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Sample records for viable pollen grains

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

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    Atlagić Jovanka

    2009-01-01

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

  2. Pollen Grains, Random Walks and Einstein

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 10; Issue 12. Pollen Grains, Random Walks and Einstein. Sriram Ramaswamy. Volume 10 Issue 12 December 2005 pp 106-124. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/010/12/0106-0124 ...

  3. Pollen Grains, Random Walks and Einstein

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 5; Issue 3. Pollen Grains, Random Walks and Einstein. Sriram Ramaswamy. General Article Volume 5 Issue 3 March 2000 pp 16-34. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/005/03/0016-0034 ...

  4. Analysis of airborne pollen grains in Kırklareli

    OpenAIRE

    ERKAN, Perihan; BIÇAKCI, Adem; Aybeke, Mehmet; Malyer, Hulusi

    2011-01-01

    A continuous aeropalynological survey of the atmosphere of Kırklareli was carried out from January 2002 to December 2003 by means of the gravimetric method using Durham apparatus. Weekly pollen grains in per cm2 were calculated. During these 2 years, a total of 11,758 pollen grains were recorded. Pollen fall in the years 2002-2003 comprised grains belonging 46 taxa. Of these taxa, 26 belonged to arboreal and 20 taxa non-arboreal plants. In 2002, 6011 pollen grains and, in 2003, 5747 pollen gr...

  5. Insights into a hydration regulating system in Cupressus pollen grains.

    Science.gov (United States)

    Danti, R; Della Rocca, G; Calamassi, R; Mori, B; Mariotti Lippi, M

    2011-08-01

    Hydration, rupture and exine opening due to the sudden and large expansion of intine are typical of taxoid-type pollen grains. A hemispheric outgrowth external to the exine was observed on Cupressus and Juniperus pollen grains before the intine swelling and exine release. However, the actual existence of this permanent or temporary structure and its precise role in pollen hydration is still being debated. The aim of this paper is to collect information on the actual presence of this peculiar outgrowth on the surface of the Cupressus pollen grain, its structure, composition and function. Pollen grains of several Cupressus species were observed using various techniques and methodologies, under light and fluorescence microscopy, phase-contrast microscopy, confocal microscopy, scanning electron microscopy, and an environmental scanning electron microscope. Observations were also performed on other species with taxoid-type pollen grains. A temporary structure located just above the pore was observed on Cupressus pollen grains, as well as on other taxoid-type pollens. It is hemispheric, layered, and consists of polysaccharides and proteins. The latter are confined to its inner part. Its presence seems to regulate the entrance of water into the grains at the beginning of pollen hydration. The presence of a temporary structure over the pore of taxoid-type pollen grains was confirmed and its structure was resolved using several stains and observation techniques. This structure plays a role in the first phases of pollen hydration.

  6. Viability of pollen grains of tetraploid banana

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    Taliane Leila Soares

    2016-01-01

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

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

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    Hélène Sénéchal

    2015-01-01

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

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

    Science.gov (United States)

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

    2015-01-01

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

  9. A statistical mixture model for estimating the proportion of unreduced pollen grains in perennial ryegrass (Lolium perenne L.) via the size of pollen grains

    NARCIS (Netherlands)

    Jansen, R.C.; Nijs, A.P.M. den

    1993-01-01

    The size of pollen grains is commonly used to indicate the ploidy level of pollen grains. In this paper observations of the diameter of pollen grains are evaluated from one diploid accession of perennial ryegrass (Lolium perenne L.), which was expected to produce diploid (unreduced) pollen grains in

  10. Analysis of airborne pollen grains in Bilecik, Turkey.

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    Türe, Cengiz; Böcük, Harun

    2009-04-01

    In this study, pollen grains in the atmosphere of Bilecik were studied for a continuous period of 2 years (2005 and 2006) by using Durham sampler. During this period, pollen grains belonging to 46 taxa were recorded, 26 of which belonged to arboreal plants and 20 to non-arboreal. Of total 14,269 pollen grains determined in Bilecik atmosphere, 6,675 were recorded in 2005 and 7,594 were in 2006. From these, 75.74% were arboreal, 21.80% were non-arboreal and 2.47% unidentifiable. Pinus sp., Poaceae, Cupressaceae, Platanus sp., Quercus sp., Salix sp., Ailanthus sp., Fagus sp., Urticaceae, Chenopodiaceae/Amaranthaceae were the main pollen producers in the atmosphere of Bilecik, respectively. Pollen concentrations reached their highest levels in May. Atmospheric pollen concentrations in February, March, September, October and November were less than those in other months.

  11. Pollen productivity and morphology of pollen grains in two cultivars of honeyberry (Lonicera kamtschatica (Sevast. Pojark.

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    Małgorzata Bożek

    2012-12-01

    Full Text Available In the years 2004-2006, investigations on the abundance of pollen production in two cultivars of Lonicera kamtschatica (Sevast. Pojark. - Atut and Duet, were conducted at the Felin Experimental Farm of the Agricultural University in Lublin. Moreover, the viability of pollen grains was estimated and measurements of their size were taken. Ten flowers of both studied cultivars supplied 11.42 mg of pollen and the average pollen productivity per 1 ha of a several-years-old plantation was 30.04 kg. The pollen of the observed plants was eagerly collected by honey bees. Pollen grains of both cultivars are suboblate. Considering their size, they can be described as large ones (P=47.55 µm, E=60.37 µm. Pollen viability for both cultivars is high, about 95%.

