy reduces muscle pathology and improves viability of a mouse model of merosin-deficient congenital muscular dystrophy.

    Science.gov (United States)

    Rooney, Jachinta E; Knapp, Jolie R; Hodges, Bradley L; Wuebbles, Ryan D; Burkin, Dean J

    2012-04-01

    Merosin-deficient congenital muscular dystrophy type 1A (MDC1A) is a lethal muscle-wasting disease that is caused by mutations in the LAMA2 gene, resulting in the loss of laminin-α2 protein. MDC1A patients exhibit severe muscle weakness from birth, are confined to a wheelchair, require ventilator assistance, and have reduced life expectancy. There are currently no effective treatments or cures for MDC1A. Laminin-α2 is required for the formation of heterotrimeric laminin-211 (ie, α2, β1, and γ1) and laminin-221 (ie, α2, β2, and γ1), which are major constituents of skeletal muscle basal lamina. Laminin-111 (ie, α1, β1, and γ1) is the predominant laminin isoform in embryonic skeletal muscle and supports normal skeletal muscle development in laminin-α2-deficient muscle but is absent from adult skeletal muscle. In this study, we determined whether treatment with Engelbreth-Holm-Swarm-derived mouse laminin-111 protein could rescue MDC1A in the dy(W-/-) mouse model. We demonstrate that laminin-111 protein systemically delivered to the muscles of laminin-α2-deficient mice prevents muscle pathology, improves muscle strength, and dramatically increases life expectancy. Laminin-111 also prevented apoptosis in laminin-α2-deficient mouse muscle and primary human MDC1A myogenic cells, which indicates a conserved mechanism of action and cross-reactivity between species. Our results demonstrate that laminin-111 can serve as an effective protein substitution therapy for the treatment of muscular dystrophy in the dy(W-/-) mouse model and establish the potential for its use in the treatment of MDC1A.

  13. Desiccation tolerance, longevity and seed-siring ability of entomophilous pollen from UK native orchid species.

    Science.gov (United States)

    Marks, Timothy R; Seaton, Philip T; Pritchard, Hugh W

    2014-09-01

    Pollinator-limited seed-set in some terrestrial orchids is compensated for by the presence of long-lived flowers. This study tests the hypothesis that pollen from these insect-pollinated orchids should be desiccation tolerant and relatively long lived using four closely related UK terrestrial species; Anacamptis morio, Dactylorhiza fuchsii, D. maculata and Orchis mascula. Pollen from the four species was harvested from inflorescences and germinated in vitro, both immediately and also after drying to simulate interflower transit. Their tolerance to desiccation and short-term survival was additionally assessed after 3 d equilibration at a range of relative humidities (RHs), and related to constructed sorption isotherms (RH vs. moisture content, MC). Ageing of D. fuchsii pollen was further tested over 2 months against temperature and RH, and the resultant survival curves were subjected to probit analysis, and the distribution of pollen death in time (σ) was determined. The viability and siring ability, following artificial pollinations, were determined in D. fuchsii pollen following storage for 6 years at -20 °C. The pollen from all four species exhibited systematic increases in germinability and desiccation tolerance as anthesis approached, and pollen from open flowers generally retained high germinability. Short-term storage revealed sensitivity to low RH, whilst optimum survival occurred at comparable RHs in all species. Similarly, estimated pollen life spans (σ) at differing temperatures were longest under the dry conditions. Despite a reduction in germination and seeds per capsule, long-term storage of D. fuchsii pollen did not impact on subsequent seed germination in vitro. Substantial pollen desiccation tolerance and life span of the four entomophilous orchids reflects a resilient survival strategy in response to unpredictable pollinator visitation, and presents an alternative approach to germplasm conservation. © The Author 2014. Published by Oxford

  14. Does pollen limitation affect population growth of the endangered Dracocephalum austriacum L.?

    NARCIS (Netherlands)

    S. Castro; T. Dostálek; S. van der Meer; G. Oostermeijer; Z. Münzbergová

    2015-01-01

    Reproductive strategies can have significant consequences for the viability of plant populations. Still, the effects of lower fruit set due to pollen limitation on plant demography and population persistence have rarely been explored. The objectives of this study were to assess the ecological factor

  15. Anomalous pollen grain development after nondifferentiating microspore division in Eremurus

    Directory of Open Access Journals (Sweden)

    M. Charzyńska

    2015-01-01

    Full Text Available Anomalous pollen grain development in Eremurus is caused by an anomalous position of the mitotic spindle and microspore protoplast division into two cells different than in differentiating division. The nuclei of the abnormal gametophytes are always spherical and that of the smaller of the two cells, notwithstanding the shape and position of the latter, has a more compact structure resembling rather that of the generative cell nucleus. Binucleate abnormal gametophytes always have equal nuclei. The wall separating the cells in abnormal pollen grains at first contains callose and, after disappearance of the latter, probably pectins and cellulose. Abnormal pollen grains contain less cytoplasmic RNA than normal ones arid most of them degenerate. If their viability is preserved they do not form' normal pollen tubes in vitro. The frequency of anomalous microspore division is higher in E. robustus (max ca. 50% than in E. himalaicus (max. ca. 30% and shows considerable seasonal variations. The results obtained suggest that disturbances in microspore development in Eremurus have a genetic background, but are stimulated by temperature variations in the period preceding mitosis in the microspore.

  16. Biologically active antimicrobial and antioxidant substances in the Helianthus annuus L. bee pollen.

    Science.gov (United States)

    Fatrcová-Šramková, Katarína; Nôžková, Janka; Máriássyová, Magda; Kačániová, Miroslava

    2016-01-01

    The objective of this study was to measure the content of flavonoids, polyphenols, and carotenoids in the Helianthus annuus L. bee pollen. It was also to evaluate the ability of the dried, frozen, and freeze-dried extracts of sunflower (H. annuus) pollen, its scavenged free radicals and reducing action. Another aim of this study was to investigate the antimicrobial in vitro action of the H. annuus pollen extracts against the Gram-positive and Gram-negative bacteria and fungi. All pollen extracts showed medium antiradical activity and reductive ability. The most effective was the freeze-dried extract in both evaluation systems. The evaluation of the protective effects of DNA using a biosensor showed an opposite trending-frozen ˃ dried ˃ freeze-dried pollen. For the evaluation of antiradical activity, the DPPH method was used, and reductive ability was assessed by means of phosphomolybdic complex formation. The comparison of the polyphenols content shows higher values in freeze-dried bee pollen than in the dried and frozen pollen. The highest content of flavonoids was found in the frozen samples and the most carotenoids were present in the dried samples. In our study, the best antibacterial effects of the dried sunflower bee pollen extracts were found against Paenibacillus larvae, Pseudomonas aeruginosa, and Enterococcus raffinosus. The best inhibitory properties of the frozen sunflower bee pollen extracts were found against Escherichia coli, Pseudomonas aeruginosa, and Paenibacillus larvae. Very good inhibitory effects of freeze-dried sunflower bee pollen were found against Paenibacillus larvae, Brochotrix thermosphacta, and Enterococcus raffinosus. The best antifungal activity of the sunflower bee pollen was found in the frozen bee pollen extracts against Aspergillus ochraceus and freeze-dried bee pollen extracts against Aspergillus niger.

  17. 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

  18. 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

  19. Vaccination for birch pollen allergy. Induction of affinity-matured or blocking IgG antibodies does not account for the reduced binding of IgE to Bet v 1

    DEFF Research Database (Denmark)

    Svenson, Morten; Jacobi, Henrik H; Bødtger, Uffe;

    2003-01-01

    Specific allergy vaccination (SAV) is associated with increased levels of allergen specific IgG in serum. It is not clear, however, to what extent qualitative changes in allergen binding to IgG may be induced as well. We therefore analyzed the binding of the major allergen in pollen of birch...

  20. A Simple Method for Collecting Airborne Pollen

    Science.gov (United States)

    Kevan, Peter G.; DiGiovanni, Franco; Ho, Rong H.; Taki, Hisatomo; Ferguson, Kristyn A.; Pawlowski, Agata K.

    2006-01-01

    Pollination is a broad area of study within biology. For many plants, pollen carried by wind is required for successful seed set. Airborne pollen also affects human health. To foster studies of airborne pollen, we introduce a simple device--the "megastigma"--for collecting pollen from the air. This device is flexible, yielding easily obtained data…

  1. 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 ...

  2. Pollen dimorphism and androgenesis in Hordeum vulgare

    Directory of Open Access Journals (Sweden)

    Krystyna Idzikowska

    2014-01-01

    Full Text Available Dimorphism of binucleate pollen grains of Hordeum vulgare has been confirmed. It is considered, however, in contrast to the accepted opinions, that some of the large pollen grains with dense cytoplasm lying close to the tapetum are the outset forms for embryoids, and not the small pollen grains with scarce cytoplasm lying in the pollen sac centre.

  3. Temperature sensitivity of a numerical pollen forecast model

    Science.gov (United States)

    Scheifinger, Helfried; Meran, Ingrid; Szabo, Barbara; Gallaun, Heinz; Natali, Stefano; Mantovani, Simone

    2016-04-01

    Allergic rhinitis has become a global health problem especially affecting children and adolescence. Timely and reliable warning before an increase of the atmospheric pollen concentration means a substantial support for physicians and allergy suffers. Recently developed numerical pollen forecast models have become means to support the pollen forecast service, which however still require refinement. One of the problem areas concerns the correct timing of the beginning and end of the flowering period of the species under consideration, which is identical with the period of possible pollen emission. Both are governed essentially by the temperature accumulated before the entry of flowering and during flowering. Phenological models are sensitive to a bias of the temperature. A mean bias of -1°C of the input temperature can shift the entry date of a phenological phase for about a week into the future. A bias of such an order of magnitude is still possible in case of numerical weather forecast models. If the assimilation of additional temperature information (e.g. ground measurements as well as satellite-retrieved air / surface temperature fields) is able to reduce such systematic temperature deviations, the precision of the timing of phenological entry dates might be enhanced. With a number of sensitivity experiments the effect of a possible temperature bias on the modelled phenology and the pollen concentration in the atmosphere is determined. The actual bias of the ECMWF IFS 2 m temperature will also be calculated and its effect on the numerical pollen forecast procedure presented.

  4. Reproductive Biology of ViciaL. I. Pollen morphology, Pollen Germination ( in situ) and Pollen Tube Growth.

    OpenAIRE

    Dane, Feruzan; MERİÇ, Çiler

    1999-01-01

    This paper is a study of the pollen germination of V. hirsuta (L.) S.F. Gray, V. pannonica Crantz., V. hybrida L., V, grandiflora Scop., V. sativa L, V. nrbonnensis L. in the anther loculi ( in situ). The morphological properties and fertilities of the pollen were had been investigated. In addition, cytological and cytochemical properties and fertilities of the pollen were had been investigated. In addition, cytological and cytochemical properites of the pollen tubes during in situ pollen...

  5. Cell viability assays: introduction.

    Science.gov (United States)

    Stoddart, Martin J

    2011-01-01

    The measurement of cell viability plays a fundamental role in all forms of cell culture. Sometimes it is the main purpose of the experiment, such as in toxicity assays. Alternatively, cell viability can be used to -correlate cell behaviour to cell number, providing a more accurate picture of, for example, anabolic -activity. There are wide arrays of cell viability methods which range from the most routine trypan blue dye exclusion assay to highly complex analysis of individual cells, such as using RAMAN microscopy. The cost, speed, and complexity of equipment required will all play a role in determining the assay used. This chapter aims to provide an overview of many of the assays available today.

  6. Assessment of cell viability.

    Science.gov (United States)

    Johnson, Simon; Nguyen, Vy; Coder, David

    2013-01-01

    Cell viability may be judged by morphological changes or by changes in membrane permeability and/or physiological state inferred from the exclusion of certain dyes or the uptake and retention of others. This unit presents methods based on dye exclusion, esterase activity, and mitochondrial membrane potential, as well as protocols for determining the pre-fixation viability of fixed cells either before or after fixation with amine-reactive dyes suitable for a range of excitation wavelengths. Membrane-impermeable dead cell and live cell dyes as well as dye-exclusion procedures for microscopy are also included.

  7. Macronutrient ratios in pollen shape bumble bee (Bombus impatiens) foraging strategies and floral preferences.

    Science.gov (United States)

    Vaudo, Anthony D; Patch, Harland M; Mortensen, David A; Tooker, John F; Grozinger, Christina M

    2016-07-12

    To fuel their activities and rear their offspring, foraging bees must obtain a sufficient quality and quantity of nutritional resources from a diverse plant community. Pollen is the primary source of proteins and lipids for bees, and the concentrations of these nutrients in pollen can vary widely among host-plant species. Therefore we hypothesized that foraging decisions of bumble bees are driven by both the protein and lipid content of pollen. By successively reducing environmental and floral cues, we analyzed pollen-foraging preferences of Bombus impatiens in (i) host-plant species, (ii) pollen isolated from these host-plant species, and (iii) nutritionally modified single-source pollen diets encompassing a range of protein and lipid concentrations. In our semifield experiments, B impatiens foragers exponentially increased their foraging rates of pollen from plant species with high protein:lipid (P:L) ratios; the most preferred plant species had the highest ratio (∼4.6:1). These preferences were confirmed in cage studies where, in pairwise comparisons in the absence of other floral cues, B impatiens workers still preferred pollen with higher P:L ratios. Finally, when presented with nutritionally modified pollen, workers were most attracted to pollen with P:L ratios of 5:1 and 10:1, but increasing the protein or lipid concentration (while leaving ratios intact) reduced attraction. Thus, macronutritional ratios appear to be a primary factor driving bee pollen-foraging behavior and may explain observed patterns of host-plant visitation across the landscape. The nutritional quality of pollen resources should be taken into consideration when designing conservation habitats supporting bee populations.

  8. Main: POLLEN1LELAT52 [PLACE

    Lifescience Database Archive (English)

    Full Text Available POLLEN1LELAT52 S000245 26-October-2005 (last modified) kehi One of two co-dependent regulatory ele... -68 region; See S000246 (POLLEN2LELAT52); AGAAA and TCCACCATA (S000246) are required for pollen specific ex...ments responsible for pollen specific activation of tomato (L.e.) lat52 gene; Found at -72 to...gene (Filichkin et al. 2004); pollen; lat52; endo-beta-mannnanase; MAN; Lycopersicon esculentum (tomato) AGAAA ...

  9. Main: POLLEN2LELAT52 [PLACE

    Lifescience Database Archive (English)

    Full Text Available POLLEN2LELAT52 S000246 11-Oct-1999 (last modified) kehi One of two co-dependent regulatory ele... region; See S000245 (POLLEN1LELAT52); AGAAA (S000245) and TCCACCATA are required for pollen specific expression; pollen; lat52; tomato (Lycopersicon esculentum) TCCACCATA ... ...ments responsible for pollen specific activation of tomato (L.e.) lat52 gene; Found at -60 to -52

  10. Pollen germination and pollen tube growth in ZP maize lines

    Directory of Open Access Journals (Sweden)

    Cerović Radosav

    2014-01-01

    Full Text Available The study was conducted on the in vitro pollen germination at 26°, 28°, 32° and 35°C for 24h of male parental lines, pollen tube growth in vivo in cross pollination of female and male parental lines that make couples in four hybrids: ZP 504 su (♀ ZPPL 51 × ♂ ZPPL 67; ZP 677 (♀ ZPPL 17 × ♂ ZPPL 201; ZP 704 (♀ ZPPL 109 × ♂ ZPPL 79, ZP 611 k (♀ ZPPL 126 × ♂ ZPPL 105, and the open pollination of female parental lines of the above mentioned hybrids. Pollen germination in vitro and pollen tube growth dynamics in vivo showed different genotypic specificities with the tests applied. The obtained results were discussed in the context of reproductive biology of ZP maize lines and aimed to create the preconditions for successful management and direction of the process in practice - seed production in certain environmental conditions.

  11. Viability, invariance and applications

    CERN Document Server

    Carja, Ovidiu; Vrabie, Ioan I

    2007-01-01

    The book is an almost self-contained presentation of the most important concepts and results in viability and invariance. The viability of a set K with respect to a given function (or multi-function) F, defined on it, describes the property that, for each initial data in K, the differential equation (or inclusion) driven by that function or multi-function) to have at least one solution. The invariance of a set K with respect to a function (or multi-function) F, defined on a larger set D, is that property which says that each solution of the differential equation (or inclusion) driven by F and issuing in K remains in K, at least for a short time.The book includes the most important necessary and sufficient conditions for viability starting with Nagumo's Viability Theorem for ordinary differential equations with continuous right-hand sides and continuing with the corresponding extensions either to differential inclusions or to semilinear or even fully nonlinear evolution equations, systems and inclusions. In th...

  12. Effects of pollen reward removal on fecundity in a self-incompatible hermaphrodite plant.

    Science.gov (United States)

    Duffy, K J; Johnson, S D

    2011-05-01

    The pollen of hermaphrodite plants is often utilised by flower-visiting animals. While pollen production has obvious benefits for plant male fitness, its consequences for plant female fitness, especially in self-incompatible hermaphrodite species, are less certain. Pollen production could either enhance seed production though increased pollinator attraction, or reduce it if ovules are discounted by deposition of self pollen, as can occur in species with late-acting self-incompatibility. To test the effects of pollen reward provision on female fitness, we artificially emasculated flowers in two populations of the succulent Aloe maculata (Asphodelaceae), which has a late-acting self-incompatibility system, over the course of its flowering period. Flowers of this species are visited by sunbirds (for nectar) and native bees (for pollen and nectar). We measured floral visitation rates, floral rejection rates, pollen deposition on stigmas and fruit and seed set in both emasculated and non-emasculated plants. We found that flowers of emasculated plants suffered reduced visitation and increased rejection (arrival without visitation) by bees, but not by sunbirds; had fewer pollen grains deposited on stigmas and showed an overall decrease in fruit set and seed set. Rates of seed abortion were, however, greatly reduced in emasculated flowers. This study shows that pollen rewards can be important for seed set, even in self-incompatible plants, which have been assumed to rely on nectar rewards for pollinator attraction. Seed abortion was, however, increased by pollen production, a result that highlights the complexity of selection on pollen production in hermaphrodite flowers.

  13. Vaccination for birch pollen allergy. Induction of affinity-matured or blocking IgG antibodies does not account for the reduced binding of IgE to Bet v 1

    DEFF Research Database (Denmark)

    Svenson, Morten; Jacobi, Henrik H; Bødtger, Uffe;

    2003-01-01

    Specific allergy vaccination (SAV) is associated with increased levels of allergen specific IgG in serum. It is not clear, however, to what extent qualitative changes in allergen binding to IgG may be induced as well. We therefore analyzed the binding of the major allergen in pollen of birch.......001). These results show that high avidity IgG of low inter-individual difference in Bet v 1 binding quality is the dominant binding factor of Bet v 1 in sera of birch pollen-allergic patients, and that SAV-induced inhibition of binding of Bet v 1 to IgE can be explained mainly or solely by increased amounts of IgG....

