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

International Nuclear Information System (INIS)

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

1977-01-01

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

Morphology-controlled synthesis of SiO{sub 2} hollow microspheres using pollen grain as a biotemplate

Energy Technology Data Exchange (ETDEWEB)

Cao Feng; Li Dongxu, E-mail: caofeng.cn@gmail.co, E-mail: dongxuli@njut.edu.c [College of Materials Science and Engineering, Nanjing University of Technology, Jiangsu Nanjing 210009 (China)

2009-04-15

Hollow surface-structured silica microspheres, a potential candidate for drug delivery systems, were synthesized using the rape pollen grain as a biotemplate via a facile sol-gel coating followed by a calcination process. Different surface morphologies relating to the controllable release property were also achieved on the as-prepared silica hollow microspheres by changing the ratio of the tetraethyl orthosilicate (TEOS) and water in sols. Differential scanning calorimetry (DSC) and thermogravity (TG), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), as well as Fourier transform infrared spectroscopy (FT-IR) were utilized to characterize the original pollen grain, the silica sols-coated pollen grain and the as-prepared hollow silica microspheres, respectively. Results indicated that the pollen grain would be removed at around 500 deg. C, and the sol coating was kept to form hollow microspheres. Physical adsorption was proved to be the main effect in the sol coating. A speculation on the formation mechanism of different morphologies is also given.

[Does a lateral gradient of membrane potential on the plasma membrane of growing pollen tube of germinating pollen grain exist?].

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Andreev, I M

2011-01-01

The data presented in the article by Breigina et al. (2009) "Changes in the membrane potential during pollen grain germination and pollen tube growth" (Tsitologiya. 51 (10): 815-823) and concerning the measurement of electric membrane potential (Delta Psi) on the plasma membrane of growing pollen tube of germinating pollen grain with the use of fluorescent potential-sensitive dye, di-4-ANEPPS, were critically analyzed in order to clarify whether a lateral gradient of Delta Psi on this membrane indeed exists. This analysis showed that the main conclusion of the authors of the above article on the existence of polar distribution of Delta Psi along the pollen tube plasma membrane is not in accordance with a number of known peculiarities of di-4-ANEPPS behavior in biological membranes and requires a significant revision. The findings in question reported by the authors, in my opinion, might be interpreted as evidence for the presence on the plasma membrane of growing pollen tube not only the membrane potential Delta Psi but also lateral gradient of so called intra-membrane dipole potential. Based on the comments made, another interpretation of the experimental results described by Breigina et al. has been offered. In addition, some drawbacks in the methodology used by the authors for measurement of Delta Psi with other fluorescent potential-sensitive dye, DiBAC3(3), are also shortly considered.

Molecular-Assisted Pollen Grain Analysis Reveals Spatiotemporal Origin of Long-Distance Migrants of a Noctuid Moth

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Hong Chang

2018-02-01

Full Text Available Pollen grains are regularly used as markers to determine an insect’s movement patterns or host (plant feeding behavior, yet conventional morphology-based pollen grain analysis (or palynology encounters a number of important limitations. In the present study, we combine conventional analytical approaches with DNA meta-barcoding to identify pollen grains attached to migrating adults of the turnip moth, Agrotis segetum (Lepidoptera: Noctuidae in Northeast China. More specifically, pollen grains were dislodged from 2566 A. segetum long-distance migrants captured on Beihuang Island (Bohai Sea and identified to many (plant species level. Pollen belonged to 26 families of plants, including Fagaceae, Oleaceae, Leguminosae, Asteraceae, Pinaceae and Rosaceae, including common species such as Citrus sinensis, Olea europaea, Ligustrum lucidum, Robinia pseudoacacia, Castanopsis echinocarpa, Melia azedarach and Castanea henryi. As the above plants are indigenous to southern climes, we deduce that A. segetum forage on plants in those locales prior to engaging in northward spring migration. Our work validates the use of DNA-assisted approaches in lepidopteran pollination ecology research and provides unique and valuable information on the adult feeding range and geographical origin of A. segetum. Our findings also enable targeted (area-wide pest management interventions or guide the future isolation of volatile attractants.

The ultrastructure of pollen grain surface in allotetraploid petunia (Petunia hybrida hort. superbissima as revealed by scanning electron microscopy

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S. Muszyński

2015-01-01

Full Text Available The ultrastructure of pollen grain surface in allotetraploid petunias was analyzed by scanning electron microscopy. The pollen grain wall is developed into characteristic pattern of convulations.

3D imaging of a rice pollen grain using transmission X-ray microscopy.

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Wang, Shengxiang; Wang, Dajiang; Wu, Qiao; Gao, Kun; Wang, Zhili; Wu, Ziyu

2015-07-01

For the first time, the three-dimensional (3D) ultrastructure of an intact rice pollen cell has been obtained using a full-field transmission hard X-ray microscope operated in Zernike phase contrast mode. After reconstruction and segmentation from a series of projection images, complete 3D structural information of a 35 µm rice pollen grain is presented at a resolution of ∼100 nm. The reconstruction allows a clear differentiation of various subcellular structures within the rice pollen grain, including aperture, lipid body, mitochondrion, nucleus and vacuole. Furthermore, quantitative information was obtained about the distribution of cytoplasmic organelles and the volume percentage of each kind of organelle. These results demonstrate that transmission X-ray microscopy can be quite powerful for non-destructive investigation of 3D structures of whole eukaryotic cells.

Labyrinths, columns and cavities: new internal features of pollen grain walls in the Acanthaceae detected by FIB-SEM.

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House, Alisoun; Balkwill, Kevin

2016-03-01

External pollen grain morphology has been widely used in the taxonomy and systematics of flowering plants, especially the Acanthaceae which are noted for pollen diversity. However internal pollen wall features have received far less attention due to the difficulty of examining the wall structure. Advancing technology in the field of microscopy has made it possible, with the use of a focused ion beam-scanning electron microscope (FIB-SEM), to view the structure of pollen grain walls in far greater detail and in three dimensions. In this study the wall structures of 13 species from the Acanthaceae were investigated for features of potential systematic relevance. FIB-SEM was applied to obtain precise cross sections of pollen grains at selected positions for examining the wall ultrastructure. Exploratory studies of the exine have thus far identified five basic structural types. The investigations also show that similar external pollen wall features may have a distinctly different internal structure. FIB-SEM studies have revealed diverse internal pollen wall features which may now be investigated for their systematic and functional significance.

Biomonitoring of pollen grains of a river bank suburban city, Konnagar, Calcutta, India, and its link and impact on local people.

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Ghosal, Kavita; Pandey, Naren; Bhattacharya, Swati Gupta

2015-01-01

Pollen grains released by plants are dispersed into the air and can become trapped in human nasal mucosa, causing immediate release of allergens triggering severe Type 1 hypersensitivity reactions in susceptible allergic patients. Recent epidemiologic data show that 11-12% of people suffer from this type of disorders in India. Hence, it is important to examine whether pollen grains have a role in dissipating respiratory problems, including allergy and astma, in a subtropical suburban city. Meteorological data were collected for a period of two years, together with aerobiological sampling with a Burkard sampler. A pollen calendar was prepared for the city. A health survey and the hospitalization rate of local people for the above problems were documented following statistical analysis between pollen counts and the data from the two above-mentioned sources. Skin Prick Test and Indirect ELISA were performer for the identification of allergenic pollen grains. Bio-monitoring results showed that a total of 36 species of pollen grains were located in the air of the study area, where their presence is controlled by many important meteorological parameters proved from SPSS statistical analysis and by their blooming periods. Statistical analysis showed that there is a high positive correlation of monthly pollen counts with the data from the survey and hospital. Biochemical tests revealed the allergic nature of pollen grains of many local species found in the sampler. Bio-monitoring, together with statistical and biochemical results, leave no doubt about the role of pollen as a bio-pollutant. General knowledge about pollen allergy and specific allergenic pollen grains of a particular locality could be a good step towards better health for the cosmopolitan suburban city.

Influence of boundary-layer dynamics on pollen dispersion and viability

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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.

Biomonitoring of pollen grains of a river bank suburban city, Konnagar, Calcutta, India, and its link and impact on local people

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Kavita Ghosal

2015-05-01

Full Text Available Introduction and objectives. Pollen grains released by plants are dispersed into the air and can become trapped in human nasal mucosa, causing immediate release of allergens triggering severe Type 1 hypersensitivity reactions in susceptible allergic patients. Recent epidemiologic data show that 11–12% of people suffer from this type of disorders in India. Hence, it is important to examine whether pollen grains have a role in dissipating respiratory problems, including allergy and astma, in a subtropical suburban city. Materials and methods. Meteorological data were collected for a period of two years, together with aerobiological sampling with a Burkard sampler. A pollen calendar was prepared for the city. A health survey and the hospitalization rate of local people for the above problems were documented following statistical analysis between pollen counts and the data from the two above-mentioned sources. Skin Prick Test and Indirect ELISA were performer for the identification of allergenic pollen grains. Results. Bio-monitoring results showed that a total of 36 species of pollen grains were located in the air of the study area, where their presence is controlled by many important meteorological parameters proved from SPSS statistical analysis and by their blooming periods. Statistical analysis showed that there is a high positive correlation of monthly pollen counts with the data from the survey and hospital. Biochemical tests revealed the allergic nature of pollen grains of many local species found in the sampler. Conclusions. Bio-monitoring, together with statistical and biochemical results, leave no doubt about the role of pollen as a bio-pollutant. General knowledge about pollen allergy and specific allergenic pollen grains of a particular locality could be a good step towards better health for the cosmopolitan suburban city.

Skin tests of pollen grains of taxodiaceae and cupressaceae in children with bronchial asthma.

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Midoro-Horiuti, T; Nouno, S; Seino, Y

1992-10-01

Atmospheric cedar pollen in the southern region of Okayama Prefecture (situated in south-western Japan) has been counted since 1988. Pollen of different species of the Taxodiaceae family (Cryptomeria japonica, Sequoia sempervirens and Metasequoia glyptostroboides) and Japanese juniper (Juniperus rigida) in the Cupressaceae family, which are propagated mainly in the southern region of Okayama Prefecture, were found among the atmospheric pollen. Scratch tests using the pollen extract from Taxodiaceae and Cupressaceae were performed on children with bronchial asthma. Forty (25%) and 30 (18.8%) of the 160 patients reacted positively to an allergen extract from the pollen grains of Japanese cedar (Cryptomeria japonica) and Japanese juniper, respectively.

Implementation and Evaluation of an Image Analysis System for Determining Viability of Pollen Grains in Temperate Rice Implementación y Evaluación de un Sistema de Análisis de Imagen para determinar la Viabilidad de Granos de Polen en Arroz Templado

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Rodrigo Ortega B

2011-03-01

Full Text Available Geographical and climatic factors limit the production of temperate rice (Oryza sativa L. in Chile. Large thermal fluctuations of air and water temperatures affect the viability of pollen, causing high levels of spikelet sterility (”blanking”, resulting in reduced yields per hectare. Counting viable pollen grains, at the time of anthesis, may allow determining, ahead, whether there will be yield losses by spikelet sterility; besides, knowing the potential pollen viability serves as a powerful tool for material selection in breeding programs, and for determining which management factors may influence ”blanking”. If performed manually, counting total and viable pollen grains can be extremely tedious, producing highly variable results. The present work had for objectives to develop and evaluate a system, based on imagery analysis, for counting total and viable pollen in rice anthers. At the time of anthesis, three panicles were collected from plot treatments of two field experiments in which the effects of different management factors (variety, water height, N rate, and spatial arrangement on spikelet sterility were evaluated. Two spikelets and four anthers were sampled from each panicle; pollen grains were extracted from anthers and photographed. Manual and digital counts were made on the images to determine total and viable pollen. Digital count was performed with the software SigmaScan Pro, setting some parameters on the imagery before counting. Precision and accuracy of the digital method were estimated. The results indicated that the digital pollen count showed a very good precision and accuracy and could be used to estimate pollen viability, and as a response variable to compare management treatments.La producción de arroz (Oryza sativa L. en Chile está limitada principalmente por factores geográficos y climáticos. Las grandes variaciones de temperatura del agua y del aire afectan la viabilidad del polen, causando altos niveles de

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

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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.

Ultrastructural demonstration of a glycoproteinic surface coat in allergenic pollen grains by combined cetylpyridinium chloride precipitation and silver proteinate staining.

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Grote, M; Fromme, H G

1984-01-01

In allergenic birch pollen grains, highly watersoluble surface substances were precipitated by the cationic detergent cetylpyridinium chloride (CPC) during aqueous fixation. After processing the pollen for electron microscopy, ultrathin sections of pollen grains were subjected to the periodic acid - thiocarbohydrazide - silver proteinate (PA-TCH-SP) procedure according to Thiery (1967) for the detection of vicinal glycol groups. It was found that the material precipitated by CPC on the surface and within the exine cavities of the pollen wall strongly reacted with the PA-TCH-SP reagent thus indicating the presence of polysaccharides on the surface of birch pollen grains. In samples which had not been treated with the cationic detergent, PA-TCH-SP reactivity was reduced to thin linings on the surface and within the exine cavities. In both cases the exine proper did not stain whereas the intine showed moderate staining. Within the aperture region of the intine, PA-TCH-SP reactivity is preferably associated with fibrillar or reticular structures. The results are discussed with special reference to biochemical findings on allergenic birch pollen proteins.

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

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Puneet Kumar

2012-01-01

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

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

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

2016-03-01

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

Seasonal fluctuations of airborne pollen grains count and its correlation with climatic factors from khairpur; sindh, pakistan

International Nuclear Information System (INIS)

Perveen, A.; Khan, M.

2014-01-01

This is the first aerobiological survey of Khairpur, Sindh. The survey was conducted from January-December, 2011 using Burkard's Seven Days Volumetric Spore trap. A total of 4559 pollen/m3 were recorded belonging to 33 plant families and 41 pollen types. The major pollen types were Poaceae (13.84%), Amaranthaceae/ Chenopodiaceae (10.40%), Cyperus rotundus (7.61%); Prosopis juliflora (6.19%), Brassica campestris (4.91%), Typha angustifolia (4.89%), Tamarix indica (4.43%), Eucalyptus globules (4.28%), Conocarpus erectus (3.73%), Asteraceae (3.01%), Guaicum officinale (2.94%), Azadirachta indica (2.74%), Malvaceae (2.15%) and Phoenix dactylifera (1.84%) constituting more than 70% of total pollen catch. The highest pollen grains concentration was observed in May-2011 with 880 pollen/m3 count while second highest pollen concentration was detected in September 2011 with 682 pollen/m3. The lowest count was found in December- 2011. Climatic factors like wind speed, average temperature, humidity and rainfall were correlated with the pollen counts. Different pollen types showed significant positive correlation with average temperature while negative correlation with humidity and wind speed. (author)

Ultrastructure of pollen grain sculpturing in several species of the Rosaceae family

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Józef Kocoń

2014-01-01

Full Text Available The sculpturing patterns of pollen grains in some species of the Rosaceae family were analyzed by SEM. Three patterns are described, typical for Prunus spinosa, Pyrus elengrifolia and Crataegus sp. The role of SEM analysis of sculpturing patterns in taxonomy can be compared to the "finger print" method in chemical plant taxonomy.

Biomonitoring of pollen grains of a river bank suburban city, Konnagar, Calcutta, India, and its link and impact on local people

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Kavita Ghosal

2015-05-01

Bio-monitoring, together with statistical and biochemical results, leave no doubt about the role of pollen as a bio-pollutant. General knowledge about pollen allergy and specific allergenic pollen grains of a particular locality could be a good step towards better health for the cosmopolitan suburban city.

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

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Leon Mejnartowicz

2014-01-01

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

Simplifying the Preparation of Pollen Grains for MALDI-TOF MS Classification

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Franziska Lauer

2017-03-01

Full Text Available Matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF MS is a well-implemented analytical technique for the investigation of complex biological samples. In MS, the sample preparation strategy is decisive for the success of the measurements. Here, sample preparation processes and target materials for the investigation of different pollen grains are compared. A reduced and optimized sample preparation process prior to MALDI-TOF measurement is presented using conductive carbon tape as target. The application of conductive tape yields in enhanced absolute signal intensities and mass spectral pattern information, which leads to a clear separation in subsequent pattern analysis. The results will be used to improve the taxonomic differentiation and identification, and might be useful for the development of a simple routine method to identify pollen based on mass spectrometry.

Isolation and characterization of allergens of Prosopis juliflora pollen grains.

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Thakur, I S; Sharma, J D

1985-12-01

Proteins and glycoproteins from Prosopis juliflora (Pj) pollen grains were separated by gel filtration, electrophoresis, DEAE cellulose chromatography and their molecular weight was determined by gel filtration and SDS-Polyacrylamide gel electrophoresis. The allergenic activity of different fractions were evaluated by in vivo skin prick test and in vitro gel diffusion test. It was found that fraction E of gel filtration and fraction III and IV of DEAE cellulose chromatography were most allergenic. This fraction E of gel filtration showed positive reaction with periodic acid Schiff's reagent as determined by SDS-gel electrophoresis.

Antioxidant Effect of Pollen Grains and Soya Lecithin on Cadmium-induced Biochemical and Structural disorders in the Ovary of Female Rats during Estrus Cycle

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Mansour, S. Z.; Ramadan, F. L.

2010-01-01

This work aims at assessing the role of pollen grains with soya lecithin on cadmium-induced damage. Cadmium chloride was administered to female albino rats (0.5 mg/kg b. wt, i.p.) during 6 weeks. Pollen grains (54 mg/kg b.wt), and soya lecithin (18 mg/kg b.wt), were given, via gavages, 7 days before cadmium administration, and during cadmium treatment. The results demonstrate that cadmium exposure induces different distortions in ovarian tissues, fibrotic follicular cortex, appearance of atretic follicles, partial oocytes degeneration and significant decreases in the number of primordial, primary, secondary and antral follicles associated with significant increase in MDA levels , significant decreases in GSH content, GSH-Px, SOD and Cat activities. Significant increases in total saturated and monounsaturated fatty acids and significant decreases in polyunsaturated fatty acids levels were recorded. Significant decreases in plasma calcium, progesterone, estradiol and HDL-C and significant increases in triglycerides, total cholesterol, LDL-C levels were recorded. Administration of pollen grains with soya lecithin has significantly improved the antioxidant status and fatty acids levels associated with regeneration of ovarian tissues. Significant amelioration in saturated and unsaturated fatty acids, and hormones levels were also recorded. It is concluded that pollen grains with soya lecithin may protect the ovary during estrus cycle from cadmium-induced toxicity. Key words: pollen, soya lecithin, cadmium, oxidative stress, ovary, fatty acids, follicle numbers

The effect of oleander glycosides on the germination of pollen grains and the mitosis of the generative nucleus in Tradescantia bracteata Small and Allium cepa L.

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J. A. Tarkowska

2015-01-01

Full Text Available The effect of water solution of a mixture of glycosides from oleander (Nerium oleander L. on the germination of pollen grains and on the mitosis of the generative nucleus in Tradescantia bracteata Small and Allium cepa L. has been studied. An inhibition of the germination and of the growth of pollen tubes was observed, proportionally to the concentration of glycosides. The pollen grains of A. cepa are more sensitive. The disturbances in mitosis lead to the formation of two or more uneven-sized doughter nuclei, or to the formation of restitution nuclei. These anomalies are more numerous in T. bracteata. From these results d t appears that pollen grains of A. cepa are characterized by a generally high physiological sensitivity and a small mitotic sensitivity, wheras for T. bracteata the opposite is true.

Micromorphological study (ultrastructure of lamina surface, seeds, ultrasculpture of pollen grains of Gladiolus L. species (Iridaceae Juss. of Ukrainian flora

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Zhygalova Svitlana L.

2014-12-01

Full Text Available Micro-morphological characteristics of the four Gladiolus L. species of the Ukrainian flora (G. imbricatus L., G. italicus Mill., G. palustris Gaudin and G. tenuis M. Bieb. as regards leaves, seeds and pollens are presented with this investigation in a detailed way. An examination of the surface structure of the leaves, seeds and pollen grains of the Gladiolus species indicates that the characteristics of the ultrastructure of leaves and of pollen grains are not diagnostic for distinguishing species, but they could be important at genus level (leaves: features such as being amphistomatic, having the same quantity of immersed stomata on both surfaces and having a high stomata index, the presence and localisation of papillae, the shape of epidermal cells; pollen grains: monosulcate type with two operculums. However, the type of surface ultrastructure of the seed coat is a diagnostic feature as at genus level so for species. It can be mentioned that propose the use of features such as the shape and position of the cicatricle, the type of cuticle, the shape and boundaries of cells of testa, and the anticlinal cell walls as diagnostic features at genera level. The shape of seeds, the presence and disposition of wing, the level of the periclinal cell walls of the seed coat and types of relief are additional diagnostic features for distinguishing of Gladiolus species.

Differential retention of pollen grains on clothing and the effectiveness of laboratory retrieval methods in forensic settings.

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Webb, Julia C; Brown, Harriet A; Toms, Hannah; Goodenough, Anne E

2018-07-01

Forensic palynology has been important in criminal investigation since the 1950s and often provides evidence that is vital in identifying suspects and securing convictions. However, for such evidence to be used appropriately, it is necessary to understand the factors affecting taphonomic variability (i.e. the variability in the fate of pollen grains before they are found during forensic examination). Here, we test the relative amount of pollen retained on clothing after a period of simulated light or heavy wear based on pollen and fabric characteristics. We also test the efficiency of forensic laboratory protocols for retrieving pollen from fabrics for analysis. There was no statistically significant difference in retention of fresh or dried pollen on any fabric type. There was a substantial difference in pollen retention according to wear intensity, with considerably more pollen being retained after light wear than after heavy wear. Pollen from insect-pollinated species was retained at higher concentrations than pollen from wind-pollinated species. This pattern was consistent regardless of wear intensity but pollination type explained more of the variability in pollen retention after light wear. Fabric type was significantly related to pollen retention, but interacted strongly with plant species such that patterns were both complex and highly species-specific. The efficiency of removing pollen with the standard washing protocol differed substantially according to plant species, fabric type, and the interaction between these factors. The average efficiency was 67.7% but this ranged from 21% to 93%, demonstrating that previous assumptions on the reliability of the technique providing a representative sample for forensic use should be reviewed. This paper highlights the importance of understanding pollen and fabric characteristics when creating a pollen profile in criminal investigations and to ensure that evidence used in testimony is accurate and robust. Crown

Pollen morphology of the Onobrychis sect. Heliobrychis in Iran

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Roya Karamian

2010-01-01

Full Text Available Pollen morphology of 20 species belonging to Onobrychis sect. Heliobrychis was studied in Iran. The pollen grains from the herbarium specimens were prepared by acetolysis method and then 8 quantitative characters were studied by light microscopy. Data analysis was carried out by cluster analysis and principal component analysis methods. Pollen grains of the sections were 3-colpate with reticulate ornamentation. Results of the study showed that although the pollen grains in the section were comparatively homogenous, but had a considerable variation in the studied quantitative characters. However among the studied characters, equatorial and polar diameters of pollen grains were the most significant characters. The members of the section can be divided into 3 groups based on these characters.

Saccharomyces cerevisiae Fermentation Effects on Pollen: Archaeological Implications

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Crystal A. Dozier

2016-03-01

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

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 ...

Flotation preferentially selects saccate pollen during conifer pollination.

Science.gov (United States)

Leslie, Andrew B

2010-10-01

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

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

International Nuclear Information System (INIS)

Li Guoping; Yang Lusheng; Huang Qunce; Qin Guangyong

2008-01-01

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

The effect of irradiation on date palm pollen grains

Energy Technology Data Exchange (ETDEWEB)

Ismail, M M; Alajaily, F R [The National Academy for Scientific Research Tripoli (Libyan Arab Jamahiriya)

1995-10-01

The evaluation of male date palm is very important in date palm culture, it is very well known that the source of pollen has its influence on fruit set, physical and chemical characters of the fruits. Date pollen was collected from previously studied male date palm trees. The pollen was subjected to the following irradiation treatments: 0,5, 10, 20, 40, 80 krad. The irradiated pollen was treated with acetocarmine and its viability was studied under the light microscope. No differences were observed between the treated pollen and the control. The pollen was germinated on agar, sucrose and boric acid media in an incubator at 27 degree C for hours. Germination count under the light microscope indicated that there were no significant differences between 5, 10, 20 krad treatments and the control, but the high doses reduced the germination percentage. The irradiated pollen used to pollinate date palm trees and the effect of metaxynia was studied. 3 tabs.

Exceptional preservation of Miocene pollen: plasmolysis captured in salt?

Energy Technology Data Exchange (ETDEWEB)

Durska, W.

2016-07-01

Exceptionally well-preserved Miocene pollen from the Bochnia salt mine of southern Poland is reported herein. The halite deposits within the salt mine belonging to Late Badenian (Miocene) marine evaporites originated in the Paratethys. Rounded and angular structures are present inside pollen grains. On the basis of the similarity with plasmolyzed pollen grains of modern plants, these structures are considered to represent cytoplasms plasmolyzed in the condensed brine prior to fossilization. Two forms of plasmolyzed cytoplasms (concave and convex) can be observed in modern pollen. Both are distinguished in the investigated fossil material. In porate and colporate grains the shape of the plasmolyzed cellular content is concave while in inaperturate it is convex. The plasmolysis form depends on the type of apertures and pollen shape. The percentage of pollen with fossilized cytoplasms within individual taxa is a valuable environmental indicator, as it depends on the proximity of the pollen-producing plant assemblages to the depositional setting. (Author)

Pollen tube branching in the ovary of five species of Oenothera

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Renata Śnieżko

2014-01-01

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

Pollen viability of Salix myrtilloides L. – an endangered species in Poland

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Magdalena Pogorzelec

2016-12-01

Full Text Available Salix myrtilloides L. (swamp willow is the most endangered species among the boreal Salix species in Poland. The number and size of its population have been decreasing constantly since the 1990s. The main aim of the study was to determine the viability of collected S. myrtilloides pollen and optimal conditions for its in vitro germination. The pollen of S. myrtilloides was collected from 25 male individuals from a population growing in the mid-forest peat bog Dekowina (Sobibór Landscape Park in May 2014. Two methods were applied to estimate the viability of fresh and stored pollen: staining pollen with 2% acetocarmine solution and in vitro germinability. Various temperature (11°C, 23°C and light conditions as well as different concentrations of glucose (1%, 2.5%, 5%, or 7.5% were tested for the optimization of in vitro germination. We documented relatively high S. myrtilloides pollen viability. Pollen tube growth was found to be largely affected by both glucose content in the medium and thermal conditions during germination. Fresh pollen germinated most effectively on the medium with 2.5% glucose (stored pollen – in 5% glucose, at 23°C and in the presence of light. We conclude that pollen viability of S. myrtilloides does not seem to be a limiting factor for reproductive success. Moreover, the pollen is not sterile even after storage for 12 months. The S. myrtilloides individuals from the Dekowina peat bog produce viable pollen grains that are able to germinate and therefore it can be used to pollinate other populations present in the Polesie Lubelskie region for gene pool enrichment.

How honey bees carry pollen

Science.gov (United States)

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

2017-11-01

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

Starch distribution in anthers, microspores and pollen grains in Aechmea recurvata (Klotzsch. L.B.Sm., Dyckia racinae L.B.Sm. and Tillandsia aeranthos (Loisel. L.B.Sm. (Bromeliaceae

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João Marcelo Santos de Oliveira

2015-03-01

Full Text Available This paper presents a comparative description of the starch distribution in the anthers, microspores and pollen grains of Aechmea recurvata, Dyckia racinae and Tillandsia aeranthos. Flowers at different stages of development were processed according to plant microtechniques for observation by light microscope. Ten stages of embryological development were used as references for the comparative analysis of starch distribution and dynamics. The structural data showed a greater starch accumulation in the parietal layers and connective of D. racinae. It was observed that in the species studied, starch began to accumulate in microspore mother cell stage. The pollen grains in D. racinae and in T. aeranthos present two amylogenesis-amylolysis cycles, while A. recurvata presents only one. One amylogenesis-amylolysis cycle occurs in the parietal layers and/or connective tissue in all three species. The pollen grains in the three species are dispersed without starch and are characterized as the starchless type. Starch dynamics presents a close relation to the development of sporangia, microspores and pollen grains. It is believed that differences in the starch distribution and accumulation are related to the abiotic factors where the species are found.

Aberrant Meiotic Modulation Partially Contributes to the Lower Germination Rate of Pollen Grains in Maize (Zea mays L.) Under Low Nitrogen Supply.

Science.gov (United States)

Zheng, Hongyan; Wu, Huamao; Pan, Xiaoying; Jin, Weiwei; Li, Xuexian

2017-02-01

Pollen germination is an essential step towards successful pollination during maize reproduction. How low niutrogen (N) affects pollen germination remains an interesting biological question to be addressed. We found that only low N resulted in a significantly lower germination rate of pollen grains after 4 weeks of low N, phosphorus or potassium treatment in maize production. Importantly, cytological analysis showed 7-fold more micronuclei in male meiocytes under the low N treatment than in the control, indicating that the lower germination rate of pollen grains was partially due to numerous chromosome loss events resulting from preceding meiosis. The appearance of 10 bivalents in the control and low N cells at diakinesis suggested that chromosome pairing and recombination in meiosis I was not affected by low N. Further gene expression analysis revealed dramatic down-regulation of Nuclear Division Cycle 80 (Ndc80) and Regulator of Chromosome Condensation 1 (Rcc1-1) expression and up-regulation of Cell Division Cycle 20 (Cdc20-1) expression, although no significant difference in the expression level of kinetochore foundation proteins Centromeric Histone H3 (Cenh3) and Centromere Protein C (Cenpc) and cohesion regulators Recombination 8 (Rec8) and Shugoshin (Sgo1) was observed. Aberrant modulation of three key meiotic regulators presumably resulted in a high likelihood of erroneous chromosome segregation, as testified by pronounced lagging chromosomes at anaphase I or cell cycle disruption at meiosis II. Thus, we proposed a cytogenetic mechanism whereby low N affects male meiosis and causes a higher chromosome loss frequency and eventually a lower germination rate of pollen grains in a staple crop plant. © The Author 2016. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

Analysis of protein profile and pollen morphology of guaiacum officinale linn

International Nuclear Information System (INIS)

Zeb, S.

2017-01-01

Asthma and allergic rhinitis is triggered by the pollen of trees, grasses and weeds. Guaiacum officinale L. tree is widely cultivated along with the road side. This species was selected to check its allergenic role.Pollen morphology of Guaiacum officinale was examined by Light microsco4pe (LM) and Scanning electron microscope (SEM). Pollen grains of Guaiacum officinale were prolate shape, having tricolpate aperture, and rugulate tectum. Pollen protein concentration of G. officinale was determined by Bradford's assay and qualitative protein analysis of pollen was done by SDS-PAGE(Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis).Total protein content in the pollen extract was 24.28mg/g of pollen. The SDS-PAGE pollen grains protein analysis showed 07 different protein bands. The molecular weight of separated proteins ranged from 25 to 65kDa. Biochemical analysis of G. officinale pollen grains revealed the presence of low molecular weight proteins therefore it is strongly suggested that this species must be considered as a potent allergy causing species. This research would help for the proper diagnosis and treatment of the bronchial allergy suffering patients. (author)

Pollen and spores of terrestrial plants

Science.gov (United States)

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

2015-01-01

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

Pollen grain morphology of Fabaceae in the Special Protection Area (SPA) Pau-de-Fruta, Diamantina, Minas Gerais, Brazil.

Science.gov (United States)

Luz, Cynthia F P da; Maki, Erica S; Horák-Terra, Ingrid; Vidal-Torrado, Pablo; Mendonça Filho, Carlos Victor

2013-01-01

The presented paper considered the pollen morphology of thirteen species belonging to seven genera of the Fabaceae family occurring in the Pau-de-Fruta Special Protection Area (SPA), Diamantina, state of Minas Gerais, Brazil. The pollen grains of six species of Chamaecrista [C. cathartica (Mart.) H.S. Irwin & Barneby, C. debilis Vogel, C. flexuosa (L.) Greene, C. hedysaroides (Vogel) H.S. Irwin & Barneby, C. glandulosa (L.) Greene, and C. papillata H.S. Irwin & Barneby] have a similar morphology, characterized by three long colporated apertures with a central constriction. The species share specific morphological features regarding pollen size, endoaperture type (circular, lalongate or lolongate) and SEM ornamentation patterns of the exine (rugulate with perforations or perforate). Andira fraxinifolia Benth., Dalbergia miscolobium Benth, Galactia martii DC, Periandra mediterranea (Vell.) Taub., Senna rugosa (G.Don) H.S. Irwin & Barneby and Zornia diphylla (L.) Pers showed different pollen types in small to large size; oblate spheroidal to prolate form; colpus or colporus apertures; circular, lalongate or lolongate endoapertures and distinctive SEM ornamentation patterns of the exine (perforate, microreticulate, reticulate or rugulate with perforations). Only Stryphnodendron adstringens (Mart.) Coville presents polyads. The pollen morphology variation of these species allowed the Fabaceae family to be characterized as eurypalynous in the SPA Pau-de-Fruta.

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

Indian Academy of Sciences (India)

Unknown

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

Atmospheric conditions during high ragweed pollen concentrations in Zagreb, Croatia

Science.gov (United States)

Prtenjak, Maja Telišman; Srnec, Lidija; Peternel, Renata; Madžarević, Valentina; Hrga, Ivana; Stjepanović, Barbara

2012-11-01

We examined the atmospheric conditions favourable to the occurrence of maximum concentrations of ragweed pollen with an extremely high risk of producing allergy. Over the 2002-2009 period, daily pollen data collected in Zagreb were used to identify two periods of high pollen concentration (> 600 grains/m3) for our analysis: period A (3-4 September 2002) and period B (6-7 September 2003). Synoptic conditions in both periods were very similar: Croatia was under the influence of a lower sector high pressure system moving slowly eastward over Eastern Europe. During the 2002-2009 period, this type of weather pattern (on ~ 70% of days), in conjunction with almost non-gradient surface pressure conditions in the area (on ~ 30% of days) characterised days when the daily pollen concentrations were higher than 400 grains/m3. Numerical experiments using a mesoscale model at fine resolution showed successful multi-day simulations reproducing the local topographic influence on wind flow and in reasonable agreement with available observations. According to the model, the relatively weak synoptic flow (predominantly from the eastern direction) allowed local thermal circulations to develop over Zagreb during both high pollen episodes. Two-hour pollen concentrations and 48-h back-trajectories indicated that regional-range transport of pollen grains from the central Pannonian Plain was the cause of the high pollen concentrations during period A. During period B, the north-westward regional-range transport in Zagreb was supplemented significantly by pronounced horizontal recirculation of pollen grains. This recirculation happened within the diurnal local circulation over the city, causing a late-evening increase in pollen concentration.

Fullerene-Based Symmetry in Hibiscus rosa-sinensis Pollen

Science.gov (United States)

Andrade, Kleber; Guerra, Sara; Debut, Alexis

2014-01-01

The fullerene molecule belongs to the so-called super materials. The compound is interesting due to its spherical configuration where atoms occupy positions forming a mechanically stable structure. We first demonstrate that pollen of Hibiscus rosa-sinensis has a strong symmetry regarding the distribution of its spines over the spherical grain. These spines form spherical hexagons and pentagons. The distance between atoms in fullerene is explained applying principles of flat, spherical, and spatial geometry, based on Euclid’s “Elements” book, as well as logic algorithms. Measurements of the pollen grain take into account that the true spine lengths, and consequently the real distances between them, are measured to the periphery of each grain. Algorithms are developed to recover the spatial effects lost in 2D photos. There is a clear correspondence between the position of atoms in the fullerene molecule and the position of spines in the pollen grain. In the fullerene the separation gives the idea of equal length bonds which implies perfectly distributed electron clouds while in the pollen grain we suggest that the spines being equally spaced carry an electrical charge originating in forces involved in the pollination process. PMID:25003375

Pollen morphology of Amygdalus L. (Rosaceae in Iran

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Mahnaz Vafadar

2011-01-01

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

R CORONAE BOREALIS STARS ARE VIABLE FACTORIES OF PRE-SOLAR GRAINS

International Nuclear Information System (INIS)

Karakas, Amanda I.; Ruiter, Ashley J.; Hampel, Melanie

2015-01-01

We present a new theoretical estimate for the birthrate of R Coronae Borealis (RCB) stars that is in agreement with recent observational data. We find the current Galactic birthrate of RCB stars to be ≈25% of the Galactic rate of Type Ia supernovae, assuming that RCB stars are formed through the merger of carbon–oxygen and helium-rich white dwarfs. Our new RCB birthrate (1.8 × 10 −3 yr −1 ) is a factor of 10 lower than previous theoretical estimates. This results in roughly 180–540 RCB stars in the Galaxy, depending on the RCB lifetime. From the theoretical and observational estimates, we calculate the total dust production from RCB stars and compare this rate to dust production from novae and born-again asymptotic giant branch (AGB) stars. We find that the amount of dust produced by RCB stars is comparable to the amounts produced by novae or born-again post-AGB stars, indicating that these merger objects are a viable source of carbonaceous pre-solar grains in the Galaxy. There are graphite grains with carbon and oxygen isotopic ratios consistent with the observed composition of RCB stars, adding weight to the suggestion that these rare objects are a source of stardust grains

Pollen morphology of the Alangiaceae

NARCIS (Netherlands)

Reitsma, Tj.

1970-01-01

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

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.