  12. Induction of viable 2n pollen in sterile Oriental × Trumpet Lilium hybrids

    NARCIS (Netherlands)

    Luo, J.R.; Arens, P.; Niu, L.X.; Tuyl, van J.M.

    2016-01-01

    In order to induce viable 2n pollen from highly sterile diploid Oriental × Trumpet (OT) (Lilium), N2O was used to treat flower buds of four sterile diploid OT cultivars (‘Nymph’, ‘Gluhwein’, ‘Yelloween’, and ‘Shocking’) at different stages of meiosis. There was no pollen germination in

  13. Concentrations of airborne pollen grains in Sivrihisar (Eskisehir), Turkey.

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    Erkara, Ismuhan Potoglu

    2008-03-01

    Pollen grains in the atmosphere of Sivrihisar were studied for a continuous period of 2 years (1 January 2005-31 December 2006) using a Durham sampler. During this period, pollen grains belonging to 41 taxa were recorded, 24 of which belonged to arboreal plants and 17 to non-arboreal. From these, 23,219 were identified in 2005 and 34,154 in 2006. Of the total pollen grains, 90.46% were arboreal, 9.43% non-arboreal, and 0.1% unidentifiable. The majority of the investigated allergic pollen grains were from Pinaceae, Cupressaceae, Fraxinus spp., Cedrus spp., Artemisia spp., Poaceae, Chenopodiaceae/Amaranthaceae, Populus spp., Quercus spp., Urticaceae and Asteraceae, respectively. Pollen concentrations reached their highest levels in May. This information was then established into a calendar form according to the pollens determined in 2005-2006, in terms of annual, monthly and weekly numbers of taxa fall per cm2. A comparison between the results and the meteorological factors revealed a close relationship between pollen concentrations in the air and meteorological conditions. An increase in pollination was also linked to increasing temperatures and the wind. It was therefore concluded that high temperatures and relative humidity were also effective in increasing the number of pollens in the air.

  14. Pollen Grain and Hybridization Studies in the Genus Capsicum

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    Tomi Lois OLATUNJI

    2016-03-01

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

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

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    Elżbieta Weryszko-Chmielewska

    2012-12-01

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

  16. Morphology and viability of castor bean genotypes pollen grains

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    Maria Selma Alves Silva Diamantino

    2016-01-01

    Full Text Available The objective of this work was to characterize the morphology and viability of the pollen of 15 genotypes of castor bean (Ricinus communis L. and to generate information that can assist in the selection of highly promising male parents for future use in genetic improvement programs aimed at producing seeds for oil extraction. Acetolysis and scanning electron microscopy was used to characterize the morphology of the pollen. The viability of the pollen grains was estimated by in vitro germination and colorimetric analysis (acetocarmine 2% and 2, 3, 5-triphenyltetrazolium chloride 1%. For the in vitro germination, pollen grains were grown in 10 types of solidified culture medium consisting of different concentrations of sucrose, boric acid, calcium nitrate, magnesium sulfate and potassium nitrate. The pollen grains had the following characteristics: medium size, isopolar and subspheroidal shape, radial symmetry, circular ambit, 3-colporate, elongated endoapertures, tectate exine and granulated sexine. The acetocarmine dye overestimated pollen viability. The media M5 and M8 were the most efficient at promoting the germination of pollen grains. The studied genotypes had high levels of viability and can therefore be used as male parents in genetic improvement programs.

  17. Pollen productivity and morphology of pollen grains in two cultivars of honeyberry (Lonicera kamtschatica (Sevast.) Pojark.)

    OpenAIRE

    Małgorzata Bożek

    2012-01-01

    In the years 2004-2006, investigations on the abundance of pollen production in two cultivars of Lonicera kamtschatica (Sevast.) Pojark. - Atut and Duet, were conducted at the Felin Experimental Farm of the Agricultural University in Lublin. Moreover, the viability of pollen grains was estimated and measurements of their size were taken. Ten flowers of both studied cultivars supplied 11.42 mg of pollen and the average pollen productivity per 1 ha of a several-years-old plantation was 30.04 kg...

  18. Size modification of recent pollen grains under different treatments

    NARCIS (Netherlands)

    Reitsma, Tj.

    1969-01-01

    The effect of various chemicals on the size of recent pollen grains of Corylus avellana L. and Quercus robur L. was studied. The size of acetolysed grains was affected by the treatment prior to acetolysis and moreover by the duration of acetolysis. Preparation methods, which produce comparable sizes

  19. Pollen Grain Preservation and Fertility in Valuable Commercial Rose Cultivars

    Science.gov (United States)

    Giovannini, Annalisa; Macovei, Anca; Caser, Matteo; Mansuino, Andrea; Ghione, Gian Guido; Savona, Marco; Carbonera, Daniela; Scariot, Valentina; Balestrazzi, Alma

    2017-01-01

    In the cut flower market, traditional breeding is still the best way to achieve new rose cultivars. The geographical delocalization of cultivar constitution (generally made in Europe and North America) and plant cultivation (large areas in Africa and South America) represents a limit point for crossing and selection. Rose breeders often need to overcome geographical distances, resulting in asynchrony in flowering among crossing parents, by storing and sending pollen. Hence, a key aspect in breeding programs is linked to pollen availability and conservation, jointly with the identification of parameters related to pollen fertility. In this study we present the results of three different trials. In the first, pollen diameter and pollen viability were chosen as fertility predictors of 10 Rosa hybrida commercial cultivars. In the second trial, aliquots of dried pollen grains of six R. hybrida cultivar were stored under two different temperatures (freezer at T = −20 °C and deep freezer at T = −80 °C) and after a wide range of conservation period, their viability was measured. In the third trial, the effective fertilization capacity of frozen pollen of 19 pollen donor cultivars was evaluated during 2015 crossing breeding plan, performing 44 hybridizations and correlating the number of seeds and the ratio seeds/crossing, obtained by each cultivar, with in vitro pollen germination ability. PMID:28441780