  14. Effect of Temperature on Pollen Fertility in Inter-Subspecific Rice Hybrids

    Institute of Scientific and Technical Information of China (English)

    YANG Jie; WAN Jian-min; ZHAI Hu-qu; WANG Cai-lin; ZHONG Wei-gong; ZOU Jiang-shi

    2004-01-01

    Seventeen rice varieties and hybrids of different types (indica, japonica, javanica, indica hybrid, japonica hybrid and inter-subspecific hybrid) were evaluated to determine the effect of temperature on pollen fertility in inter-subspecfic hybrids. The pollen fertility of inter-subspecific hybrids was greatly reduced when average daily temperature dropped to 22.0 - 23.0℃ at meiosis stage, and the extent of pollen fertility reduction varied greatly with respect to different hybrids. However, the pollen fertility reduction of indica and japonica hybrids and conventional varieties was not obvious under the same regime of temperature conditions. When the average daily temperature dropped to 20℃, the pollen development of conventional varieties and hybrids was also affected. Correlation analysis revealed that there existed a positive correlation between pollen fertility and average daily temperature. A significant difference (P<0.01) was also found between the two correlation coefficients i.e. inter-subspecific hybrids and conventional varieties. Temperature at meiosis stage of pollen mother cell was a key factor in pollen developing, and the pollen fertility of inter-subspecific hybrids was more sensitive to low temperature than that of traditional variety.

  15. Effect of the thawing time of castor bean pollen grains stored at different temperatures

    Directory of Open Access Journals (Sweden)

    Cristina Copstein Cuchiara

    2012-11-01

    Full Text Available This paper aimed at evaluating the effect of thawing time of pollen grains of castor bean cultivars undergoing different environmental conditions and storage periods. For this, pollen grains were maintained in four environments: refrigerator (4ºC, freezer (-18ºC, ultrafreezer (-72ºC, and liquid nitrogen (-196ºC for 60 days. To evaluate viability, in vitro germination was carried out in three tests: 15, 30, and 60 days, in which the pollens grains germinated within an hour were analyzed up to 6h and after 24h. In a completely randomized design, 100 pollen grains were analyzed in the 6 replications of each treatment. For the cultivar IAC 80, both after 15 and 30 days of storage in ultrafreezer, about 50% of pollen grains germinated required from 5h to 6h of incubation for the resumption of metabolism, respectively. For the cultivar AL Guarany 2002, ultrafreezer presented a higher degree of technical uniformity; however, the best germination was achieved through criopreservation. After 60 days, there was a dramatic decrease in the viability under all environmental conditions. Depending on the temperature, there may be a need for a larger thawing time for the resumption of physiological activities.

  16. Pollen sensitivity to ultraviolet-B (UV-B) suggests floral structure evolution in alpine plants.

    Science.gov (United States)

    Zhang, Chan; Yang, Yong-Ping; Duan, Yuan-Wen

    2014-03-31

    Various biotic and abiotic factors are known to exert selection pressures on floral traits, but the influence of ultraviolet-B (UV-B) light on the evolution of flower structure remains relatively unexplored. We have examined the effectiveness of flower structure in blocking radiation and the effects of UV-B on pollen viability in 42 species of alpine plants in the Hengduan Mountains, China. Floral forms were categorized as either protecting or exposing pollen grains to UV-B. The floral materials of plants with exposed and protected pollen grains were able to block UV-B at similar levels. Exposure to UV-B radiation in vitro resulted in a significantly greater loss of viability in pollen from plant species with protective floral structures. The pronounced sensitivity of protected pollen to UV-B radiation was associated with the type of flower structure. These findings demonstrate that UV-B plays an important role in the evolution of protective floral forms in alpine plants.

  17. Wavelet Based Fractal Analysis of Airborne Pollen

    CERN Document Server

    Degaudenzi, M E

    1999-01-01

    The most abundant biological particles in the atmosphere are pollen grains and spores. Self protection of pollen allergy is possible through the information of future pollen contents in the air. In spite of the importance of airborne pol len concentration forecasting, it has not been possible to predict the pollen concentrations with great accuracy, and about 25% of the daily pollen forecasts have resulted in failures. Previous analysis of the dynamic characteristics of atmospheric pollen time series indicate that the system can be described by a low dimensional chaotic map. We apply the wavelet transform to study the multifractal characteristics of an a irborne pollen time series. We find the persistence behaviour associated to low pollen concentration values and to the most rare events of highest pollen co ncentration values. The information and the correlation dimensions correspond to a chaotic system showing loss of information with time evolution.

  18. Controlling the levels of airborne pollen: can heterogeneous photocatalysis help?

    Science.gov (United States)

    Sapiña, M; Jimenez-Relinque, E; Castellote, M

    2013-10-15

    Airborne pollen is a worldwide problem because is a very important allergenic agent; it can be altered only by certain microorganisms and by some oxidizers, such as reactive oxygen species (ROS). On the other hand, heterogeneous photocatalysis (HPC) arose as a promising technology for reducing the level of contaminants in the air, based on their degradation by the production of ROS. In this paper, study of the feasibility of HPC to diminish the counts of pollen is undertaken. The research has been carried out at different levels, from solutions to mortar specimens with the evidence that HPC is able to reduce the amount of pollen grains. This is a major breakthrough that opens the door to a whole field of research, already full of gaps, whose implications could be quite controversial.

  19. Atmospheric pollen count in Monterrey, Mexico.

    Science.gov (United States)

    González-Díaz, Sandra N; Rodríguez-Ortiz, Pablo G; Arias-Cruz, Alfredo; Macías-Weinmann, Alejandra; Cid-Guerrero, Dagoberto; Sedo-Mejia, Giovanni A

    2010-01-01

    There are few reports of pollen count and identification in Mexico; therefore, it is important to generate more information on the subject. This study was designed to describe the prevalence of pollen in the city of Monterrey, Mexico, during the year 2004. Atmospheric pollen was collected with a Hirst air sampler, with an airflow of 10 L/minute during 2004. Pollen was identified with light microscopy; the average monthly pollen count as well as total was calculated from January 2004 to January 2005. The months with the highest concentration of pollen were February and March (289 and 142 grains/m(3) per day, respectively), and July and November had the lowest concentration (20 and 11 grains/m(3) per day, respectively). Most of the pollen recollected corresponded to tree pollen (72%). Fraxinus spp had the highest concentration during the year (19 grains/m(3) per day; 27.5% of the total concentration of pollen). Tree pollen predominated from January through March; with Fraxinus spp, Morus spp, Celtis spp, Cupressus spp, and Pinus spp as the most important. Weed pollen predominated in May, June, and December and the most frequently identified, were Amaranthaceae/Chenopodiaceae, Ambrosia spp, and Parietaria spp. The highest concentration of grass pollen was reported during the months of May, June, September, October, and December with Gramineae/Poaceae predominating. Tree pollen was the most abundant during the year, with the ash tree having the highest concentration. Weed and grass pollen were perennial with peaks during the year.

  20. Commercial Bee Pollen with Different Geographical Origins: A Comprehensive Approach

    Directory of Open Access Journals (Sweden)

    Leticia M. Estevinho

    2012-09-01

    Full Text Available Since the primordial of humanity, pollen has been considered a good source of nutrients and energy. Its promising healing properties have also been referred to. The present study aimed to characterize, for the first time, eight commercial pollens from Portugal and Spain available on the market studying the legislation on labeling, pollinic origin, physicochemical and microbiological analyses and identification of yeasts. Eleven botanical families were found amongst the samples. The most abundant family and the most dominant pollen was Cistaceae. The moisture content, ash, aw, pH, reducing sugars, carbohydrates, proteins, lipids and energy were analyzed and the specific parameters were within the specifications required by some countries with legislation regarding these parameters. Microbiologically commercial pollen showed acceptable safety for the commercial quality and hygiene. All samples showed negative results for toxigenic species. The microorganisms studied were aerobic mesophiles, yeasts and moulds, coliforms, Escherichia coli, Staphylococcus aureus, Salmonella and sulfite-reducing Clostridium. During the work, six yeasts species were isolated from pollen, with Rhodotorula mucilaginosa being the most abundant, as it was present in four samples.

  1. Recombinant allergens for pollen immunotherapy.

    Science.gov (United States)

    Wallner, Michael; Pichler, Ulrike; Ferreira, Fatima

    2013-12-01

    Specific immunotherapy (IT) represents the only potentially curative therapeutic intervention of allergic diseases capable of suppressing allergy-associated symptoms not only during treatment, but also after its cessation. Presently, IT is performed with allergen extracts, which represent a heterogeneous mixture of allergenic, as well as nonallergenic, compounds of a given allergen source. To overcome many of the problems associated with extract-based IT, strategies based on the use of recombinant allergens or derivatives thereof have been developed. This review focuses on recombinant technologies to produce allergy therapeuticals, especially for allergies caused by tree, grass and weed pollen, as they are among the most prevalent allergic disorders affecting the population of industrialized societies. The reduction of IgE-binding of recombinant allergen derivatives appears to be mandatory to increase the safety profile of vaccine candidates. Moreover, increased immunogenicity is expected to reduce the dosage regimes of the presently cumbersome treatment. In this regard, it has been convincingly demonstrated in animal models that hypoallergenic molecules can be engineered to harbor inherent antiallergenic immunologic properties. Thus, strategies to modulate the allergenic and immunogenic properties of recombinant allergens will be discussed in detail. In recent years, several successful clinical studies using recombinant wild-type or hypoallergens as active ingredients have been published and, currently, novel treatment forms with higher safety and efficacy profiles are under investigation in clinical trials. These recent developments are summarized and discussed.

  2. Callose (β-1,3 glucan is essential for Arabidopsis pollen wall patterning, but not tube growth

    Directory of Open Access Journals (Sweden)

    Maruyama Daisuke

    2005-10-01

    Full Text Available Abstract Background Callose (β-1,3 glucan separates developing pollen grains, preventing their underlying walls (exine from fusing. The pollen tubes that transport sperm to female gametes also contain callose, both in their walls as well as in the plugs that segment growing tubes. Mutations in CalS5, one of several Arabidopsis β-1,3 glucan synthases, were previously shown to disrupt callose formation around developing microspores, causing aberrations in exine patterning, degeneration of developing microspores, and pollen sterility. Results Here, we describe three additional cals5 alleles that similarly alter exine patterns, but instead produce fertile pollen. Moreover, one of these alleles (cals5-3 resulted in the formation of pollen tubes that lacked callose walls and plugs. In self-pollinated plants, these tubes led to successful fertilization, but they were at a slight disadvantage when competing with wild type. Conclusion Contrary to a previous report, these results demonstrate that a structured exine layer is not required for pollen development, viability or fertility. In addition, despite the presence of callose-enriched walls and callose plugs in pollen tubes, the results presented here indicate that callose is not required for pollen tube functions.

  3. Methods to isolate a large amount of generative cells, sperm cells and vegetative nuclei from tomato pollen for omics analysis

    Directory of Open Access Journals (Sweden)

    Yunlong eLu

    2015-06-01

    Full Text Available The development of sperm cells from microspores involves a set of finely regulated molecular and cellular events and the coordination of these events. The mechanisms underlying these events and their interconnections remain a major challenge. Systems analysis of genome-wide molecular networks and functional modules with high-throughput omics approaches is crucial for understanding the mechanisms; however, this study is hindered because of the difficulty in isolating a large amount of cells of different types, especially generative cells (GCs, from the pollen. Here, we optimized the conditions of tomato pollen germination and pollen tube growth to allow for long-term growth of pollen tubes in vitro with sperm cells (SCs generated in the tube. Using this culture system, we developed methods for isolating GCs, SCs and vegetative-cell nuclei (VN from just-germinated tomato pollen grains and growing pollen tubes and their purification by Percoll density gradient centrifugation. The purity and viability of isolated GCs and SCs were confirmed by microscopy examination and fluorescein diacetate staining, respectively, and the integrity of VN was confirmed by propidium iodide staining. We could obtain about 1.5 million GCs and 2.0 million SCs each from 180 mg initiated pollen grains, and 10 million VN from 270 mg initiated pollen grains germinated in vitro in each experiment. These methods provide the necessary preconditions for systematic biology studies of SC development and differentiation in higher plants.

  4. 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

  5. Season and landscape composition affect pollen foraging distances and habitat use of honey bees.

    Science.gov (United States)

    Danner, Nadja; Molitor, Anna Maria; Schiele, Susanne; Härtel, Stephan; Steffan-Dewenter, Ingolf

    2016-09-01

    Honey bees (Apis mellifera L.) show a large variation in foraging distances and use a broad range of plant species as pollen resources, even in regions with intensive agriculture. However, it is unknown how increasing areas of mass-flowering crops like oilseed rape (Brassica napus; OSR) or a decrease of seminatural habitats (SNH) change the temporal and spatial availability of pollen resources for honey bee colonies, and thus foraging distances and frequency in different habitat types. We studied pollen foraging of honey bee colonies in 16 agricultural landscapes with independent gradients of OSR and SNH area within 2 km and used waggle dances and digital geographic maps with major land cover types to reveal the distance and visited habitat type on a landscape level. Mean pollen foraging distance of 1347 decoded bee dances was 1015 m (± 26 m; SEM). In spring, increasing area of flowering OSR within 2 km reduced mean pollen foraging distances from 1324 m to only 435 m. In summer, increasing cover of SNH areas close to the colonies (within 200 m radius) reduced mean pollen foraging distances from 846 to 469 m. Frequency of pollen foragers per habitat type, measured as the number of dances per hour and hectare, was equally high for SNH, grassland, and OSR fields, but lower for other crops and forests. In landscapes with a small proportion of SNH a significantly higher density of pollen foragers on SNH was observed, indicating that pollen resources in such simple agricultural landscapes are more limited. Overall, we conclude that SNH and mass-flowering crops can reduce foraging distances of honey bee colonies at different scales and seasons with possible benefits for the performance of honey bee colonies. Further, mixed agricultural landscapes with a high proportion of SNH reduce foraging densities of honey bees in SNH and thus possible competition for pollen resources.

  6. 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.

  7. Ecological stoichiometry of the honeybee: Pollen diversity and adequate species composition are needed to mitigate limitations imposed on the growth and development of bees by pollen quality

    Science.gov (United States)

    Kuszewska, Karolina; Asselman, Michel; Denisow, Bożena; Stawiarz, Ernest; Woyciechowski, Michał; Weiner, January

    2017-01-01

    The least understood aspects of the nutritional needs of bees are the elemental composition of pollen and the bees’ need for a stoichiometrically balanced diet containing the required proportions of nutrients. Reduced plant diversity has been proposed as an indirect factor responsible for the pollinator crisis. We suggest stoichiometric mismatch resulting from a nutritionally unbalanced diet as a potential direct factor. The concentrations and stoichiometric ratios of C, N, S, P, K, Na, Ca, Mg, Fe, Zn, Mn, and Cu were studied in the bodies of honeybees of various castes and sexes and in the nectar and pollen of various plant species. A literature review of the elemental composition of pollen was performed. We identified possible co-limitations of bee growth and development resulting mainly from the scarcity of Na, S, Cu, P and K, and possibly Zn and N, in pollen. Particular castes and sexes face specific limitations. Concentrations of potentially limiting elements in pollen revealed high taxonomic diversity. High floral diversity may be necessary to maintain populations of pollen eaters. Single-species crop plantations, even if these species are rich in nectar and pollen, might limit bee growth and development, not allowing for gathering nutrients in adequate proportions. However, particular plant species may play greater roles than others in balancing honeybee diets. Therefore, we suggest specific plant species that may (1) ensure optimal growth and production of individuals by producing pollen that is exceptionally well balanced stoichiometrically (e.g., clover) or (2) prevent growth and development of honeybees by producing pollen that is extremely unbalanced for bees (e.g., sunflower). Since pollen is generally poor in Na, this element must be supplemented using “dirty water”. Nectar cannot supplement the diet with limiting elements. Stoichiometric mismatch should be considered in intervention strategies aimed at improving the nutritional base for bees

  8. Oral administration of Lactobacillus paracasei NCC 2461 for the modulation of grass pollen allergic rhinitis: a randomized, placebo-controlled study during the pollen season.

    Science.gov (United States)

    Nembrini, Chiara; Singh, Anurag; De Castro, Carlos Antonio; Mercenier, Annick; Nutten, Sophie

    2015-01-01

    The efficacy of Lactobacillus paracasei NCC 2461 in modulating allergic rhinitis was previously evaluated in two exploratory clinical studies. Oral administration with NCC 2461 reduced specific subjective symptoms following nasal provocation tests with controlled grass pollen allergen concentrations. Our aim was to confirm the anti-allergic effect of NCC 2461 in grass pollen allergic subjects exposed to natural doses of allergens during the pollen season. A double-blind, randomized, placebo-controlled, parallel study was conducted with 131 grass pollen allergic subjects from May to July 2012 in concomitance with the pollen season in Berlin. NCC 2461 or placebo was administered daily for an 8-week period to adult subjects with clinical history of allergic rhinitis to grass pollen, positive skin prick test and IgE to grass pollen. During the 8 weeks, symptoms and quality of life questionnaires were filled out, and plasma was collected for IgE analysis at screening and at the end of the intervention. All subjects were included within a 5-day interval, ensuring exposure to similar air pollen counts for each individual during the trial period. The results obtained show that symptoms increased with pollen loads, confirming a natural exposure to the allergen and presence of pollen-induced allergic rhinitis in the subjects. However, no significant differences were observed in allergic rhinitis symptoms scores, quality of life, or specific IgE levels between subjects receiving NCC 2461 as compared to placebo administration. In contrast to previous findings, oral administration of NCC 2461 did not show a beneficial effect on allergic rhinitis in a field trial. The influence of study design, allergen exposure and intervention window on the efficacy of NCC 2461 in modulating respiratory allergy should be further evaluated.

  9. Pollen Aquaporins: The Solute Factor

    Science.gov (United States)

    Pérez Di Giorgio, Juliana A.; Soto, Gabriela C.; Muschietti, Jorge P.; Amodeo, Gabriela

    2016-01-01

    In the recent years, the biophysical properties and presumed physiological role of aquaporins (AQPs) have been expanded to specialized cells where water and solute exchange are crucial traits. Complex but unique processes such as stomatal movement or pollen hydration and germination have been addressed not only by identifying the specific AQP involved but also by studying how these proteins integrate and coordinate cellular activities and functions. In this review, we referred specifically to pollen-specific AQPs and analyzed what has been assumed in terms of transport properties and what has been found in terms of their physiological role. Unlike that in many other cells, the AQP machinery in mature pollen lacks plasma membrane intrinsic proteins, which are extensively studied for their high water capacity exchange. Instead, a variety of TIPs and NIPs are expressed in pollen. These findings have altered the initial understanding of AQPs and water exchange to consider specific and diverse solutes that might be critical to sustaining pollen’s success. The spatial and temporal distribution of the pollen AQPs also reflects a regulatory mechanism that allowing a properly adjusting water and solute exchange. PMID:27881985

  10. National Allergy Bureau Pollen and Mold Report

    Science.gov (United States)

    ... the Expert Search Search AAAAI National Allergy Bureau Pollen and Mold Report Date: April 11, 2017 Location: ... 11, 2017 Click Here to View Most Recent Pollen and Spore Levels (04/10/2017) If you ...

  11. Pollen dispersal analysis using DNA markers

    OpenAIRE

    Wei Zhou; Hong Wang

    2014-01-01

    Modes of pollen dispersal are important for plant ecology, conservation, and evolutionary biology as pollen-mediated gene flow connects one generation of sexually-reproducing plants to the next. With the development of DNA molecular techniques, molecular markers (especially microsatellite markers) have replaced traditional physical markers for pollen flow analysis. Methods of paternity assignment with maximum likelihood and Bayesian inference have greatly improved the estimation of pollen flo...

  12. 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.