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

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Jana Žiarovská

2015-10-01

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

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

Science.gov (United States)

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

2017-01-01

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

Catálogo sistemático dos polens das plantas arbóreas do Brasil meridional: XXIII. Moraceae Catalogue of southern Brazilian pollen grains: XXIII. Moraceae

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Ortrud Monika Barth

1976-01-01

Full Text Available Foi estudada a morfologia polínica de espécies pertencentes a oito gêneros. Os diferentes tipos polínicos econtrados, correspondendo aos gêneros, bem como as variações das estruturas dentro de alguns deles, confirmam as relações filogenéticas nesta família. Os de morfologia mais simples correspondem a árvores ou arbustos dos gêneros Brosimum, Cecropia, Chlorophora e Coussapoa, seguindo-se Ficus, Pourouma e Sorocea; os grãos do gênero herbáceo Dorstenia apresentam uma complexa morfologia polínica. A estrutura dos esporodermas e das aberturas dos grãos de pólen comprova o seu relacionamento com outras famílias das Urticales.The pollen morphology from some species of eight genera of Moraceae has been studied. The different pollen types found, corresponding to the genera, as well as the structural variations in some of them, confirm the phylogenetic relations in this family. The specimens with a less complex pollen morphology were the trees or shrubs from the genera Brosimum, Cepropia, Chlorophora and Coussapoa, followed by Ficus, Pourouma and Sorocea; the pollen grains from the herbaceous Dorstenia show a complex pollen morphology. The structures of the sporoderm and the apertures of the pollen grains point out the relationship between these genera and other families from the Urticales.

Development of anthers and pollen in Brazilian heterostylic species of Erythroxylum (Erythroxylaceae): an ecological approach

International Nuclear Information System (INIS)

Silva, L.D.; Fernandes, C. L.

2016-01-01

This study describes the development of anthers and pollen in heterostylic flowers of two species of Erythroxylum. The features of anthers and their developmental pattern, which is of the dicotyledonous type, do not vary according to morphs or species. The pollen grains of both morphs show differences in their morphology, development, and content stored as a reserve source. In both species, thrum (short-styled) flowers presented bicellular pollen grains, while pin (long-styled) ones yielded bi- and tricellular pollen grains. The presence of inviable pollen grains in the two flower morphs of both species and the malformation of one of the four microsporanges in the thrum flowers of E. campestre are noteworthy. We verified that features found both in the anther wall and in the pollen grains could be related to the reproductive success and adaptation of the species to the Brazilian savanna biome. (author)

Messenger RNas : their utilization and degradation during pollen germination and tube growth

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Joseph P. Mascarenhas

2014-01-01

Full Text Available During pollen germination and tube growth at least 230 new proteins are synthesized, as determined by 35S-methionime labeling and two dimensional gel electrophoretic analysis of the labeled proteins. The same number and pattern of protein spots is seen whether or not actinomycin D is included in the, medium, indicating that the mRNAs present in the unger-minated pollen grain and those newly synthesized code for the same proteins. The genetic program during at least the latter part of pollen maturation prior to anthesis and that during pollen germination and tube growth thus appears to be similar if not identical. During the first hour of pollen tube growth about 500/0 of the protein synthesis that occurs utilizes previously synthesized mRNAs. The remaining 50% occurs on newly made mRNAs. The ungerminated mature pollen grain contains 196 pg of RNA and approximately 6 X 106 molecules of poly(A+ RNA, i.e. mRNAs. The rate of protein synthesis corrected for internal pool changes in the labeled amino acid used (3H-leucine is highest during the first 15 min of pollen tube growth. The rate decreases rapidly thereafter for the next 45 min. Concurrent with the reduction in rate of protein synthesis there is a reduction in the poly(A content of the pollen RNA and in the amount of poly(A per pollen, grain. The total RNA per pollen grain, however, appears not to change during this period.

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

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Reshmi Chatterjee

2014-09-01

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

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

Science.gov (United States)

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

2016-01-01

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

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

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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.

Raman spectroscopy as a tool for the characterization and classification of pollen; Raman-Spektroskopie als Werkzeug fuer die Charakterisierung und Klassifizierung von Pollen

Energy Technology Data Exchange (ETDEWEB)

Schulte, Franziska

2010-09-20

The chemical composition of pollen, the physiological containers that produce the male gametophytes of seed plants, has been a subject of research of plant physiologists, biochemists, and lately even material scientists for various reasons. The aim of this work was the analysis of whole pollen grains and pollen components by Raman Spectroscopy. These experiments were complemented by other techniques such as Enviromental Scanning Electron Microscopy (ESEM), High-Performance- Thin-Layer-Chromatography (HPTLC), Infrared Spectroscopy (IR) and Nuclear-Magnetic-Resonance Spectroscopy (NMR). As reported here, individual fresh pollen grains and their morphological constituents can be characterized and also classified in situ without prior preparation. Classification of pollen is based on their biochemical fingerprint revealed in their Raman spectrum. Raman spectroscopy is nondestructive and can be carried out with single pollen grains or fragments. It could be shown that the biochemical makeup of the pollen (as a part of the recognition/mating system) is altered during formation of a new biological species and that the species-specific chemical similarities and dissimilarities indeed reflect in the Raman spectral fingerprint. On the basis of the chemical information, unsupervised multivariate analysis consisting of hierarchical clustering revealed in most cases chemical similarities between species that were indicative of both phylogenetic relationship and matin behavior. Therefore experiments were conducted that gave the in situ Raman spectroscopic signatures ot the carotenoid molecules. As the data indicates, the in situ Raman spectra of the carotenoid molecules measured in single intact pollen grains provide in situ evidence of interspecies variations in pollen carotenoid content, structure, and/or assembly without prior purification. Results from HPTLC confirmed that carotenoid composition varied greatly between species and that the different in situ spectral

Selection of morphological features of pollen grains for chosen tree taxa

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Agnieszka Kubik-Komar

2018-05-01

Full Text Available The basis of aerobiological studies is to monitor airborne pollen concentrations and pollen season timing. This task is performed by appropriately trained staff and is difficult and time consuming. The goal of this research is to select morphological characteristics of grains that are the most discriminative for distinguishing between birch, hazel and alder taxa and are easy to determine automatically from microscope images. This selection is based on the split attributes of the J4.8 classification trees built for different subsets of features. Determining the discriminative features by this method, we provide specific rules for distinguishing between individual taxa, at the same time obtaining a high percentage of correct classification. The most discriminative among the 13 morphological characteristics studied are the following: number of pores, maximum axis, minimum axis, axes difference, maximum oncus width, and number of lateral pores. The classification result of the tree based on this subset is better than the one built on the whole feature set and it is almost 94%. Therefore, selection of attributes before tree building is recommended. The classification results for the features easiest to obtain from the image, i.e. maximum axis, minimum axis, axes difference, and number of lateral pores, are only 2.09 pp lower than those obtained for the complete set, but 3.23 pp lower than the results obtained for the selected most discriminating attributes only.

Evaluation of the botanical origin of commercial dry bee pollen load batches using pollen analysis: a proposal for technical standardization

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Ortrud M. Barth

2010-12-01

Full Text Available High quality of bee pollen for commercial purpose is required. In order to attend the consumer with the best identification of the botanical and floral origin of the product, 25 bee pollen batches were investigated using two techniques of pollen grain preparation. The first started to identify pollen loads of different colors in two grams of each well mixed batch, and the second to identify pollen grains in a pool made of all the pollen loads comprised in two grams. The best result was obtained by this last technique, when a pollen grain suspension was dropped on a microscope slide and circa 500 pollen grains were counted per sample. This analysis resulted in the recognition of monofloral and bifloral pollen batches, while the use of the first technique resulted in all samples receiving a heterofloral diagnosis.É exigida alta qualidade para a comercialização de pólen apícola. A fim de atender o consumidor com a melhor identificação da origem botânica e floral do produto, 25 partidas de pólen apícola feram investigadas usande duas diferentes técnicas na preparação dos grãos de pólen. A primeira partiu da identificação das cargas polínicas contidas em dois gramas de cada partida bem misturada segundo suas cores. A segunda visava identificar os grãos de pólen de um agrupamento ("pool" de todas as cargas polínicas contidas em dois gramas de cada amostra. O melhor resultado foi obtido pela última técnica, quando uma suspensão de grãos de pólen era gotejada sobre uma lâmina de microscopia e cerca de 500 grãos de pólen eram centades por amostra. Esta análise resultou no reconhecimento de partidas monoflorais e biflorais de pólen apícola, enquanto que usando a primeira técnica, todas as amostras receberam a diagnose heterefloral.

Pollen Characterization in Size Segregated Atmospheric Aerosol

Science.gov (United States)

Kolpakova, Anna; Hovorka, Jan; Klán, Miroslav

2017-12-01

The first stage of a High Volumetric Cascade Impactor - HiVol (BGI-900), used for sampling of aerosol particles larger than 10 micrometres in aerodynamic diameter, was tested for bioaerosol sampling. Low air flow-rate and low pressure-drop at the jets of the first stage and high air volume are advantageous parameters, which would favour the use of the first stage for bioaerosol sampling. The sampling went in urban, rural and background localities, Prague, Brezno and Laz respectively in the Czech Republic, in summer and autumn. Pollen was separated from the impaction substrate, polyurethane foam, into homogeneous deposit on Nylon filter. The homogeneity of the deposit varied within 4%. Representative portion of the deposit was analysed by a scanning electron microscopy - SEM. There were taken 485 SEM images from 12 samples in 3 localities. Pollen grains were identified in 295 SEM images and determined into 9 genus and 4 families. Median pollen grain concentrations/deformities were 9m-3/24%, 3m-3/18%, 8m-3/50% for Prague, Brezno and Láz localities respectively. The pollen grains of the Poaceae family were found with the highest frequency in all localities. Number of pollen increased with total aerosol mass in Prague locality only. There were also identified brochosomes, rather unique insect secretion products, in the samples from the Láz locality.

In vitro pollen germination of five citrus species

International Nuclear Information System (INIS)

Khan, S.A.; Perveen, A.

2014-01-01

The aim of present study is In vitro germination of the pollen grains of five Citrus species belonging to the family Rutaceae viz., Citrus aurantium L. var., aurantium Hook.f., C. limon (L.) Brum. f., C. paradisii Macfad, C. reticulata Blanco and C. sinensis (L.) Osbeck. using hanging drop technique. The germination was checked up to 48 weeks, for the pollen stored at different temperatures like 4 degree C, -20 degree C, -30 degree C and -60 degree C. The study indicates that low temperature and low relative humidity is better than high temperature and humidity with respect to pollen germination capacity and viability. Freeze dryer (-60 degree C) seems to be the best method to maintain pollen viability of stored pollen grains for a long period of time. Among five species Citrus aurantium, C. limon and C. sinensis showed high percentage of germination as compared to C. reticulata and C. paradisii. (author)

Herbivory in spiders: the importance of pollen for orb-weavers.

Science.gov (United States)

Eggs, Benjamin; Sanders, Dirk

2013-01-01

Orb-weaving spiders (Araneidae) are commonly regarded as generalist insect predators but resources provided by plants such as pollen may be an important dietary supplementation. Their webs snare insect prey, but can also trap aerial plankton like pollen and fungal spores. When recycling their orb webs, the spiders may therefore also feed on adhering pollen grains or fungal spores via extraoral digestion. In this study we measured stable isotope ratios in the bodies of two araneid species (Aculepeira ceropegia and Araneus diadematus), their potential prey and pollen to determine the relative contribution of pollen to their diet. We found that about 25% of juvenile orb-weaving spiders' diet consisted of pollen, the other 75% of flying insects, mainly small dipterans and hymenopterans. The pollen grains in our study were too large to be taken up accidentally by the spiders and had first to be digested extraorally by enzymes in an active act of consumption. Therefore, pollen can be seen as a substantial component of the spiders' diet. This finding suggests that these spiders need to be classified as omnivores rather than pure carnivores.

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

Science.gov (United States)

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

2010-06-01

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

Pollen structure visualization using high-resolution laboratory-based hard X-ray tomography.

Science.gov (United States)

Li, Qiong; Gluch, Jürgen; Krüger, Peter; Gall, Martin; Neinhuis, Christoph; Zschech, Ehrenfried

2016-10-14

A laboratory-based X-ray microscope is used to investigate the 3D structure of unstained whole pollen grains. For the first time, high-resolution laboratory-based hard X-ray microscopy is applied to study pollen grains. Based on the efficient acquisition of statistically relevant information-rich images using Zernike phase contrast, both surface- and internal structures of pine pollen - including exine, intine and cellular structures - are clearly visualized. The specific volumes of these structures are calculated from the tomographic data. The systematic three-dimensional study of pollen grains provides morphological and structural information about taxonomic characters that are essential in palynology. Such studies have a direct impact on disciplines such as forestry, agriculture, horticulture, plant breeding and biodiversity. Copyright © 2016 Elsevier Inc. All rights reserved.

Gibberellin regulates pollen viability and pollen tube growth in rice.

Science.gov (United States)

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

2007-12-01

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

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

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Cowling Wallace A

2011-06-01

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

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

African Journals Online (AJOL)

STORAGESEVER

2009-12-15

Dec 15, 2009 ... minor cross-incompatibilities and physiological studies of incompatibility ... campanula shape of the flowers attractive for insect. (bees are ..... irradiation of cacao (Theobroma cacao L.) pollen: Effect on pollen grain viability ...

Pollen Flora of Pakistan-LXV, berberidaceae

International Nuclear Information System (INIS)

Perveen, A.

2010-01-01

Pollen morphology of 12 species representing 2 genera of the family Berberidaceae from Pakistan has been examined by light and scanning electron microscope. Pollen grains usually radially symmetrical, iso polar or apolar, spheroidal or sub-prolate, spiroaperturate rarely colpate (3- more), sexine thicker than nexine. Tectal surface mostly foveolate-fossulate or sub-psilate, often rugulate - reticulate. On the basis of apertutal types and exine ornamentation four distinct pollen types are recognized, viz., Berberis calliobotrys-type, Berberis jaeschkeana-type, Berberis kunawurensis-type and Epimedium elatum-type. (author)

Pollen analysis of natural honeys from the central region of Shanxi, North China.

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Xiao-Yan Song

Full Text Available Based on qualitative and quantitative melissopalynological analyses, 19 Chinese honeys were classified by botanical origin to determine their floral sources. The honey samples were collected during 2010-2011 from the central region of Shanxi Province, North China. A diverse spectrum of 61 pollen types from 37 families was identified. Fourteen samples were classified as unifloral, whereas the remaining samples were multifloral. Bee-favoured families (occurring in more than 50% of the samples included Caprifoliaceae (found in 10 samples, Laminaceae (10, Brassicaceae (12, Rosaceae (12, Moraceae (13, Rhamnaceae (15, Asteraceae (17, and Fabaceae (19. In the unifloral honeys, the predominant pollen types were Ziziphus jujuba (in 5 samples, Robinia pseudoacacia (3, Vitex negundo var. heterophylla (2, Sophora japonica (1, Ailanthus altissima (1, Asteraceae type (1, and Fabaceae type (1. The absolute pollen count (i.e., the number of pollen grains per 10 g honey sample suggested that 13 samples belonged to Group I (<20,000 pollen grains, 4 to Group II (20,000-100,000, and 2 to Group III (100,000-500,000. The dominance of unifloral honeys without toxic pollen grains and the low value of the HDE/P ratio (i.e., honey dew elements/pollen grains from nectariferous plants indicated that the honey samples are of good quality and suitable for human consumption.

Pollen-gamma irradiation on pineapple and pollination using irradiated pollen

International Nuclear Information System (INIS)

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

1997-01-01

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

Ultrastructure and pollen morphology of Bromeliaceae species from the Atlantic Rainforest in Southeastern Brazil

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Vanessa J.D. Silva

2016-01-01

Full Text Available Pollen grain morphology of Bromeliaceae species collected in areas of the Atlantic Rainforest of southeastern Brazil was studied. The following species were analyzed: Aechmea bambusoides L.B.Sm. & Reitz, A. nudicaulis (L. Griseb., A. ramosa Mart. ex Schult.f., Ananas bracteatus (Lindl. Schult.f., Billbergia distachia (Vell. Mez, B. euphemiae E. Morren, B. horrida Regel, B. zebrina (Herb. Lindl., Portea petropolitana (Wawra Mez, Pitcairnia flammea Lindl., Quesnelia indecora Mez, Tillandsia polystachia (L. L., T. stricta Sol., T. gardneri Lindl., T. geminiflora Brongn. and Vriesea grandiflora Leme. Light and scanning electron microscopy were used and the species were grouped into three pollen types, organized according to aperture characteristics: Type I - pantoporate pollen grains observed in P. petropolitana, Type II - 2-porate pollen grains, observed in the genera Ananas, Aechmea and Quesnelia, and Type III - 1-colpate pollen grains, observed in the genera Billbergia, Pitcairnia, Tillandsia and Vriesea. Pollen data led to the construction of an identification key. The results showed that the species analyzed can be distinguished using mainly aperture features and exine ornamentation, and that these characteristics may assist in taxonomic studies of the family.

Ultrastructure and pollen morphology of Bromeliaceae species from the Atlantic Rainforest in Southeastern Brazil.

Science.gov (United States)

Silva, Vanessa J D; Ribeiro, Ester M; Luizi-Ponzo, Andrea P; Faria, Ana Paula G

2016-01-01

Pollen grain morphology of Bromeliaceae species collected in areas of the Atlantic Rainforest of southeastern Brazil was studied. The following species were analyzed: Aechmea bambusoides L.B.Sm. & Reitz, A. nudicaulis (L.) Griseb., A. ramosa Mart. ex Schult.f., Ananas bracteatus (Lindl.) Schult.f., Billbergia distachia (Vell.) Mez, B. euphemiae E. Morren, B. horrida Regel, B. zebrina (Herb.) Lindl., Portea petropolitana (Wawra) Mez, Pitcairnia flammea Lindl., Quesnelia indecora Mez, Tillandsia polystachia (L.) L., T. stricta Sol., T. gardneri Lindl., T. geminiflora Brongn. and Vriesea grandiflora Leme. Light and scanning electron microscopy were used and the species were grouped into three pollen types, organized according to aperture characteristics: Type I - pantoporate pollen grains observed in P. petropolitana, Type II - 2-porate pollen grains, observed in the genera Ananas, Aechmea and Quesnelia, and Type III - 1-colpate pollen grains, observed in the genera Billbergia, Pitcairnia, Tillandsia and Vriesea. Pollen data led to the construction of an identification key. The results showed that the species analyzed can be distinguished using mainly aperture features and exine ornamentation, and that these characteristics may assist in taxonomic studies of the family.

Taxonomic evaluation using pollen grain sculpture and seed coat characters of 11 taxa of genus Hibiscus (Malvaceae in Egypt

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M.A. El-Kholy

2011-06-01

Full Text Available Pollen grain morphology and seed coat characters of 11 cultivars belonging to two species of genus Hibiscus (Family Malvaceae namely H. esculentus, H. abelmoschus and H. sabdariffa were investigated. This study was carried out using light microscope (LM and scanning electron microscopy (SEM. Pollen morphology of this genus is fairly uniform. Generally radially symmetrical apolar, mostly spheroidal, pantoporate. Seed exomorphic characters revealed four types of ornamentations; reticulate, ocealate, foveolate and ruminate. Sodium Dodecyl Sulfate Polyacrylamide Gel Electrophoresis (SDS–PAGE was employed to characterize those taxa. Thirty-one bands of seed protein profiles have been constructed from the gel. The produced dendrograms that were analyzed by STATISCA program using UPGMA clustering method showed a close affinity among the seven H. esculentus cultivars and the four H. sabdariffa cultivars.

Spatial distribution of pollen grains and spores in surface sediments of Guanabara Bay, Rio de Janeiro, Brazil.

Science.gov (United States)

Barreto, Cintia F; Vilela, Claudia G; Baptista-Neto, José A; Barth, Ortrud M

2012-09-01

Aiming to investigate the deposition of pollen grains and spores in Guanabara Bay, Rio de Janeiro State, 61 surface sediment samples were analyzed. The results showed that the current deposition of palynomorphs in surface sediments of Guanabara Bay represents the regional vegetation of this hydrographic basin. The differential distribution of palynomorphs followed a pattern influenced by bathymetry, tidal currents speed, discharge of numerous rivers, and by human activity. The dominance of representatives of Field Vegetation reflects the changes of the original flora caused by intense human activities in the region. The continued presence and richness of pollen types of rain forest in the samples indicates that their source area might be the vegetation from riparian border of rivers in the western sector of the Bay, where the mangrove vegetation is being preserved. The large amount of damaged palynomorphs may be related to abrasion that occurs during river transport, indicating removal or reworking from their areas of origin.

Airborne pollen of Carya, Celtis, Cupressus, Fraxinus and Pinus in the metropolitan area of Monterrey Nuevo Leon, Mexico.

Science.gov (United States)

Rocha-Estrada, Alejandra; Alvarado-Vázquez, Marco Antonio; Torres-Cepeda, Teresa Elizabeth; Foroughbakhch-Pournavab, Rahim; Hernández-Piñero, Jorge Luis

2008-01-01

The concentration of pollen grains in the atmosphere over the metropolitan area of Monterrey, Nuevo Leon, Mexico, was analyzed throughout a year from March 2003-February 2004, focused on the genus Carya, Celtis, Cupressus, Fraxinus and Pinus owing to their interest as etiological pollinosis agents in diverse regions of the world. A 7-day Hirst type volumetric spore and pollen trap was located on a building roof of the city at 15 m from ground level for continuous sampling. The total quantity of pollen recorded for the study period was 21,083 grains/m(3), corresponding to 49.75 % of the taxa of interest. February and March were the months with higher pollen amounts in the air with 7,525 and 2,781 grains/m(3), respectively, and amounted to 49 % of total year through pollen. Fraxinus was the genus which contributed to the largest amount of pollen with 28 % of total grains (5,935 grains/m(3)) followed by Cupressus with 13 % (2,742 grains/ m(3)). Celtis, Pinus and Carya contributed with 5.3 % , 2.7 % , and 0.6 % of total pollen, respectively. These results indicate that Fraxinus and Cupressus are present in the area in sufficient quantity to indicate likely involvement in the origin of allergic disorders in the human population.

First report of modern pollen deposition in moss polsters in a semiarid area of Bahia, Brazil

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Daiane Alves dos Santos

2015-12-01

Full Text Available Recent studies have shown that pollen analyses of natural substrates can produce data valuable for understanding the local pollen productivity and dispersal, deposition, and preservation potential of pollen grains. In this study, we aimed to acquire novel information about the dynamics and preservation of pollen in Caatinga environment through the palynological study of moss polsters. Samples of moss polsters in soil (MPS and on rock (MPR were collected from the Canudos Biological Station in the Bahia State (Brazil and subjected to standard chemical treatments for the extraction of pollen residues. In total, 372 pollen types were recorded from the samples of which the taxonomical affinity of 140 was determined. The most represented families were Fabaceae (23 pollen types/16.42% and Asteraceae (12 pollen types/8.57%. The MPS samples had a higher pollen concentration (21,042.04 pollen grains/cm² than the MPR samples (7,829.35 pollen grains/cm². On the other hand, the MPR samples had a greater diversity (68.26% of the identified pollen types. Qualitative analysis showed that the plants of shrub and subshrub habits had the greatest representation among the pollen types (35.0%. Overall, moss polsters proved to be excellent natural air pollen collectors in Caatinga environment, provided they had moist microhabitats for their development.

Impact of cytomixis on meiosis, pollen viability and pollen size in ...

Indian Academy of Sciences (India)

Srinivas

prefers light woodlands, moist soils, rock crevices and grows among ... Well-filled pollen grains with stained nuclei were regarded as apparently .... individuals of the Bhairon Ghati population, as they did not depict any .... Ajay and Sarbhoy 1987; Haroun 1995), pollution ( Haroun ... effect of some chlorinated pesticides II.

Structure of the Pollen Exine of Rhoiptelea chiliantha

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Annie Skarby

2009-06-01

Full Text Available The exine of mature pollen grains of Rhoiptelea chiliantha was studied. The size of the pollen grains is about 23 by 27 μm. They are tricolporate with short colpi that are 1-2 μm wide and 10-12 long. The spinules of Rhoiptelea are similar in form and size to those of Gentianales. The spinules consist of rods of ca 70 nm in width. These rods are evident throughout the tectum and columellae. The columellae are of two distinct sizes. The smaller ones are ca 70 nm wide and join the tectum and the larger columellae. These larger ones appear to be composed of several 70 nm in width rods. They join the distal surface of the foot layer. The proximal surface of the foot layer is marked by a white line (referred to as a junction plane where it joins the endexine. The endexine consists of a solid-appearing component adjacent to the foot layer (referred to as endexine-1 and laminar components (endexine-2 that are attached to and apparently become a part of endexine-1. There is no indication of an arcus. In well preserved grains the aperture is covered by an operculum or operculum-like component. In well-rehydrated pollen grains there is an oncus of considerable complexity under the aperture and over the intine. The Ubisch bodies have an exine ornamented with widely-spaced spinules like the spinules on the pollen exine.

Effects of X-rays on seed setting and pollen tube growth in self-incompatible petunia

International Nuclear Information System (INIS)

Gilissen, L.J.W.

1978-01-01

The high sensitivity of seed setting and the relative insensitivity of pollen tube growth in the style to X-irradiation of pollen of Petunia hybrida L. indicated that pollen tube growth is independent of activities of the pollen genome. The S-specificity of the pollen grain in relation to incompatibility must, therefore, have built up during maturation of the pollen grain. X-irradiation of styles caused changes in some enzymes essential for basic metabolism, without affecting the pattern of compatible or incompatible pollen tube growth. Compatible and incompatible pollen tube growth in the style appeared to be independent of the metabolic state of the stylar cells and their simultaneous gene-activity. It is suggested that the S-specificity of the style, which is responsible for pollen tube growth regulation, is expressed at a very young stage of flower development. (Auth.)

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

International Nuclear Information System (INIS)

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

2011-01-01

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

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.

Pollen loads and specificity of native pollinators of lowbush blueberry.

Science.gov (United States)

Moisan-Deserres, J; Girard, M; Chagnon, M; Fournier, V

2014-06-01

The reproduction of lowbush blueberry (Vaccinium angustifolium Aiton) is closely tied to insect pollination, owing to self-incompatibility. Many species are known to have greater pollination efficiency than the introduced Apis mellifera L., commonly used for commercial purposes. In this study, we measured the pollen loads of several antophilous insect species, mostly Apoidea and Syrphidae, present in four lowbush blueberry fields in Lac-St-Jean, Québec. To measure pollen loads and species specificity toward V. angustifolium, we net-collected 627 specimens of pollinators, retrieved their pollen loads, identified pollen taxa, and counted pollen grains. We found that the sizes of pollen loads were highly variable among species, ranging from a few hundred to more than 118,000 pollen grains per individual. Bombus and Andrena species in particular carried large amounts of Vaccinium pollen and thus may have greater pollination efficiency. Also, two species (Andrena bradleyi Viereck and Andrena carolina Viereck) showed nearly monolectic behavior toward lowbush blueberry. Finally, we identified alternative forage plants visited by native pollinators, notably species of Acer, Rubus, Ilex mucronata, Ledum groenlandicum, and Taraxacum. Protecting these flowering plants should be part of management practices to maintain healthy pollinator communities in a lowbush blueberry agroecosystem.

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

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Sigifredo López Díaz

2008-01-01

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

Pollen morphology of Waltheria L. (Malvaceae-Byttnerioideae from Bahia, Brazil

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Cristiano Eduardo Amaral Silveira Júnior

2017-09-01

Full Text Available ABSTRACT Waltheria encompasses about 60 species distributed in Brazil and Mexico. To improve the palynology of the genus, we analyzed 14 species occurring in the Brazilian State of Bahia. Pollen grains were acetolyzed and examined using light microscopy and scanning electron microscopy. Non-acetolyzed pollen grains were viewed by transmission electron microscopy. The results revealed two general pollen types based on exine ornamentation, such as reticulate and echinate, which are distinct with regard to (1 size and shape, (2 apertural type and number, (3 relative length of ectoapertures, and (4 thickening of the nexine compared to the sexine. An ultrastructural analysis of the pollen wall revealed a continuous foot layer and a compact and discontinuous endexine in most cases. The sexine consisted of heterogeneous columellae, which support a perforated semitectum (echinate type or the semitectum was composed of perforations and muri-shaped thickening (reticulate type. These results confirm a high degree of pollen dimorphism in Waltheria associated with heterostyly.

Room-temperature fabrication of core-shell nano-ZnO/pollen grain biocomposite for adsorptive removal of organic dye from water

International Nuclear Information System (INIS)

Tzvetkov, George; Kaneva, Nina; Spassov, Tony

2017-01-01

Highlights: • Meso-/macro-porous nano-ZnO covered pollen grains are prepared at room temperature. • A possible formation mechanism of the core-shell microparticles was proposed. • Adsorptive removal of Malachite Green from water by the biocomposite is studied. - Abstract: A new core-shell nano-ZnO/pollen grain (n-ZnO/PG) biocomposite has been successfully synthesized via simple and low-temperature two-step liquid precipitation method. The synthetic strategy consists of grafting the surface of pine pollen grains (PG) with Zn"2"+-organic complexes followed by a treatment in Zn(CH_3COO)_2/NaOH solution, thus producing a closed n-ZnO shell around the organic core, with a thickness of ∼450 nm. Scanning electron microscopy, X-ray diffraction, FTIR, XPS and UV–vis spectroscopy measurements along with N_2 adsorption/desorption were used to characterize the resulting n-ZnO/PG biocomposite. The as-prepared core-shell microparticles are meso-/macro-porous with BET surface area of 25 m"2 g"−"1 and total pore volume of 0.26 cm"3 g"−"1. The adsorption properties of n-ZnO/PG were evaluated through adsorption of Malachite Green (MG) from aqueous medium at room temperature (25 °C). For the sake of comparison, the physico-chemical and adsorptive properties of the raw PG and pure n-ZnO were also examined. Results indicate that n-ZnO/PG is the most favorable for the adsorption of MG under the conditions used in this study. The adsorption kinetic data for PG, n-ZnO and n-ZnO/PG follow the pseudo-second order equation and the maximum adsorption capacity follows an order of n-ZnO/PG > n-ZnO > PG. For n-ZnO/PG an adsorption uptake up to 145.9 mg g"−"1 is observed. The as-prepared core-shell biocomposite material is a promising cost-effective and environmentally friendly adsorbent due to its textural properties, surface chemistry, adsorption capacity and recyclability.

Urticaceae pollen concentration in the atmosphere of North Western Spain.

Science.gov (United States)

Vega-Maray, Ana Maria; Valencia-Barrera, Rosa; Fernandez-Gonzalez, Delia; Fraile, Roberto

2003-01-01

Plants of the Urticaceae family can develop into a pest on soils enriched with nitrogen. Urticaceae pollen is a biohazard because it elicits severe pollinosis. Pollen grains were sampled by using a Lanzoni seven-day-recording trap from February 1995-December 2000 in the atmosphere of the city of Ponferrada (Leon, North Western Spain). The Spearman test was used to analyse the statistical correlation between Urticaceae pollen and certain meteorological factors in different main pollination periods. Maximum values are reached in June and July, minimum levels are recorded in January and December. The parameters bearing the greatest positive influence on the occurrence of Urticaceae pollen grains are: temperature (maximum, minimum and mean), humidity (absolute, wet-bulb temperature, dew point and mixing ratio) and south western wind direction; negative parameters are: relative humidity, rainfall and period without wind. The highest correlation coefficients were obtained with temperature and wet-bulb. Absolute humidity and wet-bulb temperature yielded better correlation than relative humidity; hence, these two parameters must be included in this type of study. The use of one main pollination period or another in statistical analysis has an influence on the coefficient value. The behaviour of the pollen grains in the atmosphere during the year also influences the results.

Xanthium strumarium L. pollen concentration in aeroplankton of Lublin in the years 2003-2005

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Elżbieta Weryszko-Chmielewska

2012-12-01

Full Text Available Xanthium strumarium (common cocklebur pollen grains are included in allergenic types. During a three-year study (2003-2005 conducted by using the gravimetric method at two trap sites in Lublin, daily concentrations, maximum concentrations and annual sums of pollen grains, as well as the length of pollen seasons of this species were compared. The pollen season of common cocklebur starts in the first or second decade of July and lasts until the third decade of September. The length of the pollen season is 70-80 days. The highest cocklebur pollen concentrations, amounting to 40-59 z·cm-2, occurred between 8 and 18 August. The maximum cocklebur pollen concentrations differed slightly in particular trap sites over the period of three years of study. A statistically significant correlation between the Xanthium strumarium pollen concentration and average temperature was demonstrated only in one year of study (2004.

Initial segmentation patterns of microspores and pollen viability in soybean cultured anthers: indication of chromosome doubling

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Milena Barcelos Cardoso

2004-09-01

Full Text Available Anthers obtained from flowers buds of soybean cultivar IAS-5 were cultured in two basal culture media (B5 and B5 long. Cytological examinations of the in vitro anthers were performed during the first 20 days of culture to assay the viability (by propionic-carmine and fluorescein diacetate tests and the stage of development of pollen grains. The frequencies of viable pollen grains varied significantly between bud sizes on the propionic-carmine analysis. The basal culture media and bud size had no clear effect on the frequencies of binucleate symmetrical and multinucleate pollen grains. Chromosome counts of metaphasic microspores throughout the culture period showed microspores with higher ploidy level in addition to normal chromosome number (n=20.Anteras obtidas de botões florais da cultivar IAS-5 de soja foram cultivadas em dois meios de cultura basais (B5 e B5 longo. Análises citológicas das anteras cultivadas in vitro foram realizadas durante os primeiros 20 dias de cultura, a fim de avaliar a viabilidade (por testes de carmim propiônico e FDA e o estágio de desenvolvimento dos grãos de pólen. As freqüências de grãos de pólen viáveis variaram significativamente entre os tamanhos de botões florais na análise com carmim propiônico. O meio de cultura basal e o tamanho do botão floral não têm um claro efeito nas freqüências de pólens binucleados simétricos e multinucleados. Contagens cromossômicas de micrósporos metafásicos ao longo do período de cultura mostraram nível de ploidia superior ao normal (n=20.

Seasonal and intradiurnal variation of airborne pollen concentrations in Bodrum, SW Turkey.

Science.gov (United States)

Tosunoglu, Aycan; Bicakci, Adem

2015-04-01

An aeropalynological study was performed in Bodrum, the famous tourism center in southwestern Turkey with a Hirst-type volumetric 7-day pollen and spore trap for 2 years (2007-2008). In Bodrum, 25,099 pollen grains as a mean value belonging to 41 taxa were recorded annually during the study period, and pollen grains from woody plant taxa had the largest atmospheric contribution of 86.99% and 24 taxa. However, 17 herbaceous plant taxa constituted 12.82% of the annual total pollen count, and 0.19% were unidentified. An average annual pollen index of 22.66% was recorded in March, despite differences from year to year. The highest pollen variability of 34 taxa was recorded in April and May. Predominant pollen types belonged to Cupressaceae/Taxaceae (42.73%), Quercus (15.95%), Pinus (9.78%), Olea europaea (9.04%), Poaceae (5.50%), Betula (1.82%), Pistacia (1.74%), Morus (1.72%), Urticaceae (1.46%), and Plantago (1.28%) and generated 91.03 of the annual total. In total, 32.59% of the mean annual total pollen index was recorded in the morning, and less pollen was recorded in the evening (18.71%). Maximum pollen concentration was recorded between 11:00 and 12:00 a.m.

The bouquet of grapevine (Vitis vinifera L. cv. Cabernet Sauvignon) flowers arises from the biosynthesis of sesquiterpene volatiles in pollen grains

Science.gov (United States)

Martin, Diane M.; Toub, Omid; Chiang, Angela; Lo, Bernard C.; Ohse, Sebastian; Lund, Steven T.; Bohlmann, Jörg

2009-01-01

Terpenoid volatiles are important information molecules that enable pollinators to locate flowers and may protect reproductive tissues against pathogens or herbivores. Inflorescences of grapevine (Vitis vinifera L.) are composed of tiny green flowers that produce an abundance of sesquiterpenoid volatiles. We demonstrate that male flower parts of grapevines are responsible for sesquiterpenoid floral scent formation. We describe temporal and spatial patterns of biosynthesis and release of floral volatiles throughout the blooming of V. vinifera L. cv. Cabernet Sauvignon. The biosynthesis of sesquiterpene volatiles, which are emitted with a light-dependent diurnal pattern early in the morning at prebloom and bloom, is localized to anthers and, more specifically, within the developing pollen grains. Valencene synthase (VvValCS) enzyme activity, which produces the major sesquiterpene volatiles of grapevine flowers, is present in anthers. VvValCS transcripts are most abundant in flowers at prebloom stages. Western blot analysis identified VvValCS protein in anthers, and in situ immunolabeling located VvValCS protein in pollen grains during bloom. Histochemical staining, as well as immunolabeling analysis by fluorescent microscopy and transmission electron microscopy, indicated that VvValCS localizes close to lipid bodies within the maturing microspore. PMID:19359488

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

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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

Pd-nanoparticles cause increased toxicity to kiwifruit pollen compared to soluble Pd(II)

International Nuclear Information System (INIS)

Speranza, Anna; Leopold, Kerstin; Maier, Marina; Taddei, Anna Rita; Scoccianti, Valeria

2010-01-01

In the present study, endpoints including in vitro pollen performance (i.e., germination and tube growth) and lethality were used as assessments of nanotoxicity. Pollen was treated with 5-10 nm-sized Pd particles, similar to those released into the environment by catalytic car exhaust converters. Results showed Pd-nanoparticles altered kiwifruit pollen morphology and entered the grains more rapidly and to a greater extent than soluble Pd(II). At particulate Pd concentrations well below those of soluble Pd(II), pollen grains experienced rapid losses in endogenous calcium and pollen plasma membrane damage was induced. This resulted in severe inhibition and subsequent cessation of pollen tube emergence and elongation at particulate Pd concentrations as low as 0.4 mg L -1 . Particulate Pd emissions related to automobile traffic have been increasing and are accumulating in the environment. This could seriously jeopardize in vivo pollen function, with impacts at an ecosystem level. - Nanoparticulate Pd - which resembles emissions from automobile catalysts - affects pollen to a higher extent than soluble Pd.