  20. Pollen Grain Preservation and Fertility in Valuable Commercial Rose Cultivars

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    Annalisa Giovannini

    2017-04-01

    Full Text Available In the cut flower market, traditional breeding is still the best way to achieve new rose cultivars. The geographical delocalization of cultivar constitution (generally made in Europe and North America and plant cultivation (large areas in Africa and South America represents a limit point for crossing and selection. Rose breeders often need to overcome geographical distances, resulting in asynchrony in flowering among crossing parents, by storing and sending pollen. Hence, a key aspect in breeding programs is linked to pollen availability and conservation, jointly with the identification of parameters related to pollen fertility. In this study we present the results of three different trials. In the first, pollen diameter and pollen viability were chosen as fertility predictors of 10 Rosa hybrida commercial cultivars. In the second trial, aliquots of dried pollen grains of six R. hybrida cultivar were stored under two different temperatures (freezer at T = −20 °C and deep freezer at T = −80 °C and after a wide range of conservation period, their viability was measured. In the third trial, the effective fertilization capacity of frozen pollen of 19 pollen donor cultivars was evaluated during 2015 crossing breeding plan, performing 44 hybridizations and correlating the number of seeds and the ratio seeds/crossing, obtained by each cultivar, with in vitro pollen germination ability.

  1. Pollen Grain Preservation and Fertility in Valuable Commercial Rose Cultivars.

    Science.gov (United States)

    Giovannini, Annalisa; Macovei, Anca; Caser, Matteo; Mansuino, Andrea; Ghione, Gian Guido; Savona, Marco; Carbonera, Daniela; Scariot, Valentina; Balestrazzi, Alma

    2017-04-24

    In the cut flower market, traditional breeding is still the best way to achieve new rose cultivars. The geographical delocalization of cultivar constitution (generally made in Europe and North America) and plant cultivation (large areas in Africa and South America) represents a limit point for crossing and selection. Rose breeders often need to overcome geographical distances, resulting in asynchrony in flowering among crossing parents, by storing and sending pollen. Hence, a key aspect in breeding programs is linked to pollen availability and conservation, jointly with the identification of parameters related to pollen fertility. In this study we present the results of three different trials. In the first, pollen diameter and pollen viability were chosen as fertility predictors of 10 Rosa hybrida commercial cultivars. In the second trial, aliquots of dried pollen grains of six R. hybrida cultivar were stored under two different temperatures (freezer at T = -20 °C and deep freezer at T = -80 °C) and after a wide range of conservation period, their viability was measured. In the third trial, the effective fertilization capacity of frozen pollen of 19 pollen donor cultivars was evaluated during 2015 crossing breeding plan, performing 44 hybridizations and correlating the number of seeds and the ratio seeds/crossing, obtained by each cultivar, with in vitro pollen germination ability.

  2. Detection and release of allergenic proteins in Parietaria judaica pollen grains.

    Science.gov (United States)

    Vega-Maray, A M; Fernández-González, D; Valencia-Barrera, R; Suárez-Cervera, M

    2006-08-01

    Rapid diffusion of allergenic proteins in isotonic media has been demonstrated for different pollen grains. Upon contact with stigmatic secretion or with the mucosa of sensitive individuals, pollen grains absorb water and release soluble low-molecular-weight proteins, these proteins enter in the secretory pathway in order to arrive at the cell surface. In this study we located allergenic proteins in mature and hydrated-activated pollen grains of Parietaria judaica L. (Urticaceae) and studied the diffusion of these proteins during the first 20 min of the hydration and activation processes. A combination of transmission electron microscopy and immunocytochemical methods was used to locate these proteins in mature pollen and in pollen grains after different periods of hydration and activation processes. Activated proteins reacting with antibodies in human serum from allergic patients were found in the cytoplasm, wall, and exudates from the pollen grains. The allergenic component of these pollen grains changes according to the pollen state; the presence of these proteins in the exine, the cytoplasm, and especially in the intine and in the material exuded from the pollen grains, is significant in the hydrated-activated studied times, whereas this presence is not significant in mature pollen grains. The rapid activation and release of allergenic proteins of P. judaica pollen appears to be the main cause of the allergenic activity of these pollen grains.

  3. Flow cytometric analysis of pollen grains collected from individual bees provides information about pollen load composition and foraging behaviour.