  13. Effects of fluorine compounds on pollen germination and fruit setting of fruit trees

    Energy Technology Data Exchange (ETDEWEB)

    Dinh, D.L.; Buchloh, G.; Oelschlaeger, W.

    1973-01-01

    Exposing pollen of apples, pears and sweet cherries to 97 ..mu..g HF/m/sup 3/ air did not impair germination in an artificial medium, and pollen tube elongation was, in fact, stimulated. In a further test, in which pollen of a late-flowering dessert apple was fumigated with 285 ..mu..g HG/m/sup 3/ air, a 6- or 18-h fumigation period stimulated tube elongation, but fumigation for 24 or 48 h reduced germination. However, tube pollen was treated with various F solutions. Germination in pears and sweet cherries was not affected by compounds containing uni- or divalent metals but F compounds with divalent cations reduced apple pollen germination. NaF, BaF/sub 2/ and CaF/sub 2/ stimulated pollen tube growth in pears and NaF, KF and CsF in sweet cherries. An HF solution at 5 ppm greatly stimulated pollen tube growth; at 10 ppm it caused the tubes to burst. In field trials with trees growing near a factory emitting F-containing pollutants (2.5 ..mu..g HF/m/sup 3/) F pollution did not reduce fruit set, but necrotic spots sometimes appeared, especially on sweet cherries. Weekly sprays of CaCl/sub 2/ reduced this damage to cherry fruits.

  14. Pollen Allergens for Molecular Diagnosis.

    Science.gov (United States)

    Pablos, Isabel; Wildner, Sabrina; Asam, Claudia; Wallner, Michael; Gadermaier, Gabriele

    2016-04-01

    Pollen allergens are one of the main causes of type I allergies affecting up to 30% of the population in industrialized countries. Climatic changes affect the duration and intensity of pollen seasons and may together with pollution contribute to increased incidences of respiratory allergy and asthma. Allergenic grasses, trees, and weeds often present similar habitats and flowering periods compromising clinical anamnesis. Molecule-based approaches enable distinction between genuine sensitization and clinically mostly irrelevant IgE cross-reactivity due to, e. g., panallergens or carbohydrate determinants. In addition, sensitivity as well as specificity can be improved and lead to identification of the primary sensitizing source which is particularly beneficial regarding polysensitized patients. This review gives an overview on relevant pollen allergens and their usefulness in daily practice. Appropriate allergy diagnosis is directly influencing decisions for therapeutic interventions, and thus, reliable biomarkers are pivotal when considering allergen immunotherapy in the context of precision medicine.

  15. Effects of different concentrations of pollen extract on brain tissues of Oncorhynchus mykiss

    Institute of Scientific and Technical Information of China (English)

    Mehmet Fuat Gulhan; Hasan Akgul; Taner Dastan; Sevgi Durna Dastan; Zeliha Selamoglu Talas

    2014-01-01

    Objective: To determine the antioxidant capacities of pollen extract applied at different concentrations on biochemical parameters in brain tissues of rainbow trouts. Methods:parameters in brain tissues of fish treated at various concentrations of the pollen extract (0.5, 2.5, 5, 10, 20 and 30 mg/L) for 96 h. The malondialdehyde levels, total antioxidant status, total oxidant status, oxidative stress index and amounts of total free sulfhydryl groups were analyzed in fish brain. Results:The effective concentration of pollen was determined with some biochemical treated compared to control group (P Conclusions: To apply the pollen to fish reduces the detrimental effects and modulates oxidative status via activating antioxidant defense systems at brain tissue. As a result, pollen can be added up to 10 mg/L to the medium of rainbow trout to improve health of fish.

  16. Wildlife Tunnel Enhances Population Viability

    Directory of Open Access Journals (Sweden)

    Rodney van der Ree

    2009-12-01

    Full Text Available Roads and traffic are pervasive components of landscapes throughout the world: they cause wildlife mortality, disrupt animal movements, and increase the risk of extinction. Expensive engineering solutions, such as overpasses and tunnels, are increasingly being adopted to mitigate these effects. Although some species readily use such structures, their success in preventing population extinction remains unknown. Here, we use population viability modeling to assess the effectiveness of tunnels for the endangered Mountain Pygmy-possum (Burramys parvus in Australia. The underpasses reduced, but did not completely remove, the negative effects of a road. The expected minimum population size of a "reconnected" population remained 15% lower than that of a comparable "undivided" population. We propose that the extent to which the risk of extinction decreases should be adopted as a measure of effectiveness of mitigation measures and that the use of population modeling become routine in these evaluations.

  17. The relationship between sperm viability and DNA fragmentation rates.

    Science.gov (United States)

    Samplaski, Mary K; Dimitromanolakis, Apostolos; Lo, Kirk C; Grober, Ethan D; Mullen, Brendan; Garbens, Alaina; Jarvi, Keith A

    2015-05-14

    In humans, sperm DNA fragmentation rates have been correlated with sperm viability rates. Reduced sperm viability is associated with high sperm DNA fragmentation, while conversely high sperm viability is associated with low rates of sperm DNA fragmentation. Both elevated DNA fragmentation rates and poor viability are correlated with impaired male fertility, with a DNA fragmentation rate of >30% indicating subfertility. We postulated that in some men, the sperm viability assay could predict the sperm DNA fragmentation rates. This in turn could reduce the need for sperm DNA fragmentation assay testing, simplifying the infertility investigation and saving money for infertile couples. All men having semen analyses with both viability and DNA fragmentation testing were identified via a prospectively collected database. Viability was measured by eosin-nigrosin assay. DNA fragmentation was measured using the sperm chromosome structure assay. The relationship between DNA fragmentation and viability was assessed using Pearson's correlation coefficient. From 2008-2013, 3049 semen analyses had both viability and DNA fragmentation testing. A strong inverse relationship was seen between sperm viability and DNA fragmentation rates, with r=-0.83. If viability was ≤50% (n=301) then DNA fragmentation was ≥ 30% for 95% of the samples. If viability was ≥75% (n=1736), then the DNA fragmentation was ≤30% for 95% of the patients. Sperm viability correlates strongly with DNA fragmentation rates. In men with high levels of sperm viability≥75%, or low levels of sperm viability≤ 30%, DFI testing may be not be routinely necessary. Given that DNA fragmentation testing is substantially more expensive than vitality testing, this may represent a valuable cost-saving measure for couples undergoing a fertility evaluation.

  18. Arabidopsis DAYU/ABERRANT PEROXISOME MORPHOLOGY9 is a key regulator of peroxisome biogenesis and plays critical roles during pollen maturation and germination in planta.

    Science.gov (United States)

    Li, Xin-Ran; Li, Hong-Ju; Yuan, Li; Liu, Man; Shi, Dong-Qiao; Liu, Jie; Yang, Wei-Cai

    2014-02-01

    Pollen undergo a maturation process to sustain pollen viability and prepare them for germination. Molecular mechanisms controlling these processes remain largely unknown. Here, we report an Arabidopsis thaliana mutant, dayu (dau), which impairs pollen maturation and in vivo germination. Molecular analysis indicated that DAU encodes the peroxisomal membrane protein ABERRANT PEROXISOME MORPHOLOGY9 (APEM9). DAU is transiently expressed from bicellular pollen to mature pollen during male gametogenesis. DAU interacts with peroxisomal membrane proteins PEROXIN13 (PEX13) and PEX16 in planta. Consistently, both peroxisome biogenesis and peroxisome protein import are impaired in dau pollen. In addition, the jasmonic acid (JA) level is significantly decreased in dau pollen, and the dau mutant phenotype is partially rescued by exogenous application of JA, indicating that the male sterility is mainly due to JA deficiency. In addition, the phenotypic survey of peroxin mutants indicates that the PEXs most likely play different roles in pollen germination. Taken together, these data indicate that DAU/APEM9 plays critical roles in peroxisome biogenesis and function, which is essential for JA production and pollen maturation and germination.

  19. 大花紫薇开花及花粉特性研究%Study on the Characteristics of Florescence and Pollen in Lagerstroemia speciosa

    Institute of Scientific and Technical Information of China (English)

    任翔翔; 张启翔; 潘会堂; 蔡明

    2009-01-01

    [Objective] To study the characteristics of florescence and pollen in Lagerstroemia speciosa. [Method] The process of flower opening and pollen tube germination of Lagerstroemia speciosa was observed and the pollen viability was determined through in vitro germination. [Result] Sepals of L.speciosa started to diverge at 4:30 am, at 7: 00 am petals flatten up, anther diverged, and the stigma secreted a large number of mucus, it was the best time for artificial pollination. Boric acid and sucrose had a great effect on in vitro pollen germination of L.speciosa, the combination which made highest rate of pollen germination, was sucrose 150 g/L + boric acid 20 mg/L + CaCl2 10 mg/L. Through the fluorescence microscope, it was known that four hours after flowering, a lot of pollen grains germinated on the stigma, six hours after flowering, lots of pollen tubes entered the style and reached to 1/4 length of the style, 12 hours after flowering, pollen tubes concentrated into a beam forward, and reached to 1/2 length of the style, 24 hours after flowering, lots of pollen tubes entered the ovary in a beam and then fertilized and produced seeds. [Conclusion] The results provide some basis for utilizing L.speciosa to breed.

  20. BURSTING POLLEN is required to organize the pollen germination plaque and pollen tube tip in Arabidopsis thaliana.

    Science.gov (United States)

    Hoedemaekers, Karin; Derksen, Jan; Hoogstrate, Suzanne W; Wolters-Arts, Mieke; Oh, Sung-Aeong; Twell, David; Mariani, Celestina; Rieu, Ivo

    2015-04-01

    Pollen germination may occur via the so-called germination pores or directly through the pollen wall at the site of contact with the stigma. In this study, we addressed what processes take place during pollen hydration (i.e. before tube emergence), in a species with extra-poral pollen germination, Arabidopsis thaliana. A T-DNA mutant population was screened by segregation distortion analysis. Histological and electron microscopy techniques were applied to examine the wild-type and mutant phenotypes. Within 1 h of the start of pollen hydration, an intine-like structure consisting of cellulose, callose and at least partly de-esterified pectin was formed at the pollen wall. Subsequently, this 'germination plaque' gradually extended and opened up to provide passage for the cytoplasm into the emerging pollen tube. BURSTING POLLEN (BUP) was identified as a gene essential for the correct organization of this plaque and the tip of the pollen tube. BUP encodes a novel Golgi-located glycosyltransferase related to the glycosyltransferase 4 (GT4) subfamily which is conserved throughout the plant kingdom. Extra-poral pollen germination involves the development of a germination plaque and BUP defines the correct plastic-elastic properties of this plaque and the pollen tube tip by affecting pectin synthesis or delivery.

  1. Seasonal variations of airborne pollen in Allahabad, India.

    Science.gov (United States)

    Sahney, Manju; Chaurasia, Swati

    2008-01-01

    Using a Burkard 7-day volumetric sampler a survey of airborne pollen grains in Allahabad was carried out from December 2004--November 2005 to assess the qualitative and quantitative occurrence of pollen grains during different months of the year, and to characterize the pollen seasons of dominant pollen types in the atmosphere of Allahabad. 80 pollen types were identified out of the total pollen catch of 3,416.34 pollen grains/m(3). Bulk of the pollen originated from anemophilous trees and grasses. Thirteen pollen types recorded more than 1 % of the annual total pollen catch. Holoptelea integrifolia formed the major component of the pollen spectrum constituting 46.21 % of the total pollen catch followed by Poaceae, Azadirachta indica, Ailanthus excelsa, Putranjiva roxburghii, Parthenium hysterophorus, Ricinus communis, Brassica compestris, Amaranthaceae/Chenopodiaceae, Madhuca longifolia, Syzygium cumini, other Asteraceae and Aegle marmelos. Highest pollen counts were obtained in the month of March and lowest in July. The pollen types recorded marked the seasonal pattern of occurrence in the atmosphere. February-May was the principal pollen season with maximum number of pollen counts and pollen types. Chief sources of pollen during this period were arboreal taxa. September-October was the second pollen season with grasses being the main source of pollen. Airborne pollen spectrum reflected the vegetation of Allahabad, except for Alnus sp., which grows in the Himalayan region. A significant negative correlation was found of daily pollen counts with minimum temperature, relative humidity and rainfall.

  2. 雷竹花粉萌发率及贮藏方法研究%Pollen germination and storage of Phyllostachys violascens

    Institute of Scientific and Technical Information of China (English)

    刘倩倩; 徐一帆; 林新春; 方伟

    2012-01-01

    Pollen germination and storage of Phyllostachys violascens were studied for bamboo crossbreeding. The results were summarized as follows: the pollen germination rate measured by in vitro pollen germination was lower than the pollen viability rate detected by triphenyltetrazolium chloride triphenyltetrazolium chloride (TTC) staining technique; the pollen germination ability could be improved by supplementing with 50 mg·L-1 boric acid in the medium; the pollen germination rate of the anthers completely outcrop but not dehiscent was higher than those of ether development stages; as for the pollen collection time, 15:30 was better than 9:30; pollen viability of Ph. violascens would be lost quickly during storage, and certain humidity and low temperature at 4℃ could be beneficial to keep the pollen viability.%为更好地开展竹类植物的杂交育种工作,对雷竹花粉的萌发率及贮藏方法进行了研究.结果表明,利用离体花粉萌发法测定的雷竹花粉萌发率远低于氯化三苯四氮唑(TTC)染色法测定的花粉生活力;添加50 mg·L-1硼酸有利于雷竹花粉萌发;不同发育阶段的花粉萌发率有明显差异,以花药完全露出未开裂的花粉萌发率为最高;花粉采集时间以15:30优于9:30;雷竹花粉不耐贮藏,4℃湿藏有利于保持花粉生活力.

  3. Airborne Pollen Grains Of Afyon, Turkey

    Institute of Scientific and Technical Information of China (English)

    Adem BICAKCI; Süheyla ERGUN; Sevcan TATLIDIL; Hulusi MALYER; Sabri OZYURT; Ahmet AKKAYA; Nihat SAPAN

    2002-01-01

    The airborne pollen grains of Afyon have been studied for a two-year period (1999-2000) with a Durham sampler. A total of 14 367 pollen grains belonging to 40 taxa have been identified and recorded with some unidentified ones. Of them, 6 732 were identified in 1999 and 7 635 in 2000. Of the total pollen grains, 69.67% were arboreal, 26.64% non-arboreal and 3.68 % unidentified. The majority of the investigated pollen grains were from Pinus, Gramineae, Cupressaceae, Platanus, Chenopodiaceae/Amaranthaceae, Quercus, Ailanthus, Moraceae, Juglans, Salix, Cedrus and Rosaceae. The highest level of pollen grains was in May.

  4. Pollen grains are efficient cloud condensation nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Pope, F D, E-mail: fdp21@cam.ac.uk [Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW (United Kingdom)

    2010-10-15

    This letter presents a laboratory study investigating the ability of pollen grains to act as cloud condensation nuclei. The hygroscopicity of pollen is measured under subsaturated relative humidities using an electrodynamic balance. It is found, along with other results, that pollen exhibits bulk uptake of water under subsaturated conditions. Through the use of an environmental scanning electron microscope it was observed that the surface of pollen is wettable at high subsaturated humidities. The hygroscopic response of the pollen to subsaturated relative humidities is parametrized using {kappa}-Koehler theory and values of the parameter {kappa} for pollen are between 0.05 and 0.1. It is found that while pollen grains are only moderately hygroscopic, they can activate at critical supersaturations of 0.001% and lower, and thus pollen grains will readily act as cloud condensation nuclei. While the number density of pollen grains is too low for them to represent a significant global source of cloud condensation nuclei, the large sizes of pollen grains suggest that they will be an important source of giant cloud condensation nuclei. Low temperature work using the environmental scanning electron microscope indicated that pollen grains do not act as deposition ice nuclei at temperatures warmer than - 15 deg. C.

  5. [Pollen as the cause of allergies].

    Science.gov (United States)

    Schmid-Grendelmeier, P

    2001-05-01

    Pollinosis or hay fever is the most common allergic disease in Switzerland. For symptoms during spring pollens of birch and related trees (alder, hazel) and also ash tree are responsible, while hay fever during summer is mainly caused by pollens of grasses, rye and mugwort. These main plant pollen allergens, relevant cross-reactivities with other pollen and food allergens are reviewed in this article. The well-established methods of pollen-counting in Switzerland allow to define the varying amounts of measurable pollen depending on geographic and climatic conditions. Similarly clinical symptoms, the diagnostic work-up of pollen allergies and therapeutic aspects including preventive measures, symptomatic therapy and specific immunotherapy are presented. Finally, occupational and travelling aspects of pollinosis are briefly discussed.

  6. Bioindication of air pollution by the reaction of pollen grains Тaraxacum officinale F. H. Wigg (on example of the Kryvyi Rig

    Directory of Open Access Journals (Sweden)

    Віталій Миколайович Гришко

    2016-05-01

    Full Text Available Influence of various level of pollution of Kryvyi Rig on pollen viability of Taraxacum officinale Wigg seeds was studied. Gametocidal influence of pollution is shown in gradual increase to 50 % of impractical pollen at the high level of pollution and increase more than twice of amount of the sterile grains induced by this factor. Also depending on the level of pollution the amount of morphologically changed pollen increases and at high level is noted the formation of a lentiform abnormal form

  7. Influence of Pollen, Chia Seeds and Cranberries Addition on the Physical and Probiotics Characteristics of Yogurt

    OpenAIRE

    Carmen Pop; Romina Vlaic; Anca Fărcaş; Liana Salanţă; Delia Ghicăşan; Cristina Semeniuc; ROTAR, Ancuţa M.

    2015-01-01

    Yoghurt is a fermented milk product obtained from fermentation of Lactobacillus bulgaricus and Streptococcus thermophilus strains. The effect of bee pollen, chia seeds and cranberries on the viability of probiotic bacteria in yogurts during storage (21 days) at refrigerated temperature (4°C) was evaluated. The yogurt supplementation with 1,4 % chia seeds and 7,6% cranberries significantly improves the stability of the lactic acid bacteria, that contained the recommended levels of (106–107 cfu...

  8. Regulation of gelsolin to plant actin filaments and its distribution in pollen

    Institute of Scientific and Technical Information of China (English)

    TAO; Zhihua; (陶志华); REN; Haiyun; (任海云)

    2003-01-01

    The effect of plasma gelsolin on plant microfilaments and its localization in plant cells were investigated. The results by using ultracentrifugation and electron microscopy showed that plant microfilaments could be severed into shorter fragments by gelsolin in a Ca2+-dependent manner. By measuring the binding ability of plasma gelsolin to pollen actin using the method of immunoprecipitation, it was shown that pollen actin could bind gelsolin at a ratio of 2.0±0.21 in the presence of Ca2+. Addition of EGTA could disassociate the actin-gelsolin complexes, reducing the ratio to 1.2±0.23, and the addition of PIP2 could further reduce the ratio to 0.8±0.1. The results indicate that plant actin has similar binding properties with plasma gelsolin as that of animal actin. By Western blotting we identified the existence of gelsolin in lily pollen. The results of immunolo-calization of gelsolin in pollen and pollen tube showed that gelsolin was mainly localized at the germinal furrow in pollen grains and at the cytoplasm in pollen tube, especially in the tip region.