Pd-nanoparticles cause increased toxicity to kiwifruit pollen compared to soluble Pd(II)

Energy Technology Data Exchange (ETDEWEB)

Speranza, Anna, E-mail: anna.speranza@unibo.i [Dipartimento di Biologia, Universita di Bologna, via Irnerio 42, 40126 Bologna (Italy); Leopold, Kerstin, E-mail: kerstin.leopold@lrz.tu-muenchen.d [Arbeitsgruppe fuer Analytische Chemie, Technische Universitaet Muenchen, Garching (Germany); Maier, Marina, E-mail: marina.maier@ch.tum.d [Arbeitsgruppe fuer Analytische Chemie, Technische Universitaet Muenchen, Garching (Germany); Taddei, Anna Rita, E-mail: artaddei@unitus.i [CIME, Universita della Tuscia, Viterbo (Italy); Scoccianti, Valeria, E-mail: valeria.scoccianti@uniurb.i [Dipartimento di Scienze dell' Uomo, dell' Ambiente e della Natura, Universita di Urbino ' Carlo Bo' , Urbino (Italy)

2010-03-15

In the present study, endpoints including in vitro pollen performance (i.e., germination and tube growth) and lethality were used as assessments of nanotoxicity. Pollen was treated with 5-10 nm-sized Pd particles, similar to those released into the environment by catalytic car exhaust converters. Results showed Pd-nanoparticles altered kiwifruit pollen morphology and entered the grains more rapidly and to a greater extent than soluble Pd(II). At particulate Pd concentrations well below those of soluble Pd(II), pollen grains experienced rapid losses in endogenous calcium and pollen plasma membrane damage was induced. This resulted in severe inhibition and subsequent cessation of pollen tube emergence and elongation at particulate Pd concentrations as low as 0.4 mg L{sup -1}. Particulate Pd emissions related to automobile traffic have been increasing and are accumulating in the environment. This could seriously jeopardize in vivo pollen function, with impacts at an ecosystem level. - Nanoparticulate Pd - which resembles emissions from automobile catalysts - affects pollen to a higher extent than soluble Pd.

Regulatory networks in pollen development under cold stress

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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.

Floral phenology, secondary pollen presentation and pollination mechanism in Inula racemosa (Angiosperms: Asteraceae

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P.A. Shabir

2013-06-01

Full Text Available Inula racemosa Hook. f. is protandrous, discharges pollen grains inside the anther tube and presents pollen secondarily onto the sweeping hairs of the style. The style and stigmatic branches present the yellow clumped pollen grains for pollination. This study describes floral functional morphology and phenology, anther dehiscence and pollen presentation, growth and behaviour of style during anthesis and pollination mechanism of I. racemosa. The species is entomophilous and is characterized by a highly asynchronous sexual phase. A large degree of asynchrony from floret to floret in a capitulum, and capitulum to capitulum in a plant, keeps the pollen dispersed for a longer duration. Two insect families were represented in the pollinator survey: Hymenoptera and Diptera. A significant correlation was observed between the number of capitula visited per bout and foraging time. We discuss morphological features of the ?owers which may enhance the pollen removal rate per bee visit and consequently cause a high visitation and pollination rate.

Room-temperature fabrication of core-shell nano-ZnO/pollen grain biocomposite for adsorptive removal of organic dye from water

Energy Technology Data Exchange (ETDEWEB)

Tzvetkov, George, E-mail: george.tzvetkov@gmail.com; Kaneva, Nina; Spassov, Tony

2017-04-01

Highlights: • Meso-/macro-porous nano-ZnO covered pollen grains are prepared at room temperature. • A possible formation mechanism of the core-shell microparticles was proposed. • Adsorptive removal of Malachite Green from water by the biocomposite is studied. - Abstract: A new core-shell nano-ZnO/pollen grain (n-ZnO/PG) biocomposite has been successfully synthesized via simple and low-temperature two-step liquid precipitation method. The synthetic strategy consists of grafting the surface of pine pollen grains (PG) with Zn{sup 2+}-organic complexes followed by a treatment in Zn(CH{sub 3}COO){sub 2}/NaOH solution, thus producing a closed n-ZnO shell around the organic core, with a thickness of ∼450 nm. Scanning electron microscopy, X-ray diffraction, FTIR, XPS and UV–vis spectroscopy measurements along with N{sub 2} adsorption/desorption were used to characterize the resulting n-ZnO/PG biocomposite. The as-prepared core-shell microparticles are meso-/macro-porous with BET surface area of 25 m{sup 2} g{sup −1} and total pore volume of 0.26 cm{sup 3} g{sup −1}. The adsorption properties of n-ZnO/PG were evaluated through adsorption of Malachite Green (MG) from aqueous medium at room temperature (25 °C). For the sake of comparison, the physico-chemical and adsorptive properties of the raw PG and pure n-ZnO were also examined. Results indicate that n-ZnO/PG is the most favorable for the adsorption of MG under the conditions used in this study. The adsorption kinetic data for PG, n-ZnO and n-ZnO/PG follow the pseudo-second order equation and the maximum adsorption capacity follows an order of n-ZnO/PG > n-ZnO > PG. For n-ZnO/PG an adsorption uptake up to 145.9 mg g{sup −1} is observed. The as-prepared core-shell biocomposite material is a promising cost-effective and environmentally friendly adsorbent due to its textural properties, surface chemistry, adsorption capacity and recyclability.

Pollen flora of pakistan-lxxi. rosaceae

International Nuclear Information System (INIS)

Perveen, A.; Qaiser, M.

2014-01-01

Pollen morphology of 50 species representing 17 genera of the family Rosaceae i.e., Alchemilla, Argimonia, Cotoneaster, Crataegus, Duchesnea, Fragaria, Eriybotyra, Filipandula, Geum, Malus, Prunus, Potentilla, Pyrus , Rosa, Sibbaldia, Sorbaria and Sorbus has been studied from Pakistan by light and scanning electron microscope. Pollen grains are usually free, radially symmetrical, isopolar, prolate-spheroidal to subprolate or oblate-spheroidal rarely perprolate, tricolporate rarely tricolpate. Tectum mostly coarsely-finely striate, rarely striate-rugulate, scabrate or spinulose often reticulate. Rosaceae is more or less eurypalynous family. Significant variation is found in P/E ratio, shape and exine ornamentation and on the basis of these characters family has been divided into seven pollen types viz., Agrimonia eupatoria-type, Alchemilla ypsilotoma-type, Cotoneaster affinis-type, Fragaria nubicola-type, Geum roylei-type, Malus pumila-type, Potentilla pamirica-type. Pollen data is useful at specific and generic level. (author)

Sycamore produces viable seed after six years

Science.gov (United States)

A. F. Ike

1966-01-01

In the early stages of any tree improvement program it is desirable to know how soon progenies of selected parents can themselves be included in a breeding program. How soon will they produce viable pollen and seed? In the case of sycamore (Platanus occidentalis L.), the information is meager: the Woody- Plant Seed Manual lists the minimum commercial seedbearing age...

Variation patterns of pollen production in palm flowers

DEFF Research Database (Denmark)

Alapetite, Elodie; Barfod, Anders; Albert, Beatrice

2016-01-01

pollen production and stamen number has never been so far investigated. The diversity in stamen number observed among palms species and genera provides an ideal case study to test for such a correlation, taking into account phylogenetic constraints. Based on a survey of flowers from 82 species...... representative of the various palm tribes and compared it to stamen number, we show that pollen production in palms ranges from hundreds to millions grains. There is a relationship between stamen number and pollen production in our sampling, particularly in Coryphoideae and Arecoideae where there is a tendency...

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

Science.gov (United States)

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

2013-09-27

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

Effect of gamma radiation on the morphology and Thermophysical properties of the pollen wall of Phoenix dactylifera L.

OpenAIRE

El-Ghazaly, Gamal; Kassem, M.E.

1994-01-01

Pollen grains of Phoenix dactylifera were exposed to different doses of gamma radiation (250,500,1000 rad and 1 M rad). To access the effect of radiation on the external morphology of the pollen grains, they were examined with SEM after each treatment. In addition the differential thermal analysis technique was used to elucidate the stability of the chemical composition of the pollen wall to gamma radiation. A portion of the treated pollen was- used to pollinate different inflorescences of tw...

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

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Ernest Stawiarz

2017-11-01

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

Determination of pollen quality and quantity in mulberry (morus alba l.)

International Nuclear Information System (INIS)

Erdogan, U.

2015-01-01

In this study, the pollen grains of eight different mulberry types in I.spir and Pazaryolu districts of Erzurum were tested for the determination of viability, germination rates, pollen production levels and morphologically homogeneity. Viability of the pollens was determined by TTC (2, 3, 5-triphenly tetrazolium chlorid) and IKI (iodine + potassium iodide) tests. Pollen germination experiments were performed with Agar-plate (1%) method in sucrose solutions of 0, 5, 10, 15, 20 and 25% concentrations. In addition, pollen production and morphologically homogeneity were determined by the Hemacytometric method. The pollen viability of all types used in this study was obtained in high ratios. Pollen germination rates were the highest for 15% and 20% sucrose solutions. The highest pollen production level was obtained from the genotype 6. The morphologically homogeneity levels of pollens changed from 97.36 to 98.86% in types. (author)

A combinatorial approach to angiosperm pollen morphology.

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Mander, Luke

2016-11-30

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

Pollen of Sarawakodendron (Celastraceae) and some related genera, with notes on techniques

NARCIS (Netherlands)

Hou, Ding

1969-01-01

1. A simple technique for acetolysis of small quantities of polliniferous (herbarium) material is described and notes on pollen photomicrography are presented. 2. Pollen grains of Sarawakodendron and six related genera, consisting of twenty-nine mostly Malesian species, have been examined and

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

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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...

Pollen morphology of the Phyllanthus species (Euphorbiaceae) occurring in New Guinea

NARCIS (Netherlands)

Punt, W.

1980-01-01

Thirty-eight species from New Guinea have been examined and their pollen grains could be grouped into nine pollen types. Five of these types are more or less morphologically related. The largest type, the P. aeneus type, comprises 17 species and represents the section Nymania (K. Schumann) J.J.

Catálogo sistemático dos pólens das plantas arbóreas do Brasil meridional XI - Loranthaceae e Olacaceae Catalogue of southern brazilian pollen grains

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Ortrud Monika Barth

1972-01-01

Full Text Available Em sequência às PROTEACEAE previamente examinadas, foram estudados nesta parte do Catálogo os grãos de pólen das LORANTHACEAE e OLACACEAE da floresta umbrófila subtropical do Sul do Brasil. Não há semelhanças pronunciadas que ligassem as três famílias através da morfologia de seus grãos de pólen. As linhas da morfologia polínica nestas famílias acompanham o desenvolvimento para formas parasitárias, especialização esta que se traduz por uma morfologia definida e constante para vários gêneros das LORANTHACEAE, a partir de grãos com aberturas mal definidas e exinas de estruturas simples nas OLACACEAE. Quanto às LORANTHACEAE, é possível fazer uma separação dos gêneros pela morfologia geral de seus grãos de pólen, sendo às vezes possível separar grupos de espécies através de detalhes na estrutura das exinas (em Struthanthus. As duas espécies estudadas das OLACACEAE, pertencendo a gêneros distintos, possuem grãos de pólen também distintos.Following our previous studies in PROTEACEAE, in this part of our Catalogue we have examined pollen grains of LORANTHACEAE and OLACACEAE of the subtropical ombrophilous forest of South of Brazil. No clear similarities have been observed in the pollen morphology between the three families. The evolution of pollen morphology in these families follow the development to parasitic forms. This can be observed through definite and constant pollen morphology of various genera of LORANTHACEAE and grains with poor defined apertures and simple exine structures in OLACACEAE. In relation to LORANTHACEAE, it is possible to differentiate the genera by their pollen morphology and, sometimes, groups of species, based on details of the exine structures (as in Struthanthus. Both species of OLACACEAE studied, belonging to different genera, present different pollen morphology.

Influence of changes in crop cultivation areas on pollen contents of honey (Research Note

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A.-L. VARIS

2008-12-01

Full Text Available Pollen counts were done on honey collected by a Finnish honey corporation in late summer 1997 from the entire beekeeping area of Finland. The most common pollen type was Brassicaceae pollen, which was represented by 60% of the grains counted. It was followed by Salix spp. (10%, Trifolium repens + T. hybridum (10% and T. pratense + T. medium (6.5% species. Pollen grains of Phacelia spp, Filipendula ulmaria, Apiaceae, Sorbus aucuparia, Malus domestica, and Rubus idaeus were also numerous. These pollen types constituted 96% of all the pollen examined. These results and those of the earlier pollen counts in Finland were compared with the cultivation areas of the most important nectariferous crops. In the 1930s white clover was the most important honey source in Finland and its pollen was very dominant in honey. Since the 1950s oilseed crops have been grown in increasing rates and pure timothy-meadow fescue pastures and hay stands with heavy N applications have decreased the share of Trifolium species. The proportion of Brassicaceae pollen has continuously increased with the increase of the growing area of turnip rape Brassica rapa ssp. oleifera and rape, B. napus ssp. oleifera. At the same time the proportion of T. repens + T. hybridum pollen has decreased so that their mutual relationships are now reversed compared to the beginning of the 1960s. Changes in land use were thus very clearly to be seen in the pollen content of honey.;

A comparison of pollen-siring ability and life history between males and hermaphrodites of subdioecious Silene acaulis

DEFF Research Database (Denmark)

Philipp, Marianne; Jakobsen, Ruth Bruus; Nachman, Gøsta Støger

2009-01-01

was performed in which females were hand A pollen-competition experiment was performed in which females were hand pollinated with a mixture of pollen from males and hermaphrodites, all with known isozyme alleles, which allowed determination of who sired each seed. We recorded plant size, flower morphology......, hermaphrodite, and male individuals. The sex expression of males and hermaphrodites can vary over years for the same individual, while females are always females. Previous studies have shown that outcrossed seeds from females become seedlings with higher survival and growth rates than those from outcrossed...... seeds from hermaphrodites.Questions: (1) Do pollen grains from males exhibit some advantage over pollen from (1) Do pollen grains from males exhibit some advantage over pollen from hermaphrodites? In particular, do they sire more seeds than hermaphrodites? (2) Is the reproductive system of S. acaulis...

219 The Revised Edition of Korean Calendar for Allergenic Pollens

Science.gov (United States)

Oh, Jae-won; Kim, Joo-Hwa; Kim, Seong-Won; Kang, Im-Joo; Kim, Bong-Seong; Kook, Myung-Hee; Park, Kang-Seo; Lee, Ha-Baik; Kim, Kyu Rang; Choi, Young-Jean

2012-01-01

Background The old version of pollen calendar was used until this year in South Korea. That calendar did not reflect current pollen distribution and concentrations that can be influenced by changes in weather and environment. A new pollen calendar of allergenic pollens was made based on the data on pollen concentrations obtained in 8 regions nationwide between 1997 and 2009 in South Korea. Methods The distribution of pollen grains was assessed every day at 8 areas (Seoul, Guri, Busan, Daegu, Jeonju, Kwangju, Kangneung, and Jeju) nationwide for 12 years between July 1, 1997 and June 30, 2009. Pollen were collected by using Burkard 7-day sampler (Burkard manufacturing Co Ltd, Hertfordshire, UK), and the collected pollens were sent every week to Hanyang Guri Hospital. Then pollens were strained with Calberla's fuchsin staining solution and were identified. The number of pollen grains per m3 was calculated. Results Alder, birch and Japanese cedar started to appear in February. Japanese cedar showed a highest pollen concentration in Jeju. Pine became the highest pollen in May, and the pollen concentrations of oak and birch also became high. Common ragweed appeared in the middle of August and showed the highest pollen concentration in the middles of September. Japanese hop showed a high concentration between the middle of August and the end of September, and mugwort appeared in the middles of August and its concentration increased up until early September. Birch appeared earlier in Kangneung, and pine showed a higher pollen concentration than in the other areas. In Daegu, Oriental thuja, alder and juniper produced a large concentration of pollens. Pine produced a large concentration of pollens between the middle of April and the end of May. Weeds showed higher concentrations in September and mugwort appeared earlier than common ragweed. In Busan where is the southeast city, the time of flowering is relatively early, and alder and Oriental thuja appeared earliest among

Biochemical and ultrastructural changes in pollen of Zea mays L. grown under enhanced UV-B radiation

International Nuclear Information System (INIS)

Santos, A.; Almeida, J.M.; Santos, I.; Salema, R.

1998-01-01

The influence of ultraviolet-B (UV-B) radiation on the development of the male gametophyte was studied in Zea mays L. cv. LG12 grown in a growth chamber under PAR light supplemented with UV-B radiation and compared with a second set of plants grown under PAR light. Pollen samples collected from both groups of plants were cultured on germination medium and it was found that UV-B had no effect on pollen germination. Total pollen protein content was not affected but UV-B absorbing pigments increased. Some ultrastructural alterations were observed in pollen and pollen tubes, in particular large amounts of electron dense deposits were seen throughout the cytoplasm and in association with the pollen wall. In mature spikes of UV-B treated plants, anthers retained numerous pollen grains in their loculi while anthers of control plants were almost empty. UV-B treatment delayed flowering by 2±3 d. These results show that UV-B treatment of maize plants interferes with flowering, pollen ultrastructure and anther maturation even though pollen germination is unaffected. The significant increase of UV-B absorbing pigments in pollen grains could represent a defence mechanism that enables plants to complete their reproductive cycle. (author)

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

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Theuerkauf, Martin; Couwenberg, John

2018-04-01

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

Experimental forensic studies of the preservation of pollen in vehicle fires.

Science.gov (United States)

Morgan, R M; Flynn, J; Sena, V; Bull, P A

2014-03-01

The implications of the recent recommendations of the Law Commission regarding the use of admissibility tests have the potential to be far reaching for forensic disciplines that rely on the expertise of highly qualified expert witnesses. These disciplines will need a concomitant body of peer-reviewed experiments that provides a basis for the interpretations of such evidence presented in court. This paper therefore, presents such results from two experiments which were undertaken to address specific issues that were raised in cases presented in the British courtroom. These studies demonstrate that there is a variability in the persistence of Lily, Daffodil and Tulip pollen when exposed to high temperatures between 0.5min and 1440min (24h). It was possible to identify all three pollen types after 30min of exposure to 400°C, and after shorter time frames the threshold for successful identification was 700°C after 0.5min for all pollen types tested and 500°C for Daffodil and Lily after 5min of heat exposure. Over longer time periods (18h (1080min)) the different pollen types were found to persist in a viable form for identification at 300°C (Lily), 200°C (Daffodil) and 50°C (Tulip). These findings, albeit from a small sample of pollen types, provide empirical contextual information that would contribute to such evidence having sufficient scientific weight to meet admissibility criteria and be viable evidence for a court. These studies demonstrate the value in seeking pollen evidence from even such extreme crime scenes as encountered in vehicular fires. Copyright © 2013 Forensic Science Society. Published by Elsevier Ireland Ltd. All rights reserved.

Pollen Processing Behavior of Heliconius Butterflies: A Derived Grooming Behavior

Science.gov (United States)

Hikl, Anna-Laetitia; Krenn, Harald W.

2011-01-01

Pollen feeding behaviors Heliconius and Laparus (Lepidoptera: Nymphalidae) represent a key innovation that has shaped other life history traits of these neotropical butterflies. Although all flower visiting Lepidoptera regularly come in contact with pollen, only Heliconius and Laparus butterflies actively collect pollen with the proboscis and subsequently take up nutrients from the pollen grains. This study focused on the behavior of pollen processing and compared the movement patterns with proboscis grooming behavior in various nymphalid butterflies using video analysis. The proboscis movements of pollen processing behavior consisted of a lengthy series of repeated coiling and uncoiling movements in a loosely coiled proboscis position combined with up and down movements and the release of saliva. The proboscis-grooming behavior was triggered by contamination of the proboscis in both pollen feeding and non-pollen feeding nymphalid butterflies. Proboscis grooming movements included interrupted series of coiling and uncoiling movements, characteristic sideways movements, proboscis lifting, and occasionally full extension of the proboscis. Discharge of saliva was more pronounced in pollen feeding species than in non-pollen feeding butterfly species. We conclude that the pollen processing behavior of Heliconius and Laparus is a modified proboscis grooming behavior that originally served to clean the proboscis after contamination with particles. PMID:22208893

Wind tunnel and field assessment of pollen dispersal in soybean [Glycine max (L.) Merr.].

Science.gov (United States)

Yoshimura, Yasuyuki

2011-01-01

Although genetically modified (GM) soybean has never been cultivated commercially in Japan, it is essential to set up the isolation distance required to prevent out-crossing between GM and conventional soybean in preparation for any future possibility of pollen transfer. The airborne soybean pollen was sampled using some Durham pollen samplers located in the range of 20 m from the field edge. In addition, the dispersal distance was assessed in a wind tunnel under constant air flow and then it was compared with the anticipated distances based on the pollen diameter. In the field, the maximum pollen density per day observed was 1.235 grains cm(-2) day(-1) at three observation points within 2.5 m from the field and inside the field the mean density did not reach the rate of 1 grain cm(-2 )day(-1) during 19 flowering days. The results of the wind tunnel experiment also showed that the plants had almost no airborne release of pollen and the dispersal distance was shorter than theoretical value due to clustered dispersal. This study showed little airborne pollen in and around the soybean field and the dispersal is restricted to a small area. Therefore, wind-mediated pollination appears to be negligible.

Pollen morphology of some asiatic species of genus salsola (chenopodiaceae) and its taxonomic relationships

International Nuclear Information System (INIS)

Toderich, K.N.; Shuyskaya, E.V.; Ozturk, M

2010-01-01

Comparative studies on the pollen grain morphology of 27 Asiatic species of the genus Salsola were conducted by using scanning electron microscope (SEM analysis) in order to assess the taxonomic value of pollen traits. The pollen are radially symmetrical isopolar, pantopolyporate, spherical or subspheroid. The pollen characters like size, pore number, chord (C/D ratio), pore diameter, exine thickness, level of sinking of pore, convexness of mesoporial exine, spinule and minute-hole densities and number of spines on pore membrane appeared to be useful characters in distinguishing the species. Interesting intraspecific variations in pollen grain morphology were recorded for the C/D ratio. This parameter is highly specific, supporting the delimitation of Salsola species, and appears to be more conservative than some flower and fruit characters. The numerical value of form index comprising the ratio between the length of polar axis and diameter (P/E) also was an informative trait for delimitation of the species investigated here. Three pollen types were recognized. Euclidean distance was used to compute the dissimilarity matrix and a cladogram prepared. The quantitative characters of pollen morphology allowed clustering of groups and ordination analyses of species from different sections/subsections within genus Salsola. These features indicated that overall pollen traits reflect the current taxonomic boundaries, except for the Salsola species allocated to Climacoptera and Halothamnus, which should be accepted as separate genera. (author)

Behavior of profilins in the atmosphere and in vitro, and their relationship with the performance of airborne pollen

Science.gov (United States)

Aloisi, Iris; Del Duca, Stefano; De Nuntiis, Paola; Vega Maray, Ana M.; Mandrioli, Paolo; Gutiérrez, Pablo; Fernández-González, Delia

2018-04-01

Most pollen allergens in the air are carried by pollen grains, but the presence of airborne smaller respirable particles containing pollen allergens has also been demonstrated. Meteorological factors drastically affect the occurrence of pollen, allergen release in the air and diffusion of the latest. In order to shed light on this phenomenon, the dynamics of pollen and the pollen panallergen profilin in the air of two European cities (León, Spain and Bologna, Italy) having different weather conditions, were analyzed. Pollen sampling was performed continuously from March to June 2015 using two seven-day recording volumetric trap of Hirst-type, while the particles for aeroallergen quantification were sampled with a Burkard Cyclone sampler and the profilin content in aerosol samples was quantified using an indirect double-antibody sandwich ELISA. In both cities, pollen and profilin concentrations followed a similar trend and showed a significant correlation; however, peaks were often misaligned, with the profilin peaks following those of pollen. Several meteorological parameters, such as relative humidity, significantly influenced pollen and allergen dispersion. In vitro pollen tests were thus performed in order to mimic pollen rehydration, occurring in natural conditions and a massive protein release from allergenic pollen was detected during the early stages of pollen rehydration when profilin was also extruded from the grains. The different timing and protein amounts released from different pollen during hydration might explain, at least in part, the non-synchronous pollen and profilin peaks detected in the atmosphere.

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

Science.gov (United States)

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

2015-05-01

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

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

Science.gov (United States)

Donald L. Copes; Nan C. Vance

2000-01-01

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

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

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Mohamed Elfatih H Bashir

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

The Impacts of Maximum Temperature and Climate Change to Current and Future Pollen Distribution in Skopje, Republic of Macedonia

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Vladimir Kendrovski

2012-02-01

Full Text Available BACKGROUND. The goal of the present paper was to assess the impact of current and future burden of the ambient temperature to pollen distributions in Skopje. METHODS. In the study we have evaluated a correlation between the concentration of pollen grains in the atmosphere of Skopje and maximum temperature, during the vegetation period of 1996, 2003, 2007 and 2009 as a current burden in context of climate change. For our analysis we have selected 9 representative of each phytoallergen group (trees, grasses, weeds. The concentration of pollen grains has been monitored by a Lanzoni volumetric pollen trap. The correlation between the concentration of pollen grains in the atmosphere and selected meteorological variable from weekly monitoring has been studied with the help of linear regression and correlation coefficients. RESULTS. The prevalence of the sensibilization of standard pollen allergens in Skopje during the some period shows increasing from 16,9% in 1996 to 19,8% in 2009. We detect differences in onset of flowering, maximum and end of the length of seasons for pollen. The pollen distributions and risk increases in 3 main periods: early spring, spring and summer which are the main cause of allergies during these seasons. The largest increase of air temperature due to climate change in Skopje is expected in the summer season. CONCLUSION. The impacts of climate change by increasing of the temperature in the next decades very likely will include impacts on pollen production and differences in current pollen season. [TAF Prev Med Bull 2012; 11(1.000: 35-40

Identification sources of pollen spectra in dry and wet atmospheric deposition in the forest-steppe zone of Altai Krai (Russia)

Science.gov (United States)

Ryabchinskaya, Natalia; Nenasheva, Galina; Malygina, Natalia

2015-04-01

Pollen spectra circulating in the atmosphere contain the important information about primary biological aerosol particles (PBAP), worldwide interest in which has significantly increased in recent decades [Despres, 2012]. It is related to the fact that many researchers suggest primary aerosols as a condensation nucleus significantly affected on the formation of clouds and precipitation and, consequently, on the hydrological cycle and climate, especially at the regional level [Andreae et al., 2008; Poschlet et al., 2010; Prenni et al., 2009]. We present the comparison of pollen spectra obtained during the dry and wet atmospheric deposition in Altai Krai (Russia) and identification of the sources/regions of their receipts. Altai Krai is located in the center of the Eurasian continent, at the border of several natural and climatic zones. A significant part of the region's territory is characterized as a forest-steppe zone with a lot of natural and anthropogenic landscapes, accompanied by continental climate. It provides a rich diversity of natural vegetation and cultural associations. During last 10 years pollen grains has been monitored in the airspace of Barnaul city (the capital of Altai Krai) located in the central part of the forest-steppe zone). During the monitoring, the attempts to determine the origin of pollen spectra (local or introduced) were made as well. In the long-term average dates of the first wave of dusting in the spring season 2014 Burkard pollen traps were used in order to monitor the airspace in Barnaul, namely dry deposition of pollen grains [Nenasheva, 2013]. To estimate the wet deposition PBAP (pollen), which can reach 80% in the middle latitudes, precipitation sampler were installed close to Burkard pollen traps in order to sample precipitation. The samples were filtered through a filter having a pore diameter of 1 µm, then prepared and examined for the presence of pollen grains. The comparison of the results of pollen analysis of 10 samples

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

Science.gov (United States)

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

2003-04-01

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

Juniper Pollen Hotspots in the Southwest

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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.

[Allergic responses to date palm and pecan pollen in Israel].

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Waisel, Y; Keynan, N; Gil, T; Tayar, D; Bezerano, A; Goldberg, A; Geller-Bernstein, C; Dolev, Z; Tamir, R; Levy, I

1994-03-15

Date palm (Phoenix dactylifera) and pecan (Carya illinoensis) trees are commonly planted in Israel for fruit, for shade, or as ornamental plants. Pollen grains of both species are allergenic; however, the extent of exposure to such pollen and the incidence of allergic response have not been studied here. We therefore investigated skin-test responses to pollen extracts of 12 varieties of palm and 9 of pecan in 705 allergic patients living in 3 cities and 19 rural settlements. Sensitivity to the pollen extracts of both species was much higher among residents of rural than of urban communities. Moreover, there was a definite relationship between the abundance of these trees in a region and the incidence of skin responders to their pollen. Sensitivity was frequent in settlements rich in these 2 species, such as those with nearby commercial date or pecan plantations. In general, sensitivity to date pollen extracts was lower than to pecan. However, differences in skin responses to pollen extracts of various clones were substantiated. Air sampling revealed that pollen pollution decreased considerably with distance from the trees. At approximately 100 m from a source concentrations of airborne pollen were low. Since planting of male palm and pecan trees in population centers would increase pollen pollution, it should be avoided.

Predominant airborne pollen in a district of Beirut, Lebanon for the period extending from March 2004 to August 2004

International Nuclear Information System (INIS)

Rahal, E.A.; Halas, Y.; Zaytoun, G.; Abdelnoor, A.M.; Zeitoun, F.

2007-01-01

Pollen grains rank high among causative agents of hay fever, allergic rhinitis,allegro-conjunctivitis, and asthma. Data on aerial pollen types, concentrations and patterns in Lebanon is lacking. Hence, we undertook the pioneering task of identifying and enumerating atmospheric pollen types in Beirut, the Lebanese capital, for the period extending from March 2004 to August 2004. Our aim was to shed some light on the prevalent sorts of airborne pollen in the city for subsequent studies attempting to assess associations between pollen types and allergic disease varieties. For this purpose, a VPPS 2000 Sampler (Lanzoni, Bologna, Italy) was employed. The daily average number of pollen detected for the span of the study was 41.32 pollen grains/m3 of air. The ten most commonly encountered pollen types were Cupressus, Pinus, Quercus, Parietaria, Fraxinus, Urtica, Buxus, Brassica, Syringa, and Chenopodium.Levels of the majority of pollen types peaked in April; however, March had the highest daily average record mostly enforced by immense bouts of Cupressus pollen. A pollen-monitoring network is in demand in Lebanon. Identification of airborne pollens in Lebanon would allow allergists to include them in a panel of potential allergens used in tests aimed at determining causative allergens in their patients. (author)

On the Relationship between Pollen Size and Genome Size

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Charles A. Knight

2010-01-01

Full Text Available Here we test whether genome size is a predictor of pollen size. If it were, inferences of ancient genome size would be possible using the abundant paleo-palynolgical record. We performed regression analyses across 464 species of pollen width and genome size. We found a significant positive trend. However, regression analysis using phylogentically independent contrasts did not support the correlated evolution of these traits. Instead, a large split between angiosperms and gymnosperms for both pollen width and genome size was revealed. Sister taxa were not more likely to show a positive contrast when compared to deeper nodes. However, significantly more congeneric species had a positive trend than expected by chance. These results may reflect the strong selection pressure for pollen to be small. Also, because pollen grains are not metabolically active when measured, their biology is different than other cells which have been shown to be strongly related to genome size, such as guard cells. Our findings contrast with previously published research. It was our hope that pollen size could be used as a proxy for inferring the genome size of ancient species. However, our results suggest pollen is not a good candidate for such endeavors.

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

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Reyaz Ahmad Malik

2014-01-01

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

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

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Lu, Yunlong; Wei, Liqin; Wang, Tai

2015-01-01

The development of sperm cells (SCs) 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 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.

ALTERNATIVES TO IMPROVE HYBRIDIZATION EFFICIENCY IN Eucalyptus BREEDING PROGRAMS

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Roselaine Cristina Pereira

2002-01-01

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

An occupational respiratory allergy caused by Sinapis alba pollen in olive farmers.

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Anguita, J L; Palacios, L; Ruiz-Valenzuela, L; Bartolomé, B; López-Urbano, M J; Sáenz de San Pedro, B; Cano, E; Quiralte, J

2007-04-01

Sinapis alba (white mustard) is a entomophilic species included in the Brassicaceae family. To date it has not been related to allergic sensitization or clinical respiratory disease. Twelve olive orchard workers had a history of rhinitis and/or bronchial asthma that occurred during control weed management and/or harvest, from January to March. They underwent skin prick tests (SPT) with S. alba pollen extract and a standard battery of aeroallergens. Sinapis alba pollen extract was prepared for performing quantitative skin tests, enzyme allergosorbent test and nasal challenge test (NCT). A portable monitoring station and an urban volumetric Hirst-type spore trap were used for the aerobiological study. Eleven patients suffered from rhinitis and bronchial asthma and one had only from rhinitis. All patients were sensitized to S. alba pollen extract, and they showed a positive NCT response. In the urban aerobiologic monitoring station the amount of S. alba pollen only exceptionally reached peaks of 21 grains/m(3), whereas in the work environment peaks of 1801 grains/m(3) were detected between 15 February and 7 April. We demonstrate the existence of a new occupational allergen for olive farmers: S. alba pollen. We point out the importance of perform aerobiological sampling within the occupational environment for the detection and quantification of the allergenic source.

Arabidopsis ACA7, encoding a putative auto-regulated Ca(2+)-ATPase, is required for normal pollen development.

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Lucca, Noel; León, Gabriel

2012-04-01

Microgametogenesis is a complex process that involves numerous well-coordinated cell activities, ending with the production of pollen grains. Pollen development has been studied at the cytological level in Arabidopsis and other plant species, where its temporal time course has been defined. However, the molecular mechanism underlying this process is still unclear, since a relative small number of genes and/or processes have been identified as essential for pollen development. We have designed a methodology to select candidate genes for functional analysis, based on transcriptomic data obtained from different stages of pollen development. From our analyses, we selected At2g22950 as a candidate gene; this gene encodes a protein belonging to the auto-regulated Ca(2+)-ATPase family, ACA7. Microarray data indicate that ACA7 is expressed exclusively in developing pollen grains, with the highest level of mRNA at the time of the second pollen mitosis. Our RT-PCR experiments showed that ACA7 mRNA is detected exclusively in developing flowers. Confocal microscopy experiments showed a plasma membrane localization for the recombinant GFP:ACA7 protein. We identified two different insertional mutant lines, aca7-1 and aca7-2; plants from both mutant lines displayed a normal vegetative development but showed large amounts of dead pollen grains in mature flowers assayed by Alexander's staining. Histological analysis indicated that abnormalities are detected after the first pollen mitosis and we found a strong correlation between ACA7 mRNA accumulation and the severity of the phenotype. Our results indicate that ACA7 is a plasma membrane protein that has an important role during pollen development, possibly through regulation of Ca(2+) homeostasis. © Springer-Verlag 2011

A fertilidade do polen e sua correlação com o número de sementes, em espécies e formas do gênero citrus

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Sílvio Moreira

1941-12-01

Full Text Available 1 - The present paper deals with the results of studies on pollen fertility, number of seeds per fruit and frequency of polyembryony in Citrus. 2 - The pollen may be divided into four groups of which the first consists of the living and functional grains, colouring deeply with carmín acetic, germinating in sugar solutions fairly well. The remainny three types : half filled grains, empty grains, and small deformed grains are all inviable. 3 - The grains are generally spherical, 15 to 40ix in diameter. The smallest grains were found in Citrus hystrix and Citrus mitis (fig. 3 and 4, while citron and the grape-fruits have the largest grains (fig. 1, 2 and 5. 4 - Size and form are reasonably constant, except the hybrid "Citran-gequat", "limão galego" without spines, orange "Ruby" (fig. 6 to 8. 5 - Percentages of viable pollen grains are given in quadros IV to X. Tahiti Lime, probably a triploid, is completely sterile. "Baía" orange (Washington Navel orange is completely male sterile, while the fruits of it may have some seeds. The two seedless varieties of "lima" and "pera" have 37,1 and 9,3% of viable pollen respectively. Regarding pollen viability oranges are the most variable. They show from 0 to 90% of good pollen (quadros IV and V. In lemons and limes the percentages vary from 50% and 80% (quadros VI to VIII. Tangerines, with exception of Satsuma owari, have generally more than 60% of good pollen. The grape-fruits, except the case of "Marsh-seedless", are characterized by a relative high pollen fertility. 6 - There is a certain variation of pollen fertility due to the external conditions. It seems to exist also a certain effect of the rootstock, on viability of pollen grains, as shown for the rootstock of "sour orange" and "rough lemon". 7 - The number of seeds per fruit was also determined and is given in the respective quadros (IV-X. 8 - There does not exist any consistent difference between open pollinated and selfed flowers in regard to

Bee Pollen Flavonoids as a Therapeutic Agent in Allergic and Immunological Disorders.

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Jannesar, Masoomeh; Sharif Shoushtari, Maryam; Majd, Ahmad; Pourpak, Zahra

2017-06-01

Bee pollen grains, as the male reproductive part of seed-bearing plants contain considerable concentrations of various phytochemicals and nutrients. Since antiquity, people throughout the world used pollens to cure colds, flu, ulcers, premature aging, anemia and colitis. It is now well-documented that some bee pollen secondary metabolites (e.g. flavonoid) may have positive health effects. In recent years, the flavonoids have attracted much interest because of their wide range of biological properties and their beneficial effects on human health. The current review, points out potential therapeutic effects of bee pollen flavonoids as one of the main bee pollen bioactive compounds in allergic and immunological diseases. Due to the fact that some types of flavonoid components in bee pollen have anti-allergic, anti-oxidant and anti-inflammatory properties, bee pollen flavonoids can be excellent candidates for future studies including phytotherapy, molecular pharmacology and substitutes for chemicals used in treating allergic and immunological disorders.