    Science.gov (United States)

    Kron, Paul; Kwok, Allison; Husband, Brian C

    2014-01-01

    Understanding the species composition of pollen on pollinators has applications in agriculture, conservation and evolutionary biology. Current identification methods, including morphological analysis, cannot always discriminate taxa at the species level. Recent advances in flow cytometry techniques for pollen grains allow rapid testing of large numbers of pollen grains for DNA content, potentially providing improved species resolution. A test was made as to whether pollen loads from single bees (honey-bees and bumble-bees) could be classified into types based on DNA content, and whether good estimates of proportions of different types could be made. An examination was also made of how readily DNA content can be used to identify specific pollen species. The method allowed DNA contents to be quickly found for between 250 and 9391 pollen grains (750-28 173 nuclei) from individual honey-bees and between 81 and 11 512 pollen grains (243-34 537 nuclei) for bumble-bees. It was possible to identify a minimum number of pollen species on each bee and to assign proportions of each pollen type (based on DNA content) present. The information provided by this technique is promising but is affected by the complexity of the pollination environment (i.e. number of flowering species present and extent of overlap in DNA content). Nevertheless, it provides a new tool for examining pollinator behaviour and between-species or cytotype pollen transfer, particularly when used in combination with other morphological, chemical or genetic techniques.

  4. DNA analysis for section identification of individual Pinus pollen grains from Belukha glacier, Altai Mountains, Russia

    Science.gov (United States)

    Nakazawa, Fumio; Uetake, Jun; Suyama, Yoshihisa; Kaneko, Ryo; Takeuchi, Nozomu; Fujita, Koji; Motoyama, Hideaki; Imura, Satoshi; Kanda, Hiroshi

    2013-03-01

    Pollen taxon in sediment samples can be identified by analyzing pollen morphology. Identification of related species based on pollen morphology is difficult and is limited primarily to genus or family. Because pollen grains of various ages are preserved at below 0 °C in glaciers and thus are more likely to remain intact or to suffer little DNA fragmentation, genetic information from such pollen grains should enable identification of plant taxa below the genus level. However, no published studies have attempted detailed identification using DNA sequences obtained from pollen found in glaciers. As a preliminary step, this study attempted to analyze the DNA of Pinus pollen grains extracted from surface snow collected from the Belukha glacier in the Altai Mountains of Russia in the summer of 2003. A 150-bp rpoB fragment from the chloroplast genome in each Pinus pollen grain was amplified by polymerase chain reaction, and DNA products were sequenced to identify them at the section level. A total of 105 pollen grains were used for the test, and sequences were obtained from eight grains. From the sequences obtained, the pollen grains were identified as belonging to the section Quinquefoliae. Trees of the extant species Pinus sibirica in the section Quinquefoliae are currently found surrounding the glacier. The consistency of results for this section suggests that the pollen in the glacier originated from the same Pinus trees as those found in the immediate surroundings.

  5. Pollen grain surface in Vaccinium myrtillus as seen in scanning electron microscopy

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    Józef Kocoń

    2014-01-01

    Full Text Available Pollen grain surface of Vaccinium myrtillus L. was analyzed by scanning electron microscopy. Pollen grains remain in tetrahedral tetrads. Grain surface is verrucose, consisting of thick, irregularly shaped muri, surrounding small, round or oval lumina. The surface of the muri is fissured, and minute papillae can also be noted.

  6. Mortality of pollen grains may result from errors of meiosis: study of pollen tetrads in Typha latifolia L.

    Science.gov (United States)

    Berdnikov, V A; Kosterin, O E; Bogdanova, V S

    2002-11-01

    In the cattail Typha latifolia the four haploid products of meiosis remain attached and form the flat tetrad of pollen grains. Gametophytic lethals arisen de novo in diploid cells of sporophyte must manifest themselves as pollen tetrads with two dead grains. This could allow to estimate the rate of recessive lethals arresting pollen grain development. We studied pollen samples collected from 44 sprouts in two populations in the vicinity of Novosibirsk. The anomalous tetrads T1, T2, T3, and T4 carrying one, two, three, and four dead grains, respectively, were detected in each sampled individual. The mean frequency of all anomalous tetrads in the two populations was 3.4% and 8.7%. The frequencies of tetrad classes varied widely among the individuals with correlation coefficient up to 0.94, but their ratios remained nearly constant. The majority of anomalous tetrads were presented by T1 and T2 classes (their sum comprising 72.7 and 74.0% in two populations), T1 being a little more abundant. The observed pattern of frequencies of tetrads with dead grains can be explained by errors of male meiosis such as chromosome non-disjunction in both meiotic divisions. The tetrads with two dead pollen grains may result mostly from non-disjunction in anaphase I, and those with one pollen grain from non-disjunction in anaphase II, thus making tetrad analysis ineffective for estimating the rate of gametophytic lethals.

  7. Pollen grain morphology of three species and a variety of Ocimum ...

    African Journals Online (AJOL)

    Pollen grains from fresh anthers of three species and a variety of Ocimum occurring in South-western Nigeria were collected and acetolysed. This was in an attempt to use the pollen charac-teristics to delimit, classify and trace probable evolutionary relationships among the taxa. The structural morphology of the pollen ...