  9. Regulation of gelsolin to plant actin filaments and its distribution in pollen

    Institute of Scientific and Technical Information of China (English)

    陶志华; 任海云

    2003-01-01

    The effect of plasma gelsolin on plant microfilaments and its localization in plant cells were investigated. The results by using ultracentrifugation and electron microscopy showed that plant microfilaments could be severed into shorter fragments by gelsolin in a Ca2+-dependent manner. By measuring the binding ability of plasma gelsolin to pollen actin using the method of immunoprecipitation, it was shown that pollen actin could bind gelsolin at a ratio of 2.0±0.21 in the presence of Ca2+. Addition of EGTA could disassociate the actin-gelsolin complexes, reducing the ratio to 1.2±0.23, and the addition of PIP2 could further reduce the ratio to 0.8±0.1. The results indicate that plant actin has similar binding properties with plasma gelsolin as that of animal actin. By Western blotting we identified the existence of gelsolin in lily pollen. The results of immunolo-calization of gelsolin in pollen and pollen tube showed that gelsolin was mainly localized at the germinal furrow in pollen grains and at the cytoplasm in pollen tube, especially in the tip region.

  10. Viability of mesenchymal stem cells during electrospinning

    Directory of Open Access Journals (Sweden)

    G. Zanatta

    2012-02-01

    Full Text Available Tissue engineering is a technique by which a live tissue can be re-constructed and one of its main goals is to associate cells with biomaterials. Electrospinning is a technique that facilitates the production of nanofibers and is commonly used to develop fibrous scaffolds to be used in tissue engineering. In the present study, a different approach for cell incorporation into fibrous scaffolds was tested. Mesenchymal stem cells were extracted from the wall of the umbilical cord and mononuclear cells from umbilical cord blood. Cells were re-suspended in a 10% polyvinyl alcohol solution and subjected to electrospinning for 30 min under a voltage of 21 kV. Cell viability was assessed before and after the procedure by exclusion of dead cells using trypan blue staining. Fiber diameter was observed by scanning electron microscopy and the presence of cells within the scaffolds was analyzed by confocal laser scanning microscopy. After electrospinning, the viability of mesenchymal stem cells was reduced from 88 to 19.6% and the viability of mononuclear cells from 99 to 8.38%. The loss of viability was possibly due to the high viscosity of the polymer solution, which reduced the access to nutrients associated with electric and mechanical stress during electrospinning. These results suggest that the incorporation of cells during fiber formation by electrospinning is a viable process that needs more investigation in order to find ways to protect cells from damage.

  11. Diversion of carbon flux from gibberellin to steviol biosynthesis by over-expressing SrKA13H induced dwarfism and abnormality in pollen germination and seed set behaviour of transgenic Arabidopsis.

    Science.gov (United States)

    Guleria, Praveen; Masand, Shikha; Yadav, Sudesh Kumar

    2015-07-01

    This paper documents the engineering of Arabidopsis thaliana for the ectopic over-expression of SrKA13H (ent-kaurenoic acid-13 hydroxylase) cDNA from Stevia rebaudiana. HPLC analysis revealed the significant accumulation of steviol (1-3 μg g(-1) DW) in two independent transgenic Arabidopsis lines over-expressing SrKA13H compared with the control. Independent of the steviol concentrations detected, both transgenic lines showed similar reductions in endogenous bioactive gibberellins (GA1 and GA4). They possessed phenotypic similarity to gibberellin-deficient mutants. The reduction in endogenous gibberellin content was found to be responsible for dwarfism in the transgenics. The exogenous application of GA3 could rescue the transgenics from dwarfism. The hypocotyl, rosette area, and stem length were all considerably reduced in the transgenics. A noteworthy decrease in pollen viability was noticed and, similarly, a retardation of 60-80% in pollen germination rate was observed. The exogenous application of steviol (0.2, 0.5, and 1.0 μg ml(-1)) did not influence pollen germination efficiency. This has suggested that in planta formation of steviol was not responsible for the observed changes in transgenic Arabidopsis. Further, the seed yield of the transgenics was reduced by 24-48%. Hence, this study reports for the first time that over-expression of SrKA13H cDNA in Arabidopsis has diverted the gibberellin biosynthetic route towards steviol biosynthesis. The Arabidopsis transgenics showed a significant reduction in endogenous gibberellins that might be responsible for the dwarfism, and the abnormal behaviour of pollen germination and seed set.

  12. Economic viability of anaerobic digestion

    Energy Technology Data Exchange (ETDEWEB)

    Wellinger, A. [INFOENERGIE, Ettenhausen (Switzerland)

    1996-01-01

    The industrial application of anaerobic digestion is a relatively new, yet proven waste treatment technology. Anaerobic digestion reduces and upgrades organic waste, and is a good way to control air pollution as it reduces methane and nitrous gas emissions. For environmental and energy considerations, anaerobic digestion is a nearly perfect waste treatment process. However, its economic viability is still in question. A number of parameters - type of waste (solid or liquid), digester system, facility size, product quality and end use, environmental requirements, cost of alternative treatments (including labor), and interest rates - define the investment and operating costs of an anaerobic digestion facility. Therefore, identical facilities that treat the same amount and type of waste may, depending on location, legislation, and end product characteristics, reveal radically different costs. A good approach for evaluating the economics of anaerobic digestion is to compare it to treatment techniques such as aeration or conventional sewage treatment (for industrial wastewater), or composting and incineration (for solid organic waste). For example, the cost (per ton of waste) of in-vessel composting with biofilters is somewhat higher than that of anaerobic digestion, but the investment costs 1 1/2 to 2 times more than either composting or anaerobic digestion. Two distinct advantages of anaerobic digestion are: (1) it requires less land than either composting or incinerating, which translates into lower costs and milder environmental and community impacts (especially in densely populated areas); and (2) it produces net energy, which can be used to operate the facility or sold to nearby industries.

  13. Fluorescence-tagged transgenic lines reveal genetic defects in pollen growth--application to the eIF3 complex.

    Directory of Open Access Journals (Sweden)

    Bijoyita Roy

    Full Text Available BACKGROUND: Mutations in several subunits of eukaryotic translation initiation factor 3 (eIF3 cause male transmission defects in Arabidopsis thaliana. To identify the stage of pollen development at which eIF3 becomes essential it is desirable to examine viable pollen and distinguish mutant from wild type. To accomplish this we have developed a broadly applicable method to track mutant alleles that are not already tagged by a visible marker gene through the male lineage of Arabidopsis. METHODOLOGY/PRINCIPAL FINDINGS: Fluorescence tagged lines (FTLs harbor a transgenic fluorescent protein gene (XFP expressed by the pollen-specific LAT52 promoter at a defined chromosomal position. In the existing collection of FTLs there are enough XFP marker genes to track nearly every nuclear gene by virtue of its genetic linkage to a transgenic marker gene. Using FTLs in a quartet mutant, which yields mature pollen tetrads, we determined that the pollen transmission defect of the eif3h-1 allele is due to a combination of reduced pollen germination and reduced pollen tube elongation. We also detected reduced pollen germination for eif3e. However, neither eif3h nor eif3e, unlike other known gametophytic mutations, measurably disrupted the early stages of pollen maturation. CONCLUSION/SIGNIFICANCE: eIF3h and eIF3e both become essential during pollen germination, a stage of vigorous translation of newly transcribed mRNAs. These data delimit the end of the developmental window during which paternal rescue is still possible. Moreover, the FTL collection of mapped fluorescent protein transgenes represents an attractive resource for elucidating the pollen development phenotypes of any fine-mapped mutation in Arabidopsis.

  14. Collection and Storage of Tectona grandis Pollen%柚木花粉收集与贮藏研究

    Institute of Scientific and Technical Information of China (English)

    黄桂华; 梁坤南; 林明平; 周再知; 马华明

    2012-01-01

    Anthesis pheology, pollen collection, viability determination and storage of Tectona grandis L. f. were introduced and studied,the results showed that pollen can be collected by water culture method and bagged method, the time for pollen collection of Indian provenances and Burma provenances were 9 to 11 o-clock and 11 to 13 o-clock,respectively. The pollen viability rose first and then decreased after anthesis,it have highest viability after anthesis 1. 5 h and no longer viable after 4. 5 h. The pollen viability decreased fast after collected and put in room temperature for wind to dry, it no longer viable after collected 2 h. The viability of pollen stored in 5 ℃ and - 15 ℃ rose first and then decreased, both of the pollen lost viability at 330 day. Both pollen germination rate and pollen tube length of pollen stored in 5 X decreased fast than that of - 15 ℃, pollen storage effect of - 15 ℃ was better than 5 ℃. Pollen stored in - 15 ℃. for 240 day can be used for controlled pollination among different teak provenances or different species of Tectona.%介绍了柚木开花生物学特性,开展了柚木花粉收集、活力测定、贮藏方法及其效果的研究.结果表明:柚木花粉收集可采用水培法和套袋法;不同种源收集花粉时间不同,印度种源和缅甸种源分别为09:~11:00时和11:00~13:00时;花开放后,花粉活力是先升后降,1.5h后花粉活力最强,4.5h后花粉即失去萌发力;随着贮藏时间的延长,5℃和-15℃干燥贮藏花粉的活力逐渐下降,贮藏到330 d,5℃和- 15℃的花粉都失去萌发力;在整个过程中,5℃的花粉萌发率和花粉管长度都比-15℃下降速度快;-15℃柚木花粉的贮藏效果优于5℃;-15℃干燥贮藏240d的柚木花粉,可满足当年柚木花期不同的种源间或柚木属不同种间人工杂交授粉.

  15. Evaluation of pollen germination of some palm males and pollination impact on bunch weight and fruit quality in Kadary date palm cultivar (Phoenix dactylifera L.).

    Science.gov (United States)

    Soliman, S S; Al-Saif, A M; Al-Obeed, R S

    2016-01-01

    The present study was carried out during two successive seasons (2013-2014) at the Research and Agriculture Experiment Station, Dirab, College of Food and Agricultural Sciences, King Saud University, Riyadh. Pollen grains, used in this trial, were collected from eleven male, namely Succary, Menify, Sallag, Dikhiny, Nabout Zamel, Serry, Khalas, Shagra, Safry, Maktumi and Kadary in order to pollinate female Kadary date palm cultivar. Results indicated that pollens of Safry male followed by Succary, Menify and Serry males increased the physical and biochemical characteristics of fruits during both seasons. Also, all the studied characters were significantly affected with different pollen males used in this trial. Pollens of Safry male gave highest fruit retention and bunch weight and best fruit quality like fruit and flesh weight, fruit size and fruit length and fruit biochemical properties as compared with other male. In vitro pollen germination of eleven males was studied using various concentration of sucrose (4, 6, 8 and 10%). The results showed that best germination was achieved with 8% sucrose concentration; however, 10% sucrose resulted in reduced percentage of pollen germination. In addition, pollen tube growth of five males (Succary, Sallag, Nabout-Zamel, Khalas and Safry) at 8% sucrose was alsostudied at 2, 4, 6 and 24 hr time interval. Elongation rate of pollen tube increased significantly after 24 hrs and it was found that pollens of Safry male gave highest pollen tube growth after 24 hrs than pollens of other male.

  16. AMS radiocarbon dating of pollen concentrates in a karstic lake system

    Science.gov (United States)

    Fletcher, William; Zielhofer, Christoph; Mischke, Steffen; Campbell, Jennifer; Bryant, Charlotte; Fink, David; Xu, Xiaomei

    2016-04-01

    .g. Pediastrum and Botryococcus. From sediment samples of ~15 g dry weight, it was possible to achieve pollen concentrates of 0.5-5 mg, with C content typically ~50% by weight. Samples with as little as 70-200 μg C were successfully measured with 0.5-1% error on the 14C age determination. This application of the pollen concentrate dating approach reinforces the importance of microscopic inspection of the residues during the separation and sieving stages. Sample specific differences mean that the pollen concentrate preparation cannot be reduced to a simplistic "black box" protocol, and dating must be undertaken alongside detailed analysis of the microfossil content of the sediments.

  17. Ragweed pollen production and dispersion modelling within a regional climate system, calibration and application over Europe

    Science.gov (United States)

    Liu, Li; Solmon, Fabien; Vautard, Robert; Hamaoui-Laguel, Lynda; Zsolt Torma, Csaba; Giorgi, Filippo

    2016-05-01

    Common ragweed (Ambrosia artemisiifolia L.) is a highly allergenic and invasive plant in Europe. Its pollen can be transported over large distances and has been recognized as a significant cause of hay fever and asthma (D'Amato et al., 2007; Burbach et al., 2009). To simulate production and dispersion of common ragweed pollen, we implement a pollen emission and transport module in the Regional Climate Model (RegCM) version 4 using the framework of the Community Land Model (CLM) version 4.5. In this online approach pollen emissions are calculated based on the modelling of plant distribution, pollen production, species-specific phenology, flowering probability, and flux response to meteorological conditions. A pollen tracer model is used to describe pollen advective transport, turbulent mixing, dry and wet deposition. The model is then applied and evaluated on a European domain for the period 2000-2010. To reduce the large uncertainties notably due to the lack of information on ragweed density distribution, a calibration based on airborne pollen observations is used. Accordingly a cross validation is conducted and shows reasonable error and sensitivity of the calibration. Resulting simulations show that the model captures the gross features of the pollen concentrations found in Europe, and reproduce reasonably both the spatial and temporal patterns of flowering season and associated pollen concentrations measured over Europe. The model can explain 68.6, 39.2, and 34.3 % of the observed variance in starting, central, and ending dates of the pollen season with associated root mean square error (RMSE) equal to 4.7, 3.9, and 7.0 days, respectively. The correlation between simulated and observed daily concentrations time series reaches 0.69. Statistical scores show that the model performs better over the central Europe source region where pollen loads are larger and the model is better constrained. From these simulations health risks associated to common ragweed pollen

  18. Evolutionary and ecological consequences of multiscale variation in pollen receipt for seed production.

    Science.gov (United States)

    Schreiber, Sebastian J; Rosenheim, Jay A; Williams, Neal W; Harder, Lawrence D

    2015-01-01

    Variation in resource availability can select for traits that reduce the negative impacts of this variability on mean fitness. Such selection may be particularly potent for seed production in flowering plants, as they often experience variation in pollen receipt among individuals and among flowers within individuals. Using analytically tractable models, we examine the optimal allocations for producing ovules, attracting pollen, and maturing seeds in deterministic and stochastic pollen environments. In deterministic environments, the optimal strategy attracts sufficient pollen to fertilize every ovule and mature every zygote into a seed. Stochastic environments select for allocations proportional to the risk of seed production being limited by zygotes or seed maturation. When producing an ovule is cheap and maturing a seed is expensive, among-plant variation selects for attracting more pollen at the expense of producing fewer ovules and having fewer resources for seed maturation. Despite this increased allocation, such populations are likely to be pollen limited. In contrast, within-plant variation generally selects for an overproduction of ovules and, to a lesser extent, pollen attraction. Such populations are likely to be resource limited and exhibit low seed-to-ovule ratios. These results highlight the importance of multiscale variation in the evolution and ecology of resource allocations.

  19. [Flora, distribution of vegetation and pollen content of the air: significance for allergics].

    Science.gov (United States)

    Tsukanova, G; Laaidi, M

    2004-09-01

    The wealth of the flora of a given region cannot be seen in its airborne pollen list. Actually, for some plants there is a low probability that their pollens are recorded in the pollen counts (entomogamous plants, in particular). Moreover, the light microscopy reduces the possibilities of determination. In France, The Aerobiological Network of Surveillance (RNSA) retains 92 taxa at different levels (gender, family, group of families), and among them allergenic as well as non allergenic taxa. From the 130 families of the France flora, 63 are taken into account in the pollen studies, 57 taxa being determined at the gender level. The comparison between the surface occupied by the tree species in the French departments of Côte-d'Or and Saône-et-Loire, and the average airborne pollen concentrations showed that usually there is no correspondence between the abundance of a plant and the number of its pollen in the records. So the flora of a region does not give enough information allowing to know the taxonomic composition and the pollen quantities in the air, which is of particular importance for allergic people.

  20. Quantitative relationship between pollen and vegetation in northern China

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    205 surface pollen samples from different communities in Northern China were analyzed to understand the quantitative relationship between pollen and its original vegetation. Pollen analysis and vegetation investigation show that the pollen assemblages differ a lot in different vegetation regions. Arboreal pollen account for more than 30% in temperate broad-deciduous forests region. In temperate steppe regions, herb pollen percentages are more than 90%, where Artemisia and Chenopodiaceae are domi- nant pollen types with Artemisia percentages more than 30%. In temperate desert, Chenopodiaceae pollen percentages are more than Artemisia, where ferns are rare. Cyperaceae pollen percentages are more than 20% in sub-alpine or cold meadows. The relations between pollen percentages and vegeta- tion cover indicate that most arboreal pollen shows a close relationship with parent plant covers, most shrubby pollen types have more or less correlations, but most herbs do not show clear correlations. For arboreal pollen types, Picea pollen shows the closest correlation with spruce trees coverage, then is Quercus and Carpinus. Betula, Larix and Juglans have also high correlation coefficients with their plants coverage, but Betula pollen is of overrepresented pollen type and more than 40% in birch forest, while Larix and Juglans pollen is underrepresented and pollen percentages are more than 10% in Larix or Juglans pure forests. Pinus is of overrepresented pollen type, and pollen percentages have some relations with plants cover. Pine forest might present when Pinus pollen percentages are more than 30%. The relations between Ulmus and Populus pollen percentages and vegetation cover are not close, where they are mixed with other arbors, they cannot be recorded easily, but if their pollen percentages are more than 1%, Ulmus or Populus trees should exist. For shrubby pollen types, the correlation be- tween Vitex pollen percentages and vegetation cover is the highest, then is Corylus

  1. Quantitative relationship between pollen and vegetation in northern China

    Institute of Scientific and Technical Information of China (English)

    XU QingHai; LI YueCong; YANG XiaoLan; ZHENG ZhenHua

    2007-01-01

    205 surface pollen samples from different communities in Northern China were analyzed to understand the quantitative relationship between pollen and its original vegetation. Pollen analysis and vegetation investigation show that the pollen assemblages differ a lot in different vegetation regions. Arboreal pollen account for more than 30%in temperate broad-deciduous forests region. In temperate steppe regions, herb pollen percentages are more than 90%,where Artemisia and Chenopodiaceae are dominant pollen types with Artemisia percentages more than 30%.In temperate desert, Chenopodiaceae pollen percentages are more than Artemisia, where ferns are rare. Cyperaceae pollen percentages are more than 20% in sub-alpine or cold meadows. The relations between pollen percentages and vegetation cover indicate that most arboreal pollen shows a close relationship with parent plant covers, most shrubby pollen types have more or less correlations, but most herbs do not show clear correlations. For arboreal pollen types, Picea pollen shows the closest correlation with spruce trees coverage, then is Quercus and Carpinus. Betula, Larix and Juglans have also high correlation coefficients with their plants coverage, but Betula pollen is of overrepresented pollen type and more than 40% in birch forest, while Larix and Juglans pollen is underrepresented and pollen percentages are more than 10%in Larix or Juglans pure forests. Pinus is of overrepresented pollen type, and pollen percentages have some relations with plants cover. Pine forest might present when Pinus pollen percentages are more than 30%.The relations between Ulmus and Populus pollen percentages and vegetation cover are not close, where they are mixed with other arbors. They cannot be recorded easily, but if their pollen percentages are more than 1%,Uimus or Populus trees should exist. For shrubby pollen types, the correlation between Vitex pollen percentages and vegetation cover is the highest, then is Corylus, Tamariaceae

  2. Pollen and pollen antigen as triggers of asthma—what to measure?

    Science.gov (United States)

    Beggs, Paul J.