Pollen analysis of the post-emergence residue of Melipona (Melikerria interrupta Latreille (Hymenoptera: Apidae bred in the central Amazon region

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Marcos Gonçalves Ferreira

2013-12-01

Full Text Available We applied an "adapted" protocol for collecting and processing pollen grains in the pollen analysis of the post-emergence residue of Melipona (Melikerria interrupta Latreille. The study was conducted at the Sant'Ana honey farm, located on the banks of the Solimões River, in the municipality of Manacapuru, in the state of Amazonas, Brazil, where a colony was monitored in October and November 2010. From that colony, 10 samples of post-emergence residue were collected. Unlike in the acetolysis method, there was no need to expose pollen grains to an acidic medium, because pollen loses its content during the larval digestive process. We identified 32 pollen types, from 19 botanical families, plus three undetermined pollen types. The most representative family was Fabaceae (Mimosoideae, with eight pollen types, Mimosa guilandinae being the most common species. Only the pollen of Miconia (Melastomataceae, with 74.10%, was classified as a common pollen. We also found that the pollen of Mimosa pudica (Fabaceae: Mimosoideae retained its content, indicating that not all resources furnished by workers are utilized by the larvae. The protocol applied here, despite omitting the acetolysis process, was efficient, providing full details of pollen contained in post-emergence residue.

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

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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.

Suicide risk in relation to air pollen counts: a study based on data from Danish registers

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Qin, Ping; Waltoft, Berit L; Mortensen, Preben B; Postolache, Teodor T

2013-01-01

Objectives Since the well-observed spring peak of suicide incidents coincides with the peak of seasonal aeroallergens as tree-pollen, we want to document an association between suicide and pollen exposure with empirical data from Denmark. Design Ecological time series study. Setting Data on suicide incidents, air pollen counts and meteorological status were retrieved from Danish registries. Participants 13 700 suicide incidents over 1304 consecutive weeks were obtained from two large areas covering 2.86 million residents. Primary and secondary outcome measures Risk of suicide associated with pollen concentration was assessed using a time series Poisson-generalised additive model. Results We noted a significant association between suicide risk and air pollen counts. A change of pollen counts levels from 0 to ‘10–suicides in the population, and from 0 to ‘30–100’ grains, a relative risk of 1.132. The observed association remained significant after controlling for effects of region, calendar time, temperature, cloud cover and humidity. Meanwhile, we observed a significant sex difference that suicide risk in men started to rise when there was a small increase of air pollen, while the risk in women started to rise until pollen grains reached a certain level. High levels of pollen had slightly stronger effect on risk of suicide in individuals with mood disorder than those without the disorder. Conclusions The observed association between suicide risk and air pollen counts supports the hypothesis that aeroallergens, acting as immune triggers, may precipitate suicide. PMID:23793651

Investigation on the pollen morphology of traditional cultivars of Prunus species in Sicily

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Anna Geraci

2012-08-01

Full Text Available In this study pollen grains of 13 cultivars and 3 rootstocks belonging to 5 species (P. armeniaca, P. domestica, P. dulcis, P. persica, P. avium of the genus Prunus collected from North-East Sicily were examined for the micromorphological characterization through the scanning electron microscopy (SEM. The length of polar axis (P and the equatorial diameter (E of grain, P/E ratio, the length of colpi (C, diameter of perforations (DP and the number of perforations in 25 μm2 (PN, the width of muri (WM, the distance between muri (DM and their number in 25 μm2 (MN, the width of grooves (WG were measured and their variation was compared among studied taxa. Moreover multivariate statistical analysis was carried out to distinguish morphometric information from measured parameters. All pollen grains are trizonocolpate, isopolar, medium-large sized and their shape varies from prolate to perprolate. Regarding outline pollen grains are subtriangular in polar view and elliptic in equatorial view. Exine sculpturing is striate with perforations on grain surface. The arrangement of ridges appears roughly parallel but too sloped (sometimes curved compared to polar axis, or branched and oriented in different directions, or perfectly parallel or more irregular with bifurcated ridges often sinuous. The analyses showed a great variability (particularly in P. domestica cultivars related in some cases to the diversity in the morphological features of the leaves and the fruits of the investigated entities.

Pollination with gamma-irradiated pollen and seed development in kiwifruit (Actinidia deliciosa var. deliciosa)

International Nuclear Information System (INIS)

Musial, K.

1997-01-01

Full text. The effects of pollen irradiation at 70 and 90 kr on seed set were studied in Actinidia deliciosa var. deliciosa. Pollination with irradiated pollen affected seed development and contents. Rising irradiation doses increased the percentages of empty seeds and decreased the percentages of seeds containing embryos with endosperm. Moreover, pollination with heavily irradiated pollen led to the formation of seeds containing the endosperm only. Embryo and endosperm size was also strongly influenced by irradiated pollen. The length of endosperms was reduced at all levels of pollen irradiation compared to the non-irradiated controls; the embryo development was conspicuously retarded. Cells in endosperm resulting from the treatments differed in the presence and number of starch grains. (author)

Cloning and characterisation of a putative pollen-specific polygalacturonase gene (CpPG1) differentially regulated during pollen development in zucchini (Cucurbita pepo L.).

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Carvajal, F; Garrido, D; Jamilena, M; Rosales, R

2014-03-01

Studies in zucchini (Cucurbita pepo L. spp. pepo) pollen have been limited to the viability and morphology of the mature pollen grain. The enzyme polygalacturonase (PG) is involved in pollen development and pollination in many species. In this work, we study anther and pollen development of C. pepo and present the cloning and characterisation of a putative PG CpPG1 (Accession no. HQ232488) from pollen cDNA in C. pepo. The predicted protein for CpPG1 has 416 amino acids, with a high homology to other pollen PGs, such as P22 from Oenothera organensis (76%) and PGA3 from Arabidopsis thaliana (73%). CpPG1 belongs to clade C, which comprises PGs expressed in pollen, and presents a 34 amino acid signal peptide for secretion towards the cell wall. DNA-blot analysis revealed that there are at least another two genes that code for PGs in C. pepo. The spatial and temporal accumulation of CpPG1 was studied by semi-quantitative- and qRT-PCR. In addition, mRNA was detected only in anthers, pollen and the rudimentary anthers of bisexual flowers (only present in some zucchini cultivars under certain environmental conditions that trigger anther development in the third whorl of female flowers). However, no expression was detected in cotyledons, stem or fruit. Furthermore, CpPG1 mRNA was accumulated throughout anther development, with the highest expression found in mature pollen. Similarly, exo-PG activity increased from immature anther stages to mature anthers and mature pollen. Overall, these data support the pollen specificity of this gene and suggest an involvement of CpPG1 in pollen development in C. pepo. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

Forensic Pollen Evidence from Clothes by the Tape Adhesive Method

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Chun-Liang Wu

2006-06-01

Full Text Available Collection and identification of pollen is becoming important in forensic applications. Many criminal cases have been reported to link suspects to the crime scene by analysis of pollen. Several methods have been used in the pollen collection and analysis, but they are expensive and tedious. Therefore, it is important to develop a simple method to collect pollen grains from clothes. We tried to recover pollen from clothing surface by using the sticky tapes method. The tape adhesive method has been widely used for sample collection for various purposes, but the efficiency of recovery of invisible pollen from clothes has rarely been reported. Therefore, to test the efficiency of the tape adhesive method in recovering pollen from clothes is important. The first author wore clothes that were made from textile S made by the mixture of cotton 60% and polyester fiber 40% to collect pollen from 26 different areas mostly in the northern part of Taiwan and then used cellophane tape D (Sirchie Finger Print Lab., Inc-No. 131LT4 to recover them from different body parts. Twenty-six pollen taxa were detected in different parts of clothes depending upon what kind of plant the first author stayed near. From the results, we concluded that the tape adhesive method is suitable in recovering pollen from clothes. We have suggested that the tape adhesive method could be part of methods for collecting pollen from clothes of suspects. It is simpler, faster and less expensive than other methods.

Determination of pollen grain viability and germination levels for pistachio and terebinth in Aydin /Turkey ecology

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Gunver-Dalkilic, G; Dayi-Dogru, O

2011-04-15

With this research, the viability levels, production potentials, and storage periods of pollen of naturally grown four male terebinth types (Pistacia terebinthus L.) and four male pistachios (Pistacia vera L.) grafted on terebinth trees were determined in Uzunlar Village, Aydin Province. For the aim of determining the pollen viability levels, TTC, IKI, and safranine solutions were used. The viability ratio ranged between 88.24% (safranine test) and 70.18% (TTC test) in pistachio trees, between 85.36% (IKI test) and 63.73% (safranine test) in terebinth types. The average amount of pollen within a flower resolved by hemacytometric method was changed between 135 000 and 176 250 depend on species and types. While the germination percentage of pollen of pistachio trees and terebinth types was 71% and 26%, respectively in the beginning of storage, that of pollen in the room conditions after fourth day, in the refrigerator from tenth day and in the deep freezer from second month was decreased to zero. (author)

Determination of pollen grain viability and germination levels for pistachio and terebinth in Aydin /Turkey ecology

International Nuclear Information System (INIS)

Gunver-Dalkilic, G.; Dayi-Dogru, O.

2011-01-01

With this research, the viability levels, production potentials, and storage periods of pollen of naturally grown four male terebinth types (Pistacia terebinthus L.) and four male pistachios (Pistacia vera L.) grafted on terebinth trees were determined in Uzunlar Village, Aydin Province. For the aim of determining the pollen viability levels, TTC, IKI, and safranine solutions were used. The viability ratio ranged between 88.24% (safranine test) and 70.18% (TTC test) in pistachio trees, between 85.36% (IKI test) and 63.73% (safranine test) in terebinth types. The average amount of pollen within a flower resolved by hemacytometric method was changed between 135 000 and 176 250 depend on species and types. While the germination percentage of pollen of pistachio trees and terebinth types was 71% and 26%, respectively in the beginning of storage, that of pollen in the room conditions after fourth day, in the refrigerator from tenth day and in the deep freezer from second month was decreased to zero. (author)

Traffic-related air pollutants induce the release of allergen-containing cytoplasmic granules from grass pollen.

NARCIS (Netherlands)

Motta, A C; Marliere, M; Peltre, G; Sterenberg, P A; Lacroix, G

2006-01-01

BACKGROUND/AIM: Pollen cytoplasmic granules (PCG) are loaded with allergens. They are released from grass pollen grains following contact with water and can form a respirable allergenic aerosol. On the other hand, the traffic-related air pollutants NO2 and O3 are known to be involved in the current

Traffic-related air pollutants induce the release of allergen-containing cytoplasmic granules from grass pollen

NARCIS (Netherlands)

Motta, AC; Marliere, M; Peltre, G; Sterenberg, PA; Lacroix, G

2006-01-01

Background/Aim: Pollen cytoplasmic granules (PCG) are loaded with allergens. They are released from grass pollen grains following contact with water and can form a respirable allergenic aerosol. On the other hand, the traffic-related air pollutants NO2 and O-3 are known to be involved in the current

Molecular identification of tuliposide B-converting enzyme: a lactone-forming carboxylesterase from the pollen of tulip.

Science.gov (United States)

Nomura, Taiji; Murase, Tatsunori; Ogita, Shinjiro; Kato, Yasuo

2015-07-01

6-Tuliposides A (PosA) and B (PosB), which are the major secondary metabolites in tulip (Tulipa gesneriana), are enzymatically converted to the antimicrobial lactonized aglycons, tulipalins A (PaA) and B (PaB), respectively. We recently identified a PosA-converting enzyme (TCEA) as the first reported member of the lactone-forming carboxylesterases. Herein, we describe the identification of another lactone-forming carboxylesterase, PosB-converting enzyme (TCEB), which preferentially reacts with PosB to give PaB. This enzyme was isolated from tulip pollen, which showed high PosB-converting activity. Purified TCEB exhibited greater activity towards PosB than PosA, which was contrary to that of the TCEA. Novel cDNA (TgTCEB1) encoding the TCEB was isolated from tulip pollen. TgTCEB1 belonged to the carboxylesterase family and was approximately 50% identical to the TgTCEA polypeptides. Functional characterization of the recombinant enzyme verified that TgTCEB1 catalyzed the conversion of PosB to PaB with an activity comparable with the native TCEB. RT-qPCR analysis of each part of plant revealed that TgTCEB1 transcripts were limited almost exclusively to the pollen. Furthermore, the immunostaining of the anther cross-section using anti-TgTCEB1 polyclonal antibody verified that TgTCEB1 was specifically expressed in the pollen grains, but not in the anther cells. N-terminal transit peptide of TgTCEB1 was shown to function as plastid-targeted signal. Taken together, these results indicate that mature TgTCEB1 is specifically localized in plastids of pollen grains. Interestingly, PosB, the substrate of TgTCEB1, accumulated on the pollen surface, but not in the intracellular spaces of pollen grains. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

Microbial Diversity of Betula Trees: Pollen, Catkins, Leaves Relatively of Flowering

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Tetiana V. Shevtsova

2016-01-01

Full Text Available Quantitative microbiological analysis by dilution plating method of pollen and additional male and female catkins, leaves of Betula verrucosa Ehrh. and its two cultivars: ‘Purpurea’ and ‘Youngii’ relatively of flowering period of Betula has been realized with the aim to provide new knowledge of the microbiological quality of anemophilous pollen for processing and its further application. Qualitative microbiological analysis with MALDI-TOF MS Biotyper was used in the identification of aerobic, anaerobic mesophilic bacteria and coliforms. Mixed microbiota was determined, consisting of aerobic (4.68–4.89 log cfu/g and anaerobic (3.30–3.48 log cfu/g mesophilic bacteria, lactobacilli (0–3.48 log cfu/g, coliform bacteria (0–4.57 log cfu/g, fungi and yeast (3.78–3.95 log cfu/g on the pollen grains, that indicates acceptable quality in comparison with the microbiological quality parameters for bee pollen. Pantoea agglomerans was found associated with pollen of Betula verrucosa Ehrh. Recommendations on the collection of anemophilous pollen were established.

The importance of pollen counts in the air: an example

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Francisco José González Minero

2016-06-01

Full Text Available The Bay of Cádiz in general and Sanlúcar de Barrameda in particular were pioneering places for aerobiological analysis in Spain. This study presents unpublished pollen data collected with a Hirst spore trap during a year. Results are structured in pollen calendar form which is easy to interpret by health professionals. This article also intends to pay tribute to those medical pioneers who began their studies in Sanlúcar de Barrameda. On this subject, we discuss the data obtained in 1941 and we relate them with data collected in 2009. The Mediterranean climate and the geographical location of Sanlúcar de Barrameda bring about an archetypical pollen calendar of the towns of the Iberian Peninsula’s southern coast. A total of 21 pollen types are quanti ed, Olea europaea L. (25.1%, Quercus (17.5%, Pinaceae (12.3%, Poaceae (10.2% and Cupressaceae (8.1% being the more abundant types . The months of highest pollen concentration are April and May. The maximum daily concentration was reached on May 13 with 825 grains/m3 of Olea europaea L. pollen. Daily concentrations of grass pollen and other herbaceous plants are not exceptionally high, but they do have a continued presence throughout the year, so the risk of pollen allergies cannot be con ned to spring.

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

International Nuclear Information System (INIS)

Singh, I.S.

1975-01-01

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

Pollen grains in quaternary sediments from the Campos Basin, state of Rio de Janeiro, Brazil: Core BU-91-GL-05

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Aline Gonçalves de Freitas

2013-12-01

Full Text Available Here, we describe pollen grains extracted from a Pleistocene-Holocene sediment core (BU-91-GL-05; 22°48'45"S; 41°54'13"W taken from the Albacora Slope (22°48'45"S; 41°54'13"W, located in the Campos Basin of the northern region of the state of Rio de Janeiro, Brazil. The analysis resulted in the identification and morphological description of 46 types of pollen: one of a gymnosperm genus (Podocarpus; and 45 of angiosperm taxa across 27 families-one family of monocotyledons (Poaceae and 26 families (30 types of dicotyledons. The most common angiosperm families were Amaranthaceae (Chenopodium, Amaranthus and Gomphrena; Fabaceae (Fabaceae type, Bauhinia, Inga and Canavalia; Malpighiaceae (Tetrapteris, Heteropteris and Peixotoa; Malvaceae (Sida, Abutilon, Hibiscus and Pseudobombax; Rubiaceae (Faramea, Borreria and Psychotria; Asteraceae (Eupatorium and tribe Vernonieae; Bignoniaceae (Bignoniaceae type, Adenocalymma and Tabebuia; and Onagraceae (Fuchsia and Ludwigia. The palynoflora in this study are associated with dense montane and submontane Atlantic Forest, semideciduous forest and restinga (coastal woodland, all of which are present in the state of Rio de Janeiro. Palynological analysis can provide important data about paleovegetation and paleoclimatic changes in the studied area during the Quaternary, specifically in the last 145,000 years.

Annual pollen sums of alnus in Lublin and Roztocze in the years 2001-2007 against selected meteorological parameters

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Bogusław M. Kaszewski

2012-12-01

Full Text Available Alder (Alnus Mill., as an anemophilous species, produces large quantities of easily dispersed pollen. Annual pollen sums recorded in south-eastern Poland (by the volumetric method - Lanzoni trap and in the area of the village of Guciów in the Central Roztocze region (pollen deposition in Tauber traps were compared. The height at which the respective trap sites were located as well as local and regional vegetation and the distance from the nearest alder communities differ in both cases, likewise, the climate of these two regions differ. The analysed pollen data series cover the years 1998-2007 in Roztocze and 2001-2007 in Lublin. Large differences have been noted in Alnus pollen deposition values between particular years. Among them, there were observed years of very high annual sums (2001, 2003, 2006, as well as years of very low pollen deposition values in both regions (2002, 2005, 2007. In the period in question, the mean value of annual Alnus pollen count for Lublin was 5372 alder pollen grains in m3 of air, and in Roztocze 1647 grains per cm2 of area. During the seven-year period of monitoring (2001-2007, very similar trends were noted with respect to airborne alder pollen concentrations at both trap sites. Pollen data have been analysed against meteorological factors affecting alder pollen production and deposition. These are total precipitation and mean monthly air temperature in June, July and August in the year preceding pollen emission and the same weather elements in January and February in the year of pollen emission. In Roztocze a statistically significant negative correlation has been found between Alnus pollen annual sums and total precipitation in August in the year preceding alder pollen emission and in February in the year of pollen emission. In both regions, the Spearman's correlation coefficient does not show any statistically significant values when comparing annual Alnus pollen sums with mean monthly temperatures of both

Pollen analysis of honey and pollen collected by Apis mellifera linnaeus, 1758 (Hymenoptera, Apidae), in a mixed environment of Eucalyptus plantation and native cerrado in Southeastern Brazil.

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Simeão, C M G; Silveira, F A; Sampaio, I B M; Bastos, E M A F

2015-11-01

Eucalyptus plantations are frequently used for the establishment of bee yards. This study was carried on at Fazenda Brejão, northwestern region of the State of Minas Gerais, Brazil. This farm is covered both with native Cerrado vegetation (Brazilian savanna) and eucalyptus plantations. This paper reports on the botanic origin of pollen pellets and honey collected from honeybee (Apis mellifera) hives along a thirteen-month period (January 2004 to January 2005). The most frequent pollen types found in the pollen pellets during the rainy season were Trema micrantha (Ulmaceae), Copaifera langsdorffii (Fabaceae), an unidentified Poaceae, unidentified Asteraceae-2, Cecropia sp. 1 (Cecropiaceae) and Eucalyptus spp. (Myrtaceae); during the dry season the most frequent pollen types were Acosmium dasycarpum (Fabaceae), Cecropia sp. 1 (Cecropiaceae) and Eucalyptus spp. (Myrtaceae). Pollen grains of Baccharis sp. (Asteraceae), Cecropia sp. 1 (Cecropiaceae), Copaifera langsdorffii (Fabaceae), Mimosa nuda (Fabaceae), Eucalyptus spp. (Myrtaceae) and Trema micrantha (Ulmaceae) were present in the honey samples throughout the study period.

Pollen analysis of honey and pollen collected by Apis mellifera linnaeus, 1758 (Hymenoptera, Apidae, in a mixed environment of Eucalyptus plantation and native cerrado in Southeastern Brazil

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C. M. G. Simeão

Full Text Available Abstract Eucalyptus plantations are frequently used for the establishment of bee yards. This study was carried on at Fazenda Brejão, northwestern region of the State of Minas Gerais, Brazil. This farm is covered both with native Cerrado vegetation (Brazilian savanna and eucalyptus plantations. This paper reports on the botanic origin of pollen pellets and honey collected from honeybee (Apis mellifera hives along a thirteen-month period (January 2004 to January 2005. The most frequent pollen types found in the pollen pellets during the rainy season were Trema micrantha (Ulmaceae, Copaifera langsdorffii (Fabaceae, an unidentified Poaceae, unidentified Asteraceae-2, Cecropia sp. 1 (Cecropiaceae and Eucalyptus spp. (Myrtaceae; during the dry season the most frequent pollen types were Acosmium dasycarpum (Fabaceae, Cecropia sp. 1 (Cecropiaceae and Eucalyptus spp. (Myrtaceae. Pollen grains of Baccharis sp. (Asteraceae, Cecropia sp. 1 (Cecropiaceae, Copaifera langsdorffii (Fabaceae, Mimosa nuda (Fabaceae, Eucalyptus spp. (Myrtaceae and Trema micrantha (Ulmaceae were present in the honey samples throughout the study period.

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

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

International Nuclear Information System (INIS)

Liu Linli; Qiang Sheng; Song Xiaoling

2004-01-01

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

Post-X-irradiation effects on petunia pollen germinating in vitro and in vivo

International Nuclear Information System (INIS)

Gilissen, L.J.W.

1978-01-01

The germination of Petunia hybrida L. pollen grains in germination medium, containing 10% sucrose and 0.01 % H 3 BO 3 , was linearly related to relative humidity (RH): being minimal at 0 % RH and maximal at 100 % RH. The low germination at 0 % RH was completely restored after transfer to 100 % RH. Germination in medium decreased with increasing X-ray exposures between O and 400 kR. This decrease was caused by pollen rupture. No in vitro germination occurred at exposures of 400 kR and more. The radiosensitivity of pollen in vitro was minimal at 80 % RH. Transfer of pollen to the stigma post-X-irradiation resulted in resistance to much higher exposures of irradiation (<750 kR). The differences in radiosensitivity of the pollen germinated in vitro and in vivo are due possibly to the differences in composition of the germination medium and the stigmatic exudate. Pollen tube growth of irradiated pollen after compatible or incompatible pollination at first showed retarded then normal tube growth. A conclusion is that X-irradiation of pollen cannot influence the characteristics of pollen tube growth after compatible or incompatible pollination. (author)

Effect of X-rays and u.v.-light on the levels of NAD(P), NAD(P)H and hydroxyproline in Pinus silvestris pollen

International Nuclear Information System (INIS)

Zelles, L.

1978-01-01

Pollen grains of Pinus Silvestris were irradiated with stimulating and inhibiting doses of X-rays and u.v.-light and the levels of NAD(P), NAD(P)H and hydroxyproline determined during tube growth. Pollen grains irradiated with stimulating doses of X-rays and u.v.-light developed longer tubes, while grains irradiated with inhibiting doses of X-rays and u.v.-light developed shorter tubes than the unirradiated controls. After 32 hr of incubation, the levels of NAD(P), NAD(P)H and hydroxyproline were at their lowest compared with unirradiated pollen. In samples with stimulating doses of irradiation NAD(P) reached its maximum earlier than in samples with inhibiting irradiation. The ratio between the concentrations of NAD(P) and NAD(P)H in the irradiated samples was higher than in the unirradiated control. The hydroxyproline content was higher in irradiated than in unirradiated pollen. (author)

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

International Nuclear Information System (INIS)

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

1996-01-01

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

Calcium in pollen-pistil interaction in 'Petunia hybrida Hat'. Pt. 3. Localization of Ca2+ ions and Ca2+-ATPase in pollinated pistil

International Nuclear Information System (INIS)

Bednarska, E.; Butowt, R.

1995-01-01

Studies were carried out of Ca 2+ and Ca 2+ -ATPase localization in pollinated (6 and 48 h after pollination) pistils of 'Petunia hybrida'. The results were confronted with Ca 2+ localization in mature pollen grain and in unpollinated pistil. It has been found that after pollination the number of Ca 2+ sequestered in the stigmal exudate and in the sporoderm of the pollen grain gets lower. That phenomenon was associated with the appearance of a large number of Sb/Ca precipitates in the submembrane cytoplasm of the germinating pollen. In the vacuolized pollen grain, i.e. grown into a pollen tube, there were only a few precipitates. In the pollen tube, Ca 2+ were found in the organelles of the tip cytoplasm and in the external pectin cell wall. Studies with the use of 45 Ca 2+ have revealed that the source of calcium ions incorporated into the pollen tube tip and its pectin wall is the transmitting tract of the style. In the transmitting tract overgrown with pollen tubes, Ca 2+ were localized in the intercellular matrix and in the transmitting cell. Sb/Ca precipitates occurred in the nuclei, around the secretary vesicles and on the plasmalemma in the transverse walls region. Elevated Ca 2+ level was found in degenerating cells (inhibited pollen tubes, transmitting cells, nucellar cells). The progressing degeneration process of the cells of the transmitting tract of the pollinated pistil was associated with a decrease in the activity of plasmalemma Ca 2+ -ATPase. (author). 30 refs, 19 figs

Impacts of air pollution exposure on the allergenic properties of Arizona cypress pollens

Energy Technology Data Exchange (ETDEWEB)

Shahali, Y; Pourpak, Z; Moin, M; Zare, A [Immunology, Asthma and Allergy Research Institute, Medical Sciences/ University of Tehran (Iran, Islamic Republic of); Majd, A, E-mail: youcef.shahali@espci.f [Department of Biology, Faculty of Sciences, Islamic Azad University, North Tehran Branch (Iran, Islamic Republic of)

2009-02-01

Epidemiological studies have demonstrated that urbanization and high levels of vehicle emissions correlated with the increasing trend of pollen-induced respiratory allergies. Numerous works have investigated the role of pollutants in the pathogenesis of respiratory diseases but impacts of anthropogenic pollution on pollen allergenic properties are still poorly understood. The objective of this survey was to evaluate impacts of the traffic-related pollution on the structure and allergenic protein content of Arizona cypress (Cupressus arizonica, CA) pollens, recognized as a rising cause of seasonal allergy in various regions worldwide. According to our results, traffic-related air pollution by its direct effects on the elemental composition of pollens considerably increased the fragility of the pollen exine, causing numerous cracks in its surface and facilitating pollen content liberation. Pollen grains were also covered by numerous submicronic orbicules which may act as effective vectors for pollen-released components into the lower regions of respiratory organs. On the other hand, this study provides us reliable explications about the low efficiency of standard commercial allergens in the diagnosis of the Arizona cypress pollen allergy in Tehran. Although traffic related pollution affects the allergenic components of CA pollens, the repercussions on the respiratory health of urban populations have yet to be clarified and need further investigations.

Impacts of air pollution exposure on the allergenic properties of Arizona cypress pollens

International Nuclear Information System (INIS)

Shahali, Y; Pourpak, Z; Moin, M; Zare, A; Majd, A

2009-01-01

Epidemiological studies have demonstrated that urbanization and high levels of vehicle emissions correlated with the increasing trend of pollen-induced respiratory allergies. Numerous works have investigated the role of pollutants in the pathogenesis of respiratory diseases but impacts of anthropogenic pollution on pollen allergenic properties are still poorly understood. The objective of this survey was to evaluate impacts of the traffic-related pollution on the structure and allergenic protein content of Arizona cypress (Cupressus arizonica, CA) pollens, recognized as a rising cause of seasonal allergy in various regions worldwide. According to our results, traffic-related air pollution by its direct effects on the elemental composition of pollens considerably increased the fragility of the pollen exine, causing numerous cracks in its surface and facilitating pollen content liberation. Pollen grains were also covered by numerous submicronic orbicules which may act as effective vectors for pollen-released components into the lower regions of respiratory organs. On the other hand, this study provides us reliable explications about the low efficiency of standard commercial allergens in the diagnosis of the Arizona cypress pollen allergy in Tehran. Although traffic related pollution affects the allergenic components of CA pollens, the repercussions on the respiratory health of urban populations have yet to be clarified and need further investigations.

Pollen diversity, viability and floral structure of some Musa genotypes

African Journals Online (AJOL)

Prof. Ogunji

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

Platanus pollen allergen, Pla a 1: quantification in the atmosphere and influence on a sensitizing population.

Science.gov (United States)

Fernández-González, D; González-Parrado, Z; Vega-Maray, A M; Valencia-Barrera, R M; Camazón-Izquierdo, B; De Nuntiis, P; Mandrioli, P

2010-11-01

The allergic response in susceptible patients does not always coincide with the presence and magnitude of airborne pollen counts. The prevalence of allergy to Platanus is currently moderate, although the percentage of monosensitized patients is low. This hinders accurate interpretation of the relationship between the amount of pollen inhaled and the patient's symptoms. This study aims to investigate the relationship between the atmospheric concentration pattern of Pla a 1 aeroallergen and the Platanus pollen. The pollen sampling was carried out using a Hirst-type volumetric trap (Burkard(©) ) for pollen grains and a Burkard Cyclone sampler (Burkard(©) ) for Pla a 1 allergen. Serum-specific IgE levels to Acer sp., Artemisia vulgaris, Betula alba, Chenopodium album, Cupressus arizonica, Cynodon dactylon, Fraxinus excelsior, Lolium perenne, Pinus sp., Plantago lanceolata, Platanus acerifolia, Populus sp., Quercus ilex and Taraxacum officinale allergens were determined using the EAST System (Hytec specific IgE EIA kit; Hycor Biomedical, Kassel, Germany). The aerobiological dynamics of Platanus pollen grains and Pla a 1 differed considerably, particularly during the Platanus pollination period. Of the 118 subjects tested, sera from 34 contained specific IgE to Platanus pollen and all of them had specific IgE to other pollen types. The presence of the aeroallergen Pla a 1 in the atmosphere appears to be independent of Platanus pollen counts over the same period, which may be contributing to allergic symptoms and sensitization. The number of polysensitized patients displaying allergy to Platanus suggested that allergic symptoms were caused by co-sensitization or cross-reactivity involving a number of allergenic particles. © 2010 Blackwell Publishing Ltd.

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.

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.

Fractionation and immunochemical characterization of Prosopis juliflora pollen allergen.

Science.gov (United States)

Thakur, I S

1986-12-01

Prosopis juliflora pollen grain crude extract gave six different molecular weight fractions varied from 81,000 to 13,000 dalton on Sephadex G-100 gel filtration. The purity of fractions of Prosopis juliflora pollen extract were checked by polyacrylamide gel electrophoresis. The fraction had an molecular weight 20,000 dalton showed four absorption maxima whereas other fractions had single absorption maxima. Allergenic activity and nature of allergens were evaluated by in vitro Radioallergosorbent test and in vivo Passive Cutaneous Anaphylaxis test. All these tests indicated that most allergenic fractions were in the 20,000 molecular weight.

The effect of Typha domingensis Pers. pollen on Balb/c mice mimicking local allergic rhinitis like symptoms

International Nuclear Information System (INIS)

Ali, S.; Khan, N.

2018-01-01

Airborne pollen grains found commonly in the air usually cause hay fever or pollinosis. Typha sp. pollen grain has been frequently reported in various aerobiological surveys from Pakistan. This study was designed to investigate the allergenic potential of Typha domingensis Pers. Animal model was developed for In vivo testing of pollen allergy. Freshly collected pollen powder was used for intranasal sensitization of Balb/c mice. In vitro testing of the pollen was also done quantitatively (Bradford's method) and qualitatively (SDS-PAGE analysis). The results of In vivo study showed that the group of mice exposed to the dried pollen powder, experienced allergy symptoms including itching and rubbing of eyes, feet, and tail along with frequent episodes of sneezing. The results were confirmed by performing differential blood count of mice. Obtained data was statistically analyzed by using Sigma plot that revealed significant 4-fold increase in eosinophil count in sensitized mice as compared to control (Two tailed t-test with p-value <0.001). SDS-PAGE analysis of extracted proteins showed that the proteins resolved into six bands of molecular weight ranging from 20 KDa- 55 KDa. In current study, data strongly depicts that T. domingensis could be possible allergenic particle. This study would also aid in allergy suffering patient therapy. (author)

Starch distribution in anthers, microspores and pollen grains in Aechmea recurvata (Klotzsch.) L.B.Sm., Dyckia racinae L.B.Sm. and Tillandsia aeranthos (Loisel.) L.B.Sm. (Bromeliaceae)

OpenAIRE

Oliveira,João Marcelo Santos de; Martins,Merielem Saldanha; Dorneles,Mariane Paludette; Freitas,Cesar Carvalho de

2015-01-01

This paper presents a comparative description of the starch distribution in the anthers, microspores and pollen grains of Aechmea recurvata, Dyckia racinae and Tillandsia aeranthos. Flowers at different stages of development were processed according to plant microtechniques for observation by light microscope. Ten stages of embryological development were used as references for the comparative analysis of starch distribution and dynamics. The structural data showed a greater starch accumulatio...

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

Science.gov (United States)

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

2003-12-01

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

Molecular evidence that rough endoplasmic reticulum is the site of calreticulin translation in Petunia pollen tubes growing in vitro.

Science.gov (United States)

Suwińska, Anna; Lenartowski, Robert; Smoliński, Dariusz Jan; Lenartowska, Marta

2015-07-01

In germinating pollen grains and growing pollen tubes, CRT is translated on ER membrane-bound ribosomes in the regions where its activity is required for stabilization of tip-focused Ca (2+) gradient. Pollen tube growth requires coordination of signaling, exocytosis, and actin cytoskeletal organization. Many of these processes are thought to be controlled by finely tuned regulation of cytoplasmic Ca(2+) in discrete regions of the tube cytoplasm. Most notably, a mechanism must function to maintain a steep gradient of Ca(2+) that exists at the tip of growing pollen tube. Several pieces of evidence point to calreticulin (CRT) as a key Ca(2+)-binding/-buffering protein involved in pollen germination and pollen tube growth. We previously hypothesized that in germinating pollen and growing tubes, CRT is translated on the ribosomes associated with endoplasmic reticulum (ER) in the regions where its activity might be required. In this report, we have addressed this idea by identifying the sites where CRT mRNA, CRT protein, 18S rRNA, and rough ER are localized in Petunia pollen tubes. We observed all four components in the germinal aperture of pollen grains and in subapical regions of elongating tubes. These results seem to support our idea that CRT is translated on ER membrane-bound ribosomes during pollen germination and pollen tube growth. In elongated pollen tubes, we found CRT mainly localized in the subapical zone, where ER and Golgi stacks are abundant. In eukaryotic cells, these organelles serve as mobile intracellular stores of easily releasable Ca(2+), which can be buffered by proteins such as CRT. Therefore, we postulate that subapical-localized CRT is involved in pollen tube growth by maintaining the stable tip-focused Ca(2+) gradient and thus modulating local Ca(2+) concentration within the tube cytoplasm.

Assessment of Salix spp. pollen availability to insects based on aerobiological investigations

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Elżbieta Weryszko-Chmielewska

2017-06-01

Full Text Available Pollen and nectar produced by flowers of species from the genus Salix are an important source of food for various insect groups in early spring. Most willows are entomophilous species; however, substantial amounts of airborne Salix pollen can be noted. The aim of the study was to evaluate the content of pollen of this taxon in the air of Lublin (central-east Poland in 2001–2016 and to identify the period of its greatest availability to insects. In 2015, we compared the course of the Salix pollen season in Lublin (51°14'37" N; 22°32'25" E and in the Roztoczański National Park (50°34'57" N; 23°04'24" E, Poland. We found that the date of the pollen season onset fluctuated greatly between March 16 and April 17. The greatest availability of Salix pollen to insects was noted from the end of the first 10-day-period of April to the first 10-day-period of May. The mean annual sum of airborne Salix pollen grains was 833. In Lublin, Salix pollen accounted for ca. 1.25% of the total airborne pollen content of different plant taxa. The investigations have demonstrated a 2-year cycle of Salix pollen abundance. The comparison of the pollen seasons in Lublin and in the Roztoczański National Park indicates that considerably greater amounts of pollen occur in the urban area than in the air of the Roztoczański National Park.

Palynology after Y2K--Understanding the Source Area of Pollen in Sediments

Science.gov (United States)

Davis, M. B.

Pollen grains preserved in lake and bog sediment provide a record of past vegetation that has been an important source of information about climate and land cover during the Quaternary Period. Yet from the beginning, questions have been raised about the source area of pollen in sediment. Interpretation has been hampered by the lack of well-developed theory treating the relationship between the spatial distribution of trees on the landscape and the percentages of pollen in sediment. Within the past decade, however, new theory, models, and empirical data show how heterogeneous vegetation is represented by pollen. The distinction between "local" and "regional" pollen is explained by the Prentice-Sugita dispersal/deposition models, which predict how the ratio of regional to local pollen changes with lake size. Sugita's model simulating a landscape with heterogeneous vegetation predicts the size of the relevant source area-the area of vegetation reflected in between-lake variations in pollen loading-while demonstrating that regional pollen from beyond this distance is homogeneous at all lakes of similar size. By predicting the way landscape patterns will be reflected in pollen records, simulation models can improve research design and lead to more detailed and spatially precise records of past vegetation, enhancing continental-scale climate reconstructions.

Pollen morphology of Rhizophora L. in Peninsular Malaysia

Energy Technology Data Exchange (ETDEWEB)

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

2013-11-27

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

Pollen morphology of Rhizophora L. in Peninsular Malaysia

International Nuclear Information System (INIS)

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

2013-01-01

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

Pollen aroma fingerprint of two sunflower (Helianthus annuus L.) genotypes characterized by different pollen colors.