  8. Micromorphology of pollen grains of three cultivars of Prunus armeniaca L.

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    Mirosława Chwil

    2014-04-01

    Full Text Available Pollen grains of various cultivars of Prunus armeniaca L. produce striated sculpture of the exine. These grains are included in the trizonocolporate class. In polar view, pollen grains have a triangular outline, while in equatorial view an elliptical outline. The exine of grains forms a pattern of striae characteristic for a given taxon. Flowers of various P. armeniaca cultivars produce pollen grains with the polar (P and equatorial (E length ranging 31-60 μm and 24-36 μm, respectively. The aim of this study was to determine the micromorphology of pollen grains of three P. armeniaca cultivars – ‘Harcot’, ‘Early Orange’ and ‘Wczesna z Morden’, using light and scanning electron microscopy. A comparative study of the morphological characteristics of pollen grains was carried out to determine their size, shape and exine ornamentation. Observations of pollen grains were performed under a light microscope (Nikon Eclipse 400 and a scanning electron microscope (SEM (Tescan Vega II LMU. In terms of their size, pollen grains of the studied P. armeniaca cultivars were classified as large. Their shape was determined to be prolatum. In equatorial view of pollen grains, the striae run along the polar axis. These structures in the exine are arranged parallel to each other, can be branched or arched. The width of striae ranges from 0.27 μm (‘Early Orange’ to 0.62 μm (‘Harcot’. The largest distances between the striae were found in pollen grains of ‘Harcot’ (0.33 μm, whereas much smaller distances were observed in ‘Early Orange’ and ‘Wczesna z Morden’ (0.13-0.14 μm. In pollen grains of P. armeniaca the tectum is perforated. In an area of 10 μm2, the tectum forms 4-9 perforations with a pore diameter of 0.1-0.6 μm.

  9. Lipid transfer proteins in Parietaria judaica L. pollen grains: immunocytochemical localization and function.

    Science.gov (United States)

    Vega-Maray, Ana M; Fernández-González, Delia; Valencia-Barrera, Rosa; Polo, Florentino; Seoane-Camba, Juan A; Sudrez-Cervera, Maria

    2004-09-01

    Parietariajudaica L. (Urticaceae) pollen is considered one of the most common causes of allergic respiratory symptoms in the Mediterranean area. The localization of lipid transfer proteins (LTPs) in P. judaica mature and hydrated-activated pollen grains was investigated applying a combination of transmission electron microscopy (TEM) with immunocytochemical methods. Our results show that the content of LTPs in P. judaica pollen grains changes during the process of hydration. The localization of judaica LTPs in the cytoplasm and in the lipid bodies associated with vacuoles demonstrated that LTPs represent primarily intracellular proteins. On the other hand, exposure of the pollen grains to germination medium induced the release of LTPs from the pollen grain. Thus, LTPs are cytoplasmic proteins that are secreted to become available for pollen-stigma interactions and probably induce the IgE antibody responses in allergic patients.

  10. In vitro Pollen Grain Germination and Tube Growth of Ten Iranian Jujube (Ziziphus jujuba Cultivars

    Directory of Open Access Journals (Sweden)

    Hossein ROUHAKHSH

    2014-06-01

    Full Text Available Jujube (Ziziphus jujuba is a species particularly prone to erratic fruit set. Several causes such as pollen germination and tube growth involve in this behaviour. Thus, the present research aimed to evaluate and compare of pollen grains germination and tube growth of ten Iranian jujube cultivars on in vitro condition. A factorial trial based on completely randomized design with five replications was carried out. The pollen grains were collected from un-opened-flowers of Al-Ghour’, ‘Bardaskan’, ‘Doroh’, ‘Gazik’, ‘Ghom’, ‘Giouk’, ‘Kangan’, ‘Kalkestan’, ‘Magham Sari’ and ‘Noghab’ cultivars at balloon stage. This study showed that there were significant differences among the cultivars in all measured factors. The highest percentage of pollen grains germination was observed for ‘Gazik’, followed by ‘Bardaskan’, while the lowest was in ‘Al-Ghour’. The percentage of pollen grains germination increased with the increasing time of incubation period up to 36 h. Also, flowering times are found to be effective in germination of pollen grains, which 1 flash had highest percentage of germination of pollen grains than in comparison to other flowering times. The results also showed that the mean time germination varied from 24.52-25.92 h, mean hourly germination from 0.67-1.55, hourly germination speed from 0.64-1.48 and coefficient of velocity of germination of pollen grains from 0.058-0.061. The length of pollen tube was found between 44.4 and 624.8 µm. These data demonstrated that cultivar is the main factor determining pollen grains germination and tube growth in jujube, which this important information can be useful for selection of superior desirable jujube genotypes for bringing to commercial cultivation.

  11. Hygroscopic weight gain of pollen grains from Juniperus species.

    Science.gov (United States)

    Bunderson, Landon D; Levetin, Estelle

    2015-05-01

    Juniperus pollen is highly allergenic and is produced in large quantities across Texas, Oklahoma, and New Mexico. The pollen negatively affects human populations adjacent to the trees, and since it can be transported hundreds of kilometers by the wind, it also affects people who are far from the source. Predicting and tracking long-distance transport of pollen is difficult and complex. One parameter that has been understudied is the hygroscopic weight gain of pollen. It is believed that juniper pollen gains weight as humidity increases which could affect settling rate of pollen and thus affect pollen transport. This study was undertaken to examine how changes in relative humidity affect pollen weight, diameter, and settling rate. Juniperus ashei, Juniperus monosperma, and Juniperus pinchotii pollen were applied to greased microscope slides and placed in incubation chambers under a range of temperature and humidity levels. Pollen on slides were weighed using an analytical balance at 2- and 6-h intervals. The size of the pollen was also measured in order to calculate settling rate using Stokes' Law. All pollen types gained weight as humidity increased. The greatest settling rate increase was exhibited by J. pinchotii which increased by 24 %.

  12. Correlation between pollen aperture pattern and callose deposition in late tetrad stage in three species producing atypical pollen grains.