    Although it has been recognised for many years that biological particulate matter in the atmospheric environment can trigger symptoms of allergic respiratory diseases such as asthma, the results of studies examining the relationships between pollen counts and the occurrence of such diseases have been inconsistent. In addition to the size of pollen grains as an explanation for such disagreement between studies, their is now a body of literature which has demonstrated that airborne pollen allergen can exist in sub-pollen sizes and out of the "pollen season", and that little correlation can occur between allergen levels and pollen counts. These findings not only explain disagreement between epidemiological studies using pollen counts but may raise doubts over the plausibility of any results from such studies. The paper reviews the results of a selection of epidemiological studies of pollen counts and asthma as well as studies which have documented the existence of pollen-free airborne allergen. It is concluded that future epidemiological studies should measure allergen rather than pollen grain counts, using methods that have been developed specifically for this purpose. Further research is required to determine if the presence of airborne pollen-free allergen is a universal phenomenon in pollens and perhaps in moulds as well.

  3. Pollen transport in the Shiyang River drainage, arid China

    Institute of Scientific and Technical Information of China (English)

    ZHU Yan; XIE Yaowen; CHENG Bo; CHEN Fahu; ZHANG Jiawu

    2003-01-01

    In order to assess the contribution of the pollen transported by wind and fluvial flows to the pollen spectra in Shiyang River drainage, a typical small endorheic drainage in arid lands of northwest China, preliminary studies on modern pollen rain along two transects with 91 surface soil samples, 8 atmospheric samples, 30 modern fluvial flow samples and 50 riverbed mud samples, were carried out. Results show that dispersal agents (air, flowing water) have dissimilareffects on transport of pollen and the structure of pollen spectra. Fluvial flow has a stronger capacity than wind to transport large quantities of pollen overlong distances. Pollen transported by fluvial flow makes a large contribution to the pollen spectra of riverbed alluvial sediments. Paleoenvironmental reconstructions undertaken using pollen spectra from fluvial sediments in arid lands arestrongly influenced by pollen transport. Therefore, the sources, the transportation agents and the depositional condition of pollen should be systematically investigated before pollen assemblages are used to derive the environmental significance in such settings.

  4. Projected carbon dioxide to increase grass pollen and allergen exposure despite higher ozone levels.

    Science.gov (United States)

    Albertine, Jennifer M; Manning, William J; DaCosta, Michelle; Stinson, Kristina A; Muilenberg, Michael L; Rogers, Christine A

    2014-01-01

    One expected effect of climate change on human health is increasing allergic and asthmatic symptoms through changes in pollen biology. Allergic diseases have a large impact on human health globally, with 10-30% of the population affected by allergic rhinitis and more than 300 million affected by asthma. Pollen from grass species, which are highly allergenic and occur worldwide, elicits allergic responses in 20% of the general population and 40% of atopic individuals. Here we examine the effects of elevated levels of two greenhouse gases, carbon dioxide (CO2), a growth and reproductive stimulator of plants, and ozone (O3), a repressor, on pollen and allergen production in Timothy grass (Phleum pratense L.). We conducted a fully factorial experiment in which plants were grown at ambient and/or elevated levels of O3 and CO2, to simulate present and projected levels of both gases and their potential interactive effects. We captured and counted pollen from flowers in each treatment and assayed for concentrations of the allergen protein, Phl p 5. We found that elevated levels of CO2 increased the amount of grass pollen produced by ∼50% per flower, regardless of O3 levels. Elevated O3 significantly reduced the Phl p 5 content of the pollen but the net effect of rising pollen numbers with elevated CO2 indicate increased allergen exposure under elevated levels of both greenhouse gases. Using quantitative estimates of increased pollen production and number of flowering plants per treatment, we estimated that airborne grass pollen concentrations will increase in the future up to ∼200%. Due to the widespread existence of grasses and the particular importance of P. pratense in eliciting allergic responses, our findings provide evidence for significant impacts on human health worldwide as a result of future climate change.

  5. Pollen limitation and reproductive assurance in Antillean Gesnerieae: a specialists vs. generalist comparison.

    Science.gov (United States)

    Martén-Rodríguez, Silvana; Fenster, Charles B

    2010-01-01

    Pollen limitation of female fecundity is widespread among angiosperms, a signal that pollinators frequently fail to transfer pollen to fertilize all ovules. Recent surveys have suggested that pollen limitation is associated with floral specialization. This study uses a group of Antillean Gesneriaceae with contrasting pollination systems (bat, hummingbird, and generalist) to assess the premise that plants with specialized pollination systems and infrequent pollinator visitation experience greater pollen limitation of fruit and seed set than their generalist congeners. Alternatively, specialists may possess mechanisms that reduce pollen limitation, such as autonomous self-pollination. A survey of autonomous self-pollination conducted on 13 Gesneria and Rhytidophyllum species during 2006-2008 revealed no significant association between reproductive assurance mechanisms and pollination system specialization. However, high levels of potential autonomous self-pollination were only found among specialized hummingbird-pollinated species. A comparison of fruit and seed set between emasculated and unmanipulated flowers provided evidence for autonomous selfing acting as a reproductive assurance mechanism in three out of four ornithophilous species. Furthermore, the Puerto Rican population of G. reticulata relies almost exclusively on self-pollination for reproduction. Two-year pollen supplementation experiments conducted on nine Gesnerieae species from the Dominican Republic and Puerto Rico provided evidence for significant pollen limitation associated with pollination specialization including both bat- and hummingbird-pollinated Gesnerieae; no pollen limitation was detected in any of the four generalist species. No pollen limitation was detected either in two ornithophilous Gesneria species with low hummingbird visitation and high levels of autonomous self-pollination. This study provides support for the idea that generalized pollination systems may, in some cases, buffer

  6. In vitro exposure of Ostrya carpinifolia and Carpinus betulus pollen to atmospheric levels of CO, O3 and SO 2.

    Science.gov (United States)

    Cuinica, Lázaro G; Abreu, Ilda; Esteves da Silva, Joaquim C G

    2014-02-01

    Ostrya spp. and Carpinus spp. pollen was in vitro exposed to three atmospheric pollutants: CO, O3 and SO2. Two levels of each pollutant were used, and the first level corresponds to a concentration about the atmospheric hour-limit value acceptable for human health protection in Europe and the second level to about the triple of the first level. Experiments were done under artificial solar light with temperature and relative humidity controlled. The viability of the exposed pollen samples showed a significant decrease. Also, the germination percentage showed a significant decrease in both exposed pollens, and the effect was most pronounced for SO2, followed by O3 and CO. A general decreasing trend in the total soluble protein content of the exposed pollen samples when compared with the control was observed, but it was only statistically significant for the Ostrya spp pollen. The results showed marked effects were observed on the Ostrya spp. and Carpinus spp. pollen when exposed to air pollutant levels that can be considered safe for human health protection.

  7. Specific probiotics alleviate allergic rhinitis during the birch pollen season

    Institute of Scientific and Technical Information of China (English)

    Arthur C Ouwehand; Merja Nermes; Maria Carmen Collado; Nina Rautonen; Seppo Salminen; Erika Isolauri

    2009-01-01

    AIM: To investigate whether birch pollen allergy symptoms are linked with gut microbiota changes and whether probiotics have an effect on these. METHODS: Forty seven children with confirmed birch pollen allergy were randomized to receive either a probiotic combination of Lactobacillus acidophilus ( L. acidophi lus) NCFMTM (ATCC 700396) and Bifidobacterium lactis ( B. lactis) Bl-04 (ATCC SD5219) or placebo in a double-blind manner for 4 mo, starting prior to onset of the birch pollen season. Symptoms were recorded in a diary. Blood samples were taken for analysis of cytokines and eosinophils. Fecal samples were analysed for microbiota components, calprotectin and IgA. Nasal swabs were taken for analysis of eosinophils.RESULTS: The pollen season induced a reduction in Bifidobacterium, Clostridium and Bacteroides which could not be prevented by the probiotic intervention. During the intervention, significantly higher numbers 106 bacteria/g feces ( P < 0.0001) were observed in the probiotic group compared to the placebo group. During May, there was a tendency for fewer subjects,(76.2% vs 95.2%, P = 0.078) to report runny nose,while during June, fewer subjects, 11.1% vs 33.3%,reported nasal blocking in the probiotics group ( P = 0.101). Concomitantly, fewer subjects in the probiotic group had infiltration of eosinophils in the nasal mucosa compared to the placebo group, 57.1%vs 95% ( P = 0.013). Eye symptoms tended to be slightly more frequent in the probiotic group, 12.5 d [interquartile range (IQR) 6-18] vs 7.5 d (IQR 0-11.5)( P = 0.066) during May. Fecal IgA was increased in the placebo group during the pollen season; this increase was prevented by the probiotics ( P = 0.028).CONCLUSION: Birch pollen allergy was shown to be associated with changes in fecal microbiota composition. The specific combination of probiotics used was shown to prevent the pollen-induced infiltration of eosinophils into the nasal mucosa, and indicated a trend for reduced nasal symptoms.

  8. Roles of pollen-specific boron efflux transporter, OsBOR4, in the rice fertilization process.

    Science.gov (United States)

    Tanaka, Nobuhiro; Uraguchi, Shimpei; Saito, Akihiro; Kajikawa, Masataka; Kasai, Koji; Sato, Yutaka; Nagamura, Yoshiaki; Fujiwara, Toru

    2013-12-01

    Arabidopsis thaliana BOR1 was the first boron (B) transporter identified in living systems. There are four AtBOR1-like genes, OsBOR1, 2, 3 and 4, present in the rice genome. We characterized the activity, expression and physiological function of OsBOR4. OsBOR4 is an active efflux transporter of B. Quantitative PCR analysis and OsBOR4 promoter-green fluorescent protein (GFP) fusion revealed that OsBOR4 was both highly and specifically expressed in pollen. We obtained five Tos17 insertion mutants of osbor4. The pollen grains were viable and development of floral organs was normal in the homozygous osbor4 mutants. We observed that in all Tos17 insertion lines tested, the frequency of osbor4 homozygous plants was lower than expected in the progeny of self-fertilized heterozygous plants. These results establish that OsBOR4 is essential for normal reproductive processes. Pollen from osbor4 homozygous plants elongated fewer tubes on wild-type stigmas, and tube elongation of mutant pollen was less efficient compared with the wild-type pollen, suggesting reduced competence of osbor4 mutant pollen. The reduced competence of mutant pollen was further supported by the crosses of independent Tos17-inserted alleles of OsBOR4. Our results suggest that OsBOR4, a boron efflux transporter, is required for normal pollen germination and/or tube elongation.

  9. Production of reactive oxygen species and reactive nitrogen species by angiosperm stigmas and pollen: potential signalling crosstalk?

    Science.gov (United States)

    McInnis, Stephanie M; Desikan, Radhika; Hancock, John T; Hiscock, Simon J

    2006-01-01

    Angiosperm stigmas exhibit high levels of peroxidase activity when receptive to pollen. To explore possible function(s) of this peroxidase activity we investigated amounts of reactive oxygen species (ROS), particularly hydrogen peroxide, in stigmas and pollen. Because nitric oxide (NO) was recently implicated in pollen tube growth, we also investigated amounts of NO in pollen and stigmas. Reactive oxygen species accumulation was assessed with confocal microscopy and light microscopy using ROS probes DCFH2-DA and TMB, respectively. NO was assayed using the NO probe DAF-2DA and confocal microscopy. Stigmas from various different angiosperms were found to accumulate ROS, predominantly H2O2, constitutively. In Senecio squalidus and Arabidopsis thaliana high amounts of ROS/H2O2 were localized to stigmatic papillae. ROS/H2O2 amounts appeared reduced in stigmatic papillae to which pollen grains had adhered. S. squalidus and A. thaliana pollen produced relatively high amounts of NO compared with stigmas; treating stigmas with NO resulted in reduced amounts of stigmatic ROS/H2O2. Constitutive accumulation of ROS/H2O2 appears to be a feature of angiosperm stigmas. This novel finding is discussed in terms of a possible role for stigmatic ROS/H2O2 and pollen-derived NO in pollen-stigma interactions and defence.

  10. Proteomic Analysis of Silk Viability in Maize Inbred Lines and Their Corresponding Hybrids.

    Science.gov (United States)

    Ma, Zhihui; Qin, Yongtian; Wang, Yafei; Zhao, Xiaofeng; Zhang, Fangfang; Tang, Jihua; Fu, Zhiyuan

    2015-01-01

    A long period of silk viability is critical for a good seed setting rate in maize (Zea mays L.), especially for inbred lines and hybrids with a long interval between anthesis and silking. To explore the molecular mechanism of silk viability and its heterosis, three inbred lines with different silk viability characteristics (Xun928, Lx9801, and Zong3) and their two hybrids (Xun928×Zong3 and Lx9801×Zong3) were analyzed at different developmental stages by a proteomic method. The differentially accumulated proteins were identified by mass spectrometry and classified into metabolism, protein biosynthesis and folding, signal transduction and hormone homeostasis, stress and defense responses, and cellular processes. Proteins involved in nutrient (methionine) and energy (ATP) supply, which support the pollen tube growth in the silk, were important for silk viability and its heterosis. The additive and dominant effects at a single locus, as well as complex epistatic interactions at two or more loci in metabolic pathways, were the primary contributors for mid-parent heterosis of silk viability. Additionally, the proteins involved in the metabolism of anthocyanins, which indirectly negatively regulate local hormone accumulation, were also important for the mid-parent heterosis of silk viability. These results also might imply the developmental dependence of heterosis, because many of the differentially accumulated proteins made distinct contributions to the heterosis of silk viability at specific developmental stages.

  11. Proteomic Analysis of Silk Viability in Maize Inbred Lines and Their Corresponding Hybrids.

    Directory of Open Access Journals (Sweden)

    Zhihui Ma

    Full Text Available A long period of silk viability is critical for a good seed setting rate in maize (Zea mays L., especially for inbred lines and hybrids with a long interval between anthesis and silking. To explore the molecular mechanism of silk viability and its heterosis, three inbred lines with different silk viability characteristics (Xun928, Lx9801, and Zong3 and their two hybrids (Xun928×Zong3 and Lx9801×Zong3 were analyzed at different developmental stages by a proteomic method. The differentially accumulated proteins were identified by mass spectrometry and classified into metabolism, protein biosynthesis and folding, signal transduction and hormone homeostasis, stress and defense responses, and cellular processes. Proteins involved in nutrient (methionine and energy (ATP supply, which support the pollen tube growth in the silk, were important for silk viability and its heterosis. The additive and dominant effects at a single locus, as well as complex epistatic interactions at two or more loci in metabolic pathways, were the primary contributors for mid-parent heterosis of silk viability. Additionally, the proteins involved in the metabolism of anthocyanins, which indirectly negatively regulate local hormone accumulation, were also important for the mid-parent heterosis of silk viability. These results also might imply the developmental dependence of heterosis, because many of the differentially accumulated proteins made distinct contributions to the heterosis of silk viability at specific developmental stages.

  12. Pollen types of the Egyptian species of tribe Lactuceae (subfamily Cichorioideae-Compositae)

    OpenAIRE

    Osman, A.K.E.

    2006-01-01

    Pollen morphology of forty six Egyptian species representing twenty three genera of the tribe Lactuceae was investigated using light and scanning electron microscopy. Seven pollen types were recognized: Geropogon pollen type, Koelpinia pollen type, Lactuca pollen type, Launaea pollen type, Rhagadiolus pollen type, Scolymus pollen type and Scorzonera pollen type. Descriptions, a key, light microscope (LM) and scaning electron microscope (SEM) micrographs of each pollen type are provided.

  13. 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.

  14. 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

  15. Transgenic lilies via pollen mediated transformation

    NARCIS (Netherlands)

    Leede-Plegt, van der L.M.; Kronenburg-van de Ven, van B.C.E.; Franken, J.; Tuyl, van J.M.; Tunen, van A.J.; Dons, J.J.M.

    1997-01-01

    We have developed a procedure for the production of transgenic lilies by using the pollen grain as vector for DNA delivery. First, a particle gun was used for the introduction of the NPTII gene (for kanamycin resistance) into pollen of lily (Lilium longiflorum), cv ‘Gelria’. Subsequently the bombard

  16. Reference: POLLEN1LELAT52 [PLACE

    Lifescience Database Archive (English)

    Full Text Available POLLEN1LELAT52 Bate N, Twell D Functional architecture of a late pollen promoter: polle...n-specific transcription is developmentally regulated by multiple stage-specific and co-dependent activator elements Plant Mol Biol 37:859-869 (1998) PubMed: 9678581; ...

  17. Reference: POLLEN1LELAT52 [PLACE

    Lifescience Database Archive (English)

    Full Text Available POLLEN1LELAT52 Filichkin SA, Leonard JM, Monteros A, Liu PP, Nonogaki H. A novel en...do-beta-mannanase gene in tomato LeMAN5 is associated with anther and pollen development. Plant Physiol. 134 1080-1087 (2004) PubMed: 14976239 ...

  18. Reference: POLLEN2LELAT52 [PLACE

    Lifescience Database Archive (English)

    Full Text Available POLLEN2LELAT52 Bate N, Twell D Functional architecture of a late pollen promoter: polle...n-specific transcription is developmentally regulated by multiple stage-specific and co-dependent activator elements Plant Mol Biol 37:859-869 (1998) PubMed: 9678581; ...

  19. Using three-dimensional discrete spherical Fourier descriptors based on surface curvature voxels for pollen particle recognition

    Institute of Scientific and Technical Information of China (English)

    Xie Yong-Hua; Michael OhEigeartaigh

    2010-01-01

    This paper presents a new method for extract three-dimensional (3D) discrete spherical Fourier descriptors based on surface curvature voxeis for pollen particle recognition.In order to reduce the high amount of pollen information and noise disturbance,the geometric normalized curvature voxels with the principal curvedness are first extracted to represent the intrinsic pollen volumetric data.Then the curvature voxels are decomposed into radial and angular components with spherical harmonic transform in spherical coordinates.Finally the 3D discrete Fourier transform is applied to the decomposed curvature voxels to obtain the 3D spherical Fourier descriptors for pollen recognition.Experimental results show that the presented descriptors are invariant to different pollen particle geometric transformations,such as pose change and spatial rotation,and can obtain high recognition accuracy and speed simultaneously.

  20. You sneeze, you lose:: The impact of pollen exposure on cognitive performance during high-stakes high school exams.

    Science.gov (United States)

    Bensnes, Simon Søbstad

    2016-09-01

    Pollen is known to cause allergic reactions and affect cognitive performance in around 20% of the population. Although pollen season peaks when students take high-stakes exams, the effect of pollen allergies on school performance has received nearly no attention from economists. Using a student fixed effects model and administrative Norwegian data, this paper finds that increasing the ambient pollen levels by one standard deviation at the mean leads to a 2.5% standard deviation decrease in test scores, with potentially larger effects for allergic students. There also appear to be longer-run effects. The findings imply that random increases in pollen counts reduce test scores for allergic students relative to their peers, who consequently will be at a disadvantage when competing for jobs or higher education. This paper contributes to the literature by illuminating the interplay between individual health and human capital accumulation, which in turn can impact long-run economic growth.