Science.gov (United States)

Bertoli, Alessandra; Fambrini, Marco; Doveri, Silvia; Leonardi, Michele; Pugliesi, Claudio; Pistelli, Luisa

2011-09-01

Samples of fresh pollen grains, collected from capitula in full bloom from two genotypes of sunflower (Helianthus annuus L.) and characterized by a different color, i.e., white-cream (WC) and orange (O), were analyzed by the HS-SPME (headspacesolid phase microextraction)/GC/MS technique. This study defined for the first time the fingerprint of the sunflower pollen, separated from the disc flowers, to define its contribution to the inflorescence aroma. In the GC/MS fingerprints of the WC and O genotypes, 61 and 62 volatile compounds were identified, respectively. Monoterpene hydrocarbons (34% in O vs. 28% in WC) and sesquiterpene hydrocarbons (37% in O vs. 31% in WC) were ubiquitous in all samples analyzed and represented the main chemical classes. α-Pinene (21% in O vs. 20% in WC) and sabinene (11% in O vs. 6% in WC) were the dominant volatiles, but also a full range of aliphatic hydrocarbons and their oxygenated derivatives gave a decisive contribution to the aroma composition (10% in O vs. 12% in WC). In addition, dendrolasin (3% in O vs. 4% in WC) and some minor constituents such as (E)-hex-2-en-1-ol (0.4% in O vs. 0.1% in WC) were pointed out not only for their contribution to the pollen scent, but also for their well-known role in the plant ecological relationships. Having evaluated two pollen morphs with different carotenoid-based colors, the study sought to highlight also the presence of some volatile precursors or derivatives of these pigments in the aroma. However, the pollen aroma of the two selected genotypes made a specific chemical contribution to the sunflower inflorescence scent without any influence on carotenoid derivatives. 2011 Verlag Helvetica Chimica Acta AG, Zürich.

Dynamics of vegetative cytoplasm during generative cell formation and pollen maturation in Arabidopsis thaliana

Science.gov (United States)

Kuang, A.; Musgrave, M. E.

1996-01-01

Ultrastructural changes of pollen cytoplasm during generative cell formation and pollen maturation in Arabidopsis thaliana were studied. The pollen cytoplasm develops a complicated ultrastructure and changes dramatically during these stages. Lipid droplets increase after generative cell formation and their organization and distribution change with the developmental stage. Starch grains in amyloplasts increase in number and size during generative and sperm cell formation and decrease at pollen maturity. The shape and membrane system of mitochondria change only slightly. Dictyosomes become very prominent, and numerous associated vesicles are observed during and after sperm cell formation. Endoplasmic reticulum appears extensively as stacks during sperm cell formation. Free and polyribosomes are abundant in the cytoplasm at all developmental stages although they appear denser at certain stages and in some areas. In mature pollen, all organelles are randomly distributed throughout the vegetative cytoplasm and numerous small particles appear. Organization and distribution of storage substances and appearance of these small particles during generative and sperm cell formation and pollen maturation are discussed.

Investigations of the Propagation of Plant Pollen by an Indicator Activation Method

Energy Technology Data Exchange (ETDEWEB)

Fendrik, I.; Glubrecht, H. [Technische Hochschule, Hanover (Germany)

1967-10-15

The study of the propagation of plant pollen is of special interest in ecology and plant breeding. Generally, radioactive labelling cannot be applied for this purpose since radioactive contamination of the materials under investigation cannot be tolerated. Instead, labelling can be performed by the use of an indicator element that has a high cross-section for neutron activation. This substance is introduced into the plant under consideration. The flying pollen is caught by polyethylene foils by means of electrostatic attraction. The foils with the pollen are irradiated in a nuclear reactor with a suitable flux of thermal neutrons. The labelled pollen grains can be detected and counted by autoradiography or by direct measurement. The method has proved satisfactory for pines and sugar beet. Indicator elements used for detection by neutron activation were manganese and dysprosium. (author)

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

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Babić Vojka

2017-01-01

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

Pollen of Syzygium (Myrtaceae) from SE Asia, especially Thailand

NARCIS (Netherlands)

Parnell, J.

2003-01-01

Pollen of 57 species of Syzygium from SE Asia were surveyed by SEM. The grains are all ± triangular in polar view, uniformly small (mean diameter 10.4 μm) with few surface sculpturing features. All species examined exhibit a distinct apocolpium and, usually, apocolpial field. The presence of an

Calcium in pollen-pistil interaction in `Petunia hybrida Hat`. Pt. 3. Localization of Ca{sup 2+} ions and Ca{sup 2+}-ATPase in pollinated pistil

Energy Technology Data Exchange (ETDEWEB)

Bednarska, E.; Butowt, R. [Uniwersytet Mikolaja Kopernika, Torun (Poland)

1995-12-31

Studies were carried out of Ca{sup 2+} and Ca{sup 2+}-ATPase localization in pollinated (6 and 48 h after pollination) pistils of `Petunia hybrida`. The results were confronted with Ca{sup 2+} localization in mature pollen grain and in unpollinated pistil. It has been found that after pollination the number of Ca{sup 2+} sequestered in the stigmal exudate and in the sporoderm of the pollen grain gets lower. That phenomenon was associated with the appearance of a large number of Sb/Ca precipitates in the submembrane cytoplasm of the germinating pollen. In the vacuolized pollen grain, i.e. grown into a pollen tube, there were only a few precipitates. In the pollen tube, Ca{sup 2+} were found in the organelles of the tip cytoplasm and in the external pectin cell wall. Studies with the use of {sup 45}Ca{sup 2+} have revealed that the source of calcium ions incorporated into the pollen tube tip and its pectin wall is the transmitting tract of the style. In the transmitting tract overgrown with pollen tubes, Ca{sup 2+} were localized in the intercellular matrix and in the transmitting cell. Sb/Ca precipitates occurred in the nuclei, around the secretary vesicles and on the plasmalemma in the transverse walls region. Elevated Ca{sup 2+} level was found in degenerating cells (inhibited pollen tubes, transmitting cells, nucellar cells). The progressing degeneration process of the cells of the transmitting tract of the pollinated pistil was associated with a decrease in the activity of plasmalemma Ca{sup 2+}-ATPase. (author). 30 refs, 19 figs.

Environmental behaviour of airborne Amaranthaceae pollen in the southern part of the Iberian Peninsula, and its role in future climate scenarios.

Science.gov (United States)

Cariñanos, Paloma; Alcázar, Purificación; Galán, Carmen; Domínguez, Eugenio

2014-02-01

The Amaranthaceae family includes a number of species which, through a series of specific adaptations, thrive in salty soils, arid environments and altered human settlements. Their ability to tolerate high temperatures favours summer flowering, giving rise to the widespread involvement of Amaranthaceae pollen grains in summer allergies, both in Mediterranean Europe and in areas with arid climates. This study analysed a 21-year set of historical airborne Amaranthaceae pollen records for an area located in the southern part of the Iberian Peninsula, in order to chart species' environmental reaction to changing climate conditions which occurred in the last decades. Airborne pollen data were collected from January 1991 to December 2011 using a Hirst-type volumetric impact sampler. Results showed that Amaranthaceae pollen remained in the atmosphere for over 6 months along the year, from early spring until early autumn. The annual Pollen Index ranged from barely 200 grains to almost 2000 grains, and was strongly influenced by rainfall during the flowering period, which prompted the development of new individuals and thus an increase in pollen production. A trend was noted towards increasingly early pollen peak dates; peaks were recorded in August-September in years with summer rainfall, but as early as May-June in years when over 50% of annual rainfall was recorded in the months prior to flowering. The gradual decline in the annual Pollen Index over later years is attributable not only to growing urbanisation of the area but also to a change in rainfall distribution pattern. High maximum temperatures in spring were also directly related to the peak date and the Pollen Index. This ability to adapt to changeable and occasionally stressful and restrictive, environmental conditions places Amaranthaceae at a competitive advantage with respect to other species sharing the same ecological niche. An increased presence of Amaranthaceae is likely to have a greater impact on future

Pollen mitochondria in cytoplasmically male sterile tobacco zygotic and embryonic cells

International Nuclear Information System (INIS)

Symillides, Y.

1985-09-01

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

Pollen morphology of the subfamily arecoideae griff. (family-arecaceae) from pakistan and kashmir

International Nuclear Information System (INIS)

Rasheed, A.A.; Perveen, A.; Abid, R.

2016-01-01

Pollen morphological characters are potentially informative in the systematic of monocotyledons including (Arecaceae), at supra and infra familial level. The pollen morphology of 8 species (subfamily Arecoideae) clearly shows that the qualitative pollen characters (such as aperture, exine pattern and shape) are found to be taxonomically important as compared to the quantitative characters (such as size of the grain and exine thickness).Considerable pollen variations have been found within the subfamily Arecoideae with regard to size, shape, aperture type and exine pattern. For instance, 7 out of 8 species have monosulcate pollen (i.e., 87.5%) and a remaining species (viz., Elaeis guineensis Jacq.) have trichotomosulcate pollen. The pollen are frequently elliptical, but in some cases rounded-triangular pollen were also found. Similarly, there is a great diversity in exine pattern such as punctate, reticulate, vermiculate, spinose, rugulate and perforate or combination of these types have also been found, but the most predominant pattern is the reticulate type. On the basis of pollen aperture, size and exine pattern, four pollen types have been recognized such as Areca-type, Dypsis-type, Cocos-type and Elaies-type. The data obtained from the palynological studies have been analyzed by Agglomerative cluster analysis choosing the Euclidean distance and Ward's method for a group linkage method. The objective of the present work is to classify studied taxa on the basis of pollen characters and to quantify the species relationships representing the subfamily Arecoideae based on numerical techniques. (author)

Small RNA Sequencing Reveals Differential miRNA Expression in the Early Development of Broccoli (Brassica oleracea var. italica) Pollen.

Science.gov (United States)

Li, Hui; Wang, Yu; Wu, Mei; Li, Lihong; Jin, Chuan; Zhang, Qingli; Chen, Chengbin; Song, Wenqin; Wang, Chunguo

2017-01-01

Pollen development is an important and complex biological process in the sexual reproduction of flowering plants. Although the cytological characteristics of pollen development are well defined, the regulation of its early stages remains largely unknown. In the present study, miRNAs were explored in the early development of broccoli ( Brassica oleracea var. italica ) pollen. A total of 333 known miRNAs that originated from 235 miRNA families were detected. Fifty-five novel miRNA candidates were identified. Sixty of the 333 known miRNAs and 49 of the 55 predicted novel miRNAs exhibited significantly differential expression profiling in the three distinct developmental stages of broccoli pollen. Among these differentially expressed miRNAs, miRNAs that would be involved in the developmental phase transition from uninucleate microspores to binucleate pollen grains or from binucleate to trinucleate pollen grains were identified. miRNAs that showed significantly enriched expression in a specific early stage of broccoli pollen development were also observed. In addition, 552 targets for 127 known miRNAs and 69 targets for 40 predicted novel miRNAs were bioinformatically identified. Functional annotation and GO (Gene Ontology) analysis indicated that the putative miRNA targets showed significant enrichment in GO terms that were related to plant organ formation and morphogenesis. Some of enriched GO terms were detected for the targets directly involved in plant male reproduction development. These findings provided new insights into the functions of miRNA-mediated regulatory networks in broccoli pollen development.

In vivo and in vitro pollen maturation in Lilium: influence of carbohydrates

Directory of Open Access Journals (Sweden)

Christophe Clement

2014-01-01

Full Text Available The purpose of this study was to develop a protocol for in vitro conform pollen maturation, as a model to study the involvement of carbohydrates on pollen maturation in Lilium. In vivo and in vitro pollen maturations were followed and compared by transmission electron microscopy, and several in vitro parameters were tested in terms of carbohydrate physiology. In vivo, pollen maturation was initiated at the vacuolated microspore stage, and consisted of two successive phases. The first phase was characterized by reactivation of microspore organelles, followed by microspore mitosis, starch synthesis and vacuole breakdown. During the second phase, starch was progressively degraded whereas lipid and phytine reserves accumulated. In vivo, pollen maturation occured within 14 days and pollen germination rate was 73.6 ± 2.2%. We then attempted to realise in vitro pollen maturation starting from the vacuolated microspore stage. The best results were obtained with flower buds cultivated at 26oC, in 100 µmol/m2/s light, with a 16h/8h photoperiod on a modified Heller's medium supplemented with NAA (10-2 mg/l and sucrose (M/6. In these conditions, pollen maturation occured within 7 days only. In vitro matured pollen is cytologically comparable to in vivo developed pollen grains and the germination rate was 72.4 ± 3.7%. When flower buds were cultivated in the dark, the germination rate decreased, but this could be compensated by providing high sucrose concentrations (1M in the medium. Further, photosynthesis inhibitors had the same effect on pollen maturation than the darkness, strongly suggesting that photosynthesis occurs in the flower bud and is important for pollen maturation in Lilium.

In vitro germination and the effect of acute gamma irradiation on pollen of Pinus patula Schiede et Deppe

International Nuclear Information System (INIS)

Kapoor, M.L.; Dobriyal, N.D.

1980-01-01

In-vitro study revealed that the best medium for germinating P. patula pollen was 12,5% Sucrose with 0.001% Boron in 2% agar medium. After gamma irradiation the LD-50 based on pollen germination and germination energy index was 1.174 kr and 1.148 kr respectively. Pollen was viable on the 90th day when used after storing at 10 0 C in desiccator. Gamma doses for haploid breeding and mutation breeding are suggested. ANOVA showed that differences between the different media used for germination and gamma-ray doses were highly significant. (orig.) [de

The Impact of the Invasive Alien Plant, Impatiens glandulifera, on Pollen Transfer Networks.

Directory of Open Access Journals (Sweden)

Carine Emer

Full Text Available Biological invasions are a threat to the maintenance of ecological processes, including pollination. Plant-flower visitor networks are traditionally used as a surrogated for pollination at the community level, despite they do not represent the pollination process, which takes place at the stigma of plants where pollen grains are deposited. Here we investigated whether the invasion of the alien plant Impatiens glandulifera (Balsaminaceae affects pollen transfer at the community level. We asked whether more alien pollen is deposited on the stigmas of plants on invaded sites, whether deposition is affected by stigma type (dry, semidry and wet and whether the invasion of I. glandulifera changes the structure of the resulting pollen transfer networks. We sampled stigmas of plants on 10 sites invaded by I. glandulifera (hereafter, balsam and 10 non-invaded control sites. All 20 networks had interactions with balsam pollen, although significantly more balsam pollen was found on plants with dry stigmas in invaded areas. Balsam pollen deposition was restricted to a small subset of plant species, which is surprising because pollinators are known to carry high loads of balsam pollen. Balsam invasion did not affect the loading of native pollen, nor did it affect pollen transfer network properties; networks were modular and poorly nested, both of which are likely to be related to the specificity of pollen transfer interactions. Our results indicate that pollination networks become more specialized when moving from the flower visitation to the level of pollen transfer networks. Therefore, caution is needed when inferring pollination from patterns of insect visitation or insect pollen loads as the relationship between these and pollen deposition is not straightforward.

Profiling and functional classification of esterases in olive (Olea europaea) pollen during germination.

Science.gov (United States)

Rejón, Juan D; Zienkiewicz, Agnieszka; Rodríguez-García, María Isabel; Castro, Antonio J

2012-10-01

A pollen grain contains a number of esterases, many of which are released upon contact with the stigma surface. However, the identity and function of most of these esterases remain unknown. In this work, esterases from olive pollen during its germination were identifided and functionally characterized. The esterolytic capacity of olive (Olea europaea) pollen was examined using in vitro and in-gel enzymatic assays with different enzyme substrates. The functional analysis of pollen esterases was achieved by inhibition assays by using specific inhibitors. The cellular localization of esterase activities was performed using histochemical methods. Olive pollen showed high levels of non-specific esterase activity, which remained steady after hydration and germination. Up to 20 esterolytic bands were identified on polyacrylamide gels. All the inhibitors decreased pollen germinability, but only diisopropyl fluorophosphate (DIFP) hampered pollen tube growth. Non-specific esterase activity is localized on the surface of oil bodies (OBs) and small vesicles, in the pollen intine and in the callose layer of the pollen tube wall. Acetylcholinesterase (AChE) activity was mostly observed in the apertures, exine and pollen coat, and attached to the pollen tube wall surface and to small cytoplasmic vesicles. In this work, for the first time a systematic functional characterization of esterase enzymes in pollen from a plant species with wet stigma has been carried out. Olive pollen esterases belong to four different functional groups: carboxylesterases, acetylesterases, AChEs and lipases. The cellular localization of esterase activity indicates that the intine is a putative storage site for esterolytic enzymes in olive pollen. Based on inhibition assays and cellular localization of enzymatic activities, it can be concluded that these enzymes are likely to be involved in pollen germination, and pollen tube growth and penetration of the stigma.

A microfluidic platform for the investigation of elongation growth in pollen tubes

International Nuclear Information System (INIS)

Agudelo, C G; Sanati, A; Ghanbari, M; Packirisamy, M; Geitmann, A

2012-01-01

Pollen tubes are an excellent model for the investigation of plant cell growth: they elongate at very high rates and are easily cultured in vitro. One major constraint in the study of pollen tube growth has been the difficulty in providing an in vitro testing environment that physically resembles the in vivo conditions. This work presents the development of a microfluidic platform for the study and manipulation of individual pollen tubes. The platform is fabricated from polydimethylsiloxane using a Silicon/SU-8 mold and makes use of microfluidics to distribute pollen grains to serially arranged microchannels into which the tubes grow to allow for individual testing. A 2D finite element fluid analysis is done to assist optimization of the architectural design. Validation of the device is carried out by growing Camellia japonica pollen. Results show that pollen tube germination and growth rate within the microfluidic network are similar to those obtained in conventional plate or batch assays. The microfluidic network allows for specific testing of a variety of structural features as demonstrated with a simple collision test, and it permits the straightforward integration of further single-cell test assays. (paper)

The Influence of Garden Size and Floral Cover on Pollen Deposition in Urban Community Gardens

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Kevin C. Matteson

2009-01-01

Full Text Available Many cucurbits, such as cucumbers, squashes and pumpkins, depend on pollinating bees in order to set fruit. However, fruit yield and progeny vigor in these plants generally decreases as heterospecific pollen deposition increases. We studied how the spatial area dedicated to cucumbers (Cucumis sativis, versus other flowering plants, influenced the deposition of conspecific and heterospecific pollen on cucumber plants in New York City community gardens. We also examined the effect of garden size on conspecific and heterospecific pollen deposition on cucumber plants. Female flowers were collected from potted cucumber plants that had been experimentally placed into the gardens, specifically for this study, or that were established in raised beds by members of the community garden. In the laboratory, pollen grains were isolated from the flower by acetolysis, and the number of heterospecific and conspecific cucumber pollen grains were quantified. Conspecific pollen deposition was positively and significantly associated with the size of a community garden, as well as with the area of each garden dedicated to non-cucumber, flowering plants (i.e. floral cover and the area of each garden dedicated to cucumber plants (i.e. cucumber cover. Although floral cover explained a greater proportion of the variance, cucumber cover had the strongest effect on conspecific pollen deposition. Heterospecific pollen deposition was positively and significantly related to garden area. However, no significant relationship was found between heterospecific pollen deposition and floral cover, or cucumber cover. Based upon these results, we hypothesize that floral cover positively impacts conspecific pollen deposition by attracting a greater number of pollinators into an urban garden, and that total cucumber area positively impacts conspecific pollen deposition when pollinators are locally foraging within a garden. We suggest that the arrangement of plants within a garden can

Pollen spectrum, a cornerstone for tracing the evolution of the eastern Central Asian desert

Science.gov (United States)

Lu, Kai-Qing; Xie, Gan; Li, Min; Li, Jin-Feng; Trivedi, Anjali; Ferguson, David K.; Yao, Yi-Feng; Wang, Yu-Fei

2018-04-01

The temperate desert in arid Central Asia (ACA) has acted as a thoroughfare for the ancient Silk Road and today's Belt and Road, linking economic and cultural exchanges between East and West. The interaction between human sustainable development and the dynamic change in the desert ecosystem in this region is an area of concern for governments and scientific communities. Nevertheless, the lack of a pollen spectrum of the dominant taxa within the temperate desert vegetation and a corresponding relation between pollen assemblages and specific desert vegetation types is an obstacle to further understanding the formation and maintenance of this desert ecosystem. In this work, we link pollen assemblages to specific desert vegetation types with a new pollen spectrum with specific pollen grains, specific plant taxa and related habitats, providing a solid foundation for further tracing the evolution of the desert ecosystem in eastern arid Central Asia.

Grass pollen (Poaceae in the air of Sosnowiec (Poland, 1997 - 2006

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Kazimiera Chłopek

2012-12-01

Full Text Available The article presents the analysis results of the grass pollen seasons from 1997 to 2006 in Sosnowiec. The research was carried out by means of the volumetric method with the use of a Burkard device. The duration of the pollen seasons was determined by means of the 98% method. The influence of meteorological conditions on the starting date and duration of the grass pollen seasons has been estimated in the article. The beginning of the pollen seasons was recorded between 23 April and 23 May. It has been demonstrated that the average duration of the pollen season amounted to 138 days. The period of maximum concentrations was recorded in June and the first half of July. The highest daily concentration was found in 2000 (495 grains in m3 and the highest annual sums in 2002 and 2000. The daily concentration distribution curve has shown three peaks. The highest values were recorded from 7 am until 11 am, from 13 pm until 17 pm and from 19 pm until 21 pm. It has been found that there is a significant influence of weather conditions (temperature, precipitation and relative humidity on the beginning and duration of the pollen seasons and the period of maximum concentrations.

Pollen viability, physiology, and production of maize plants exposed to pyraclostrobin+epoxiconazole.

Science.gov (United States)

Junqueira, Verônica Barbosa; Costa, Alan Carlos; Boff, Tatiana; Müller, Caroline; Mendonça, Maria Andréia Corrêa; Batista, Priscila Ferreira

2017-04-01

The use of fungicides in maize has been more frequent due to an increase in the incidence of diseases and also the possible physiological benefits that some of these products may cause. However, some of these products (e.g., strobilurins and triazoles) may interfere with physiological processes and the formation of reproductive organs. Therefore, the effect of these products on plants at different developmental stages needs to be better understood to reduce losses and maximize production. The effect of the fungicide pyraclostrobin+epoxiconazole (P+E) was evaluated at different growth stages in meiosis, pollen grain viability and germination, physiology, and production of maize plants in the absence of disease. An experiment was carried out with the hybrid DKB390 PROII and the application of pyraclostrobin+epoxiconazole at the recommended dose and an untreated control at 3 different timings (S1 - V10; S2 - V14; S3 - R1) with 5 replications. Gas exchange, chlorophyll fluorescence, pollen viability and germination, as well as the hundred-grain weight were evaluated. Anthers were collected from plants of S1 for cytogenetic analysis. The fungicide pyraclostrobin+epoxiconazole reduced the viability of pollen grains (1.4%), but this was not enough to reduce production. Moreover, no differences were observed in any of the other parameters analyzed, suggesting that P+E at the recommended dose and the tested stages does not cause toxic effects. Copyright © 2016 Elsevier Inc. All rights reserved.

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

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A. M. Shantasov

2014-01-01

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

Environmental pollution changes in membrane lipids, antioxidants and vitality of Scots pine (Pinus sylvestris L. pollen

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Paweł M. Pukacki

2011-01-01

Full Text Available Investigations were carried out on pollen grains of Scots pine (Pinus sylvestris L. collected from trees at 1.5, 3, 4 km and control, 20 km from the Luboń factory producing mineral fertilisers. The percentage of germination of pollen formed close to the pollution source was ca 20% lower compared to the control pollen. Lowered vitality of the pollen was effected in changes of the structure of cytoplasmic membranes. Pollen from the polluted area contained ca 15% less total phospholipids, mainly phosphatidylcholine and phosphatytidylinositol and had a lower content of soluble proteins and less of low molecular antioxidants, such as thiols and ascorbic acid. Composition of total fatty acid in phospholipids fractions showed a significant reduction in the degree of unsaturation of fatty acids. Pollen originating from the polluted area and stored at -30°C showed considerably stronger degradation of cytoplasmic membranes than control.

Pollen morphology of the family crassulaceae from pakistan and kashmir and its taxonomic implications

International Nuclear Information System (INIS)

Qasir, M.; Perveen, A.; Sarwar, G.R.

2015-01-01

Pollen morphology of 28 species representing 9 genera viz., Bryophyllum, Kalanchoe, Pseudosedum, Rhodiola, Rosularia, Hylotelephium, Sedum, Tillaea and Orostachys of the family Crassulaceae from Pakistan has been studied by light and scanning electron microscope. Pollen grains are usually free, radially symmetrical, isopolar, sub-oblate to oblate-spheroidal, or prolate-spheroidal to subprolate often prolate and tricolporate. Tectum mostly striate-rugulate or sub-psilate rarely reticulate-rugulate. Significant variation is found in shape and exine ornamentation and on the basis these characters family has been divided into three pollen types' viz., Rhodiola sinuata-type, Rosularia viguieri-type and Sedum hispanicum-type. Numerical analysis of based on pollen characters of 28 species was also carried out to determine the phylogenetic relationships of various genera and the species of the family Crassulaceae. (author)

[Sensitization to Castanea sativa pollen and pollinosis in northern Extremadura (Spain)].

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Cosmes Martín, P M; Moreno Ancillo, A; Domínguez Noche, C; Gutiérrez Vivas, A; Belmonte Soler, J; Roure Nolla, J M

2005-01-01

Castanea sativa pollen allergy has generally been considered to be uncommon and clinically insignificant. In our geographical area (Plasencia, Cáceres, Spain) Castanea sativa pollen is a major pollen. To determine the atmospheric fluctuations and prevalence of patients sensitized to Castanea pollen in our region and to compare this sensitization with sensitizations to other pollens. Patients with respiratory symptoms attending our outpatient clinic for the first time in 2003 were studied. The patients underwent skin prick tests with commercial extracts of a battery of inhalants including Castanea sativa pollen. Serologic specific IgE to Castanea sativa pollen was determined using the CAP system (Pharmacia and Upjohn, Uppsala, Sweden). Airborne pollen counts in our city were obtained using Cour collection apparatus over a 4-year period (2000 to 2003). The most predominant pollens detected were (mean of the maximal weekly concentrations over 4 years in pollen grains/m3): Quercus 968, Poacea 660, Olea 325, Platanus 229, Pinus 126, Cupresaceae 117, Plantago 109, Alnus 41, Populus 40, Castanea 32. We studied 346 patients (mean age: 24.1 years). In 210 patients with a diagnosis of pollinosis, the percentages of sensitization were: Dactylis glomerata 80.4%, Olea europea 71.9%, Fraxinus excelsior 68%, Plantago lanceolata 62.8%, Chenopodium album 60.9%, Robinia pseudoacacia 49%, Artemisia vulgaris 43.8%, Platanus acerifolia 36.6%, Parietaria judaica 36.1%, Populus nigra 32.3%, Betula alba 27.6%, Quercus ilex 21.4%, Alnus glutinosa 20.9%, Cupressus arizonica 7.6% and Castanea sativa 7.1%. Fifteen patients were sensitized to Castanea sativa and 14 had seasonal rhinoconjunctivitis and asthma. Ten patients had serum specific IgE to Castanea pollen (maximum value: 17.4 Ku/l). Castanea pollen is present in our area in large amounts from the 23rd to the 28th weeks of the year, with a peak pollen count in the 25th week. The most important allergenic pollens in northern Extremadura

Current glimpse of airborne allergenic pollen in Indian subcontinent

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Kavita Ghosal

2015-12-01

Full Text Available Respiratory allergic diseases such as bronchial asthma, rhinitis, urticaria, atopic dermatitis have been steadily increasing all over the world, including India. Owing to its alarming trend, several aerobiological surveys have been undertaken in different parts of India to delineate the variety of pollen and spore load. In this review, we have reported the current state of aerobiological knowladge in India with particular reference to allergenic airborn pollen occurence in 2001–2015. Pollen have been found to contribute a significant proportion in the air and caused allergy symptoms in the local inhabitants. Aerobiological records, a questionnaire survey and hospitalization records have been employed for the analysis. Holoptelea integrifolia, Amaranthus spinosus in northern region, Sorghum vulgare, Pennisetum, Gynandropsis gynandra, Parthenium hysterophorus, Dolichandrone platycalyx in southern regions, and Parthenium hysterophorus from the western region; Cynodon dactylon, Cenchrus ciliaris in the central area; Acacia auriculiformis, Cleome gynandra, Catharanthus roseus, Phoenix sylvestris, Areca catechu, and Lantana camara in the eastern regions as potential aeroallergens in India. The statistical approach confirmed the correlation between hospitalization rate associated with allergy-related health troubles and the prevalent allergenic pollen in the air. The Poaceae group has been found to be dominant throughout India. Immuno-biochemical studies identified various protein with allergenic potential found in the pollen recorded. Epitope identification and homology of the major allergenic protein Cat r1 of Catharanthus sp and Par j 1 of Parietaria judaica have been found. Identification of allergenic pollen grains and the modern approach concerning cross-reactivity and epitope revelation of dominant airborne pollen have important clinical implications for the prevention, diagnosis and treatments of allergic diseases in India.

Meteorological factors and pollen season dynamics of selected herbaceous plants in Szczecin, 2004-2008

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Małgorzata Puc

2012-12-01

Full Text Available The pollen of mugwort, plantain, sorrel, nettle and pigweed is an important airborne allergen source worldwide. The occurrence of pollen grains in the air is a seasonal phenomenon and estimation of seasonal variability in the pollen count permits evaluation of the threat posed by allergens over a given area. The aim of the study was to analyse the dynamics of Artemisia, Plantago, Rumex, Urticaceae and Chenopodiaceae pollen season in Szczecin (western Poland in 2004-2008 and to establish a relationship between the meteorological parameters versus the pollen count of the taxa studied. Measurements were performed by the Hirst volumetric trap (model Lanzoni VPPS 2000. Consecutive phases during the pollen season were defined for each taxon (1, 5, 25, 50, 75, 95, 99% of annual total and duration of the season was determined using the 98% method. On the basis of this analysis, temporary differences in the dynamics of the seasons were most evident for Artemisia. Correlation analysis with weather parameters demonstrated that the maximum wind speed, mean and maximum air temperature, relative humidity and dew point are the main factors influencing the average daily pollen concentrations in the atmosphere.

Consumption of Bt Rice Pollen Containing Cry1C or Cry2A Protein Poses a Low to Negligible Risk to the Silkworm Bombyx mori (Lepidoptera: Bombyxidae)

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Yang, Yan; Liu, Yue; Cao, Fengqin; Chen, Xiuping; Cheng, Lisheng; Romeis, Jörg; Li, Yunhe; Peng, Yufa

2014-01-01

By consuming mulberry leaves covered with pollen from nearby genetically engineered, insect-resistant rice lines producing Cry proteins derived from Bacillus thuringiensis (Bt), larvae of the domestic silkworm, Bombyx mori (Linnaeus) (Lepidoptera: Bombyxidae), could be exposed to insecticidal proteins. Laboratory experiments were conducted to assess the potential effects of Cry1C- or Cry2A-producing transgenic rice (T1C-19, T2A-1) pollen on B. mori fitness. In a short-term assay, B. mori larvae were fed mulberry leaves covered with different densities of pollen from Bt rice lines or their corresponding near isoline (control) for the first 3 d and then were fed mulberry leaves without pollen. No effect was detected on any life table parameter, even at 1800 pollen grains/cm2 leaf, which is much higher than the mean natural density of rice pollen on leaves of mulberry trees near paddy fields. In a long-term assay, the larvae were fed Bt and control pollen in the same way but for their entire larval stage (approximately 27 d). Bt pollen densities ≥150 grains/cm2 leaf reduced 14-d larval weight, increased larval development time, and reduced adult eclosion rate. ELISA analyses showed that 72.6% of the Cry protein was still detected in the pollen grains excreted with the feces. The low exposure of silkworm larvae to Cry proteins when feeding Bt rice pollen may be the explanation for the relatively low toxicity detected in the current study. Although the results demonstrate that B. mori larvae are sensitive to Cry1C and Cry2A proteins, the exposure levels that harmed the larvae in the current study are far greater than natural exposure levels. We therefore conclude that consumption of Bt rice pollen will pose a low to negligible risk to B. mori. PMID:25014054

Viabilidade do pólen e desenvolvimento do tubo polínico em macieira (Malus spp. Germination of pollen and the development of pollen tubes in apple (Malus spp.

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Adriana Cibele de Mesquita Dantas

2005-12-01

Full Text Available No presente trabalho, estudaram-se características associadas à germinação in vitro e ao desenvolvimento in vivo do tubo polínico em seis variedades-copa e de porta-enxertos de macieira como subsídios para o estabelecimento de programas de melhoramento genético. Utilizou-se de pólen de seis cultivares de macieira inoculado em meio de cultura com ágar (10 g.L-1 em água destilada, combinados com concentrações de sacarose (0; 10; 20; 30; 40 e 50% e ácido bórico (0 e 40 mg.L-1. Para o estudo do desenvolvimento do tubo polínico, realizou-se coleta das flores em quatro períodos (6; 12; 24 e 48 horas após as polinizações em M9 x Marubakaido e a autofecundação em M9, sendo os tubos polínicos analisados em coloração de azul de anilina acidificada/carmim acético e em fluorescência. A sacarose, em concentrações entre 15% a 25%, pode ser empregada com sucesso para a germinação in vitro de grãos de pólen da macieira. O ácido bórico não teve efeito positivo para esta característica. Na ausência do ácido bórico e na presença de 15% de sacarose, observaram-se os maiores percentuais de germinação: Fuji (51,1%, Imperatriz (31,7%, M.9 (20,8%, Catarina (19,2%, Gala (13,7% e Marubakaido (6,1%. Quanto ao desenvolvimento do tubo polínico, com 12 horas da polinização, iniciou-se a germinação no pólen, no estigma, no cruzamento M.9 x Marubakaido, e após 24 horas da polinização observou-se 83% de germinação. As técnicas de coloração com azul de anilina acidificada com carmim acético e de visualização em fluorescência foram eficientes na visualização e coloração dos grãos de pólen e do desenvolvimento dos tubos polínicos.In the present work it was studied features associated to the germination of pollen and the development of pollen tubes in six apple varieties as subsidies for the establishment of genetic improvement programs. Pollen grains were inoculated in culture medium with distilled water, agar (10

Does the increase in ambient CO2 concentration elevate allergy risks posed by oak pollen?

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Kim, Kyu Rang; Oh, Jae-Won; Woo, Su-Young; Seo, Yun Am; Choi, Young-Jin; Kim, Hyun Seok; Lee, Wi Young; Kim, Baek-Jo

2018-05-01

Oak pollen is a major respiratory allergen in Korea, and the distribution of oak trees is expected to increase by ecological succession and climate change. One of the drivers of climate change is increasing CO2, which is also known to amplify the allergy risk of weed pollen by inducing elevated allergenic protein content. However, the impact of CO2 concentration on tree pollen is not clearly understood due to the experimental difficulties in carrying out extended CO2 treatment. To study the response of pollen production of sawtooth oak trees (Quercus acutissima) to elevated levels of ambient CO2, three open-top chambers at the National Institute of Forest Science in Suwon, Korea were utilized with daytime (8 am-6 pm) CO2 concentrations of ambient (× 1.0, 400 ppm), × 1.4 ( 560 ppm), and × 1.8 ( 720 ppm) treatments. Each chamber had three sawtooth oak trees planted in September 2009. One or two trees per chamber matured to bloom in 2016. Five to six catkins were selected per tree and polyethylene bags were attached to collect pollen grains. The total number of catkins per tree was counted and the number and weight of pollen grains per catkin were measured. Oak allergen—Que a 1 (Allergon Co., Uppsala, Sweden)—was extracted and purified to make an ELISA kit by which the antigen levels in the pollen samples were quantified. Total pollen counts per tree of the × 1.4 and × 1.8 treatments showed significant increase of 353 and 1299%, respectively, from the × 1.0 treatment (p < 0.001). Allergenic protein contents at the × 1.4 and × 1.8 treatments also showed significant increase of 12 and 11%, respectively (p = 0.011). The × 1.8 treatment induced significant difference from the × 1.0 treatment in terms of pollen production and allergenic protein content, whereas the × 1.4 treatment showed mixed significance. In summary, the oak trees under the elevated CO2 levels, which are expected in the changing climate, produced significantly higher amount of pollen and

Pollen, water, and wind: Chaotic mixing in a puddle of water

DEFF Research Database (Denmark)

Jensen, Kaare Hartvig

2016-01-01

and nutrient distribution in puddles and small ponds.The flow patterns are generated by wind blowing across the puddle surface. This causes a shear stress at the atmospheric interface, which drives a flow in the liquid below. Chaotic mixing can occur if the wind direction changes over time. A fluid patch......This paper talks about how pine pollen grains dispersedin an approximately 1 m wide and 1 cm deep water puddle. The pollen has mixed due to wind blowing across the liquid surface, revealing a strikingly complex flow pattern. The flows revealed by nature’s tracer particles may influence circulation...

Classification of grass pollen through the quantitative analysis of surface ornamentation and texture.

Science.gov (United States)

Mander, Luke; Li, Mao; Mio, Washington; Fowlkes, Charless C; Punyasena, Surangi W

2013-11-07

Taxonomic identification of pollen and spores uses inherently qualitative descriptions of morphology. Consequently, identifications are restricted to categories that can be reliably classified by multiple analysts, resulting in the coarse taxonomic resolution of the pollen and spore record. Grass pollen represents an archetypal example; it is not routinely identified below family level. To address this issue, we developed quantitative morphometric methods to characterize surface ornamentation and classify grass pollen grains. This produces a means of quantifying morphological features that are traditionally described qualitatively. We used scanning electron microscopy to image 240 specimens of pollen from 12 species within the grass family (Poaceae). We classified these species by developing algorithmic features that quantify the size and density of sculptural elements on the pollen surface, and measure the complexity of the ornamentation they form. These features yielded a classification accuracy of 77.5%. In comparison, a texture descriptor based on modelling the statistical distribution of brightness values in image patches yielded a classification accuracy of 85.8%, and seven human subjects achieved accuracies between 68.33 and 81.67%. The algorithmic features we developed directly relate to biologically meaningful features of grass pollen morphology, and could facilitate direct interpretation of unsupervised classification results from fossil material.

Airborne pollen in Funchal city, (Madeira Island, Portugal) - First pollinic calendar and allergic risk assessment.