    Science.gov (United States)

    Albert, Béatrice; Ressayre, Adrienne; Nadot, Sophie

    2011-02-01

    Pollen grains of flowering plants display a fascinating diversity of forms, in spite of their minute size. The observed diversity is determined by the developmental mechanisms implicated in the establishment of pollen morphological features. Pollen grains are generally surrounded by an extremely resistant wall interrupted in places by apertures that play a key role in reproduction, being the places at which pollen tube growth is initiated. Aperture shape, number, and position are determined during microsporogenesis (male meiosis), the earliest step in pollen ontogeny. We investigate in detail the unfolding of microsporogenesis in three species that present uncommon aperture pattern (i.e., disulculate in Calycanthus floridus [Calycanthaceae, magnoliids], tetraporate in Hohenbergia stellata [Bromeliaceae, monocots], and monoporate in Typha latifolia [Typhaceae, monocots]). We performed a comparative analysis of microsporogenesis and aperture distribution within tetrads in these species with contrasting aperture arrangements. This was done using aniline blue coloration and UV light microscope observations. KEYS RESULTS: We show that aperture localization and features of callose deposition on intersporal walls produced during cytokinesis coincide in all three species examined. Such a correlation suggests that patterns of callose deposition are strongly involved in determining aperture localization. In flowering plants, patterns of male meiosis and especially callose deposition following meiosis may be implicated in the diversity of pollen aperture patterns.

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

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    Luiz Fernando de Oliveira da Silva

    2015-01-01

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

  14. Counting pollen grains using readily available, free image processing and analysis software.

    Science.gov (United States)

    Costa, Clayton M; Yang, Suann

    2009-10-01

    Although many methods exist for quantifying the number of pollen grains in a sample, there are few standard methods that are user-friendly, inexpensive and reliable. The present contribution describes a new method of counting pollen using readily available, free image processing and analysis software. Pollen was collected from anthers of two species, Carduus acanthoides and C. nutans (Asteraceae), then illuminated on slides and digitally photographed through a stereomicroscope. Using ImageJ (NIH), these digital images were processed to remove noise and sharpen individual pollen grains, then analysed to obtain a reliable total count of the number of grains present in the image. A macro was developed to analyse multiple images together. To assess the accuracy and consistency of pollen counting by ImageJ analysis, counts were compared with those made by the human eye. Image analysis produced pollen counts in 60 s or less per image, considerably faster than counting with the human eye (5-68 min). In addition, counts produced with the ImageJ procedure were similar to those obtained by eye. Because count parameters are adjustable, this image analysis protocol may be used for many other plant species. Thus, the method provides a quick, inexpensive and reliable solution to counting pollen from digital images, not only reducing the chance of error but also substantially lowering labour requirements.

  15. Developmental and ultrastructural characters of the pollen grains and tapetum in species of Nymphaea subgenus Hydrocallis.

    Science.gov (United States)

    Zini, Lucía Melisa; Galati, Beatriz Gloria; Zarlavsky, Gabriela; Ferrucci, María Silvia

    2017-07-01

    Variations in pollen characters and tapetum behavior were recently acknowledged in the early-divergent family Nymphaeaceae and even within the genus Nymphaea, which probably is not monophyletic; some traits such as infratectum and tapetum type are also a matter of different interpretations. In this study, developmental characters of the pollen grains and tapetum in Nymphaea subgenus Hydrocallis are provided for the first time. Observations were made in N. amazonum, N. gardneriana, and N. prolifera using light, scanning, and transmission electron microscopy. Tapetum is of the secretory type and produces orbicules. At microspore and pollen grain stages, the distal and proximal walls differ considerably. This result supports the operculate condition of the aperture in Hydrocallis, and such aperture might be plesiomorphic for Nymphaeoideae. The infratectum is intermediate, composed of inter-columellae granular elements, robust columellae consisting of agglomerated granules, complete columellae, and fused columellae. Narrow microchannels are present and persist until the mature pollen grain stage. The membranous granular layer is often present in the pollen grains of Nymphaeaceae. In N. gardneriana, this layer is most probably a component of the intine because it is lost after acetolysis. Orbicules in the Nymphaeaceae are characterized as spherical or subspherical, with a smooth sporopolleninic wall that surrounds an electron-lucent core and with individual orbicules that usually merge to give irregular aggregations. The aperture, pollen wall ultrastructure, and the tapetum of the studied species are discussed in an evolutionary and systematic context, and these characters are also compared with those of other angiosperm lineages.

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

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    Cristina Copstein Cuchiara

    2012-11-01

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

  17. Addition of rye chromosome 4R to wheat increases anther length and pollen grain number.

    Science.gov (United States)

    Nguyen, Vy; Fleury, Delphine; Timmins, Andy; Laga, Hamid; Hayden, Matthew; Mather, Diane; Okada, Takashi

    2015-05-01

    The research identified rye chromosome 4R arms associated with good pollinator traits, and demonstrated possible use of rye genetic resources to develop elite pollinators for hybrid wheat breeding. Bread wheat (Triticum aestivum) is a predominantly self-pollinating plant which has relatively small-sized anthers and produces a low number of pollen grains. These features limit the suitability of most wheat lines as pollinators for hybrid seed production. One strategy for improving the pollination ability of wheat is to introgress cross-pollination traits from related species. One such species is rye (Secale cereale L.), which has suitable traits such as high anther extrusion, long anthers containing large amounts of pollen and long pollen viability. Therefore, introducing these traits into wheat is of great interest in hybrid wheat breeding. Here, we investigated wheat-rye chromosome addition lines for the effects of rye chromosomes on anther and pollen development in wheat. Using a single nucleotide polymorphism genotyping array, we detected 984 polymorphic markers that showed expected syntenic relationships between wheat and rye. Our results revealed that the addition of rye chromosomes 1R or 2R reduced pollen fertility, while addition of rye chromosome 4R increased anther size by 16% and pollen grain number by 33%. The effect on anther length was associated with increases in both cell size and the number of endothecium cells and was attributed to the long arm of chromosome 4R. In contrast, the effect on pollen grain number was attributed to the short arm of chromosome 4R. These results indicate that rye chromosome 4R contains at least two genetic factors associated with increased anther size and pollen grain number that can favourably affect pollination traits in wheat.