  1. Viability and Virulence of Entomopathogenic Nematodes Exposed to Ultraviolet Radiation.

    Science.gov (United States)

    Shapiro-Ilan, David I; Hazir, Selcuk; Lete, Luis

    2015-09-01

    Entomopathogenic nematodes (EPNs) can be highly effective biocontrol agents, but their efficacy can be reduced due to exposure to environmental stress such as from ultraviolet (UV) radiation. Our objectives were to 1) compare UV tolerance among a broad array of EPN species, and 2) investigate the relationship between reduced nematode viability (after exposure to UV) and virulence. Nematodes exposed to a UV radiation (254 nm) for 10 or 20 min were assessed separately for viability (survival) and virulence to Galleria mellonella. We compared 9 different EPN species and 15 strains: Heterorhabditis bacteriophora (Baine, fl11, Oswego, and Vs strains), H. floridensis (332), H. georgiana (Kesha), H. indica (HOM1), H. megidis (UK211), Steinernema carpocapsae (All, Cxrd, DD136, and Sal strains), S. feltiae (SN), S. rarum (17C&E), and S. riobrave (355). In viability assessments, steinernematids, particularly strains of S. carpocapsae, generally exhibited superior UV tolerance compared with the heterorhabditids. However, some heterorhabditids tended to be more tolerant than others, e.g., H. megidis and H. bacteriophora (Baine) were most susceptible and H. bacteriophora (Vs) was the only heterorhabditid that did not exhibit a significant effect after 10 min of exposure. All heterorhabditids experienced reduced viability after 20 min exposure though several S. carpocapsae strains did not. In total, after 10 or 20 min exposure, the viability of seven nematode strains did not differ from their non-UV exposed controls. In virulence assays, steinernematids (particularly S. carpocapsae strains) also tended to exhibit higher UV tolerance. However, in contrast to the viability measurements, all nematodes experienced a reduction in virulence relative to their controls. Correlation analysis revealed that viability among nematode strains is not necessarily related to virulence. In conclusion, our results indicate that the impact of UV varies substantially among EPNs, and viability alone

  2. Adenosine-5'-phosphosulfate kinase is essential for Arabidopsis viability.

    Science.gov (United States)

    Mugford, Sarah G; Matthewman, Colette A; Hill, Lionel; Kopriva, Stanislav

    2010-01-04

    In Arabidopsis thaliana, adenosine-5'-phosphosulfate kinase (APK) provides activated sulfate for sulfation of secondary metabolites, including the glucosinolates. We have successfully isolated three of the four possible triple homozygous mutant combinations of this family. The APK1 isoform alone was sufficient to maintain WT levels of growth and development. Analysis of apk1 apk2 apk3 and apk1 apk3 apk4 mutants suggests that APK3 and APK4 are functionally redundant, despite being located in cytosol and plastids, respectively. We were, however, unable to isolate apk1 apk3 apk4 mutants, most probably because the apk1 apk3 apk4 triple mutant combination is pollen lethal. Therefore, we conclude that APS kinase is essential for plant reproduction and viability.

  3. New insights into ragweed pollen allergens.

    Science.gov (United States)

    Bordas-Le Floch, Véronique; Groeme, Rachel; Chabre, Henri; Baron-Bodo, Véronique; Nony, Emmanuel; Mascarell, Laurent; Moingeon, Philippe

    2015-11-01

    Pollen allergens from short ragweed (Ambrosia artemisiifolia) cause severe respiratory allergies in North America and Europe. To date, ten short ragweed pollen allergens belonging to eight protein families, including the recently discovered novel major allergen Amb a 11, have been recorded in the International Union of Immunological Societies (IUIS) allergen database. With evidence that other components may further contribute to short ragweed pollen allergenicity, a better understanding of the allergen repertoire is a requisite for the design of proper diagnostic tools and efficient immunotherapies. This review provides an update on both known as well as novel candidate allergens from short ragweed pollen, identified through a comprehensive characterization of the ragweed pollen transcriptome and proteome.

  4. Preservation of cycad and Ginkgo pollen

    Science.gov (United States)

    Frederiksen, N.O.

    1978-01-01

    Pollen grains of Ginkgo, Cycas, and Encephalartos were chemically treated together with pollen of Quercus, Alnus, and Pinus, the latter three genera being used as standards. The experiments showed that: (1) boiling the pollen for 8-10 hours in 10% KOH had little if any effect on any of the grains; (2) lengthy acetolysis treatment produced some degradation or corrosion, particularly in Ginkgo and Cycas, but the grains of even these genera remained easily recognizable; (3) oxidation with KMnO4 followed by H2O2 showed that pollen of Ginkgo, Cycas, and Encephalartos remains better preserved than that of Quercus and Alnus, and although Ginkgo and Encephalartos probably are slightly less resistant to oxidation than Pinus, no great differences exists between these monosulcate types and Pinus. Thus the experiments show that, at least for sediments low in bacteria, cycad and Ginkgo pollen should be well represented in the fossil record as far as their preservational capabilities are concerned. ?? 1978.

  5. A Pollen Coat–Inducible Autoinhibited Ca2+-ATPase Expressed in Stigmatic Papilla Cells Is Required for Compatible Pollination in the Brassicaceae[W

    Science.gov (United States)

    Iwano, Megumi; Igarashi, Motoko; Tarutani, Yoshiaki; Kaothien-Nakayama, Pulla; Nakayama, Hideki; Moriyama, Hideki; Yakabe, Ryo; Entani, Tetsuyuki; Shimosato-Asano, Hiroko; Ueki, Masao; Tamiya, Gen; Takayama, Seiji

    2014-01-01

    In the Brassicaceae, intraspecific non-self pollen (compatible pollen) can germinate and grow into stigmatic papilla cells, while self-pollen or interspecific pollen is rejected at this stage. However, the mechanisms underlying this selective acceptance of compatible pollen remain unclear. Here, using a cell-impermeant calcium indicator, we showed that the compatible pollen coat contains signaling molecules that stimulate Ca2+ export from the papilla cells. Transcriptome analyses of stigmas suggested that autoinhibited Ca2+-ATPase13 (ACA13) was induced after both compatible pollination and compatible pollen coat treatment. A complementation test using a yeast Saccharomyces cerevisiae strain lacking major Ca2+ transport systems suggested that ACA13 indeed functions as an autoinhibited Ca2+ transporter. ACA13 transcription increased in papilla cells and in transmitting tracts after pollination. ACA13 protein localized to the plasma membrane and to vesicles near the Golgi body and accumulated at the pollen tube penetration site after pollination. The stigma of a T-DNA insertion line of ACA13 exhibited reduced Ca2+ export, as well as defects in compatible pollen germination and seed production. These findings suggest that stigmatic ACA13 functions in the export of Ca2+ to the compatible pollen tube, which promotes successful fertilization. PMID:24569769

  6. A Novel C2-Domain Phospholipid-Binding Protein,OsPBP1.Is Required for Pollen Fertility in Rice

    Institute of Scientific and Technical Information of China (English)

    Wen-Qiang Yang; Ying Lai; Mei-Na Li; Wen-Ying Xu; Yong-Biao Xue

    2008-01-01

    Pollen fertility is a crucial factor for successful pollination and essential for seed formation.Recent studies have suggested that a diverse range of internal and external factors,signaling components and their related pathways are likely involved in pollen fertility.Here,we reporta single C2-domain containing protein.OsPBPl.initially identified through cDNA microarray analysis.OsP8P1 is a single copy gene and preferentially expressed in pistil and pollen but downregulated by pollination.OsPBP1 had a calcium concentration-dependent phospholipid-binding activity and was localized mainly in cytoplasm and nucleus,but translocated onto the plasma membrane in response to an intracellular Ca2+increase.Pollen grains of antisense OsPBP1 transgenic Iines were largely nonviable.germinated poorly in vitro and of low fertility,OsPBP1 protein was localized in a region peripheral to pollen wall and vesicles of elongating pollen tube.and its repressed expression reduced substantially this association and led to alteration of microfilament polymerization during pollen germination.Taken together,these results indicate that OsPBP1 is a novel functional C2-domain phosphoIipids-binding protein that is required for pollen fertility likely by regulating Ca2+ and phospholipid signaling pathways.

  7. LFR Demonstrator Materials Viability

    Energy Technology Data Exchange (ETDEWEB)

    Caro, M

    2006-08-02

    Interest in fast reactor development has increased with the Department of Energy's introduction of the Global Nuclear Energy Partnership (GNEP) [1]. The GNEP program plans development of a sodium cooled Advanced Burner Reactor (ABR) that can be used to reduce the amount spent LWR fuel in storage and the number of high level waste sites needed for expansion of nuclear power throughout the world over the 21st century. In addition, the program proposes to make nuclear power more available while reducing the proliferation concerns by revising policies and technology for control of weapons useable materials. This would be accomplished with establishment of new institutional arrangements based on selective siting of reprocessing, enrichment and waste disposal facilities. The program would also implement development of small reactors suitable for use in developing countries or remote regions with small power grids. Over the past several years, under the Department of Energy (DOE) NERI and GEN IV programs research has been conducted on small lead cooled reactors. The Small Secure Transportable Autonomous Reactor (SSTAR) [2] is the most recent version of this type of reactor and research is continuing on it in the GEN IV program in parallel with GNEP. SSTAR is a small (10MWe-100MWe) reactor that is fueled once for life. It complements the GNEP program very well in that it serves one of the world markets not currently addressed by large reactors and its development requirements are similar to those for the ABRs. In particular, the fuel and structural materials for these fast spectrum reactors share common thermal and neutron environments. The coolants, sodium in ABR and lead or lead-bismuth eutectic (LBE) in SSTAR, are the major developmental difference. This report discusses the status of structural materials for fast reactor core and primary system components and selected aspects of their development.

  8. Nutrigenomics in honey bees: digital gene expression analysis of pollen's nutritive effects on healthy and varroa-parasitized bees

    Directory of Open Access Journals (Sweden)

    Parrinello Hughes

    2011-10-01

    Full Text Available Abstract Background Malnutrition is a major factor affecting animal health, resistance to disease and survival. In honey bees (Apis mellifera, pollen, which is the main dietary source of proteins, amino acids and lipids, is essential to adult bee physiological development while reducing their susceptibility to parasites and pathogens. However, the molecular mechanisms underlying pollen's nutritive impact on honey bee health remained to be determined. For that purpose, we investigated the influence of pollen nutrients on the transcriptome of worker bees parasitized by the mite Varroa destructor, known for suppressing immunity and decreasing lifespan. The 4 experimental groups (control bees without a pollen diet, control bees fed with pollen, varroa-parasitized bees without a pollen diet and varroa-parasitized bees fed with pollen were analyzed by performing a digital gene expression (DGE analysis on bee abdomens. Results Around 36, 000 unique tags were generated per DGE-tag library, which matched about 8, 000 genes (60% of the genes in the honey bee genome. Comparing the transcriptome of bees fed with pollen and sugar and bees restricted to a sugar diet, we found that pollen activates nutrient-sensing and metabolic pathways. In addition, those nutrients had a positive influence on genes affecting longevity and the production of some antimicrobial peptides. However, varroa parasitism caused the development of viral populations and a decrease in metabolism, specifically by inhibiting protein metabolism essential to bee health. This harmful effect was not reversed by pollen intake. Conclusions The DGE-tag profiling methods used in this study proved to be a powerful means for analyzing transcriptome variation related to nutrient intake in honey bees. Ultimately, with such an approach, applying genomics tools to nutrition research, nutrigenomics promises to offer a better understanding of how nutrition influences body homeostasis and may help reduce

  9. Nutrigenomics in honey bees: digital gene expression analysis of pollen's nutritive effects on healthy and varroa-parasitized bees

    National Research Council Canada - National Science Library

    Alaux, Cédric; Dantec, Christelle; Parrinello, Hughes; Le Conte, Yves

    2011-01-01

    .... In honey bees (Apis mellifera), pollen, which is the main dietary source of proteins, amino acids and lipids, is essential to adult bee physiological development while reducing their susceptibility to parasites and pathogens...

  10. Pollen and seed dispersal among dispersed plants.

    Science.gov (United States)

    Ghazoul, Jaboury

    2005-08-01

    The ecological significance of spacing among plants in contributing to the maintenance of species richness, particularly in tropical forests, has received considerable attention that has largely focussed on distance- and density-dependent seed and seedling mortality. More recently it has become apparent that plant spacing is also relevant to pollination, which often constrains seed production. While seed and seedling survival is reduced at high conspecific densities, pollination success, by contrast, is positively correlated to local conspecific density. Distance-dependent mechanisms acting on pollination and seed production have now been described for a variety of plants, with relatively isolated plants or fragmented populations generally suffering reduced fecundity due to pollen limitation. Yet there is considerable variability in the vulnerability of plant species to pollination failure, which may be a function of breeding system, life history, the pollination vector, the degree of specialisation among plants and their pollinators, and other indirect effects of habitat change acting on plants or pollinators. As reduced tree densities and population fragmentation are common outcomes of anthropogenically altered landscapes, understanding how pollination processes are affected in such degraded landscapes can inform effective conservation and management of remaining natural areas.

  11. Symmetric pollen mitosis I and suppression of pollen mitosis II prevent pollen development in Brachiaria jubata (Gramineae

    Directory of Open Access Journals (Sweden)

    C. Risso-Pascotto

    2005-11-01

    Full Text Available Microsporogenesis and pollen development were analyzed in a tetraploid (2n = 4x = 36 accession of the forage grass Brachiaria jubata (BRA 007820 from the Embrapa Beef Cattle Brachiaria collection that showed partial male sterility. Microsporocytes and pollen grains were prepared by squashing and staining with 0.5% propionic carmine. The meiotic process was typical of polyploids, with precocious chromosome migration to the poles and laggards in both meiosis I and II, resulting in tetrads with micronuclei in some microspores. After callose dissolution, microspores were released into the anther locule and appeared to be normal. Although each microspore initiated its differentiation into a pollen grain, in 11.1% of them nucleus polarization was not observed, i.e., pollen mitosis I was symmetric and the typical hemispherical cell plate was not detected. After a central cytokinesis, two equal-sized cells showing equal chromatin condensation and the same nuclear shape and size were formed. Generative cells and vegetative cells could not be distinguished. These cells did not undergo the second pollen mitosis and after completion of pollen wall synthesis each gave rise to a sterile and uninucleate pollen grain. The frequency of abnormal pollen mitosis varied among flowers and also among inflorescences. All plants were equally affected. The absence of fertile sperm cells in a considerable amount of pollen grains in this accession of B. jubata may compromise its use in breeding and could explain, at least in part, why seed production is low when compared with the amount of flowers per raceme.

  12. Pollen dispersal in sugar beet production fields.

    Science.gov (United States)

    Darmency, Henri; Klein, Etienne K; De Garanbé, Thierry Gestat; Gouyon, Pierre-Henri; Richard-Molard, Marc; Muchembled, Claude

    2009-04-01

    Pollen-mediated gene flow has important implications for biodiversity conservation and for breeders and farmers' activities. In sugar beet production fields, a few sugar beet bolters can produce pollen as well as be fertilized by wild and weed beet. Since the crop, the wild beets, and the weed beets are the same species and intercross freely, the question of pollen flow is an important issue to determine the potential dispersal of transgenes from field to field and to wild habitats. We report here an experiment to describe pollen dispersal from a small herbicide-resistant sugar beet source towards male sterile target plants located along radiating lines up to 1,200 m away. Individual dispersal functions were inferred from statistical analyses and compared. Pollen limitation, as expected in root-production fields, was confirmed at all the distances from the pollen source. The number of resistant seeds produced by bait plants best fitted a fat-tailed probability distribution curve of pollen grains (power-law) dependent on the distance from the pollen source. A literature survey confirmed that power-law function could fit in most cases. The b coefficient was lower than 2. The number of fertilized flowers by background (herbicide-susceptible) pollen grains was uniform across the whole field. Airborne pollen had a fertilization impact equivalent to that of one adjacent bolter. The individual dispersal function from different pollen sources can be integrated to provide the pollen cloud composition for a given target plant, thus allowing modeling of gene flow in a field, inter-fields in a small region, and also in seed-production area. Long-distance pollen flow is not negligible and could play an important role in rapid transgene dispersal from crop to wild and weed beets in the landscape. The removing of any bolting, herbicide-resistant sugar beet should be compulsory to prevent the occurrence of herbicide-resistant weed beet, thus preventing gene flow to wild

  13. Bee pollen improves muscle protein and energy metabolism in malnourished old rats through interfering with the Mtor signaling pathway and mitochondrial activity.

    Science.gov (United States)

    Salles, Jérôme; Cardinault, Nicolas; Patrac, Véronique; Berry, Alexandre; Giraudet, Christophe; Collin, Marie-Laure; Chanet, Audrey; Tagliaferri, Camille; Denis, Philippe; Pouyet, Corinne; Boirie, Yves; Walrand, Stéphane

    2014-12-01

    Although the management of malnutrition is a priority in older people, this population shows a resistance to refeeding. Fresh bee pollen contains nutritional substances of interest for malnourished people. The aim was to evaluate the effect of fresh bee pollen supplementation on refeeding efficiency in old malnourished rats. Male 22-month-old Wistar rats were undernourished by reducing food intake for 12 weeks. The animals were then renourished for three weeks with the same diet supplemented with 0%, 5% or 10% of fresh monofloral bee pollen. Due to changes in both lean mass and fat mass, body weight decreased during malnutrition and increased after refeeding with no between-group differences (p bee pollen-enriched diets showed a significant increase in muscle mass compared to restricted rats (p bee pollen-containing diets. In conclusion, refeeding diets that contain fresh monofloral bee pollen improve muscle mass and metabolism in old, undernourished rats.

  14. Alnus as a disturbing factor in pollen diagrams

    NARCIS (Netherlands)

    Janssen, C.R.

    1959-01-01

    It is commonly accepted that percentages of pollen in a pollen diagram do not express the exact composition of forests in earlier times. This inaccuracy is due to several factors, for instance the different quantities of pollen produced by plants, the distance of transport etc. A pollen diagram tell

  15. THE BIOMASS OF Streptococcus thermophilus AND Bifidobacterium longum IN DAIRY MEDIUM WITH BEE POLLEN

    Directory of Open Access Journals (Sweden)

    N. N. Lomova

    2015-02-01

    Full Text Available The present study was carried out to investigate the effect of adding different concentrations of bee pollen on the biomass of Streprococus thermophilus and B. longum in the dairy environment. Sampling, preparation and conducting of tests were performed by standard methods of analysis. The counts of Str. thermophilus and B. longum were carried out by using M17 and MRS agar media. The phases growth were determined graphically. Established, that bee pollen stimulates the accumulation of biomass Str. thermophilus on 9–15%, and B. longum – on 2,3–12,7% in an amount of up to 0.2–1.0%. Bee pollen reduces the duration of the lag phase for both types of microorganisms almost to its complete disappearance (1.0%. Pollen (1% prolong stationary phase for streptococci and bifidobacteria to 30% and 20%, respectively. And also, will provide the biomass in the amount of 6 ± 0,1·109 CFU/cm3 (Str. Thermophilus and 2,8 ± 0,1·108 CFU/cm3 (B. longum. Str. thermophilus and B. longum readily assimilate essential micronutrients pollen. Components of bee pollen can act growth stimulants (bifidogenic factor for the studied strains. The data obtained will form the basis of biotechnology dairy drink with bee products.