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Camacho, Irene Câmara

2015-01-01

Nowadays, pollen calendars are useful tools for clinical guidance intended for allergy sufferers, because they can be used to prevent and manage allergic respiratory diseases, thus improving the quality of life. An aeropalinological study was performed in the city of Funchal with the purpose of establishing a pollen calendar and determining allergic risk, based on a seven year study (2003-2009). The airborne pollen monitoring was carried out with a Hirst type volumetric spore trap, following well-established guidelines. The mean annual pollen index was 1,635.09 and comprised 42 different pollen types. Airborne pollen levels were higher between March - June, accounting for 57.9% of the annual counts. Arboreal pollen grains (52.72%) prevailed in the atmosphere together with herbs and grasses (44.64%), while fern spores (2.29%) and unidentified pollen (0.35%) were scarce. The main pollen types were Urticaceae (20.64%), Poaceae (16.02%), Cupressaceae (13.61%), Pinaceae (9.07%), Myrtaceae (5.93%) and Ericaceae (5.02%). The pollen calendar comprised a total of 14 taxa and is similar to Mediterranean regions, with the exception of Olea europaea, Quercus sp., Betula sp. and Alnus sp. pollen types which are rare or absent. The main pollen season of major pollen taxa is significantly longer in Funchal (on average 239 days) than other European sites, especially for Urticaceae and Poaceae, but the pollen peaks were substantially lower. The pollen calendar for Funchal is the first ever created for Madeira region. Taking into account the low pollen index and number of allergy-risk days recorded (39 days in 7 years), the air quality of Funchal can be considered good.

Pollenmorphology of Lysipomia H.B.K. and Rhizocephalum Wedd. (Campanulaceae) and the revision of the pollen determination “Valeriana stenophylla” Killip

NARCIS (Netherlands)

Hammen, van der T.; Cleef, A.M.

1978-01-01

Fossil pollen grains from the Quaternary of Colombia, formerly provisionally indicated as “Valeriana” stenophylla Killip, have now been identified as those of the Andean genus Lysipomia H.B.K. (Campanulaceae). In the genus Lysipomia s.l. (fide McVaugh) two considerably different pollen types are

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.

Conservation des pollens de deux plantes mellifères (Vitellaria paradoxa et Steganotaenia araliacea de la région de l'Adamaoua Cameroun

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Youmbi, E.

2011-01-01

Full Text Available Conservation of Pollens of Two Honey Species (Vitellaria paradoxa and Steganotaenia araliaceae in the Region of Adamawa (Cameroon. The Adamaoua Region of Cameroon is a significant apiculture zone. The threats on the plant bioversity of this zone calls for the conservation of pollens, which in turn is necessary for the improvement and conservation of melliferous plants. Permanent maintenance of the flora is essential in research where pollens serve as base of plant material. In order to optimize conservation parameters of pollens of the two melliferous plants threatened (Vitellaria paradoxa and Steganotaenia araliaceae, in vitro tests (base medium, sucrose concentration, temperature, pH, dehydration time, and then storage of pollens in the fridge (+ 10 °C as well as in the freezer (- 20 °C were carried out. According to the results, pollen of the two plant species showed high germination rate in the Heslop-Harrison medium supplemented with 10 and 15% sucrose respectively for V. paradoxa and S. araliaceae. The optimum germination rates (39% and 20% were obtained respectively at pH 5.6 and 5.9 while optimum temperature was at 30 °C. Pollen of S. araliaceae were more tolerant to dehydration 8 weeks after drying in a desiccator containing silice grains. Pollen of two species still germinated more than 1% after 8 weeks of storage in the freezer. One week dehydration considerably extended storage period of pollens of the two plant species compared to the control. In the defined conditions, pollen grains of the two species can be stored for future use in plant breeding programs.

First records of pollen rain in bromeliad tanks in an area of caatinga in northeastern Brazil

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Jéssica Mirella de Souza Gomes

2014-06-01

Full Text Available Species of Bromeliaceae have leaves in a spiral configuration. Because of the shape of the rosette thus formed and the imbricate configuration of the leaf sheaths, there is usually a tank in which rainwater and other components of the environment, including pollen grains, accumulate, making such tanks effective pollen rain collectors. The objective of this study was to use bromeliads as a tool to increase knowledge about the vegetation of the caatinga (shrublands in the Canudos region of the state of Bahia, located in the semi-arid zone of Brazil, as well as to analyze the dynamics of pollen dispersal and deposition. To that end, we collected samples of the water from the tanks of bromeliads at the Canudos Biological Station. A total of 149 pollen types were detected, 88 of which could be identified botanically. The families that were the most well-represented among the pollen types were Fabaceae (with 25, Asteraceae (with 9, and Euphorbiaceae (with 7. Ten pollen types were presented as potential indicators of caatinga vegetation. We conclude that tank bromeliads are useful for gathering information about pollen rain and pollen dynamics, as well as about the transport and deposition of pollen in the caatinga.

Evaluation of Selected Ornamental Asteraceae as a Pollen Source for Urban Bees

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Wróblewska Anna

2016-12-01

Full Text Available Offering more floral resources for urban bees can be achieved by growing ornamental bee plants. The aim of the present study was to evaluate selected Asteraceae (Calendula officinalis ‘Persimmon Beauty’ and ‘Santana’, Centaurea macrocephala, Cosmos sulphureus, Dahlia pinnata, Tagetes patula, Tithonia rotundifolia, and Zinnia elegans as pollen sources for pollinators. Under urban conditions in Lublin, SE Poland, the investigated plants flowered from late June to the end of October. The mass of pollen produced in florets and capitula was found to be species-related. The highest pollen amounts per 10 florets (10.1 mg as well as per capitulum (249.7 mg were found for C. macrocephala. The mass of pollen yielded by a single plant depended on both the pollen mass delivered per disk florets and the proportion of disk florets in capitulum, and the flowering abundance of the plants. A single plant of D. pinnata and a single plant of T. rotundifolia each produced the largest pollen mass. Mean pollen yield per 1m2 of a plot ranged from 6.2 g (Z. elegans to 60.7 g (D. pinnata. Pollen grains are tricolporate, with echinate exine, medium or small in size. They can be categorised as oblatespherical, spherical, and prolatespherical. The principal visitors to C. macrocephala, C. sulphureus, and C. officinalis were honey bees, whereas bumble bees dominated on T. rotundifolia and D. pinnata. A magnet plant for butterflies was Z. elegans. Among the investigated species, D. pinnata, C. macrocephala, and T. rotundifolia were found to be the most valuable sources of pollen flow for managed and wild bees.

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

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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

Trigona corvina: An Ecological Study Based on Unusual Nest Structure and Pollen Analysis

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David W. Roubik

2009-01-01

Full Text Available We found that the nest of Trigona corvina (Apidae; Meliponini consists mainly of pollen exines from bee excrement, forming a scutellum shield encasing the colony. A 20-year-old nest (1980–2000 from a lowland Panama forested habitat was sawed in half longitudinally, and a 95 cm transect was systematically sampled each 5 cm. Samples subjected to detailed pollen analysis held 72 botanical species belonging to 65 genera in 41 families. Over 90% of scutellum pollen volume was Cecropiaceae and Arecaceae, among >1013 grains. Potentially the oldest samples, in the middle of the nest, indicate that Mimosoideae, Euphorbiaceae, and Bombacaceae (now Malvaceae were lost when Africanized honey bee competitors colonized Panama in 1984. Cecropia deposited in the nest increased markedly after landscape-level vegetation disturbance. Pollen from Cavanillesia demonstrated that the foraging range encompassed 3 km2 and perhaps 500 plant species. Trigona corvina primarily foraged on plants with large inflorescences, consistent with foraging theory considering their aggressive behavior.

Airborne grass (Poaceae) pollen in southern Spain. Results of a 10-year study (1987-96).

Science.gov (United States)

González Minero, F J; Candau, P; Tomás, C; Morales, J

1998-03-01

This work reports an exhaustive study of the aerobiology of the Gramineae in Seville, Spain, which is typical of coastal Mediterranean areas. Sampling was done with a Cour trap installed on the roof terrace of the School of Pharmacy, Seville, from 1987 to 1996, both inclusive. The climatic pattern of that period was characterized by two exceptionally wet years (1989 and 1996), between which were 5 consecutive years of drought (1990-5). This typically Mediterranean climate affects grass aerobiology. The annual amounts of total grass pollen are low, never exceeding 2500 grains/m3. The start, length, and intensity of the pollen season are significantly correlated with preseasonal meteorologic factors (precipitation and temperature), but intraseasonal meteorologic conditions have no effect on the three variables. The relationships are stated by three equations that, while further years of observations are anticipated, can be considered models to forecast the characteristics of the pollen season: the starting date depends on the mean temperatures of January and February, and the length and intensity of the season depend on the rainfall between the beginning of January and the starting date of the season. For the study period, the weekly concentrations (pollen curves) throughout the year showed no typical pattern of variation over the years, so that it was impossible to make mid- and long-term forecasts of the variation in weekly concentration. The most noteworthy aspects of grass pollen curves are a long pollen season, which starts in February or March and lasts until September or October; peaks of higher concentration (> 100 grains/m3) in May and June, associated with increases in temperature and absence of precipitation; and other peaks in the summer months that may be as high as the spring peaks.

Formation and function of a new pollen aperture pattern in angiosperms: The proximal sulcus of Tillandsia leiboldiana (Bromeliaceae).

Science.gov (United States)

Albert, Béatrice; Matamoro-Vidal, Alexis; Raquin, Christian; Nadot, Sophie

2010-02-01

Pollen grains are generally surrounded by an extremely resistant wall interrupted in places by apertures that play a key role in reproduction; pollen tube growth is initiated at these sites. The shift from a proximal to distal aperture location is a striking innovation in seed plant reproduction. Reversals to proximal aperture position have only very rarely been described in angiosperms. The genus Tillandsia belongs to the Bromeliaceae family, and its aperture pattern has been described as distal monosulcate, the most widespread aperture patterns recorded in monocots and basal angiosperms. Here we report developmental and functional elements to demonstrate that the sulcate aperture in Tillandsia leiboldiana is not distal as previously described but proximal. Postmeitotic tetrad observation indicates unambiguously the proximal position of the sulcus, and in vitro germination of pollen grains confirms that the aperture is functional. This is the first report of a sulcate proximal aperture with proximal germination. The observation of microsporogenesis reveals specific features in the patterns of callose thickenings in postmeiotic tetrads.

Using SPIRAL (Single Pollen Isotope Ratio AnaLysis) to estimate C 3- and C 4-grass abundance in the paleorecord

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Nelson, David M.; Hu, Feng Sheng; Scholes, Daniel R.; Joshi, Neeraj; Pearson, Ann

2008-05-01

C 3 and C 4 grasses differ greatly in their responses to environmental controls and influences on biogeochemical processes (e.g. water, carbon, and nutrient cycling). Difficulties in distinguishing between these two functional groups of grasses have hindered paleoecological studies of grass-dominated ecosystems. Stable carbon isotopic analysis of individual grains of grass pollen using a spooling-wire microcombustion device interfaced with an isotope-ratio mass spectrometer holds promise for improving C 3 and C 4 grass reconstructions. This technique, SPIRAL (Single Pollen Isotope Ratio AnaLysis), has only been evaluated using pollen of known C 3 and C 4 grasses. To test the ability of SPIRAL to reproduce the abundance of C 3 and C 4 grasses on the landscape, we measured δ13C values of > 1500 individual grains of grass pollen isolated from the surface sediments of ten lakes in areas that span a large gradient of C 3- and C 4-grass abundance, as determined from vegetation surveys. Results indicate a strong positive correlation between the δ13C-based estimates of % C 4-grass pollen and the abundance of C 4 grasses on the landscape. The % C 4-grass pollen slightly underestimates the actual abundance of C 4 grasses at sites with high proportions of C 4 grasses, which can be corrected using regression analysis. Comparison of the % C 4-grass pollen with C/N and δ13C measurements of bulk organic matter illustrates the distinct advantages of grass-pollen δ13C as a proxy for distinguishing C 3 and C 4 shifts within the grass family. Thus SPIRAL promises to advance our understanding of grassland ecology and evolution.

Over-expression of miR158 causes pollen abortion in Brassica campestris ssp. chinensis.

Science.gov (United States)

Ma, Zhiming; Jiang, Jianxia; Hu, Ziwei; Lyu, Tianqi; Yang, Yang; Jiang, Jingjing; Cao, Jiashu

2017-02-01

We identified and cloned the two precursors of miR158 and its target gene in Brassica campestris ssp. chinensis, which both had high relative expression in the inflorescences. Further study revealed that over-expression of miR158 caused reduced pollen varbility, which was caused by the degradation of pollen contents from the binucleate microspore stage. These results first suggest the role of miR158 in pollen development of Brassica campestris ssp. chinensis. MicroRNAs (miRNAs) play crucial roles in many important growth and development processes both in plants and animals by regulating the expression of their target genes via mRNA cleavage or translational repression. In this study, miR158, a Brassicaceae specific miRNA, was functionally characterized with regard to its role in pollen development of non-heading Chinese cabbage (Brassica campestris ssp. chinensis). Two family members of miR158 in B. campestris, namely bra-miR158a1 and bra-miR158a2, and their target gene bra027656, which encodes a pentatricopeptide repeat (PPR) containing protein, were identified. Then, qRT-PCR analysis and GUS-reporter system revealed that both bra-miR158 and its target gene had relatively high expression levels in the inflorescences. Further study revealed that over-expression of miR158 caused reduced pollen varbility and pollen germination ratio, and the degradation of pollen contents from the binucleate microspore stage was also found in those deformed pollen grains, which led to pollen shrinking and collapse in later pollen development stage. These results first shed light on the importance of miR158 in pollen development of Brassica campestris ssp. chinensis.

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

International Nuclear Information System (INIS)

Filatov, P.S.

1976-01-01

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

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.

Effect of micro-scale wind on the measurement of airborne pollen concentrations using volumetric methods on a building rooftop

Science.gov (United States)

Miki, Kenji; Kawashima, Shigeto; Fujita, Toshio; Nakamura, Kimihito; Clot, Bernard

2017-06-01

Evaluating airborne pollen concentrations is important for the understanding of the spatiotemporal dispersion of pollen grains. Using two identical pollen monitors in parallel, we performed two experiments in order to study the influences of a) the physical characteristics (orientation) of the air inlet and b) the presence of obstacles in proximity to the monitors on airborne pollen concentration data. The first experiment consisted of an evaluation of airborne pollen concentrations using two different types of orifices; 1) a vertically oriented inlet and 2) a wind vane intake, both attached to the same type of automatic pollen sampler. The second experiment investigated the relationship between vertical wind speed and horizontal wind direction around an obstacle with the goal of studying the impact of micro-scale wind on pollen sampling efficiency. The results of the two experiments suggest that the wind path near an obstacle might be redirected in a vertical direction before or after the wind flows over the obstacle, which causes measurement errors of airborne pollen concentrations that are proportional to the vertical wind speed, especially when a vertically oriented inlet is used.

Airborne pollen and spore survey in relation to allergy and plant ...

African Journals Online (AJOL)

Airborne bio-particles of allergic significance were recorded at a height of 15m in Nsukka during September 1999 – February 2000. Spores of fungi and pollen grains, which are important part of the exposure that may lead to allergic discomfort and plant diseases, dominated the particles. Other primary sources of the allergic ...

Mugwort (Artemisia L., nettle (Urtica L. and plantain (Plantago L. pollen in the atmosphere of Wrocław in the years 2002-2004

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Małgorzata Malkiewicz

2012-12-01

Full Text Available The paper includes the results of pollen season analysis of the selected plants (mugwort, nettle, plantain regarded as the most allergenic in Wrocław in 2002-2004. The studies were carried out using volumetric method (Burkard trap. The results show strong variation in pollen seasons. The average duration of the pollen season of Artemisia was 82 days. The highest pollen concentration of mugwort was recorded in 2004 (156 grains × m-3. The start of nettle pollen seasons varied in studied period on average by 24 days, on average, but its end was almost the same. The pollen season of Urtica was the earliest in 2004. It started on 5th May and lasted 136 days. The annual pollen total of Plantago was relatively low, on average 0.2-0.4% in annual pollen totals.

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

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Andrea Obersteiner

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

Seasonal and Spatial Variations of Indoor Pollen in a Hospital

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Santiago Fernández-Rodríguez

2009-12-01

Full Text Available The airborne indoor pollen in a hospital of Badajoz (Spain was monitored over two years using a personal Burkard sampler. The air was sampled in four places indoors—one closed room and one open ward on each of the ground and the third floors—and one place outdoors at the entrance to the hospital. The results were compared with data from a continuous volumetric sampler. While 32 pollen types were identified, nearly 75% of the total counts were represented by just five of them. These were: Quercus, Cupressaceae, Poaceae, Olea, and Plantago. The average indoor concentration was 25.2 grains/m3, and the average indoor/outdoor ratio was 0.27. A strong seasonal pattern was found, with the highest levels in spring and winter, and the indoor concentrations were correlated with the outdoor one. Indoor air movement led to great homogeneity in the airborne pollen presence: the indoor results were not influenced by whether or not the room was isolated, the floor level, or the number of people in or transiting the site during sampling. The presence of ornamental vegetation in the area surrounding the building affected the indoor counts directly as sources of the pollen.

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

Science.gov (United States)

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

2013-11-01

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

Pollen

Science.gov (United States)

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

Are the birch trees in Southern England a source of Betula pollen for North London?

Science.gov (United States)

Skjøth, C. A.; Smith, M.; Brandt, J.; Emberlin, J.

2009-01-01

Birch pollen is highly allergenic. Knowledge of daily variations, atmospheric transport and source areas of birch pollen is important for exposure studies and for warnings to the public, especially for large cities such as London. Our results show that broad-leaved forests with high birch tree densities are located to the south and west of London. Bi-hourly Betula pollen concentrations for all the days included in the study, and for all available days with high birch pollen counts (daily average birch pollen counts >80 grains/m3), show that, on average, there is a peak between 1400 hours and 1600 hours. Back-trajectory analysis showed that, on days with high birch pollen counts ( n = 60), 80% of air masses arriving at the time of peak diurnal birch pollen count approached North London from the south in a 180 degree arc from due east to due west. Detailed investigations of three Betula pollen episodes, with distinctly different diurnal patterns compared to the mean daily cycle, were used to illustrate how night-time maxima (2200-0400 hours) in Betula pollen counts could be the result of transport from distant sources or long transport times caused by slow moving air masses. We conclude that the Betula pollen recorded in North London could originate from sources found to the west and south of the city and not just trees within London itself. Possible sources outside the city include Continental Europe and the Betula trees within the broad-leaved forests of Southern England.

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

International Nuclear Information System (INIS)

Candan, F.

2015-01-01

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

The recovery of pollen evidence from documents and its forensic implications.

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Morgan, R M; Davies, G; Balestri, F; Bull, P A

2013-12-01

Three experiments were undertaken to establish the potential for forensic palynological analysis in cases of suspected document fraud. The first study tested 6 different types of paper and 9 different types of ink (n=54) and it was established that the best retainer of particulates (in this case a proxy was used in the form of UV powder) was medium biro ink and Wove and Connoisseur paper. It was found that for the different paper types 42-52% of the particulates collected were found in the ink and thus both the paper and the ink are potentially valuable sources of trace evidence in a forensic investigation. The second study sought to address the differences in the spatial distribution of particulates on documents when writing took place before or after the paper was treated with UV particulates. Ninety-six observations were made for each piece of paper tested and it was found that when the writing took place after the particulates were applied to the paper; more particulates were retained on the paper in contrast to when the writing took place before the particulate treatment. The spatial distribution of particulates was also affected, with particulates being retained in the folds of the paper when the writing took place before particulate treatment in contrast to a more erratic pattern that emerged due to the pressure of the hand of the writer when the writing took place after the particulate treatment. The third study utilised lily (Lilium) pollen grains and the findings broadly concurred with the second study. The main difference identified was when the writing took place before the particulates were applied; when UV powder was used the particulates were retained in the folds of the paper whereas this pattern was not seen to the same degree when pollen grains were used due to their 'stickier' nature. Envelopes and the pen nibs were also found to be rich sources of pollen grains after the experiments were undertaken. These studies have implications for the

An experimental test of whether habitat corridors affect pollen transfer.

Energy Technology Data Exchange (ETDEWEB)

Townsend, Patricia A.; Levey, Douglas J.

2005-02-01

Abstract. Negative effects of habitat fragmentation are thought to be diminished when habitat patches are joined by a corridor. A key assumption is that corridors facilitate exchange rates of organisms between otherwise isolated patches. If the organisms are pollinators, corridors may be important for maintaining genetically viable populations of the plants that they pollinate. We tested the hypothesis that corridors increase the movement of insect pollinators into patches of habitat and thereby increase pollen transfer for two species of plants, one pollinated by butterflies (Lantana camara) and the other by bees and wasps (Rudbeckia hirta). We worked in an experimental landscape consisting of 40 greater than or equal to 1-ha patches of early-successional habitat in a matrix of forest. Within each of eight experimental units, two patches were connected by a corridor (150 X 25 m), and three were not. Patch shape varied to control for the area added by the presence of a corridor. Differences in patch shape also allowed us to test alternative hypotheses of how corridors might function. The Traditional Corridor Hypothesis posits that corridors increase immigration and emigration by functioning as movement conduits between patches. The Drift Fence Hypothesis posits that corridors function by ‘‘capturing’’ organisms dispersing through the matrix, redirecting them into associated habitat patches. Using fluorescent powder to track pollen, we found that pollen transfer by butterflies between patches connected by a corridor was significantly higher than between unconnected patches (all values mean plus or minus 1 SE: 59% plus or minus 9.2% vs. 25% plus or minus 5.2% of flowers receiving pollen). Likewise, pollen transfer by bees and wasps was significantly higher between connected patches than between unconnected patches (30% plus or minus 4.2% vs. 14.5% plus or minus 2.2%). These results support the Traditional Corridor Hypothesis. There was little support, however

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

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Dresselhaus, Thomas; Franklin-Tong, Noni

2013-07-01

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

A comparison of controlled self-pollination and open pollination results based on maize grain quality

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Hanna Sulewska

2014-05-01

Full Text Available Maize (Zea mays L. grain endosperm is triploid (3n, of which 2n come from the male (transferred by pollen and only 1n from the female plant, thus a major impact of the male form can be expected on grain quality parameters. A good example of this relationship is the phenomenon of xenia. The aim of this study was to determine the effect of pollen on grain quality. The field experiment was conducted in 2011; seeds were harvested from eight cultivars: Bosman, Blask, Tur, Kozak, Bielik, Smok, SMH 220 and Kresowiak, derived from free pollination and controlled self-pollination of maize. Analyses of nutrient contents and starch content in the grain were conducted in the laboratory. In addition, 1000 grain weight and the hectoliter weight of all grain samples were recorded. The results confirmed differences in grain quality of maize hybrids obtained by self-pollination and by open pollination. Grain of maize plants obtained by open-pollination was characterised by higher contents of N-free extract and starch, and lower protein content. Undertaking further studies on this subject may indicate specific recommendations for agricultural practice, such as mixtures of hybrids with good combining abilities, which will contribute to improved grain quality without additional costs.

Ecological implications of reduced pollen deposition in alpine plants: a case study using a dominant cushion plant species.

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Reid, Anya; Hooper, Robyn; Molenda, Olivia; Lortie, Christopher J

2014-01-01

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.

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.

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.

Reproductive characterization of interspecific hybrids among Capsicum species

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Carlos Eduardo da Silva Monteiro

2011-01-01

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

The pollen complex from postglacial sediments of the Laptev Sea as a bioindicator

Science.gov (United States)

Naidina, O. D.

2014-05-01

The first results of comparison of palynological analysis (pollen of terrestrial plants), SEM analysis of pollen morphology, and radiocarbon age dating (AMS14C) of sediments of the eastern shelf of the Laptev Sea show that the diverse taxonomic composition of pollen spectra provides an integrated idea of the vegetation and climate of the region over 11.2 calendar kiloyears. It is found that phases of the tree and shrub vegetation development (maxima of pollen of Betula sect. Nanae and Pinus s/g Haploxylon) correspond to the warm epochs in the Holocene. It is obvious that birch phytocoenoses first settled in the southern tundra subzone with increasing temperature, and then coniferous communities of forest tundra. An occurrence of pollen of shrubby birches (Nanae) suggests compliance of permafrost landscapes with cold climate conditions, i.e., with an annual average temperature of -2°C and amount of precipitation of less than 500 mm. Owing to a progressive increase in summer temperatures, dwarf cedar and pine communities advanced toward the seashore. The SEM analysis results show that a significant proportion of regional coniferous pollen belongs to representatives of Pinus pumila (Pall.) and P. sylvestris L. In addition, the SEM study of the exine of Pinus sylvestris L. and P. pumila (Pall.) Regel pollen grains confirmed polymorphism in coniferous pollen. According to the inverse relationship between climate and vegetation, frequent climate fluctuations that are typical of progressive and differential postglacial transgression were revealed. An increase in arboreal pollen transfer onto the shelf later than 9.1 cal. ka coincides with the time of forest boundary migration to the north due to the warming of the Earth's climate. At that time, the tundra vegetation was replaced by forest-tundra vegetation, the maximum stage of sea transgression began, and there appeared a trend of increasing temperature and moisture.

External application of gametophyte-specific ZmPMEI1 induces pollen tube burst in maize.

Science.gov (United States)

Woriedh, Mayada; Wolf, Sebastian; Márton, Mihaela L; Hinze, Axel; Gahrtz, Manfred; Becker, Dirk; Dresselhaus, Thomas

2013-09-01

Regulated demethylesterification of homogalacturonan, a major component of plant cell walls, by the activity of pectin methylesterases (PMEs), plays a critical role for cell wall stability and integrity. Especially fast growing plant cells such as pollen tubes secrete large amounts of PMEs toward their apoplasmic space. PME activity itself is tightly regulated by its inhibitor named as PME inhibitor and is thought to be required especially at the very pollen tube tip. We report here the identification and functional characterization of PMEI1 from maize (ZmPMEI1). We could show that the protein acts as an inhibitor of PME but not of invertases and found that its gene is strongly expressed in both gametophytes (pollen grain and embryo sac). Promoter reporter studies showed gene activity also during pollen tube growth toward and inside the transmitting tract. All embryo sac cells except the central cell displayed strong expression. Weaker signals were visible at sporophytic cells of the micropylar region. ZmPMEI1-EGFP fusion protein is transported within granules inside the tube and accumulates at the pollen tube tip as well as at sites where pollen tubes bend and/or change growth directions. The female gametophyte putatively influences pollen tube growth behavior by exposing it to ZmPMEI1. We therefore simulated this effect by applying recombinant protein at different concentrations on growing pollen tubes. ZmPMEI1 did not arrest growth, but destabilized the cell wall inducing burst. Compared with female gametophyte secreted defensin-like ZmES4, which induces burst at the very pollen tube tip, ZmPMEI1-induced burst occurs at the subapical region. These findings indicate that ZmPMEI1 secreted by the embryo sac likely destabilizes the pollen tube wall during perception and together with other proteins such as ZmES4 leads to burst and thus sperm release.

Prevalence of airborne allergenic Amaranthus viridis pollen in seven different regions of Saudi Arabia

International Nuclear Information System (INIS)

Hasnain, Syed M.; Fatima, K.; Al-Frayh, A.

2007-01-01

Amaranthus pollen grains are known to have highly allergenic and potential cause of respiratory allergic diseases. Nevertheless, data on the prevalence of Amaranthus pollen in the environment is limited and almost non-existent for Saudi Arabia. We conducted an investigation to record the airborne incidence of A.viridis and other allergenic pollen in Al-Khobar, Dammam, Hail, Jeddah, Jizan, Qassim and Taif, using Burkard Volumetric Samplers. The samples were operated continuously for one year at each location. The data revealed A.viridis as one of the major components of outdoor airspora, constituting a maximum of 96% of total pollen counts in Hail, followed by Al-Khobar (89%), Jeddah (87%), Qassim (85%), Taif (84%), Dammam (83%) and Jizan (61%). These higher percentages contributed largely to the total weed pollen catch during August to November in all seven regions. In addition, the data also showed that A. virdis pollen were present throughout the year with distinct seasonal variations. The diel periodicities for at least five sites averaged over a year showed mid-day to early evening maxima. The maximum concentration approached 3000 mt. cube of air in October and 1827 mt. cube of air in September. The data also exhibited, a seasonal pattern, in their maximum appearance. Further studies related to biochemical and allergological aspects are needed to confirm the allergenic impact of Amaranthus pollen and sensitization in allergic individuals in the Kingdom of Saudi Arabia. (author)

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. ...

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

Science.gov (United States)

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

2015-01-01

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

Phleum pratense pollen starch granules induce humoral and cell-mediated immune responses in a rat model of allergy.

Science.gov (United States)

Motta, A; Peltre, G; Dormans, J A M A; Withagen, C E T; Lacroix, G; Bois, F; Steerenberg, P A

2004-02-01

Timothy grass (Phleum pratense) pollen allergens are an important cause of allergic symptoms. However, pollen grains are too large to penetrate the deeper airways. Grass pollen is known to release allergen-bearing starch granules (SG) upon contact with water. These granules can create an inhalable allergenic aerosol capable of triggering an early asthmatic response and are implicated in thunderstorm-associated asthma. We studied the humoral (IgE) and bronchial lymph node cells reactivities to SG from timothy grass pollen in pollen-sensitized rats. Brown-Norway rats were sensitized (day 0) and challenged (day 21) intratracheally with intact pollen and kept immunized by pollen intranasal instillation by 4 weeks intervals during 3 months. Blood and bronchial lymph nodes were collected 7 days after the last intranasal challenge. SG were purified from fresh timothy grass pollen using 5 microm mesh filters. To determine the humoral response (IgE) to SG, we developed an original ELISA inhibition test, based on competition between pollen allergens and purified SG. The cell-mediated response to SG in the bronchial lymph node cells was determined by measuring the uptake of [3H]thymidine in a proliferation assay. An antibody response to SG was induced, and purified SG were able to inhibit the IgE ELISA absorbance by 45%. Pollen extract and intact pollen gave inhibitions of 55% and 52%, respectively. A cell-mediated response was also found, as pollen extract, intact pollen and SG triggered proliferation of bronchial lymph node cells. It was confirmed that timothy grass pollen contains allergen-loaded SG, which are released upon contact with water. These granules were shown to be recognized by pollen-sensitized rats sera and to trigger lymph node cell proliferation in these rats. These data provide new arguments supporting the implication of grass pollen SG in allergic asthma.

Investigation of heterogeneous ice nucleation in pollen suspensions and washing water

Science.gov (United States)

Dreischmeier, Katharina; Budke, Carsten; Koop, Thomas

2014-05-01

Biological particles such as pollen often show ice nucleation activity at temperatures higher than -20 °C. Immersion freezing experiments of pollen washing water demonstrate comparable ice nucleation behaviour as water containing the whole pollen bodies (Pummer et al., 2012). It was suggested that polysaccharide molecules leached from the grains are responsible for the ice nucleation. Here, heterogeneous ice nucleation in birch pollen suspensions and their washing water was investigated by two different experimental methods. The optical freezing array BINARY (Bielefeld Ice Nucleation ARraY) allows the direct observation of freezing of microliter-sized droplets. The IN spectra obtained from such experiments with birch pollen suspensions over a large concentration range indicate several different ice nucleation active species, two of which are present also in the washing water. The latter was probed also in differential scanning calorimeter (DSC) experiments of emulsified sub-picoliter droplets. Due to the small droplet size in the emulsion samples and at small concentration of IN in the washing water, such DSC experiments can exhibit the ice nucleation behaviour of a single nucleus. The two heterogeneous freezing signals observed in the DSC thermograms can be assigned to two different kinds of ice nuclei, confirming the observation from the BINARY measurements, and also previous studies on Swedish birch pollen washing water (Augustin et al., 2012). The authors gratefully acknowledge funding by the German Research Foundation (DFG) through the project BIOCLOUDS (KO 2944/1-1) and through the research unit INUIT (FOR 1525) under KO 2944/2-1. We particularly thank our INUIT partners for fruitful collaboration and sharing of ideas and IN samples. S. Augustin, H. Wex, D. Niedermeier, B. Pummer, H. Grothe, S. Hartmann, L. Tomsche, T. Clauss, J. Voigtländer, K. Ignatius, and F. Stratmann, Immersion freezing of birch pollen washing water, Atmos. Chem. Phys., 13, 10989

The effect of UV irradiated vegetative and generative nuclei as well as cytoplasm on pollen tube growth of Pinus Silvestris

International Nuclear Information System (INIS)

Zelles, L.; Seibold, H.W.; Ernst, D.E.W.; Technische Univ. Hannover

1976-01-01

Pollen grains of Pinus Silvestris were irradiated with UV-rays, and the stimulation, or restraint of gemination was studied. Gemination of the pollen was retarded by irradiation of the nucleus. This book place proportionally to the increasing doses: The conditions of irradiation and the effects of the stimulation and retardation are described in detail. Different dose rates with different effects on nucleus and cytoplasma are observed. (AJ) [de

Major grass pollen allergen Lol p 1 binds to diesel exhaust particles: implications for asthma and air pollution.

Science.gov (United States)

Knox, R B; Suphioglu, C; Taylor, P; Desai, R; Watson, H C; Peng, J L; Bursill, L A

1997-03-01

Grass pollen allergens are known to be present in the atmosphere in a range of particle sizes from whole pollen grains (approx. 20 to 55 microns in diameter) to smaller size fractions Lol p 1, immunogold labelling with specific monoclonal antibodies and a high voltage transmission electron-microscopic imaging technique. DECP are visualized as small carbon spheres, each 30-60 nm in diameter, forming fractal aggregates about 1-2 microns in diameter. Here we test our hypothesis and show by in vitro experiments that the major grass pollen allergen, Lol p 1, binds to one defined class of fine particles, DECP. DECP are in the respirable size range, can bind to the major grass pollen allergen Lol p 1 under in vitro conditions and represent a possible mechanism by which allergens can become concentrated in polluted air and thus trigger attacks of asthma.

Surmounting self-incompatibility in pineapple (Ananas comosus L.) with pollen irradiation

International Nuclear Information System (INIS)

Subramanian, N.; Iyer, C.P.A.; Singh, Rajendra

1981-01-01

Irradiation was investigated as a tool to overcome self-incompatibility in pineapple. Pollen grains were irradiated with 15, 20, 25 kr gamma radiation from cobalt-60 and were used for pollination on the stigma of the same inflorescence. Observations on seed-set were made when the fruits were ripe. It was observed that 20 kr gamma radiation was effective in overcoming self-incompatibility. (M.G.B.)

Pólen 2n e mecanismos meióticos de formação em Solanum commersonii ssp 2n pollen and meiotic mechanisms of Formation in Solanum commersonii ssp

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Lívia Gracielle Oliveira Tomé

2009-04-01

. commersonii subsp. malmeanum Bitt. (SCM were evaluated. In the evaluation, two hundred viable pollen grains were stained (2% acetic carmin and measured. The pollen grains measuring 25 µm in diameter or more were considered nonreduced. The clone Solanum commersonii subsp. commersonii Dun. (SCC 100 produces 26.1% of non-reduced pollen grains caused by parallel spindles and fusion spindles, which may be used in breeding program.

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

KAUST Repository

Synek, Lukas

2017-03-30

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

Bee Pollen

Science.gov (United States)

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

Modelling of pollen dispersion in the atmosphere: evaluation with a continuous 1β+1δ lidar

Science.gov (United States)

Sicard, Michaël; Izquierdo, Rebeca; Jorba, Oriol; Alarcón, Marta; Belmonte, Jordina; Comerón, Adolfo; De Linares, Concepción; Baldasano, José Maria

2018-04-01

Pollen allergenicity plays an important role on human health and wellness. It is thus of large public interest to increase our knowledge of pollen grain behavior in the atmosphere (source, emission, processes involved during their transport, etc.) at fine temporal and spatial scales. First simulations with the Barcelona Supercomputing Center NMMB/BSC-CTM model of Platanus and Pinus dispersion in the atmosphere were performed during a 5-day pollination event observed in Barcelona, Spain, between 27 - 31 March, 2015. The simulations are compared to vertical profiles measured with the continuous Barcelona Micro Pulse Lidar system. First results show that the vertical distribution is well reproduced by the model in shape, but not in intensity, the model largely underestimating in the afternoon. Guidelines are proposed to improve the dispersion of airborne pollen by numerical prediction models.

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.

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

Viabilidade in vitro de grãos de pólen de bananeira sob diferentes concentrações de ácido bórico e sacarose In vitro viability of banana pollen grain under different concentrations of boric acid and sucrose

Directory of Open Access Journals (Sweden)

Ronaldo Viana dos Reis

2011-06-01

Full Text Available Neste trabalho, objetivou-se avaliar a germinação do grão de pólen e o comprimento do tubo polínico das bananeiras diplóides M53, 8987-01 e 9197-03, Calcutá, Lidi e 86B79-12. O delineamento utilizado foi inteiramente casualizado com cinco doses de sacarose (0, 5, 10, 15, 20% e seis concentrações de ácido bórico (0, 100, 200, 300, 400 e 500 Mg L-1 com quatro repetições. Foram utilizados grãos de pólen retirados da inflorescência masculina dos diplóides Musa acuminata (AA. O pólen foi distribuído em placas de Petri, contendo o seguinte meio de cultura: 1,27 mM de Ca(NO32.2H2O, 0,87 mM de MgSO4.7H2O, 0,99 mM de KNO3, 0,7% de ágar com pH ajustado para 7,0, variando as concentrações de sacarose e de ácido bórico. As avaliações foram realizadas 24 horas após a distribuição do pólen no meio de cultura. O meio de cultura padrão para germinação de grãos de pólen suplementado com 15% de sacarose proporcionou uma maior percentagem de germinação para os diplóides de bananeira avaliados. A concentração de ácido bórico adicionado ao meio de cultura para a germinação de grãos de pólen de bananeira diplóide é dependente do genótipo.The objective of this work was to evaluate the germination of pollen grain and pollen tube length of banana diploids (M53, 8987-01 e 9197-03, Calcutta, Lidi and 86B79-12. Five concentrations of sucrose (0, 5, 10, 15 and 20% and six concentrations of boric acid (0, 100, 200, 300, 400 and 500 mg L-1 were used, in a completely randomized experimental design, with four replicates. The pollen was distributed in Petri dishes containing the following culture medium: 1.27 mM Ca(NO32.2H2O, 0.87 mM MgSO4.7H2O, 0.99 mM KNO3, and 0.7% agar; pH adjusted to 7.0, varying the sucrose and boric acid concentrations. The evaluations were performed 24 hours after the distribution of the pollen in the culture medium. The standard culture medium for germination of pollen grains with 15% sucrose provided the

Mutations in AtPS1 (Arabidopsis thaliana parallel spindle 1 lead to the production of diploid pollen grains.