  18. Authentication of bee pollen grains in bright-field microscopy by combining one-class classification techniques and image processing.

    Science.gov (United States)

    Chica, Manuel

    2012-11-01

    A novel method for authenticating pollen grains in bright-field microscopic images is presented in this work. The usage of this new method is clear in many application fields such as bee-keeping sector, where laboratory experts need to identify fraudulent bee pollen samples against local known pollen types. Our system is based on image processing and one-class classification to reject unknown pollen grain objects. The latter classification technique allows us to tackle the major difficulty of the problem, the existence of many possible fraudulent pollen types, and the impossibility of modeling all of them. Different one-class classification paradigms are compared to study the most suitable technique for solving the problem. In addition, feature selection algorithms are applied to reduce the complexity and increase the accuracy of the models. For each local pollen type, a one-class classifier is trained and aggregated into a multiclassifier model. This multiclassification scheme combines the output of all the one-class classifiers in a unique final response. The proposed method is validated by authenticating pollen grains belonging to different Spanish bee pollen types. The overall accuracy of the system on classifying fraudulent microscopic pollen grain objects is 92.3%. The system is able to rapidly reject pollen grains, which belong to nonlocal pollen types, reducing the laboratory work and effort. The number of possible applications of this authentication method in the microscopy research field is unlimited. Copyright © 2012 Wiley Periodicals, Inc.

  19. 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.

  20. The epidermal cell structure of the secondary pollen presenter in Vangueria infausta (Rubiaceae: Vanguerieae) suggests a functional association with protruding onci in pollen grains.

    Science.gov (United States)

    Tilney, Patricia M; van Wyk, Abraham E; van der Merwe, Chris F

    2014-01-01

    Secondary pollen presentation is a well-known phenomenon in the Rubiaceae with particularly conspicuous pollen presenters occurring in the tribe Vanguerieae. These knob-like structures are formed by a modification of the upper portion of the style and stigma, together known as the stylar head complex. In the flower bud and shortly before anthesis, the anthers surrounding the stylar head complex dehisce and release pollen grains which adhere to the pollen presenter. The epidermal cells of the pollen presenter facing the anthers are radially elongated with a characteristic wall thickening encircling the anticlinal walls of each cell towards the distal end. These cells were studied in the pollen presenter of Vangueria infausta using electron and light microscopy in conjunction with histochemical tests and immunohistochemical methods. Other prominent thickenings of the cell wall were also observed on the distal and proximal walls. All these thickenings were found to be rich in pectin and possibly xyloglucan. The terms "thickenings of Igersheim" and "bands of Igersheim" are proposed to refer, respectively, to these wall structures in general and those encircling the anticlinal walls of each cell near the distal end. The epidermal cells have an intricate ultrastructure with an abundance of organelles, including smooth and rough endoplasmic reticulum, Golgi apparatus, mitochondria and secretory vesicles. This indicates that these cells are likely to have an active physiological role. The pollen grains possess prominent protruding onci and observations were made on their structure and development. Walls of the protruding onci are also rich in pectin. Pectins are hydrophilic and known to be involved in the dehydration and rehydration of pollen grains. We hypothesise that the thickenings of Igersheim, as well as the protruding onci of the pollen grains, are functionally associated and part of the adaptive syndrome of secondary pollen presentation, at least in the Vanguerieae.

  1. Boric acid in germination of pollen grains and fruit set of peach cultivars in subtropical region

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    Filipe Bittencourt Machado de Souza

    Full Text Available ABSTRACT The pollination and fertilization process directly affects the crop yield of peach. Previous studies have shown that some cultivars lack consistent cropping (yield variation in subtropical regions. The application of boric acid at flowering can minimize this problem. This study quantified the germination of pollen grains and fruit set on 18 cultivars of peach in a subtropical region when treated with boric acid at bud. The initial spray treatments were three concentrations of boric acid (400 mgL-1, 800 mgL-1 and 1,200 mgL-1 plus a control treatment of water. Treatments were sprayed on the shoots when the flower buds were flower bud swelling on early maturing cultivars Aurora 2 and Doçura 2. There is a cultivar difference where 'Aurora 2' had a negative effect from the application of boric acid on the percentage of germinated pollen grains and fruit set. 'Doçura 2' has a positive results at the concentration of 400 mgL-1 of boric acid. In a follow-up experiment with 18 cultivars, using only the water control and 400 mgL-1 boric acid treatment, boron increases pollen grain germination and fruit set for some cultivars. The increase in germination and fruit set varies significantly among the cultivars. The concentration of 400 mgL-1 of boric acid increases pollen germination and fruit set, but not in all cultivars.