  16. Biocontrol attack increases pollen limitation under some circumstances in the invasive plant Centaurea solstitialis.

    Science.gov (United States)

    Swope, Sarah M

    2014-01-01

    Herbivore damage often deters pollinator visitation and many invasive plants in North America are pollinator-dependent. This has important implications for the biological control of invasive plants because it means that agents that deter pollinators may have a larger than expected impact on the plant. Yet interactions between pollinators and biocontrol agents are rarely evaluated. Centaurea solstitialis, one of the most problematic invasive species in California, is dependent on pollinators for reproduction. I factorially manipulated infection by a biocontrol pathogen and pollen supplementation to test for (1) pollen limitation in C. solstitialis, (2) whether infection increased pollen limitation, and (3) whether this varied across a soil moisture gradient. Plants growing on north-facing slopes where soil moisture was higher experienced mild pollen limitation in the absence of the pathogen and more pronounced pollen limitation when they were infected. Plants on drier south-facing slopes did not suffer from pollen limitation but instead appeared to suffer from resource limitation. Pathogen infection directly reduced seed set in C. solstitialis by 67-72%. On north-facing slopes, infection had an additional, indirect effect by increasing the degree of pollen limitation plants experienced. The trait that mediates this indirect pathogen-pollinator interaction is the number of inflorescences plants produced: infected plants made fewer inflorescences which led to greater pollen limitation. Although in the present study this outcome is dependent on abiotic factors that vary over small spatial scales, exploiting other invasive plants' dependence on pollinators by selecting agents that deter visitation may enhance agent impact.

  17. Targeting of Pollen Tubes to Ovules Is Dependent on Nitric Oxide (NO) Signaling

    Institute of Scientific and Technical Information of China (English)

    Ana Margarida Prado; Renato Cola(c)o; Nuno Moreno; Ana Catarina Silva; José A.Feijó

    2008-01-01

    The guidance signals that drive pollen tube navigation inside the pistil and micropyle targeting are still, to a great extent,unknown.Previous studies in vitro showed that nitric oxide (NO) works as a negative chemotropic cue for pollen tube growth in lily(Lilium longiflorum).Furthermore, Arabidopsis thaliana Atnos1 mutant plants,which show defective NO production,have reduced fertility.Here, we focus in the role of NO in the process of pollen-pistil communication, using Arabidopsis in-vivo and lily semi-vivo assays.Cross-pollination between wild-type and Atnos1 plants shows that the mutation affects the pistil tissues in a way that is compatible with abnormal pollen tube guidance.Moreover,DAF-2DA staining for NO in kanadi floral mutants showed the presence of NO in an asymmetric restricted area around the micropyle.The pollen-pistil interaction transcriptome indicates a time-course-specific modulation of transcripts of AtNOS1 and two Nitrate Reductases(nr1 and nr2),which collectively are thought to trigger a putative NO signaling pathway.Semivivo assays with isolated ovules and lily pollen further showed that NO is necessary for micropyle targeting to occur.This evidence is supported by CPTIO treatment with subsequent formation of balloon tips in pollen tubes facing ovules.Activation of calcium influx in pollen tubes partially rescued normal pollen tube morphology,suggesting that this pathway is also dependent on Ca2+ signaling.A role of NO in modulating Ca2+ signaling was further substantiated by direct imaging the cytosolic free Ca2+ concentration during NO-induced re-orientation,where two peaks of Ca2+ occur-one during the slowdown/stop response,the second during re-orientation and growth resumption.Taken together,these results provide evidence for the participation of NO signaling events during pollen-pistil interaction.Of special relevance,NO seems to directly affect the targeting of pollen tubes to the ovule's micropyle by modulating the action of its

  18. A combinatorial morphospace for angiosperm pollen

    Science.gov (United States)

    Mander, Luke

    2016-04-01

    The morphology of angiosperm (flowering plant) pollen is extraordinarily diverse. This diversity results from variations in the morphology of discrete anatomical components. These components include the overall shape of a pollen grain, the stratification of the exine, the number and form of any apertures, the type of dispersal unit, and the nature of any surface ornamentation. Different angiosperm pollen morphotypes reflect different combinations of these discrete components. In this talk, I ask the following question: given the anatomical components of angiosperm pollen that are known to exist in the plant kingdom, how many unique biologically plausible combinations of these components are there? I explore this question from the perspective of enumerative combinatorics using an algorithm I have written in the Python programming language. This algorithm (1) calculates the number of combinations of these components; (2) enumerates those combinations; and (3) graphically displays those combinations. The result is a combinatorial morphospace that reflects an underlying notion that the process of morphogenesis in angiosperm pollen can be thought of as an n choose k counting problem. I compare the morphology of extant and fossil angiosperm pollen grains to this morphospace, and suggest that from a combinatorial point of view angiosperm pollen is not as diverse as it could be, which may be a result of developmental constraints.

  19. Pollen

    Science.gov (United States)

    ... most common grasses that can cause allergies are: Bermuda grass Johnson grass Kentucky bluegrass Orchard grass Sweet ... Health Sciences 111 T.W. Alexander Drive Research Triangle Park, N.C. 27709 NIEHS Staff: Request an ...

  20. Variation in Pollen-Donor Composition among Pollinators in an Entomophilous Tree Species, Castanea crenata, Revealed by Single-Pollen Genotyping

    OpenAIRE

    Yoichi Hasegawa; Yoshihisa Suyama; Kenji Seiwa

    2015-01-01

    Background In plants, reproductive success is largely determined by the composition of pollen (i.e., self-pollen and outcross-pollen from near and distant pollen-donors) transported as a result of pollinator foraging behavior (e.g., pollen carryover). However, little evidence is available on how and to what extent the pollen carryover affects the pollen-donor composition and on which insect taxa are effective outcross-pollen transporters under field conditions. In this study, we explored role...

  1. Deep-sea pollen research in China

    Institute of Scientific and Technical Information of China (English)

    SUN Xiangjun; LUO Yunli; CHEN Huaicheng

    2003-01-01

    This paper briefly presents the progress of deep-sea pollen research in China since the beginning ofninetieths of the last Century. All the deep-sea pollen contri-butions mainly come from the South China Sea (SCS) andthe East China Sea (ECS). The German-Chinese joint cruise(Sonne 95) and ODP 184 cruise initiated by Chinese scientistsin the SCS provided excellent material for the deep-sea pol-len research. So far a number of pollen results of 20-30 kaand million years from the SCS have been published. A couple of deep-sea pollen records from Okinawa Through of the ECS also came out. The high resolution pollen records obtained from the continuous deposits with high sedimentation rates and reliable age control of the deep-sea sediments provided a high time resolution history (hundred to millennial scales) of vegetation, environment and monsoon evolution of the pollen source areas (southern China and Japan). Spectral analysis of deep-sea pollen records from the SCS discovered orbital (100, 41, 23, 10 ka) and suborbital cyclicities (Heinrich and Dansgaard/Oscheger-O/D events) in the vege-tation changes. Moreover, cross spectral analysis showed that the trend of vegetation changes in northern SCS was regulated mainly by changes of the ice volume in the Northern Hemisphere. The pollen record of the last 20 ka from the Okinawa Through of the ECS indicates that the marine environmental change lagged that on the terrestrail by about 1000 year. The asynchronous environmental changes between land and sea were probably caused by the time difference in thermohaline circulation. This study underscored the role of the deep-sea plant fossils as a bridge across the land and sea.

  2. 8{sup th} Wood Energy Symposium - On the way to Sustainability and Measures to Reduce Emissions and Improve Financial Viability; 8. Holzenergie-Symposium - Wege zur Nachhaltigkeit und Massnahmen zur Emissionsminderung und Wirtschaftlichkeitsverbesserung

    Energy Technology Data Exchange (ETDEWEB)

    Nussbaumer, T. (ed.)

    2004-07-01

    These conference proceedings published by the Swiss Federal Office of Energy (SFOE) contain the 12 papers presented at the 8{sup th} Wood Energy Symposium held at the Swiss Federal Institute of Technology in Zurich in October 2004. The topics covered include the harvesting factor of energy systems using wood combustion, a review of the contribution made by biomass to total energy supply using renewable energy, industrial wood-pellets production and the 'QM Holzheizwerke' program (quality management in wood-fired heating installations) as a successful Swiss export. Also, reports are presented on the hydraulic integration of automatic wood-based heating systems, dioxin and polycyclic aromatic hydrocarbons (PAH) emissions caused by illegal burning of waste, the use and disposal of ash from automatic wood-fired heating systems and the thermal use of wood wastes in power stations. Four further papers deal with incineration installations for draft (wastes produced in the brewing of beer), a district heating power station in Berlin that burns 262,000 tonnes of waste wood per year and the combustion of wet sawmill wastes in combined heat and power installations. Finally, a comparison is presented of the economic viability of district heating and oil-fired heating systems. The proceedings are completed with details on the 20 contributors involved in the symposium.

  3. Genomic expression profiling of mature soybean (Glycine max) pollen

    OpenAIRE

    Singh Mohan B; Gresshoff Peter M; Wong Chui E; Bhalla Prem L; Haerizadeh Farzad

    2009-01-01

    Abstract Background Pollen, the male partner in the reproduction of flowering plants, comprises either two or three cells at maturity. The current knowledge of the pollen transcriptome is limited to the model plant systems Arabidopsis thaliana and Oryza sativa which have tri-cellular pollen grains at maturity. Comparative studies on pollen of other genera, particularly crop plants, are needed to understand the pollen gene networks that are subject to functional and evolutionary conservation. ...

  4. Proteomic analyses of apoplastic proteins from germinating Arabidopsis thaliana pollen

    OpenAIRE

    Ge, Weina; Song, Yun; Zhang, Cuijun; Zhang, Yafang; Burlingame, Alma L; Guo, Yi

    2011-01-01

    Pollen grains play important roles in the reproductive processes of flowering plants. The roles of apoplastic proteins in pollen germination and in pollen tube growth are comparatively less well understood. To investigate the functions of apoplastic proteins in pollen germination, the global apoplastic proteins of mature and germinated Arabidopsis thaliana pollen grains were prepared for differential analyses by using 2-dimensional fluorescence difference gel electrophoresis (2-D DIGE) satura...

  5. Comparative Evaluation of Viability Assays for Storage of Ornamental Giner (Hedychium spp.) Pollen

    Science.gov (United States)

    In the United States, Hedychium plants are mostly grown in the southern part of the country where they generally flower in the summer and fall, but some species bloom in winter and spring times. This asynchronous flowering could constitute an impediment for breeders of that region to fully take adv...

  6. Spontaneous autotetraploidy and its impact on morphological traits and pollen viability in Solanum aethiopicum

    Science.gov (United States)

    We report for the first time the incidence of spontaneous autotetraploidy in Solanum aethiopicum (PI 636107). Stomatal dimensions and frequency, chloroplast numbers per guard cell, flow cytometry, and chromosome counts were used to differentiate the diploid plants from tetraploids. The impact of inc...

  7. The viability of perilabyrinthine osteocytes

    DEFF Research Database (Denmark)

    Bloch, Sune Land; Kristensen, Søren Lund; Sørensen, Mads Sølvsten

    2012-01-01

    Bone remodeling is highly inhibited around the inner ear space, most likely by the anti-resorptive action of the inner ear cytokine osteoprotegerin (OPG) entering perilabyrinthine bone through the lacuno-canalicular porosity (LCP). This extracellular signaling pathway depends on the viability of ...

  8. 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

  9. Meiotic abnormalities underlying pollen sterility in wild potato hybrids and spontaneous populations.

    Science.gov (United States)

    Larrosa, F H; Maune, J F; Erazzú, L E; Camadro, E L

    2012-01-01

    Wild potato species are widely distributed in the Americas, where they spontaneously grow in very diverse habitats. These species - with low chromosome differentiation - form polyploid series with 2n = 2x, 3x, 4x and 6x (x =12). They are isolated in nature by external and internal hybridisation barriers that can be incomplete, allowing hybridisation in areas of sympatry. Nevertheless, most accessions in germplasm banks, regardless of genetic background of the sampled spontaneous populations, have been assigned specific categories based on morphological characters. To further investigate the extent of hybridisation in the group and for comparative purposes, pollen viability was estimated in (i) artificial hybrids between a commercial cultivar (Calén INTA) of the common potato (tetraploid Solanum tuberosum ssp. tuberosum) and the tetraploid cytotype of the related wild species S. gourlayi, and (ii) samples of plants (accessions) and inflorescences of natural populations from Argentina, tentatively classified as 'presumed hybrids' (S. infundibuliforme-S. gourlayi) and 'species' (S. infundibuliforme, S. gourlayi and S. chacoense). Regardless of origin, 98 out of 103 plants analysed had zero to 70% pollen viability (zero to 40% in eight of them). Pollen grains were of variable size and morphology and, in mostly male sterile plants, the only viable pollen grains were 2n and/or 4n. Furthermore, male sterile plants shared various abnormalities in meiosis I and II (unpaired chromosomes, unequal chromosome distribution, precocious/lagging chromosomes, parallel, tripolar, fused and multiple spindles, unequal size nuclei, dyads, triads and pentads in addition to normal tetrads, among others). These results provide novel evidence to support field observations of early potato botanists on the extent of spontaneous hybridisation in wild Argentinian potato populations, which is not reflected in the current taxonomy and has significant consequences for germplasm conservation and

  10. The importance of the stationary and individual pollen monitoring for the diagnostic of pollen allergy

    Directory of Open Access Journals (Sweden)

    Dorota Myszkowska

    2012-12-01

    Full Text Available The aim of the study was to evaluate pollen seasons of selected taxa with particular reference to allergic taxa such as birch (Betula sp., grasses (Poaceae, mugwort (Artemisia sp. in Cracow in 2003 and 2004 (project number 3 PO5D 034 24 funded by the State Committee for Scientific Research. Pollen concentrations obtained using the stationary Burkard trap and personal Partrap FA 52 were compared. The volumetric method was used in the study. Average daily concentrations (pollen grains × m-3 were obtained by counting pollen grains every hour along 4 longitudinal transects and applying an appropriate conversion factor. Duration of the pollen season was determined using the 95% method. Variations in annual totals of pollen grains (birch and mugwort, in start dates (especially for grasses and in the season duration (birch and grasses were found. The comparison of pollen concentrations obtained using the stationary and personal traps at the same place showed non statistically significant correlation for all the studied taxa and statistically significant correlations for birch, mugwort and grasses (Spearman rank correlation. However, the statistically significant differences between the concentrations obtained using Burkard and Partrap carried by patients (Wilcoxon's test were noted. Very low concentrations of pollen grains measured indoor (work, flats and the influence of the local plants growing in separate place (courtyard of the Allergology Department on the pollen concentration were found.

  11. Phosphoproteomics Profiling of Tobacco Mature Pollen and Pollen Activated in vitro.

    Science.gov (United States)

    Fíla, Jan; Radau, Sonja; Matros, Andrea; Hartmann, Anja; Scholz, Uwe; Feciková, Jana; Mock, Hans-Peter; Čapková, Věra; Zahedi, René Peiman; Honys, David

    2016-04-01

    Tobacco mature pollen has extremely desiccated cytoplasm, and is metabolically quiescent. Upon re-hydration it becomes metabolically active and that results in later emergence of rapidly growing pollen tube. These changes in cytoplasm hydration and metabolic activity are accompanied by protein phosphorylation. In this study, we subjected mature pollen, 5-min-activated pollen, and 30-min-activated pollen to TCA/acetone protein extraction, trypsin digestion and phosphopeptide enrichment by titanium dioxide. The enriched fraction was subjected to nLC-MS/MS. We identified 471 phosphopeptides that carried 432 phosphorylation sites, position of which was exactly matched by mass spectrometry. These 471 phosphopeptides were assigned to 301 phosphoproteins, because some proteins carried more phosphorylation sites. Of the 13 functional groups, the majority of proteins were put into these categories: transcription, protein synthesis, protein destination and storage, and signal transduction. Many proteins were of unknown function, reflecting the fact that male gametophyte contains many specific proteins that have not been fully functionally annotated. The quantitative data highlighted the dynamics of protein phosphorylation during pollen activation; the identified phosphopeptides were divided into seven groups based on the regulatory trends. The major group comprised mature pollen-specific phosphopeptides that were dephosphorylated during pollen activation. Several phosphopeptides representing the same phosphoprotein had different regulation, which pinpointed the complexity of protein phosphorylation and its clear functional context. Collectively, we showed the first phosphoproteomics data on activated pollen where the position of phosphorylation sites was clearly demonstrated and regulatory kinetics was resolved.

  12. The effect of temperature on pollen germination and pollen tube growth of sour cherry cultivars

    Directory of Open Access Journals (Sweden)

    Milatović Dragan P.

    2014-01-01

    Full Text Available The study was carried out to determine the effect of three different temperatures (5, 15 and 25°C on in vitro pollen germination and pollen tube growth of five sour cherry cultivars: ‘Heimanns Konservenweichsel’, ‘Kelleriis 14’, ‘Oblačinska’, ‘Rexelle’ and ‘Šumadinka’. Pollen germination a % agar % Temperature significantly affected pollen germination. High germination rates (50-70% were obtained at both 15°C and 25°C. Satisfactory germination rates (42-51% were also obtained at 5°C in some cultivars (‘Rexelle’, ‘Šumadinka’ and ‘Heimanns Konservenweichsel’. The influence of temperature on the pollen tube growth was more prominent. The length of pollen tubes was three to six times higher at 15°C and 25°C in comparison with 5°C. This has led to the conclusion that the temperature of 5°C, although it could be adequate for pollen germination, is not high enough for optimal pollen tube growth. was determined by germinating pollen grains in culture medium containing 0.7agar-and 15sucrose. [Projekat Ministarstva nauke Republike Srbije, br. TR-31063

  13. Pollen Grain Germination and Pollen Tube Growth in Pistil of Rice

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The germination of pollen grain in vitro and the growth of pollen tube in the pistil of rice were observed with a microscope.The stigma was removed at different time points after pollination to study its effect on seed setting rate.The rice pollen grain started to germinate at 2 min after pollination and the pollen tube penetrated stigma into style in 5-10 min,30 min later the end of pollen tube reached the bottom of ovary,and only some pollen tubes arrived at embryo sac at 40 min after pollination.Meanwhile,a small amount of catlose began to deposit in the pollen tubes,a great deal of callose was observed at 50 min after pollination,whereas the pollen grain began to shrink.The growing rates of pollen tube in the rice stigma,style and ovary were 1500,5000,and 5400 pm/h,respectively.The seed setting rate was quite low when the stigma was removed at about 10-15 min after pollination,gradually increased when it removed at 20 min to 50 min after pollination,and over 60%when it removed at 50 min after pollination and finally tended to be stable.

  14. Pollen-limited reproduction in blue oak: Implications for wind pollination in fragmented populations

    Science.gov (United States)

    Knapp, E.E.; Goedde, M.A.; Rice, K.J.