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Isabelle d'Erfurth

2008-11-01

Full Text Available Polyploidy has had a considerable impact on the evolution of many eukaryotes, especially angiosperms. Indeed, most--if not all-angiosperms have experienced at least one round of polyploidy during the course of their evolution, and many important crop plants are current polyploids. The occurrence of 2n gametes (diplogametes in diploid populations is widely recognised as the major source of polyploid formation. However, limited information is available on the genetic control of diplogamete production. Here, we describe the isolation and characterisation of the first gene, AtPS1 (Arabidopsis thaliana Parallel Spindle 1, implicated in the formation of a high frequency of diplogametes in plants. Atps1 mutants produce diploid male spores, diploid pollen grains, and spontaneous triploid plants in the next generation. Female meiosis is not affected in the mutant. We demonstrated that abnormal spindle orientation at male meiosis II leads to diplogamete formation. Most of the parent's heterozygosity is therefore conserved in the Atps1 diploid gametes, which is a key issue for plant breeding. The AtPS1 protein is conserved throughout the plant kingdom and carries domains suggestive of a regulatory function. The isolation of a gene involved in diplogamete production opens the way for new strategies in plant breeding programmes and progress in evolutionary studies.

The determination of the botanical origin in honeys with over-represented pollen: combination of melissopalynological, sensory and physicochemical analysis.

Science.gov (United States)

Rodopoulou, Maria-Anna; Tananaki, Chrysoula; Dimou, Maria; Liolios, Vasilios; Kanelis, Dimitrios; Goras, Georgios; Thrasyvoulou, Andreas

2018-05-01

Pollen analysis of honey is the basic method for the determination of its botanical origin. However, the presence of over-represented pollen in honeys may lead the analysis to false results. This can be more severe if this pollen is present in unifloral under-represented honeys of commercial importance (e.g. thyme honey). In the present study, we investigated the abundance of over-represented pollen grains on several quality characteristics in honey samples. In particular, we mixed honeys characterised as over-represented, specifically chestnut and eucalyptus, with thyme honeys in different analogies, and we also analysed the melissopalynological, organoleptic, physicochemical (water content, electrical conductivity, colour) and volatile characteristics of the blends. The most sensitive parameters were the microscopic characteristics, followed by the organoleptic ones. Blends of thyme honey with an originally low percentage of thyme pollen were the most influenced and could not be characterised as unifloral regarding their melissopalynological characteristics, even when they were mixed with small quantities of honeys with over-represented pollen (i.e. 5%). The present study confirms that, in the case of presence of over-represented pollen in honeys, pollen analysis alone cannot give trustworthy results for the determination of the botanical origin, even though their exclusion during pollen analysis, when they are present in percentages of up to 30%, could provide more accurate results. Consequently, pollen analysis should also be combined with the other analyses, especially in honeys with under-represented and over-represented pollens, to give safer results for the botanical characterisation of honeys. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

The patterns of Corylus and Alnus pollen seasons and pollination periods in two Polish cities located in different climatic regions.

Science.gov (United States)

Puc, Małgorzata; Kasprzyk, Idalia

2013-01-01

This study compares phenological observations of Corylus (hazel) and Alnus (alder) flowering with airborne pollen counts of these taxa recorded using volumetric spore traps (2009-2011). The work was carried out in the Polish cities of Szczecin and Rzeszów that are located in different climatic regions. Correlations between pollen concentrations and meteorological data were investigated using Spearman's rank correlation analysis. The timings of hazel and alder pollination and the occurrence of airborne pollen varied greatly and were significantly influenced by meteorological conditions ( p  sunlight (insolated) and sheltered from the wind. On the other hand, a delay in the timing of pollination was observed in quite sunny but very windy sites. In Rzeszów, maximum hazel pollen concentrations did not coincide with the period of full pollination (defined as between 25 % hazel and alder and 75 % of flowers open). Conversely, in Szczecin, the highest hazel pollen concentrations were recorded during phenophases of the full pollination period. The period when the highest alder pollen concentrations were recorded varied between sites, with Rzeszów recording the highest concentrations at the beginning of pollination and Szczecin recording alder pollen throughout the full pollination period. Substantial amounts of hazel and alder pollen grains were recorded in the air of Rzeszów (but not Szczecin) before the onset of the respective pollen seasons.

Radioprotective effect of the pollen

International Nuclear Information System (INIS)

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

1990-10-01

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

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

Science.gov (United States)

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

2014-07-01

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

La longévité du pollen de colza

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Pierre Jacqueline

2002-01-01

Full Text Available Connaître la longévité d’un pollen est une donnée particulièrement intéressante dans le cadre des études de risques de dissémination du pollen. En effet, cela permet de savoir combien de temps une parcelle dont la floraison est terminée reste une source de pollen fécondant. Par ailleurs, une étude de la longévité du pollen pourrait permettre de mieux comprendre les résultats en apparence contradictoires obtenus au cours de diverses expérimentations menées sur la dissémination du pollen de colza. Ainsi, alors que des travaux montrent que ce pollen est peu anémophile [1] et qu’au niveau de la parcelle sa dispersion se fait sur de courtes distances [2-4], des cas de contaminations sur de grandes distances ont été signalés [5] et les relevés palynologiques effectués sur des filtres (placés à 10 m de hauteur, voire plus confirment que ce pollen peut se disperser sur de grandes distances [6]. Toutefois, on ignore si le pollen ainsi collecté est viable ou non. Si l’on fait l’hypothèse que cette dernière dispersion se fait par le biais de la mise en suspension du pollen dans l’air dans les couches de l’atmosphère et que son transport dure un certain temps, il devient également nécessaire de connaître la durée de vie du pollen pour mieux évaluer les risques de ce type de dissémination. Au plan méthodologique, mesurer la longévité du pollen peut a priori paraître simple. Cependant les critères retenus peuvent être nombreux et divers : mesure de la viabilité, mesure du pouvoir germinatif in vitro ou in vivo, mesure du pouvoir fécondant réel. Dans chacun des cas, les techniques appliquées sont différentes et chacune comporte des biais parfois importants tels que des faux-positifs dans les tests colorimétriques de viabilité, l’incidence du milieu de culture dans les tests de germination in vitro, sans parler des tests présentant des risques carcinogènes pour l’expérimentateur [7]. De plus

Distribution of exogenous DNA in upland cotton by pollen tube pathway

International Nuclear Information System (INIS)

Yang Shuhua; Ge Cailin; Zhu Jing; Wang Zegang; Luo Shishi; Ni Wanchao

2007-01-01

The distribution of exogenous DNA in upland cotton by pollen tube pathway was studied. The results showed that the exogenous DNA could be transported into ovules by dripping and injection. The optimum time for treatment is at 33 h after pollination. The radioactivity in ovules by dripping exogenous DNA was lower than that by injecting. In autoradiogram, the number of sliver grains in the treated ovules was more than that in the controls. (authors)

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

Science.gov (United States)

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

2014-01-01

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

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

DEFF Research Database (Denmark)

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

2012-01-01

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

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

International Nuclear Information System (INIS)

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

1987-01-01

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

Double-blind, placebo-controlled immunotherapy with mixed grass-pollen allergoids. II. Comparison between parameters assessing the efficacy of immunotherapy.

Science.gov (United States)

Bousquet, J; Maasch, H; Martinot, B; Hejjaoui, A; Wahl, R; Michel, F B

1988-09-01

Specific immunotherapy is effective in alleviating symptoms in grass pollen-induced rhinitis, but there are no clear data demonstrating a correlation between symptom-medication scores and objective parameters. Twenty-five patients taking part in a double-blind, placebo-controlled immunotherapy with mixed grass pollen-formalinized allergoids were studied. All patients had the same investigations. Symptom-medication scores were significantly (p less than 0.005, Mann-Whitney U test) reduced in the treated group by comparison to the placebo-treated patients. Nasal challenges performed with threefold increasing numbers of orchard grass-pollen grains demonstrated that patients treated with allergoid tolerated a significantly (p less than 0.005, Wilcoxon W test) greater number of grains after treatment, whereas there was no mean difference in the placebo-treated patients. There was a significant (p less than 0.005, Spearman rank-correlation) correlation between nasal challenges and symptom scores during the season. The skin prick test end point was significantly (p less than 0.001, Wilcoxon W test) reduced after treatment in the allergoid-treated group and remained unchanged in the placebo-treated group. There was a significant (p less than 0.001) correlation between the skin prick test end point and symptom scores during the season. Serum grass-pollen IgG titrated by a solid-phase radioimmunoassay with Staphylococcus A protein was significantly (p less than 0.01, Wilcoxon W test) increased after treatment with allergoid, but there was no significant correlation between IgG titer and symptom scores during the season. Serum grass-pollen IgE increased (p less than 0.04, Wilcoxon W test) in the treated group but there was no correlation with symptom scores.

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

African Journals Online (AJOL)

PRECIOUS

2009-11-02

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

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

Science.gov (United States)

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

2015-10-01

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

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

Science.gov (United States)

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

2015-11-01

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

ANTHROPOGENIC POLLEN INDICATORS (API FROM ARCHAEOLOGICAL SITES AS LOCAL EVIDENCE OF HUMAN-INDUCED ENVIRONMENTS IN THE ITALIAN PENINSULA

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A. M. Mercuri

2013-04-01

Full Text Available Pollen data from twenty-six archaeological sites are reviewed to investigate the development of human-induced environments through the presence of selected Anthropogenic Pollen Indicators (API. The sites are located in six Italian regions - Veneto, Emilia Romagna, Tuscany, Basilicata, Calabria, and Sicily - and in the Republic of San Marino. Their chronology spans from the Bronze to the Renaissance ages, from approximately 4200 to 500 years BP. The API which are common in these sites are properly considered important markers of human activity and anthropization in the Mediterranean area. The most frequent API taxa in pollen spectra are seven: Artemisia, Centaurea, Cichorieae and Plantago are ubiquitous and therefore they have the major relevance, followed by cereals and Urtica, and by Trifolium type. The spread of plants producing these pollen grains is sometimes marked by high percentage values in pollen spectra. Pollen records show that, as expected, cereals and wild synanthropic herbs were widespread near archaeological sites but local differences are evident. Ecological and chrono-cultural reasons may be at the base of the observed differences. In general, the synanthropic plants well represent the xeric environments that developed as a result of the continuous human pressure and changes in soil compositions. These changes have occurred especially during the mid and late Holocene.

Exogenous γ-aminobutyric acid (GABA) affects pollen tube growth via modulating putative Ca2+-permeable membrane channels and is coupled to negative regulation on glutamate decarboxylase

Science.gov (United States)

Yu, Guang-Hui; Zou, Jie; Feng, Jing; Peng, Xiong-Bo; Wu, Ju-You; Wu, Ying-Liang; Palanivelu, Ravishankar; Sun, Meng-Xiang

2014-01-01

γ-Aminobutyric acid (GABA) is implicated in pollen tube growth, but the molecular and cellular mechanisms that it mediates are largely unknown. Here, it is shown that exogenous GABA modulates putative Ca2+-permeable channels on the plasma membranes of tobacco pollen grains and pollen tubes. Whole-cell voltage-clamp experiments and non-invasive micromeasurement technology (NMT) revealed that the influx of Ca2+ increases in pollen tubes in response to exogenous GABA. It is also demonstrated that glutamate decarboxylase (GAD), the rate-limiting enzyme of GABA biosynthesis, is involved in feedback controls of Ca2+-permeable channels to fluctuate intracellular GABA levels and thus modulate pollen tube growth. The findings suggest that GAD activity linked with Ca2+-permeable channels relays an extracellular GABA signal and integrates multiple signal pathways to modulate tobacco pollen tube growth. Thus, the data explain how GABA mediates the communication between the style and the growing pollen tubes. PMID:24799560

Spatial distribution of pollen grains and spores in surface sediments of Guanabara Bay, Rio de Janeiro, Brazil

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Cintia F. Barreto

2012-09-01

Full Text Available Aiming to investigate the deposition of pollen grains and spores in Guanabara Bay, Rio de Janeiro State, 61 surface sediment samples were analyzed. The results showed that the current deposition of palynomorphs in surface sediments of Guanabara Bay represents the regional vegetation of this hydrographic basin. The differential distribution of palynomorphs followed a pattern influenced by bathymetry, tidal currents speed, discharge of numerous rivers, and by human activity. The dominance of representatives of Field Vegetation reflects the changes of the original flora caused by intense human activities in the region. The continued presence and richness of pollen types of rain forest in the samples indicates that their source area might be the vegetation from riparian border of rivers in the western sector of the Bay, where the mangrove vegetation is being preserved. The large amount of damaged palynomorphs may be related to abrasion that occurs during river transport, indicating removal or reworking from their areas of origin.Com objetivo de investigar a deposição dos grãos de pólen e esporos na Baía de Guanabara, Estado do Rio de Janeiro, 61 amostras de sedimentos superficiais foram analisadas. Os resultados mostraram que a deposição atual dos palinomorfos nos sedimentos superficiais da Baía de Guanabara representa a vegetação regional de sua bacia hidrográfica. A distribuição diferencial dos palinomorfos seguiu um padrão influenciado pela batimetria, velocidade das corretes de marés, descarga dos numerosos rios e pela atividade humana. A dominância dos taxa representantes da Vegetação Campestre reflete as mudanças da flora original causadas por intensas atividades humanas na região. A presença contínua e a grande riqueza de tipos polínicos da Floresta Ombrófila nas amostras, indica que a área fonte pode ser a vegetação das bordas dos rios do setor oeste da Baía, onde a vegetação de mangue está sendo preservada. A

Aerobiological study of pollen and mold in Seoul, Korea

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Jae-Won Oh

1998-01-01

Full Text Available In a large number of allergic individuals, inhalant allergens are important causative and triggering agents in respiratory allergies. It is essential to survey the pollen and mold around the patient’s environment for the diagnosis and treatment of airborne allergy. Rotorod samplers were installed at well-ventilated places in seven collecting stations in Seoul, the capital of Korea, which has a population of 12 million. Airborne particles carrying allergens were collected daily from each station for 2 years (1 October 1995 to 30 September 1997. After being stained with Calberla’s fuchsin, they were identified, counted and recorded. The weather in Seoul was also recorded. Pollen was found from the middle of February through to the end of December. The peak date for pollen was 12 May (peak mean daily count: 701 grains/m3/day and for mold it was 23 June (peak mean daily count: 936 spores/m3/day. Alder, birch, pine, oak, maple, elm, juniper, willow, and gingko trees were prevalent during the tree season, lasting from the middle of February to late July. Then sagebrush, ragweed, Japanese hop, and pigweed followed during the weed season, which lasts from the middle of July to the end of December. In skin prick test results, house dust mite was the most common positive allergen in Seoul, followed by cockroach. Among the pollens, mugwort was the most common positive, followed by ragweed mix, alder, birch, and grasses mix. Among the molds, there were high counts of Cladosporium and Alternaria during the year, excluding January. Ascospore of Lepto-spheria was highest during the monsoon season.

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

DEFF Research Database (Denmark)

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

2005-01-01

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

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

International Nuclear Information System (INIS)

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

1984-01-01

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

Pollen reference collection digitization

NARCIS (Netherlands)

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

2016-01-01

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

Allergenic weed pollen forecast under the mathematical modeling method implementation in ukraine.

Science.gov (United States)

Motruk, Irina I; Antomonov, Michael Yu; Rodinkova, Victoria V; Aleksandrova, Olena E; Yermishev, Oleh V

2018-01-01

Introduction: Allergies are the most common reason of the chronic diseases in developed countries and represent an important medical, social and economic issue, the relevance of which is growing both in these countries and in Ukraine. The most famous of these allergens group is the pollen of ambrosia and pollen of poaceae, which are ubiquitously distributed in the subtropical and temperate climate. The aim: The objective of our study was to develop the mathematical models, which will be able to indicate the probability of the pollen circulation, and thus these models can simplify the forecast of symptoms risk and improve the prophylaxis of pollinosis. Materials and methods: The research was conducted on the basis of the research center of National Pirogov Memorial Medical University, Vinnytsia in the years 2012-2014. A volumetric sampler of the Hirst type was used for the air sampling. The observation was conducted from the first of April to the thirty-first of October. For the initial preparation of the tables and intermediate calculations, Excel software package was used. The software STATISTICA 10.0 was applied to calculate the average coefficients values and their statistical characteristics (beta-values, errors of the mean values, Student's t-test, veracity and the factors percentage contribution into the function variation). Results: Statistically significant correlation between pollen concentrations of herbaceous plants and individual meteorological factors was found; classificational functions were designed by which it is possible to calculate the probability of presence or absence of Artemisia pollen in the atmosphere; the risks of increasing of the Artemisia pollen concentration are determined under exceeding of the critical temperature of 18°С, relative humidity of 67% and atmospheric pressure of 980 Pa. Conclusions. The results of the research can be used to predict the emission of potentially hazardous concentrations of weed pollen grains in the

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

Science.gov (United States)

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

2013-01-01

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

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

Directory of Open Access Journals (Sweden)

Garance Di Pasquale

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

The effect of geographical and climatic properties on grass pollen and Phl p 5 allergen release

Science.gov (United States)

Alan, Şenol; Şahin, Aydan Acar; Sarışahin, Tuğba; Şahin, Serap; Kaplan, Ayşe; Pınar, Nur Münevver

2018-04-01

The Poaceae family, including grasses, comprises several cosmopolitan and allergenic species. The aim of this study was to determine the correlations between Poaceae pollen and Phl p 5 allergen concentrations in two cities with different geographical and climatic properties in Turkey. Pollen were collected from Burkard traps in Ankara and Zonguldak. Phl p 5 sampling was carried out between March and October in both 2015 and 2016 using a BGI900 Cascade High Volume Air Sampler (900 L/min.). The concentrations of Phl p 5 were measured by the enzyme-linked immunosorbent assay (ELISA) technique. The annual sum of Poaceae pollen (pollen index) during 2015-2016 was 5454 in Ankara and 4142 in Zonguldak. The total Phl p 5 concentration was 1309 pg/m3 in Zonguldak, whereas it was 8181 pg/m3 in Ankara over 2 years. About 90% of the allergen was found in the fraction with particulate matter (PM) > 10 μm in both cities. It was found that the main meteorological parameter which affected pollen and Phl p 5 was temperature in both stations. Rainfall was also found to be important for Zonguldak, due to its climatic and geographic properties. Lastly, we suggest that the primary wind direction, which is from the south of Zonguldak, could have a `drift effect' for allergens because of the airborne pollen concentrations and the dates on which the allergen is released into the atmosphere. The wind direction may be an important factor in the distribution of allergen and pollen grains in stations, especially those with a hilly topography.

Coconut (Cocos nucifera l.) pollen cryopreservation.

Science.gov (United States)

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

2014-01-01

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

Anther and pollen development in some species of Poaceae (Poales

Directory of Open Access Journals (Sweden)

AT. Nakamura

Full Text Available Anther and pollen development were studied in Olyra humilis Nees, Sucrea monophylla Soderstr, (Bambusoideae, Axonopus aureus P. Beauv., Paspalum polyphyllum Nees ex Trin. (Panicoideae, Eragrostis solida Nees, and Chloris elata Desv. (Chloridoideae. The objective of this study was to characterise, embryologically, these species of subfamilies which are considered basal, intermediate and derivate, respectively. The species are similar to each other and to other Poaceae. They present the following characters: tetrasporangiate anthers; monocotyledonous-type anther wall development, endothecium showing annular thickenings, secretory tapetum; successive microsporogenesis; isobilateral tetrads; spheroidal, tricellular, monoporate pollen grains with annulus and operculum. Nevertheless, the exine patterns of the species studied are distinct. Olyra humilis and Sucrea monophylla (Bambusoideae show a granulose pattern, whereas in the other species, it is insular. In addition, Axonopus aureus and Paspalum polyphyllum (Panicoideae have a compactly insular spinule pattern, while Chloris elata and Eragrostis solida (Chloridoideae show a sparsely insular spinule pattern. The exine ornamentation may be considered an important feature at the infrafamiliar level.

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

Science.gov (United States)

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

2015-06-01

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

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

Science.gov (United States)

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

2014-09-01

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

Storage of strawberry pollen

Directory of Open Access Journals (Sweden)

Rafet Aslantaş

2013-12-01

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

Pollen spectrum of the honey of uruçu bee (Melipona scutellaris Latreille, 1811 (Hymenoptera: Apidae in the North Coast of Bahia State

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Larissa Silva Souza

2015-10-01

Full Text Available Regional-level studies of floral resources used by social bees for honey production can contribute to the improvement of management strategies for bee pastures and colonies, by identifying the most visited flowers and thus characterizing the various geographical origins of honey. The objective of this study was to investigate, through pollen analysis, the types of pollen and nectar sources used by the uruçu bee (Melipona scutellaris L. in the North Coast of Bahia. Honey samples were taken monthly from five colonies in an apiary from August 2010 to July 2011. Pollen analysis of honey was performed by using the acetolysis method, followed by qualitative and quantitative analysis of pollen grains. Fifty pollen types belonging to 40 genera and 17 families were identified. The results indicate predominance of pollen types belonging to the families Fabaceae and Myrtaceae, which suggests that the bees preferred foraging from trees and shrubs. These plants should be included in regional reforestation projects in order to improve management of this bee species and honey production.

Short-term effects of airborne pollens on asthma attacks as seen by general practitioners in the Greater Paris area, 2003-2007.

Science.gov (United States)

Huynh, Bich Tram; Tual, Séverine; Turbelin, Clément; Pelat, Camille; Cecchi, Lorenzo; D'Amato, Gennaro; Blanchon, Thierry; Annesi-Maesano, Isabella

2010-09-01

To investigate for the first time the short-term effects of airborne pollen counts on general practitioner (GP) consultations for asthma attacks in the Greater Paris area between 2003-2007. Counts were available for common pollens (Betula, Cupressa, Fraxinus and Poaceae). Weekly data on GP visits for asthma attacks were obtained from the French GP Sentinel Network. A quasi-Poisson regression with generalised additive models was implemented. Short-term effects of pollen counts were assessed using single and multi-pollen models after adjustment for air pollution and influenza. A mean weekly incidence rate of 25.4 cases of asthma attacks per 100,000 inhabitants was estimated during the study period. The strongest significant association between asthma attacks and pollen counts was registered for grass (Poaceae) in the same week of asthma attacks, with a slight reduction of the effect observed in the multi-pollen model. Adjusted relative risk for Poaceae was 1.54 (95% CI: 1.33-1.79) with an inter-quartile range increase of 17.6 grains/m3 during the pollen season. For the first time, a significant short-term association was observed between Poaceae pollen counts and consultations for asthma attacks as seen by GPs. These findings need to be confirmed by more consistent time-series and investigations on a daily basis.

Isolation of two independent allyl alcohol resistant Adh-1 null mutants following selection of pollen and seeds.

NARCIS (Netherlands)

Wisman, E.; Ramanna, M.S.; Zabel, P.

1993-01-01

The Adh-1 null mutant (B15-1-8) isolated previously was used to establish conditions that allow the selection of ADH-deficient pollen grains and seeds of tomato. New Adh-1 null mutants were then selected among the progenies derived from crosses between the genetically unstable tomato lines Yvms,

Paleoenvironment interpretation of a 1760 years B.P. old sediment in a mangrove area of the Bay of Guanabara, using pollen analysis

OpenAIRE

Barth, Ortrud M.; São-Thiago, Luiz E.U.; Barros, Marcia A.

2006-01-01

A sediment sample was obtained at 122 cm from the top of a drilling core in the Guapimirim mangrove, Bay of Guanabara, and analyzed using pollen analysis. This muddy core reached a sandy ground at 133 cm. 14C datation got the age of 1760 ± 50 years B.P. The most frequent pollen grains were mangrove species of Rhizophora mangle, Laguncularia racemosa and Avicennia schaueriana. "Restinga" and tropical rain forest vegetation was recognized behind the mangrove. After the last sea transgression at...

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

International Nuclear Information System (INIS)

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

2015-01-01

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

Aging in a long-lived clonal tree.

Directory of Open Access Journals (Sweden)

Dilara Ally

2010-08-01

Full Text Available From bacteria to multicellular animals, most organisms exhibit declines in survivorship or reproductive performance with increasing age ("senescence". Evidence for senescence in clonal plants, however, is scant. During asexual growth, we expect that somatic mutations, which negatively impact sexual fitness, should accumulate and contribute to senescence, especially among long-lived clonal plants. We tested whether older clones of Populus tremuloides (trembling aspen from natural stands in British Columbia exhibited significantly reduced reproductive performance. Coupling molecular-based estimates of clone age with male fertility data, we observed a significant decline in the average number of viable pollen grains per catkin per ramet with increasing clone age in trembling aspen. We found that mutations reduced relative male fertility in clonal aspen populations by about 5.8 x 10(-5 to 1.6 x 10(-3 per year, leading to an 8% reduction in the number of viable pollen grains, on average, among the clones studied. The probability that an aspen lineage ultimately goes extinct rises as its male sexual fitness declines, suggesting that even long-lived clonal organisms are vulnerable to senescence.

Floral sources to Tetragonisca angustula (Hymenoptera: Apidae and their pollen morphology in a Southeastern Brazilian Atlantic Forest

Directory of Open Access Journals (Sweden)

Juliana Almeida Braga

2012-12-01

Full Text Available The stingless bees are important flowers visitors of several plant species, due to their feeding habits and foraging behavior, constituting an important group to maintain biodiversity and the dynamics of tropical communities. Among stingless bees, Tetragonisca angustula is widely distributed in tropical habitats, and has been considered an important pollinator of different plant families. To support a rational economic use of this group, there is a need to characterize the plant species that represent important sources as part of their diet, as preferred, alternative or casual food sources. The aim of this survey was to distinguish the plant species that T. angustula visited most often. The study was undertaken in four regions of the Atlantic Rainforest in Rio de Janeiro state (Brazil over a year from March 2008 to February 2009. For this, we collected bees, flowering plants and bee pollen loads from the four sites, and evaluated pollen morphology in the laboratory. Field observations showed the presence of plants belonging to ten different families and pollen loads showed the presence of pollen types belonging to 26 plant families. There were strong differences between pollen types, especially regarding pollen grain shape. The present survey suggests a high value of these plant species as trophic resources for the T. angustula in the understory of Atlantic Rainforest. Changes in these fragments of this forest may compromise the availability of resources for Tetragonisca angustula species and other stingless bees.

Aerobiology and pollen allergy in Islamabad

Energy Technology Data Exchange (ETDEWEB)

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

2009-10-15

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

Aerobiology and pollen allergy in Islamabad

International Nuclear Information System (INIS)

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

2009-01-01

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

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.

De novo post-pollen mitosis II tobacco pollen tube transcriptome

Czech Academy of Sciences Publication Activity Database

Hafidh, Said; Breznenová, Katarína; Honys, David

2012-01-01

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

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

International Nuclear Information System (INIS)

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

2015-01-01

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

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

Science.gov (United States)

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

2011-10-01

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

Dual Function of Novel Pollen Coat (Surface) Proteins: IgE-binding Capacity and Proteolytic Activity Disrupting the Airway Epithelial Barrier

Science.gov (United States)

Bashir, Mohamed Elfatih H.; Ward, Jason M.; Cummings, Matthew; Karrar, Eltayeb E.; Root, Michael; Mohamed, Abu Bekr A.; Naclerio, Robert M.; Preuss, Daphne

2013-01-01

Background The pollen coat is the first structure of the pollen to encounter the mucosal immune system upon inhalation. Prior characterizations of pollen allergens have focused on water-soluble, cytoplasmic proteins, but have overlooked much of the extracellular pollen coat. Due to washing with organic solvents when prepared, these pollen coat proteins are typically absent from commercial standardized allergenic extracts (i.e., “de-fatted”), and, as a result, their involvement in allergy has not been explored. Methodology/Principal Findings Using a unique approach to search for pollen allergenic proteins residing in the pollen coat, we employed transmission electron microscopy (TEM) to assess the impact of organic solvents on the structural integrity of the pollen coat. TEM results indicated that de-fatting of Cynodon dactylon (Bermuda grass) pollen (BGP) by use of organic solvents altered the structural integrity of the pollen coat. The novel IgE-binding proteins of the BGP coat include a cysteine protease (CP) and endoxylanase (EXY). The full-length cDNA that encodes the novel IgE-reactive CP was cloned from floral RNA. The EXY and CP were purified to homogeneity and tested for IgE reactivity. The CP from the BGP coat increased the permeability of human airway epithelial cells, caused a clear concentration-dependent detachment of cells, and damaged their barrier integrity. Conclusions/Significance Using an immunoproteomics approach, novel allergenic proteins of the BGP coat were identified. These proteins represent a class of novel dual-function proteins residing on the coat of the pollen grain that have IgE-binding capacity and proteolytic activity, which disrupts the integrity of the airway epithelial barrier. The identification of pollen coat allergens might explain the IgE-negative response to available skin-prick-testing proteins in patients who have positive symptoms. Further study of the role of these pollen coat proteins in allergic responses is

Dual function of novel pollen coat (surface proteins: IgE-binding capacity and proteolytic activity disrupting the airway epithelial barrier.

Directory of Open Access Journals (Sweden)

Mohamed Elfatih H Bashir

Full Text Available BACKGROUND: The pollen coat is the first structure of the pollen to encounter the mucosal immune system upon inhalation. Prior characterizations of pollen allergens have focused on water-soluble, cytoplasmic proteins, but have overlooked much of the extracellular pollen coat. Due to washing with organic solvents when prepared, these pollen coat proteins are typically absent from commercial standardized allergenic extracts (i.e., "de-fatted", and, as a result, their involvement in allergy has not been explored. METHODOLOGY/PRINCIPAL FINDINGS: Using a unique approach to search for pollen allergenic proteins residing in the pollen coat, we employed transmission electron microscopy (TEM to assess the impact of organic solvents on the structural integrity of the pollen coat. TEM results indicated that de-fatting of Cynodon dactylon (Bermuda grass pollen (BGP by use of organic solvents altered the structural integrity of the pollen coat. The novel IgE-binding proteins of the BGP coat include a cysteine protease (CP and endoxylanase (EXY. The full-length cDNA that encodes the novel IgE-reactive CP was cloned from floral RNA. The EXY and CP were purified to homogeneity and tested for IgE reactivity. The CP from the BGP coat increased the permeability of human airway epithelial cells, caused a clear concentration-dependent detachment of cells, and damaged their barrier integrity. CONCLUSIONS/SIGNIFICANCE: Using an immunoproteomics approach, novel allergenic proteins of the BGP coat were identified. These proteins represent a class of novel dual-function proteins residing on the coat of the pollen grain that have IgE-binding capacity and proteolytic activity, which disrupts the integrity of the airway epithelial barrier. The identification of pollen coat allergens might explain the IgE-negative response to available skin-prick-testing proteins in patients who have positive symptoms. Further study of the role of these pollen coat proteins in allergic

Pollen morphology of the genus Eremanthus Less. (Vernonieae, Asteraceae Morfologia polínica de espécies do gênero Eremanthus Less. (Vernonieae, Asteraceae

Directory of Open Access Journals (Sweden)

BenoÎt Loeuille

2012-03-01

Full Text Available In order to evaluate the significance of the pollen morphology for generic and infrageneric taxonomy of the genus Eremanthus (Vernonieae, Asteraceae, and to provide additional data for its phylogenetic reconstruction, the pollen of 20 of the 23 species of the genus was examined using light and scanning electron microscopy. Acetolysed pollen grains were measured, described, and illustrated using light microscopy, while non-acetolysed pollen grains were analyzed using scanning electron microscopy. Pollen grains of these species are isopolar, oblate-spheroidal in most of the species, more rarely prolate spheroidal or suboblate, subtriangular amb, tricolporate and subechinolophate. The variation among quantitative characters does not correlate with the macromorphological subdivision of the genus or with the generic or specific limits.Com a finalidade de avaliar a importância da morfologia polínica para a taxonomia de Eremanthus (Vernonieae, Asteraceae em nível genérico e infragenérico e fornecer dados adicionais para a sua reconstrução filogenética, os grãos de pólen de 20 das 23 espécies do gênero foram examinados usando a microscopia de luz e eletrônica de varredura. Os grãos de pólen foram acetolisados, medidos, descritos e ilustrados sob microscópio de luz. Para a análise em microscópio eletrônico de varredura foram utilizados grãos de pólen com e/ou sem tratamento químico. As espécies apresentaram grãos de pólen isopolares, oblato-esferoidais, na maioria dos táxons, mais raramente prolato-esferoidais ou suboblatos, âmbito subtriangular, tricolporados e subechinolofados. A variação entre os caracteres quantitativos não se correlacionam com a subdivisão macromorfológica do gênero nem com os limites genéricos ou específicos.

Development of a regional-scale pollen emission and transport modeling framework for investigating the impact of climate change on allergic airway disease

Science.gov (United States)

Zhang, R.; Duhl, T.; Salam, M. T.; House, J. M.; Flagan, R. C.; Avol, E. L.; Gilliland, F. D.; Guenther, A.; Chung, S. H.; Lamb, B. K.; VanReken, T. M.

2014-03-01

Exposure to bioaerosol allergens such as pollen can cause exacerbations of allergenic airway disease (AAD) in sensitive populations, and thus cause serious public health problems. Assessing these health impacts by linking the airborne pollen levels, concentrations of respirable allergenic material, and human allergenic response under current and future climate conditions is a key step toward developing preventive and adaptive actions. To that end, a regional-scale pollen emission and transport modeling framework was developed that treats allergenic pollens as non-reactive tracers within the coupled Weather Research and Forecasting Community Multiscale Air Quality (WRF/CMAQ) modeling system. The Simulator of the Timing and Magnitude of Pollen Season (STaMPS) model was used to generate a daily pollen pool that can then be emitted into the atmosphere by wind. The STaMPS is driven by species-specific meteorological (temperature and/or precipitation) threshold conditions and is designed to be flexible with respect to its representation of vegetation species and plant functional types (PFTs). The hourly pollen emission flux was parameterized by considering the pollen pool, friction velocity, and wind threshold values. The dry deposition velocity of each species of pollen was estimated based on pollen grain size and density. An evaluation of the pollen modeling framework was conducted for southern California (USA) for the period from March to June 2010. This period coincided with observations by the University of Southern California's Children's Health Study (CHS), which included O3, PM2.5, and pollen count, as well as measurements of exhaled nitric oxide in study participants. Two nesting domains with horizontal resolutions of 12 and 4 km were constructed, and six representative allergenic pollen genera were included: birch tree, walnut tree, mulberry tree, olive tree, oak tree, and brome grasses. Under the current parameterization scheme, the modeling framework tends to

From Allergens to Battery Anodes: Nature-Inspired, Pollen Derived Carbon Architectures for Room- and Elevated- Temperature Li-ion Storage

Science.gov (United States)

Tang, Jialiang; Pol, Vilas G.

2016-02-01

The conversion of allergic pollen grains into carbon microstructures was carried out through a facile, one-step, solid-state pyrolysis process in an inert atmosphere. The as-prepared carbonaceous particles were further air activated at 300 °C and then evaluated as lithium ion battery anodes at room (25 °C) and elevated (50 °C) temperatures. The distinct morphologies of bee pollens and cattail pollens are resembled on the final architecture of produced carbons. Scanning Electron Microscopy images shows that activated bee pollen carbon (ABP) is comprised of spiky, brain-like, and tiny spheres; while activated cattail pollen carbon (ACP) resembles deflated spheres. Structural analysis through X-ray diffraction and Raman spectroscopy confirmed their amorphous nature. X-ray photoelectron spectroscopy analysis of ABP and ACP confirmed that both samples contain high levels of oxygen and small amount of nitrogen contents. At C/10 rate, ACP electrode delivered high specific lithium storage reversible capacities (590 mAh/g at 50 °C and 382 mAh/g at 25 °C) and also exhibited excellent high rate capabilities. Through electrochemical impedance spectroscopy studies, improved performance of ACP is attributed to its lower charge transfer resistance than ABP. Current studies demonstrate that morphologically distinct renewable pollens could produce carbon architectures for anode applications in energy storage devices.

Native Bee Diversity and Pollen Foraging Specificity in Cultivated Highbush Blueberry (Ericaceae: Vaccinium corymbosum) in Rhode Island.

Science.gov (United States)

Scott, Zachary; Ginsberg, Howard S; Alm, Steven R

2016-12-01

We identified 41 species of native bees from a total of 1,083 specimens collected at cultivated highbush blueberry plantings throughout Rhode Island in 2014 and 2015. Andrena spp., Bombus spp., and Xylocopa virginica (L.) were collected most often. Bombus griseocollis (DeGeer), B. impatiens Cresson, B. bimaculatus Cresson, B. perplexus Cresson, and Andrena vicina Smith collected the largest mean numbers of blueberry pollen tetrads. The largest mean percent blueberry pollen loads were carried by the miner bees Andrena bradleyi Viereck (91%), A. carolina Viereck (90%), and Colletes validus Cresson (87%). The largest mean total pollen grain loads were carried by B. griseocollis (549,844), B. impatiens (389,558), X. virginica (233,500), and B. bimaculatus (193,132). Xylocopa virginica was the fourth and fifth most commonly collected bee species in 2014 and 2015, respectively. They exhibit nectar robbing and females carried relatively low blueberry pollen loads (mean 33%). Overall, we found 10 species of bees to be the primary pollinators of blueberries in Rhode Island. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

Long Distance Pollen Transport to the Arctic: a Useful Proxy to Calibrate Atmospheric Circulation?

Science.gov (United States)

Rousseau, D.; Schevin, P.; Duzer, D.; Jolly, D.; Cambon, G.

2004-12-01

Tracing modern atmosphere dynamics is important to constrain models used for past climate reconstruction. The main types of tracers of arctic air masses are chemical and show different patterns. Dust in the ice at the summit of the Greenland ice cap has been shown, through isotope analyses, to have originated from Chinese deserts, mostly the Takla Makan and Gobi. Conversely, the chemical composition of the aerosols reaching the summit of the ice cap associated with backward air masses trajectories points to source areas in North America, Europe and Asia. A total of four pollen traps have been displayed on both western and eastern coasts of Greenland during the last four years in order to assess long distance transport in the Arctic domain and to identify potential vegetation source areas associated with air mass pathways. We are demonstrating the long distance transport of pollen originating from North America, Great Lakes area to southern Greenland at least during two consecutives years, 2002 and 2003. Thus a regular pattern of air masses responsible for the transport of pollen grains from North America to Greenland should be constant, as already described for anthropogenic pollutants. Another pollen trap was installed on the sea ice during the ice-sea drift expedition from North Pole of French explorer Dr. Jean-Louis Etienne in 2002. In that case we demonstrate two long distance transport to the North Pole from two different Eurasian regions during 2002: western Europe and eastern Siberia. Until now the use of pollen as an air mass tracer had not yet been investigated. Here we show that first evidence pollen represents a biological alternative to understand both present and past air mass dynamics in the Arctic and its associated relationship with biosphere changes.

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

Directory of Open Access Journals (Sweden)

Yuka Nagata

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

Preparation and characterisation of biodegradable pollen-chitosan microcapsules and its application in heavy metal removal.

Science.gov (United States)

Sargın, İdris; Kaya, Murat; Arslan, Gulsin; Baran, Talat; Ceter, Talip

2015-02-01

Biosorbents have been widely used in heavy metal removal. New resources should be exploited to develop more efficient biosorbents. This study reports the preparation of three novel chitosan microcapsules from pollens of three common, wind-pollinated plants (Acer negundo, Cupressus sempervirens and Populus nigra). The microcapsules were characterized (Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy and elemental analysis) and used in removal of heavy metal ions: Cd(II), Cr(III), Cu(II), Ni(II) and Zn(II). Their sorption capacities were compared to those of cross-linked chitosan beads without pollen grains. C. sempervirens-chitosan microcapsules exhibited better performance (Cd(II): 65.98; Cu(II): 67.10 and Zn(II): 49.55 mg g(-1)) than the other microcapsules and the cross-linked beads. A. negundo-chitosan microcapsules were more efficient in Cr(III) (70.40 mg g(-1)) removal. P. nigra-chitosan microcapsules were found to be less efficient. Chitosan-pollen microcapsules (except P. nigra-chitosan microcapsules) can be used in heavy metal removal. Copyright © 2014 Elsevier Ltd. All rights reserved.

Allergenic pollen pollinosis in Madrid.

Science.gov (United States)

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

1995-07-01

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

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

Science.gov (United States)

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

2016-04-01

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

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

Science.gov (United States)

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

2016-01-01

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

MICROBIAL QUALITY OF HONEY MIXTURE WITH POLLEN

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Ján Mareček

2011-02-01

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

The phenological phases of flowering and pollen seasons of spring flowering tree taxa against a background of meteorological conditions in Kraków, Poland

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Danuta Stępalska

2016-06-01

Full Text Available The aim of the study was to compare phenological observations of pollen seasons of selected early spring trees. Special attention was paid to meteorological conditions which favored or did not favor tree flowering and pollen release. For this reason, we used phenological observation, pollen counts, and meteorological data in five sites in the center of Kraków in the period 2009–2011. Phenological phases (5 of four tree species: Alnus glutinosa, Alnus incana, Corylus avellana, and Betula pendula, were analyzed. It was found that in case of A. glutinosa the pollen season often preceded the flowering period, while for A. incana those two phenomena were more correlated. As regards Corylus avellana, the beginning of the pollen season and phenological phases was simultaneous. However, pollen grains occurred in the air longer, even by a dozen or so days. The phenological phases and pollen seasons of Alnus and Corylus were dependent on meteorological conditions. To give the definition of the relationship between pollen concentration and weather conditions, Spearman rank correlation analysis was applied. High Alnus and Corylus pollen concentrations were found on sunny days with a maximum temperature over 10°C and no precipitation, and when the snow cover was gone. In case of Betula, the phenological phases of the full pollination period usually coincided with the periods of high pollen concentrations. However, Betula pollen sometimes appears earlier and stays in the air longer than the flowering period of local trees in the nearest vicinity. This situation indicates long-distance transport or secondary deposition.

Hybridizing pines with diluted pollen

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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...

Parasitized honey bees are less likely to forage and carry less pollen.

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Lach, Lori; Kratz, Madlen; Baer, Boris

2015-09-01

Research into loss of pollination capacity has focused primarily on documenting pollinator declines and their causes with comparatively little attention paid to how stressors may affect pollinating behavior of surviving pollinators. The European honey bee, Apis mellifera is one of the world's most important generalist pollinators, and Nosema apis is a widespread microsporidian gut parasite of adult A. mellifera. We individually fed 960 newly eclosed A. mellifera workers either a sucrose solution or 400 N. apis spores in a sucrose solution and tagged them with a unique radio frequency identification (RFID) tag to monitor their foraging behavior. We found spore-fed bees were less likely to forage than those fed sugar only. Those that did forage started foraging when they were older and stopped foraging when they were younger than bees fed sugar only. However, inoculated and non-inoculated bees did not significantly differ in the number of foraging trips taken per day, the total hours foraged over their lifetime, or homing ability. Inoculated returning foragers were 4.3 times less likely to be carrying available pollen than non-inoculated returning foragers and the number of pollen grains carried was negatively correlated with the number of N. apis spores. In an arena of artificial flowers, inoculated bees had a tendency (p=0.061) to choose sugar flowers over pollen flowers, compared to non-inoculated bees which visited pollen and sugar flowers equally. These results demonstrate that even a relatively low dose of a widespread disease of A. mellifera may adversely affect bees' ability to pollinate. Copyright © 2015 Elsevier Inc. All rights reserved.

Accuracy and Consistency of Grass Pollen Identification by Human Analysts Using Electron Micrographs of Surface Ornamentation

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Luke Mander

2014-08-01

Full Text Available Premise of the study: Humans frequently identify pollen grains at a taxonomic rank above species. Grass pollen is a classic case of this situation, which has led to the development of computational methods for identifying grass pollen species. This paper aims to provide context for these computational methods by quantifying the accuracy and consistency of human identification. Methods: We measured the ability of nine human analysts to identify 12 species of grass pollen using scanning electron microscopy images. These are the same images that were used in computational identifications. We have measured the coverage, accuracy, and consistency of each analyst, and investigated their ability to recognize duplicate images. Results: Coverage ranged from 87.5% to 100%. Mean identification accuracy ranged from 46.67% to 87.5%. The identification consistency of each analyst ranged from 32.5% to 87.5%, and each of the nine analysts produced considerably different identification schemes. The proportion of duplicate image pairs that were missed ranged from 6.25% to 58.33%. Discussion: The identification errors made by each analyst, which result in a decline in accuracy and consistency, are likely related to psychological factors such as the limited capacity of human memory, fatigue and boredom, recency effects, and positivity bias.

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

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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.

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

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

2015-01-01

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

Human Invariant Natural Killer T Cells Respond to Antigen-Presenting Cells Exposed to Lipids from Olea europaea Pollen.

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Abos Gracia, Beatriz; López Relaño, Juan; Revilla, Ana; Castro, Lourdes; Villalba, Mayte; Martín Adrados, Beatriz; Regueiro, Jose Ramon; Fernández-Malavé, Edgar; Martínez Naves, Eduardo; Gómez Del Moral, Manuel

2017-01-01

Allergic sensitization might be influenced by the lipids present in allergens, which can be recognized by natural killer T (NKT) cells on antigen-presenting cells (APCs). The aim of this study was to analyze the effect of olive pollen lipids in human APCs, including monocytes as well as monocyte-derived macrophages (Mϕ) and dendritic cells (DCs). Lipids were extracted from olive (Olea europaea) pollen grains. Invariant (i)NKT cells, monocytes, Mϕ, and DCs were obtained from buffy coats of healthy blood donors, and their cell phenotype was determined by flow cytometry. iNKT cytotoxicity was measured using a lactate dehydrogenase assay. Gene expression of CD1A and CD1D was performed by RT-PCR, and the production of IL-6, IL-10, IL-12, and TNF-α cytokines by monocytes, Mϕ, and DCs was measured by ELISA. Our results showed that monocytes and monocyte-derived Mϕ treated with olive pollen lipids strongly activate iNKT cells. We observed several phenotypic modifications in the APCs upon exposure to pollen-derived lipids. Both Mϕ and monocytes treated with olive pollen lipids showed an increase in CD1D gene expression, whereas upregulation of cell surface CD1d protein occurred only in Mϕ. Furthermore, DCs differentiated in the presence of human serum enhance their surface CD1d expression when exposed to olive pollen lipids. Finally, olive pollen lipids were able to stimulate the production of IL-6 but downregulated the production of lipopolysaccharide- induced IL-10 by Mϕ. Olive pollen lipids alter the phenotype of monocytes, Mϕ, and DCs, resulting in the activation of NKT cells, which have the potential to influence allergic immune responses. © 2017 S. Karger AG, Basel.

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

International Nuclear Information System (INIS)

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

1979-01-01

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

Pollen tube growth test (PTGT) in environmental biomonitoring and predictive radiation biology studies: problem and prospect

International Nuclear Information System (INIS)

Pandey, Devi D.

2012-01-01

In Environmental and Human Bio monitoring studies of Hazardous xenobiotics over living system particularly at cell level, it is desirable to have easy and sensitive test system like Cell Viability assay, MNT, Cell Culture photo toxicity Test, PTGT etc. Out of these the PTGT quite better than other because the in vitro culture of pollen grain can provides a sensitive indication of toxicity at cellular level, since germination and growth of pollen tube will inhibited in presence of toxic substance like DDT, Heavy metal, even Radionuclide's. This test system is easy, economical and widely accepted through out world. In PTGT pollen tube never containing Chloroplast or other plastids so pollen tube resembles animals more than a plant organ and is therefore also a suitable as model for Genotoxicity Assessment of compounds harmful to animal and humans. Lack of plastids in PT, PTGT will not identify the toxic effect of compounds that targets Non cyclic and cyclic photoposphorylation of photosynthesis. This test system valid in International Toxicity Testing Protocol. But this method is time consuming and problem in measurement of pollen tube growing in a culture medium became usually bent and make measurement difficult. Other disadvantage of this method is requirement of DMSO to dissolve test substance of low water suitability in culture medium. DMSO shown to have no effect on PTG at Concentration not more than 1% but some extent interfere with results. Values of PTG are quantified in ED50/IC50 that is the concentration of test compounds that reduces pollen tube growth to 50% of control. So PTGT could be very sensitive and easy to assess in common lab in International way. (author)

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

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Liu, Chao; Yin, Yan

2016-01-25

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

Stigma-pollen recognition: a new look

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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.

Pollen calendar of the city of Salamanca (Spain). Aeropalynological analysis for 1981-1982 and 1991-1992.

Science.gov (United States)

Hernández Prieto, M; Lorente Toledano, F; Romo Cortina, A; Dávila González, I; Laffond Yges, E; Calvo Bullón, A

1998-01-01

We report a study on the contents of airborne pollen in the city of Salamanca (Spain) aimed at establishing a pollen calendar for the city for the yearly periods of maximum concentrations, relating these with quantifiable atmospheric variables over two two-year periods with an interval of 10 years between them: 1981-82 and 1991-92. The pollen was captured with Burkard spore-traps, based on Hirst's volumetric method. Determinations were made daily and were used to make preparations, previously stained with basic fuscin, for study under light microscopy at x 1,000 magnification. 946 preparations were analyzed, corresponding to the same number of days distributed over 150 weeks of the periods studied. The results afforded the identification of 48 different types of pollen grain: Grasses (Poaceae), Olea europea (olive), Quercus rotundifolia (Holm-oak), other Quercus spp. (Q. pyrenaica, Q. suber, Q. faginea, etc.), Cupressaceae (Cupressus sempervivens, C. arizonica, Juniperus communis etc.), Plantago (Plantago lanceolata, Plantago media, etc.), Pinaceae (Pinus communis, Abies alba, etc.), Rumex sp. (osier), Urtica dioica (nettle), Parietaria (Parietaria officinalis, P. judaica), Chenopodio-Amaranthaceae (Chenopodium sp., Amaranthus sp., Salsola kali, etc.), Artemisia vulgaris (Artemisia), other Compositae (Taraxacum officinalis, Hellianthus sp. etc.), Castanea sativa (Chestnut), Ligustrum sp. (privet), Betula sp. (birch), Alnus sp. (common alder), Fraxinus sp (ash), Populus sp. (poplar), Salix sp. (willow), Ulmus sp. (elm), Platanus sp. (plantain, plane), Carex sp. (sweet flag), Erica sp. (common heather), Leguminosae or Fabaceae:--Papillionaceae (Medicago sp.; Cercis sp., Robina sp.)--Cesalpinoideae Acacia sp. (Acacia),--Mimosoideae: Sophora japonica, Umbelliferae (Foeniculum sp., Cirsium sp., etc.), Centaurea sp., Cistus sp. (rock rose), Typha sp (bulrush), Mirtaceae (Myrtus communis), Juglans regia (Walnut), Galium verum, Filipendula sp. (spirea/drop wort), Rosaceae

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

Science.gov (United States)

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

2014-01-01

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

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

Science.gov (United States)

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

2011-02-01

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

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.

Sensitization to cereals and peanut evidenced by skin prick test and specific IgE in food-tolerant, grass pollen allergic patients

DEFF Research Database (Denmark)

Martens, Maria; Schnoor, Heidi J; Malling, Hans-Jørgen

2011-01-01

The botanical relation between grass and cereal grains may be relevant when diagnosing food allergy to cereals. The aim was to investigate the diagnostic specificity of skin prick test (SPT) and specific immunoglobulin E (sIgE) tests to cereals and peanut in grass pollen allergic subjects without...

Paleoenvironment interpretation of a 1760 years B.P. old sediment in a mangrove area of the Bay of Guanabara, using pollen analysis

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Barth Ortrud M.

2006-01-01

Full Text Available A sediment sample was obtained at 122 cm from the top of a drilling core in the Guapimirim mangrove, Bay of Guanabara, and analyzed using pollen analysis. This muddy core reached a sandy ground at 133 cm. 14C datation got the age of 1760 ? 50 years B.P. The most frequent pollen grains were mangrove species of Rhizophora mangle, Laguncularia racemosa and Avicennia schaueriana. "Restinga" and tropical rain forest vegetation was recognized behind the mangrove. After the last sea transgression at 2500 years B.P., the water level lowered to its actual size, allowing the installation of this mangrove.

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

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Ruiz-Valenzuela, Luis; Aguilera, Fátima

2018-05-01

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

Late Quaternary landscape evolution of northeastern Amazonia from pollen and diatom records

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DARCILÉA F. CASTRO

2013-03-01

Full Text Available The main goal of this study was to reconstruct the Late Pleistocene-Holocene floristic composition in an area of the northern Brazilian Amazonia, comparing the results with other Amazonian localities in order to discuss the factors that have influenced phytophysiognomic changes over this time period. The work in eastern Marajó Island at the mouth of the Amazonas River was approached based on analysis of 98 pollen and diatom samples from core data distributed along a proximal to distal transect of a paleoestuarine system. The results indicated high concentration of Rhizophora, associated with arboreal pollen grains typical of the modern Amazonian rainforest during the last 40,000 cal yrs BP. Pollen composition also included wetland herbs. Diatoms were dominated by marine and fresh water taxa. Wetland forest, mangrove and, subordinately herbs remained constant during most of the latest Pleistocene-early/middle Holocene. At 5,000 cal yrs BP, there was a distinguished change from forest and mangrove to wet grassland savanna due to sea level fluctuation. As marine influence decreased, the estuary gave rise to fresh water lacustrine and swamp environments, with establishment of herbaceous campos. A main conclusion from this study is that solely the occurrence of herbaceous savanna can not be used as a definitive indicator of past dry climates in Amazonian areas.

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

Science.gov (United States)

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

2016-05-01

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

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

Directory of Open Access Journals (Sweden)

Sabine Konzmann

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

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

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F.M. Chambers

2011-09-01

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

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

DEFF Research Database (Denmark)

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

2013-01-01

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

Radiation-induced pollen germination, tube growth, its localized cytochemical constituents, fruit set and fruit size in alkaloid yielding species Solanum torvum L

International Nuclear Information System (INIS)

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

1990-01-01

The volume of pollen, total number of pollen/flower, the percent of pollen germination and tube growth of long-styled flower were higher than the short-styled flowers in S. torvum. In addition, the pollination studies were conducted among the four selected sets for optimum fruit set investigation. Fruit set was not seen in both the first and second sets (female shorts-short male and female short-long male). However, the maximum fruit set was obtained in the fourth set (female long-male long). Pollen grains of long-styled flowers irradiated with 1-800 krad were germinated in the basal medium. The percent of pollen germination and the tube growth was stimulated over the control with 1 and 50 krad dose exposures, but increasing dose rates inhibited both the above processes. Utilization of insoluble polysaccharides, and the synthesis of RNA and protein were enhanced over the control with the effect of 50 krad. The higher (800 krad) dose exposures inhibited all the above cytochemical constituents. Various dose-treated pollens were used to pollinate the stigma surface of the long-styled flowers. The fruit set, fruit volume, fresh and dry weight of fruits, and the number of seed set/fruit, were enhanced over the control by 1 and 50 krad, while the higher doses caused inhibitory effect. Interestingly, the fruit set was not caused by radiation doses 400 krad and above. (author)

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....

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

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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.

Monitoring, modelling and forecasting of the pollen season

DEFF Research Database (Denmark)

Scheifinger, Helfried; Belmonte, Jordina; Buters, Jeroen

2013-01-01

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

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

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Lukáš Hleba

2013-10-01

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

Spatiotemporal Variation in the Environmental Controls of C4-Grass Origin and Ecology: Insights from Grass-Pollen δ13C Data

Science.gov (United States)

Nelson, D. M.; Urban, M.; Hu, F.

2014-12-01

Understanding the environmental factors controlling the origin and shifting abundance of C4 grasses in Earth's history is useful for projecting the response of C4-grass dominated grasslands to future environmental change. Unfortunately, grass pollen is typically morphologically indistinct, making palynological analysis a blunt tool for studying C4-grasses in the paleorecord. δ13C of individual grass-pollen grains using a spooling wire microcombustion device interfaced with an isotope ratio mass spectrometer (Single Pollen Isotope Ratio AnaLysis, SPIRAL) overcomes this challenge and the potential biases of δ13C data from other substrates (e.g. leaf waxes). To assess the presence and relative abundance of C3- and C4-grass pollen in samples of unknown composition, we developed a hierarchical Bayesian model, trained with ~1,900 δ13C values from pollen grains of 31 grass species. Surface-sediment data from Africa, Australia, and North America demonstrate the reliability of this technique for quantifying C4-grass abundance on the landscape. To investigate the timing and control of the origin of C4-grasses we analyzed samples from the Oligocene-Miocene from Europe and from the Eocene from North America. Results indicate that C4 grasses appeared on the landscape of southwest Europe no later than the early Oligocene, implying that low atmospheric pCO2 may not have been the main driver and/or precondition for the development of C4 photosynthesis in the grass family. In contrast, we found no evidence for C4 grasses in the southeast United States before pCO2 fell. In application of SPIRAL to the late Quaternary, we found that shifts in pCO2 and moisture balance exerted key controls on the relative abundance of C3 and C4 grasses in Africa and Australia. Overall, our results imply that as in the past, future changes in the C3/C4 composition of grass-dominated ecosystems will likely exhibit striking spatiotemporal variability as a result of differing combinations of

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

NARCIS (Netherlands)

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

2003-01-01

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

Seasonal variation in diurnal atmospheric grass pollen concentration profiles

DEFF Research Database (Denmark)

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

2014-01-01

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

Behavior on flowers, structures associated to pollen transport and nesting biology of Perditomorpha brunerii and Cephalurgus anomalus (Hymenoptera: Colletidae, Andrenidae

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Maria Cristina Gaglianone

2000-03-01

Full Text Available Nesting and foraging behavior were studied in Cephalurgus anomalus and Perditomorpha brunerii, two oligolectic bee species on Malvaceae flowers, in the University of São Paulo campus, Ribeirão Preto, Brazil. Bees were monitored on flowers of Sida, Malvastrum, Gaya and Wissadula. Perditomorpha brunerii females collect pollen with the forelegs and abdomen to transport it in short-branched hairs on the hind tibia and metasomal sterna; males patrol flowers and spend the night in closed flowers of Sida cerradoensis and Sida sp. C. anomalus females lean the dorsal region of the body against the petals and collect pollen with the forelegs, accumulating the grains on the mesepisterna before placing them into sparse unbranched hairs on the anterior outer side of the hind tibiae; males patrol and wait for females in flowers, where the copulate throughout the foraging season. Both species nest in the soil among the host plants. P. brunerii bees build solitary nests; whereas in C. anomalus one or more foraging females are associated with an individual nest. The nests, in both species, consist of a descent straight main tunnel and cells arranged singly and horizontally at the end of the branches, which are filled with soil. The efficient foraging behavior, location of the nests among the host plants and scopal setae that allow the transport of large pollen grains in large amounts indicate an intimate association between these two bee species and Malvaceae flowers.

The revised edition of korean calendar for allergenic pollens.

Science.gov (United States)

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

2012-01-01

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

Pollen and Seed Morphology of Rhinacanthus Nees and Hypoestes Sol. ex R. Br. (Acanthaceae) of Yemen

International Nuclear Information System (INIS)

Al-Hakimi, A.S.; Maideen, H.; Latiff, A.; Al-Hakimi, A.S.

2015-01-01

Pollens and seeds of Hypoestes and Rhinacanthus collected from different field localities in Taiz and Soqotra Island, Yemen were investigated by using light and scanning electron microscopes. Pollen grains of Hypoestes were prolate in equatorial view, lobate trigonal to lobate circular in polar view whereas those of Rhinacanthus were sub spheroidal and rounded trigonal in polar view. The aperture was tricolporate and exine ornamentation was coarsely reticulate for all species in the two genera. Scanning electron microscopy and morphological observations showed that mature dry seeds of Hypoestes and Rhinacanthus have various sizes and shapes, the surface ornamentations observed were reticulate to cristate, an addition to the tuberculum and papillae. The three Hypoestes species differ in the seed structure which are useful for identification and their high structural diversity provides an important taxonomic value for species differentiation. (author)

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

Science.gov (United States)

Özdemir, Seςil Kepil; Özgüςlü, Selcan

2017-09-17

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

Two-peaked dose curves for irradiated pollen growth

International Nuclear Information System (INIS)

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

1992-01-01

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

The water kefir grain inoculum determines the characteristics of the resulting water kefir fermentation process.

Science.gov (United States)

Laureys, D; De Vuyst, L

2017-03-01

To investigate the influence of the water kefir grain inoculum on the characteristics of the water kefir fermentation process. Three water kefir fermentation processes were started with different water kefir grain inocula and followed as a function of time regarding microbial species diversity, community dynamics, substrate consumption profile and metabolite production course. The inoculum determined the water kefir grain growth, the viable counts on the grains, the time until total carbohydrate exhaustion, the final metabolite concentrations and the microbial species diversity. There were always 2-10 lactic acid bacterial cells for every yeast cell and the majority of these micro-organisms was always present on the grains. Lactobacillus paracasei, Lactobacillus hilgardii, Lactobacillus nagelii and Saccharomyces cerevisiae were always present and may be the key micro-organisms during water kefir fermentation. Low water kefir grain growth was associated with small grains with high viable counts of micro-organisms, fast fermentation and low pH values, and was not caused by the absence of exopolysaccharide-producing lactic acid bacteria. The water kefir grain inoculum influences the microbial species diversity and characteristics of the fermentation process. A select group of key micro-organisms was always present during fermentation. This study allows a rational selection of a water kefir grain inoculum. © 2016 The Society for Applied Microbiology.

Stable carbon isotope analyses of nanogram quantities of particulate organic carbon (pollen) with laser ablation nano combustion gas chromatography/isotope ratio mass spectrometry

Science.gov (United States)

Sluijs, Appy; Laks, Jelmer J.; Reichart, Gert‐Jan

2016-01-01

Rationale Analyses of stable carbon isotope ratios (δ 13C values) of organic and inorganic matter remains have been instrumental for much of our understanding of present and past environmental and biological processes. Until recently, the analytical window of such analyses has been limited to samples containing at least several μg of carbon. Methods Here we present a setup combining laser ablation, nano combustion gas chromatography and isotope ratio mass spectrometry (LA/nC/GC/IRMS). A deep UV (193 nm) laser is used for optimal fragmentation of organic matter with minimum fractionation effects and an exceptionally small ablation chamber and combustion oven are used to reduce the minimum sample mass requirement compared with previous studies. Results Analyses of the international IAEA CH‐7 polyethylene standard show optimal accuracy, and precision better than 0.5‰, when measuring at least 42 ng C. Application to untreated modern Eucalyptus globulus (C3 plant) and Zea mays (C4 plant) pollen grains shows a ~ 16‰ offset between these species. Within each single Z. mays pollen grain, replicate analyses show almost identical δ 13C values. Conclusions Isotopic offsets between individual pollen grains exceed analytical uncertainties, therefore probably reflecting interspecimen variability of ~0.5–0.9‰. These promising results set the stage for investigating both δ 13C values and natural carbon isotopic variability between single specimens of a single population of all kinds of organic particles yielding tens of nanograms of carbon. © 2016 The Authors. Rapid Communications in Mass Spectrometry Published by John Wiley & Sons Ltd. PMID:27766694

Effect of gamma-radiation on grapevine pollen

International Nuclear Information System (INIS)

Bozhinova-Boneva, I.

1974-01-01

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

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

Science.gov (United States)

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

2011-08-01

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

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.

Hourly pattern of allergenic alder and birch pollen concentrations in the air: Spatial differentiation and the effect of meteorological conditions

Science.gov (United States)

Borycka, K.; Kasprzyk, I.

2018-06-01

In temperate climate widespread alder and birch are an important source of strong aeroallergens. The diurnal pattern of airborne pollen concentrations depends on the rhythm of pollen release from anthers as well as weather conditions, convection air currents, long-distance transport, pollen trap location and local vegetation. The aim of the study was to present a diurnal pattern of Alnus (alder) and Betula (birch) pollen concentrations in the air in a horizontal and vertical gradient and examine the weather parameters that had the greatest impact on the pattern. The study was conducted in Rzeszów City, southeast Poland over three years. Pollen grains were collected using a Hirst volumetric spore trap at three sampling points: two at 12 m the agl, and one at 1.5 m agl. Data were analysed using circular statistics and a nonlinear function. For alder, three models of hourly patterns were elaborated and the most common presented early morning minimum and early afternoon maximum. For birch, the most common model has one peak at night and a marked decrease in concentrations in early morning, although a second model has peak during early afternoon. A model with 3 peaks is much less common. These models are characteristic for warm temperate climate regions, where alders and birches are common. The diurnal patterns did not depend on the localization of traps or proximity of the pollen source, although these factors influenced the hourly concentrations, with higher values observed at roof level. Significant relationships between the hourly pollen counts and meteorological parameters were observed only for alder. Three incidents of increasing birch pollen concentrations were observed during the first two hours of precipitation and linked to a convection effect. Unstable weather conditions caused by air convection might strongly modify the circadian pattern and cause the nightly peaks concentrations. The general results are that people suffering from allergies may be exposed

Phytoindication of the ecogenotoxic impact caused by traffic emissions through pollen abortivity in the road liner communications

International Nuclear Information System (INIS)

Matova, D.; Micieta, K.

2015-01-01

This contribution refers to evaluation of ecogenotoxicity which is caused by traffic emissions at places in the vicinity. For detection of the genotoxic stress was used test of pollen grain abortivity assay with higher wild plant species. Higher plants are suitable as bioindicators of environmental pollution. From our research we could say, that the amount of pollutants from the traffic has increasing character and that accumulation of xenobiotics in plants actually exists. (authors)

Pollen as indicator of radionuclide pollution

International Nuclear Information System (INIS)

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

1977-01-01

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

Late Glacial-Holocene Pollen-Based Vegetation History from Pass Lake, Prince of Wales Island, Southeastern Alaska

Science.gov (United States)

Ager, Thomas A.; Rosenbaum, Joseph G.

2009-01-01

A radiocarbon-dated history of vegetation development since late Wisconsin deglaciation has been reconstructed from pollen evidence preserved in a sediment core from Pass Lake on Prince of Wales Island, southeastern Alaska. The shallow lake is in the south-central part of the island and occupies a low pass that was filled by glacial ice of local origin during the late Wisconsin glaciation. The oldest pollen assemblages indicate that pine woodland (Pinus contorta) had developed in the area by ~13,715 cal yr B.P. An abrupt decline in the pine population, coinciding with expansion of alder (Alnus) and ferns (mostly Polypodiaceae) began ~12,875 yr B.P., and may have been a response to colder, drier climates during the Younger Dryas climatic interval. Mountain hemlock (Tsuga mertensiana) began to colonize central Prince of Wales Island by ~11,920 yr B.P. and was soon followed by Sitka spruce (Picea sitchensis). Pollen of western hemlock (Tsuga heterophylla) began to appear in Pass Lake sediments soon after 11,200 yr B.P. The abundance of western hemlock pollen in the Pass Lake core during most of the Holocene appears to be the result of wind transport from trees growing at lower altitudes on the island. The late Holocene pollen record from Pass Lake is incomplete because of one or more unconformities, but the available record suggests that a vegetation change occurred during the late Holocene. Increases in pollen percentages of pine, cedar (probably yellow cedar, Chamaecyparis nootkatensis), and heaths (Ericales) suggest an expansion of muskeg vegetation occurred in the area during the late Holocene. This vegetation change may be related to the onset of cooler, wetter climates that began as early as ~3,774 yr B.P. in the region. This vegetation history provides the first radiocarbon-dated Late Glacial-Holocene terrestrial paleoecological framework for Prince of Wales Island. An analysis of magnetic properties of core sediments from Pass Lake suggests that unconformities

ECONOMY AND ENVIRONMENT OF THE GREEK COLONIAL SYSTEM IN SOUTHERN ITALY: POLLEN AND NPPS EVIDENCE OF GRAZING FROM THE RURAL SITE OF FATTORIA FABRIZIO (VI-IV CENT. BC; METAPONTO, BASILICATA

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A. Florenzano

2013-03-01

Full Text Available This paper reports a study case showing integrated analyses of microscopic records from an archaeological site of southern Italy. Pollen and non pollen palynomorphs-NPPs were found in archaeological layers and were basic in reconstructing both the past environment and the economic activities of the site. The site, Fattoria Fabrizio, is a modest 4th-cenury BC farmhouse of the chora (rural territory of the Greek city (polis of Metaponto (Basilicata. Pollen analyses in addition to the study of NPPs have been particularly worthwhile for palaeoenvironmental and palaeoeconomical reconstructions of this site and others in the chora. The pollen spectra delineate an open plant landscape, with scanty woodlands and presence of local wet environments. Olea pollen is fairly well represented in all samples, suggesting that this tree was an important element of the agricultural economy of the chora. Shrubby grasslands and a well-developed maquis characterized the territory, probably as result of grazing activities by sheep and goats. Accordingly, the high percentages of Poaceae and Cichorieae pollen, together with coprophilous fungal spores (such as Sordaria type and Sporormiella type, suggest that pastoral activities were widely practiced. The low number of Cerealia pollen grains suggests that the inhabitants’ fields covered small areas or were quite far from the farmhouse.  

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

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

2016-02-01

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

Diâmetro dos grãos de pólen e tamanho dos estômatos em acessos diplóides e tetraplóides de Hemarthria altissima (Poiret Stapf & Hubbard (Gramineae Pollen grain diameter and stomatal size in diploid and tetraploid accessions of Hemarthria altissima (Poiret Stapf & Hubbard (Gramineae

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Solange Bosio Tedesco

1999-06-01

Full Text Available Sete acessos da gramínea forrageira Hemarthria altissima, diplóides e tetraplóides africanos e tetraplóides brasileiros, foram analisados com fins de caracterizar, nos diferentes níveis de ploidia, os parâmetros diâmetro dos grãos de pólen e tamanho dos estômatos, com o objetivo de utilizar esses critérios para inferência de níveis de ploidia nessa espécie. As medidas foram feitas com o auxílio de um microscópio com ocular micrométrica. Os resultados demostraram que o diâmetro dos grãos de pólen podem ser utilizados para caracterizar diferentes níveis de ploidia, enquanto que o tamanho dos estômatos não é um critério seguro nessa espécie.Seven accessions of african diploid and tetraploid and brazilian tetraploid plants of Hemarthria altissima were studied to distinguish, in each ploidy level, the characters of pollen grain diameter and stomatal size. Measurements were performed with ocular micrometer microscope. Results demonstrated that pollen grain diameter can be used to characterize different ploidy levels, but the stomatal size is not a reliable criterion in this species.

Fraxinus pollen as a source of environmental pollution

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María Fernández-González

2016-06-01

Full Text Available In Southern Europe there are but a few studies focused on the allergenic impact of ash (Fraxinus pollen as a result of its scarce distribution. In the city of Ourense this type of pollen represents 2% of the total atmospheric pollen recorded. The goal of this study is to determine the atmospheric concentrations of Fraxinus pollen and its allergen in Ourense’s atmosphere in 2015, and to assess their relationship with the main meteorological variables. The aim is to assess whether the pollen counts match the actual exposure conditions for allergen-sensitive patients. A Lanzoni VPPS-2000 volumetric sampler was used for pollen sampling, whereas a Burkard Cyclone sampler was used for allergen detection.The flowering period of Fraxinus was long, having a duration of 76 days between the third week of January and the rst week of April as consequence of the asynchronous flowering of the different species growing in the study area. The presence of the ash allergen in the atmosphere can be detected using the main olive tree allergen, Ole e 1. Our study indicates that the combination of pollen counts and allergen quanti cation should be contemplated to estimate the real exposure of sensitive people. In the case of Fraxinus pollen, there may be allergy risk periods before and after the occurrence of the highest pollen concentrations in the atmosphere as a result of special rain and humidity conditions during its flowering period.

Quality of durable cookies enriched with rape bee pollen

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Miriam Solgajová

2014-03-01

Full Text Available The objective of this study was to enrich durable cookies with different additions of rape (Brassica napus var. napus bee pollen to increase nutritional properties of cookie samples and to improve technological and sensorial properties as well. Bee pollen is an important raw material due to its nutritional and functional properties. Cookie samples were prepared by substituting wheat flour with rape bee pollen in the amount of 16 % (1 g of bee pollen per cookie and 32 % (2 g of bee pollen per cookie using bee pollen from two localities Lenártovce and Nové Zámky. In baked samples beside sensory properties also chemical parameters and technological parameters of cookies were evaluated. It was found out that with the gradual addition of rape bee pollen the amount of ash content increased and the highest ash content was analysed in variants II and IV (0.71 and 0.77 % using 32 % addition of rape bee pollen. In terms of reducing sugars, addition of bee pollen caused that the content of reducing sugars in the products increased slightly. The highest reducing sugar content was determined in variant II. (24.59 %. On the other hand amount of crude protein the most considerably raised by addition of 2 g of pollen per cookie. The highest content of crude protein was analysed in variants II and IV (8.72 and 9.00 %. From the results of a linear models in which the dependent variables were the ash, crude protein and moisture it was determined the significant effect (p <0.05 only of the pollen addition. In the case of the model with the dependent variable reducing sugars it was found out significant effect (p<0.0001 of pollen addition and locality and their interactions. With the gradual addition of bee pollen values of technological parameters such as diameter and weight of cookies increased and thickness of products decreased. Based on sensory scores using a 9-point Hedonic scale the best sensorial acceptability (7.4 was found in variant I (1 g of bee

Molecular cloning and immunochemical characterization of a novel major Japanese cedar pollen allergen belonging to the aspartic protease family.

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Ibrahim, Ahmed Ragaa Nour; Kawamoto, Seiji; Aki, Tsunehiro; Shimada, Yayoi; Rikimaru, Satoshi; Onishi, Nobukazu; Babiker, Elfadil Elfadl; Oiso, Isao; Hashimoto, Kunihiko; Hayashi, Takaharu; Ono, Kazuhisa

2010-01-01

Japanese cedar (Cryptomeria japonica) pollen is a major cause of seasonal pollinosis in Japan. Protease activity in the pollen grains may trigger pro-allergic responses but no such proteases have yet been identified as pollen allergens. We report the molecular cloning and immunochemical characterization of a novel C. japonica pollen allergen belonging to the aspartic protease family. We focused on the C. japonica pollen allergen spot No. 63 (CPA63, 47.5% IgE binding frequency) on our 2-dimensional IgE immunoblot map. The internal amino acid sequences were determined using time-of-flight mass spectrometry. Full-length cpa63 cDNA was cloned by rapid amplification of cDNA ends (RACE)-PCR. Recombinant CPA63 (r-CPA63) was expressed using the baculovirus-insect cell culture system and its IgE binding capacity was analyzed by enzyme-linked immunosorbent assay (ELISA). The proteolytic activity of r-CPA63 was also assessed using a putative mature enzyme produced upon autolysis. cpa63 cDNA encoded a 472 amino acid polypeptide showing about 40% sequence identity to members of the plant atypical aspartic protease family. ELISA showed that r-CPA63 was recognized by IgE antibodies in the serum of 58% (18/31) of Japanese cedar pollinosis patients. We also demonstrated an aspartic protease-like enzyme activity of the putative mature r-CPA63. We have identified the first plant aspartic protease allergen from Japanese cedar pollen. The availability of the CPA63 sequence and its recombinant allergen production system are useful not only for pharmaceutical applications but also for further examination of the role of protease activity in the pathogenesis of cedar pollinosis. 2010 S. Karger AG, Basel.

The formation of pollen in male flowers and yearly atmospheric pollen counts of Cryptomeria japonica in the following year

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Hideaki Taira

1998-01-01