    2001-01-01

    Human activities are fragmenting forests and woodlands worldwide, but the impact of reduced tree population densities on pollen transfer in wind-pollinated trees is poorly understood. In a 4-year study, we evaluated relationships among stand density, pollen availability, and seed production in a thinned and fragmented population of blue oak (Quercus douglasii). Geographic coordinates were established and flowering interval determined for 100 contiguous trees. The number of neighboring trees within 60 m that released pollen during each tree's flowering period was calculated and relationships with acorn production explored using multiple regression. We evaluated the effects of female flower production, average temperature, and relative humidity during the pollination period, and number of pollen-producing neighbors on individual trees' acorn production. All factors except temperature were significant in at least one of the years of our study, but the combination of factors influencing acorn production varied among years. In 1996, a year of large acorn crop size, acorn production was significantly positively associated with number of neighboring pollen producers and density of female flowers. In 1997, 1998, and 1999, many trees produced few or no acorns, and significant associations between number of pollen-producing neighbors and acorn production were only apparent among moderately to highly reproductive trees. Acorn production by these reproductive trees in 1997 was significantly positively associated with number of neighboring pollen producers and significantly negatively associated with average relative humidity during the pollination period. In 1998, no analysis was possible, because too few trees produced a moderate to large acorn crop. Only density of female flowers was significantly associated with acorn production of moderately to highly reproductive trees in 1999. The effect of spatial scale was also investigated by conducting analyses with pollen producers

  15. Effect of air pollutant NO₂ on Betula pendula, Ostrya carpinifolia and Carpinus betulus pollen fertility and human allergenicity.

    Science.gov (United States)

    Cuinica, Lázaro G; Abreu, Ilda; Esteves da Silva, Joaquim

    2014-03-01

    Pollen of Betula pendula, Ostrya carpinifolia and Carpinus betulus was exposed in vitro to two levels of NO2 (about 0.034 and 0.067 ppm) - both below current atmospheric hour-limit value acceptable for human health protection in Europe (0.11 ppm for NO2). Experiments were performed under artificial solar light with temperature and relative humidity continuously monitored. The viability, germination and total soluble proteins of all the pollen samples exposed to NO2 decreased significantly when compared with the non-exposed. The polypeptide profiles of all the pollen samples showed bands between 15 and 70 kDa and the exposure to NO2 did not produce any detectable changes in these profiles. However, the immunodetection assays indicated higher IgE recognition by patient sera sensitized to the pollen extracts from all exposed samples in comparison to the non-exposed samples. The common reactive bands to the three pollen samples correspond to 58 and 17 kDa proteins.

  16. Pine pollen inhibits cell apoptosis-related protein expression in the cerebral cortex of mice with arsenic poisoning

    Institute of Scientific and Technical Information of China (English)

    Yanhong Luo; Yaodong Wei; Taizhong Wang; Dongzhu Chen; Tiansheng Lu; Ruibo Wu; Keke Si

    2012-01-01

    Previous studies have demonstrated that pine pollen can inhibit cerebral cortical cell apoptosis in mice with arsenic poisoning. The present study sought to detect the influence of pine pollen on apoptosis-related proteins. Immunohistochemistry, western blotting and enzyme-linked immuno-sorbent assays were used to measure the levels of apoptosis-related proteins in the cerebral cortex of mice with arsenic poisoning. Results indicated that pine pollen suppressed cell apoptosis in the cerebral cortex of arsenic-poisoned mice by reducing Bax, Bcl-2 protein expression and increasing p53 protein expression.

  17. Molecular biomarkers for grass pollen immunotherapy.

    Science.gov (United States)

    Popescu, Florin-Dan

    2014-03-26

    Grass pollen allergy represents a significant cause of allergic morbidity worldwide. Component-resolved diagnosis biomarkers are increasingly used in allergy practice in order to evaluate the sensitization to grass pollen allergens, allowing the clinician to confirm genuine sensitization to the corresponding allergen plant sources and supporting an accurate prescription of allergy immunotherapy (AIT), an important approach in many regions of the world with great plant biodiversity and/or where pollen seasons may overlap. The search for candidate predictive biomarkers for grass pollen immunotherapy (tolerogenic dendritic cells and regulatory T cells biomarkers, serum blocking antibodies biomarkers, especially functional ones, immune activation and immune tolerance soluble biomarkers and apoptosis biomarkers) opens new opportunities for the early detection of clinical responders for AIT, for the follow-up of these patients and for the development of new allergy vaccines.

  18. Vitality and storage condition of Syringa pollen

    Institute of Scientific and Technical Information of China (English)

    ZHOULi; LUOFeng-xia; DAILi-min; ZHANGHui-hua

    2003-01-01

    The fresh pollen vitality,the effect of different storage conditions on the pollen vitality,and the difference of vitality among the species of seven species of Syringa were determined in Shenyang,China.The results indicated that the pollen vitality (81.5%) of Syringa villosa was the highest among the seven tested species,followed by S.microphylla and S.meyeri,and that of S.oblata var.affinis was the lowest.The low temperature was the best condition for storage of pollen of Syringa,and the most proper temperature for the storage was 0-2℃.The storability of S.microphylla was the best of all,and it could be stored over 60 days at the temperature of 0-2℃,next was S.villosa and S.meyeri.

  19. Pollen-projektiga Rootsis / Lembit Jakobson

    Index Scriptorium Estoniae

    Jakobson, Lembit

    2009-01-01

    Avastusõppe projektist "Pollen" Eesti (2006-2009) mille eesmärk on kõiki lapsi kaasav uurimisõpe. Kevadisel koolivaheajal tutvus kümmekond Eesti õpetajat uurimisõppega Stockholmi kahes algkoolis

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

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    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.

  1. Pollen Morphology and Determination of Pollen Activity Methods Comparison of Stizolobium cochinchinesis%藜豆花粉的形态及其活力测定方法比较

    Institute of Scientific and Technical Information of China (English)

    张凤银; 魏传斌; 徐小玉; 雷刚

    2014-01-01

    为藜豆的杂交育种及传粉生物学研究等提供基础资料与科学依据,筛选适宜的花粉活力快速测定方法,以白花黑籽藜豆花粉为材料,用光学显微镜观察花粉形态及萌发花粉管的数目,并用 TTC 法、I-KI 法和醋酸洋红法对其花粉活力进行了测定。结果表明:成熟的藜豆花粉近似圆球形,有3个萌发孔,但只有1个萌发孔长出花粉管;TTC 法着色效果差,I-IK 着色时间长(约20 min),而醋酸洋红染色法着色快(约2 min),染色清晰;醋酸洋红法适合藜豆花粉活力的快速测定。%In order to provide basic data and scientific evidence for the study of hybrid breeding and pollination biology,and also to select the suitable method for rapid measurement of life viability,the study was carried out to observe the pollen morphology and number of germination pollen tube of S.cochinchinesis by optical microscope,to observe the pollen morphology using TTC staining method,I-KI staining method and aceto-carmine staining method and to measure the life viability of the velvet bean pollen.The results indicated that the mature pollen was of approximately round ball form and had three germination apertures,but only one of which would grow up with pollen tube.The I-KI staining method and the TTC staining were the inappropriate methods for bad staining method and long staining time(about 20 min)respectively.The method of aceto-carmine staining was the best way to determine the pollen viability of S.cochinchinesis for staining rapidly and ideal staining effect.

  2. Are there changes in Germany regarding the start of the pollen season, the season length and the pollen concentration of the most important allergenic pollens?

    Energy Technology Data Exchange (ETDEWEB)

    Kaminski, Uwe [Centre for Human Biometeorological Research, Freiburg (Germany). German Meteorological Service; Glod, Tom [Univ. of Trier (Germany). FB Physical Geography

    2011-10-15

    For the regions Northwest, Northeast and Southern Germany we examined the main allergic pollen (Hazel, Alder, Birch, grasses and Mugwort) for trends on the basis of the pollen counts of the Pollen Information Service (PID) reference-stations. From these stations information about changes on the start of the pollen season, the season length and the total amount as well as the peak-concentration of pollen during the last years (1988-2009 for Northwest and Southern Germany and 1994-2009 for Northeast Germany) are examined. Possible trends are analysed by means of the Mann-Kendall test for their significance. The results demonstrate that the changes, regarding the start of the pollen season and the total pollen amount, are strongest in Southern and Northeast Germany. Data show for all regions that tree pollen becomes the significant allergen. (orig.)

  3. Quantitative DNA Analyses for Airborne Birch Pollen.

    Directory of Open Access Journals (Sweden)

    Isabell Müller-Germann

    Full Text Available Birch trees produce large amounts of highly allergenic pollen grains that are distributed by wind and impact human health by causing seasonal hay fever, pollen-related asthma, and other allergic diseases. Traditionally, pollen forecasts are based on conventional microscopic counting techniques that are labor-intensive and limited in the reliable identification of species. Molecular biological techniques provide an alternative approach that is less labor-intensive and enables identification of any species by its genetic fingerprint. A particularly promising method is quantitative Real-Time polymerase chain reaction (qPCR, which can be used to determine the number of DNA copies and thus pollen grains in air filter samples. During the birch pollination season in 2010 in Mainz, Germany, we collected air filter samples of fine (<3 μm and coarse air particulate matter. These were analyzed by qPCR using two different primer pairs: one for a single-copy gene (BP8 and the other for a multi-copy gene (ITS. The BP8 gene was better suitable for reliable qPCR results, and the qPCR results obtained for coarse particulate matter were well correlated with the birch pollen forecasting results of the regional air quality model COSMO-ART. As expected due to the size of birch pollen grains (~23 μm, the concentration of DNA in fine particulate matter was lower than in the coarse particle fraction. For the ITS region the factor was 64, while for the single-copy gene BP8 only 51. The possible presence of so-called sub-pollen particles in the fine particle fraction is, however, interesting even in low concentrations. These particles are known to be highly allergenic, reach deep into airways and cause often severe health problems. In conclusion, the results of this exploratory study open up the possibility of predicting and quantifying the pollen concentration in the atmosphere more precisely in the future.

  4. Quantitative DNA Analyses for Airborne Birch Pollen.

    Science.gov (United States)

    Müller-Germann, Isabell; Vogel, Bernhard; Vogel, Heike; Pauling, Andreas; Fröhlich-Nowoisky, Janine; Pöschl, Ulrich; Després, Viviane R

    2015-01-01

    Birch trees produce large amounts of highly allergenic pollen grains that are distributed by wind and impact human health by causing seasonal hay fever, pollen-related asthma, and other allergic diseases. Traditionally, pollen forecasts are based on conventional microscopic counting techniques that are labor-intensive and limited in the reliable identification of species. Molecular biological techniques provide an alternative approach that is less labor-intensive and enables identification of any species by its genetic fingerprint. A particularly promising method is quantitative Real-Time polymerase chain reaction (qPCR), which can be used to determine the number of DNA copies and thus pollen grains in air filter samples. During the birch pollination season in 2010 in Mainz, Germany, we collected air filter samples of fine (<3 μm) and coarse air particulate matter. These were analyzed by qPCR using two different primer pairs: one for a single-copy gene (BP8) and the other for a multi-copy gene (ITS). The BP8 gene was better suitable for reliable qPCR results, and the qPCR results obtained for coarse particulate matter were well correlated with the birch pollen forecasting results of the regional air quality model COSMO-ART. As expected due to the size of birch pollen grains (~23 μm), the concentration of DNA in fine particulate matter was lower than in the coarse particle fraction. For the ITS region the factor was 64, while for the single-copy gene BP8 only 51. The possible presence of so-called sub-pollen particles in the fine particle fraction is, however, interesting even in low concentrations. These particles are known to be highly allergenic, reach deep into airways and cause often severe health problems. In conclusion, the results of this exploratory study open up the possibility of predicting and quantifying the pollen concentration in the atmosphere more precisely in the future.

  5. Pollen characteristics in some Diospyros species

    Directory of Open Access Journals (Sweden)

    Olga Grygorieva

    2013-04-01

    Full Text Available Aim of the work was to study the general characteristics and essential morphological traits of pollen grains viz the size, shape of pollen grains and number, form and position of apertures in Diospyros kaki L.f., D. virginiana L., D. lotus L. species and interspecies hybrid of D. virginiana × D. kaki. Significant differences were detected among the tested species and the interspecific hybrid as well as between individual genotypes of D. lotus , especially in the equatorial axis.

  6. 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.

  7. The transmitting tissue of Nicotiana tabacum is not essential to pollen tube growth, and its ablation can reverse prezygotic interspecific barriers.

    Science.gov (United States)

    Smith, Alan G; Eberle, Carrie A; Moss, Nicole G; Anderson, Neil O; Clasen, Benjamin M; Hegeman, Adrian D

    2013-12-01

    The Nicotiana tabacum transmitting tissue is a highly specialized file of metabolically active cells that is the pathway for pollen tubes from the stigma to the ovules where fertilization occurs. It is thought to be essential to pollen tube growth because of the nutrients and guidance it provides to the pollen tubes. It also regulates gametophytic self-incompatibility in the style. To test the function of the transmitting tissue in pollen tube growth and to determine its role in regulating prezygotic interspecific incompatibility, genetic ablation was used to eliminate the mature transmitting tissue, producing a hollow style. Despite the absence of the mature transmitting tissue and greatly reduced transmitting-tissue-specific gene expression, self-pollen tubes had growth to the end of the style. Pollen tubes grew at a slower rate in the transmitting-tissue-ablated line during the first 24 h post-pollination. However, pollen tubes grew to a similar length 40 h post-pollination with and without a transmitting tissue. Ablation of the N. tabacum transmitting tissue significantly altered interspecific pollen tube growth. These results implicate the N. tabacum transmitting tissue in facilitating or inhibiting interspecific pollen tube growth in a species-dependent manner and in controlling prezygotic reproductive barriers.

  8. Pollen dispersal analysis using DNA markers

    Directory of Open Access Journals (Sweden)

    Wei Zhou

    2014-01-01

    Full Text Available Modes of pollen dispersal are important for plant ecology, conservation, and evolutionary biology as pollen-mediated gene flow connects one generation of sexually-reproducing plants to the next. With the development of DNA molecular techniques, molecular markers (especially microsatellite markers have replaced traditional physical markers for pollen flow analysis. Methods of paternity assignment with maximum likelihood and Bayesian inference have greatly improved the estimation of pollen flow characteristics with regard to direction, distance, and strength. Pollen dispersal curves have been characterized by single parameter, two-parameter, multi-parameter, and two-component composite models to better evaluate the shape of dispersal distributions. These innovative techniques and methods have been successfully applied to assess pollination patterns in studies of plant sexual polymorphism, population connectivity, and natural hybridization, which, in turn, have provided important insights into basic theories of evolution, ecology, and conservation. In the coming years, high-throughput sequencing technologies are expected to accelerate the application of molecular marker-based pollen flow analysis across a wide range of plant taxa.

  9. Pollen and sperm heteromorphism: convergence across kingdoms?

    Science.gov (United States)

    Till-Bottraud, I; Joly, D; Lachaise, D; Snook, R R

    2005-01-01

    Sperm competition theory predicts that males should produce many, similar sperm. However, in some species of animals and plants, males exhibit a heteromorphism that results in the production of at least two different types of sperm or pollen grains. In animals, sperm heteromorphism typically corresponds to the production of one fertile morph and one (or more) sterile morph(s), whereas in plants two or more pollen morphs (one of which can be either sterile or fertile) are produced in all flowers but sometimes in different anthers. Heteromorphism has arisen independently several times across phyla and at different phylogenetic levels. Here, we compare and contrast sperm and pollen heteromorphism and discuss the evolutionary hypotheses suggested to explain heteromorphism in these taxa. These hypotheses include facilitation, nutritive contribution, blocking, cheap filler, sperm flushing or killing for animals; outcrossing and precise cross-pollen transfer or bet-hedging strategy for plants; cryptic female choice for both. We conclude that heteromorphism in the two phyla is most likely linked to a general evolutionary response to sexual selection, either to increase one male's sperm or pollen success in competition with other males, or mediate male/female interactions. Therefore, although sperm and pollen are not homologous, we suggest that heteromorphism represents an example of convergence across kingdoms.

  10. Plant Sterol Diversity in Pollen from Angiosperms.

    Science.gov (United States)

    Villette, Claire; Berna, Anne; Compagnon, Vincent; Schaller, Hubert

    2015-08-01

    Here we have examined the composition of free sterols and steryl esters of pollen from selected angiosperm species, as a first step towards a comprehensive analysis of sterol biogenesis in the male gametophyte. We detected four major sterol structural groups: cycloartenol derivatives bearing a 9β,19-cyclopropyl group, sterols with a double bond at C-7(8), sterols with a double bond at C-5(6), and stanols. All these groups were unequally distributed among species. However, the distribution of sterols as free sterols or as steryl esters in pollen grains indicated that free sterols were mostly Δ(5)-sterols and that steryl esters were predominantly 9β,19-cyclopropyl sterols. In order to link the sterol composition of a pollen grain at anthesis with the requirement for membrane lipid constituents of the pollen tube, we germinated pollen grains from Nicotiana tabacum, a model plant in reproductive biology. In the presence of radiolabelled mevalonic acid and in a time course series of measurements, we showed that cycloeucalenol was identified as the major neosynthesized sterol. Furthermore, the inhibition of cycloeucalenol neosynthesis by squalestatin was in full agreement with a de novo biogenesis and an apparent truncated pathway in the pollen tube.

  11. Morphological Research on Indigenous Sambucus Species Pollen

    Directory of Open Access Journals (Sweden)

    Mircea TAMAS

    2009-06-01

    Full Text Available The pollen grains have a definite shape, size, colour, structure for each species, genus and family and these characters are useful for systematical botany. The pollen has nutritive properties due to its content: proteins, lipids, carbohydrates, vitamins, hormones and minerals. In the Romanian flora vegetate three species of Sambucus, but only S. nigra L. (elder or black elder supplies a vegetal medical product, Sambuci flos or elder flowers, whereas the others species S. ebulus L. (dwarf elder and S. racemosa L. (mountain elder or red elder are considered adulterations. The pollen of Sambucus species were already studied using optical microscopy (Tarnavschi et al., but the images are in one single layout, therefore the structure details cannot be easily notice. In this context the pollen grains of the three species already mentioned above were studied by SEM (Scanning Electron Microscopy. The results demonstrated that this pollen have a small-middle size, oblat-sphaeroidal-prolat shape, threecolpat and the exine adornments are of reticulate type, haemitectate with sticks in the meshs of polygonale net. The flavonoids content is lower than in others species (0.146-0.564 %. The SEM analyse of Sambucus pollen allow a reliable identification of the genus but less for the species.

  12. Pollen-related allergy in Europe.

    Science.gov (United States)

    D'Amato, G; Spieksma, F T; Liccardi, G; Jäger, S; Russo, M; Kontou-Fili, K; Nikkels, H; Wüthrich, B; Bonini, S

    1998-06-01

    The increasing mobility of Europeans for business and leisure has led to a need for reliable information about exposure to seasonal airborne allergens during travel abroad. Over the last 10 years or so, aeropalynologic and allergologic studies have progressed to meet this need, and extensive international networks now provide regular pollen and hay-fever forecasts. Europe is a geographically complex continent with a widely diverse climate and a wide spectrum of vegetation. Consequently, pollen calendars differ from one area to another; however, on the whole, pollination starts in spring and ends in autumn. Grass pollen is by far the most frequent cause of pollinosis in Europe. In northern Europe, pollen from species of the family Betulaceae is a major cause of the disorder. In contrast, the mild winters and dry summers of Mediterranean areas favor the production of pollen types that are rarely found in central and northern areas of the continent (e.g., the genera Parietaria, Olea, and Cupressus). Clinical and aerobiologic studies show that the pollen map of Europe is changing also as a result of cultural factors (e.g., importation of plants for urban parklands) and greater international travel (e.g., the expansion of the ragweed genus Ambrosia in France, northern Italy, Austria, and Hungary). Studies on allergen-carrying paucimicronic or submicronic airborne particles, which penetrate deep into the lung, are havi