  2. Identification of teosinte, maize, and Tripsacum in Mesoamerica by using pollen, starch grains, and phytoliths.

    Science.gov (United States)

    Holst, Irene; Moreno, J Enrique; Piperno, Dolores R

    2007-11-06

    We examined pollen grains and starch granules from a large number of modern populations of teosinte (wild Zea spp.), maize (Zea mays L.), and closely related grasses in the genus Tripsacum to assess their strengths and weaknesses in studying the origins and early dispersals of maize in its Mesoamerican cradle of origin. We report new diagnostic criteria and question the accuracy of others used previously by investigators to identify ancient maize where its wild ancestor, teosinte, is native. Pollen grains from teosinte overlap in size with those of maize to a much greater degree than previously reported, making the differentiation of wild and domesticated maize in palynological studies difficult. There is presently no valid method for separating maize and teosinte pollen on a morphological basis. Starch grain analysis, a recently developed tool of archaeobotany, appears to be of significant utility in distinguishing the seeds of teosinte from maize. We propose that the differences in starch grain morphology and size between wild and domesticated maize defined in this study may be associated with domestication genes in Zea that have been documented in the starch biosynthesis pathway. As previously reported, phytoliths effectively discriminate the female reproductive structures of Tripsacum, teosinte, and maize. Multiproxy microfossil studies of archaeological and paleoecological contexts appear to be effective tools for investigating the earliest stages of maize domestication and dispersals.

  3. In vitro germination and viability of pollen grains of banana diploids

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    Taliane Leila Soares

    2008-01-01

    Full Text Available The objective of this study was to evaluate the influence of pH on in vitro germination and pollen grain viabilityof banana diploids (AA generated by the breeding program of Embrapa Mandioca e Fruticultura Tropical. The pollen grainswere inoculated in culture medium containing 15% sucrose, 0.01% H3BO3, 0.01% KNO3, 0.03% Ca(NO32.4H2O, 0.02%MgSO4.7H2O, solidified with 0.8% agar and pH adjusted to 5.8 or 7.0. Pollen viability was evaluated by staining with 1%acetic carmine. The germination percentages of the genotypes 9187-01 (90.0% and M-53 (89.7% in pH 7.0 medium werehighest, while the pollen tube length of genotype 9187-01 was approximately half the size (1.79mm of genotype M-53(3.84mm. The pollen viability of the genotypes evaluated was higher than 85%, even for the diploids with a low in vitrogermination percentage.

  4. Pollen donor composition during the early phases of reproduction revealed by DNA genotyping of pollen grains and seeds of Castanea crenata.

    Science.gov (United States)

    Hasegawa, Yoichi; Suyama, Yoshihisa; Seiwa, Kenji

    2009-06-01

    In plants, pollen donor composition can differ during the early phases of reproduction through various selection mechanisms favouring self, related or nonrelated pollen donors, but such differences have not been examined under natural conditions because paternity is difficult to analyse in a natural setting. Here, we performed paternity analyses based on microsatellite genotyping of individual pollen grains deposited on female flowers (n = 773) and seeds (n = 304) to evaluate pollen donor composition from three individuals of the insect-pollinated monoecious tree Castanea crenata in a natural forest. Spatial genetic structure was also investigated. A mean self-pollen rate of 90.2% was observed at the pollination stage, but a low selfing rate of 0.3% was observed at the seed stage. In outcross events, however, pairwise distance and relatedness between maternal and paternal parents were not different between pollination and seed stages. We also observed significant positive relatedness, based on clear fine-scale genetic structure of individual trees within 80 m of one another, and 71% of seeds were derived using pollen grains of related trees within 80 m. The results suggest that the mechanism of self-incompatibility strongly avoids self-pollen before seed production. However, the avoidance of biparental inbreeding was not obvious between pollination and seed stages.

  5. Stomatocyst 29 Cabała is a pollen grain, not a chrysophyte cyst

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    Jolanta Piątek

    2011-01-01

    Full Text Available Stomatocyst 29 Cabała was described from the Żabie Oko lake in the Tatra Mts, Poland, in 2005 as a chrysophycean stomatocyst new to science. The examination of the recently found specimens in the Dwoisty Staw Gąsienicowy lake in the Tatra Mts, including their chemical composition, showed that stomatocyst 29 is not a cyst, but a pollen grain.

  6. Pollen

    Science.gov (United States)

    ... automatic dryer rather than hanging them outside. Otherwise pollen can collect on clothing and be carried indoors. This content is ... Health Sciences 111 T.W. Alexander Drive Durham, N.C. 27709 NIEHS Staff: Request an Update ...

  7. 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....

  8. Using pollen grains as novel hydrophilic solid-phase extraction sorbents for the simultaneous determination of 16 plant growth regulators.

    Science.gov (United States)

    Lu, Qian; Wu, Jian-Hong; Yu, Qiong-Wei; Feng, Yu-Qi

    2014-11-07

    In this article, pollen grains were for the first time used as a hydrophilic solid-phase extraction (HILIC-SPE) sorbent for the determination of 16 plant growth regulators (PGRs) in fruits and vegetables. Fourier transform infrared spectroscopy (FT-IR), scanning electronic microscopy (SEM) and nitrogen sorption porosimetry (NSP) were used to investigate the chemical structure and the surface properties of the pollen grains. Pollen grains exhibited an excellent adsorption capacity for some polar compounds due to their particular functional groups. Several parameters influencing extraction performance were investigated. A green and simple HILIC-SPE-method using pollen grain cartridge for purification of fruit and vegetable extractions, followed by ultra-high performance liquid chromatography-triple quadrupole tandem mass spectrometry (UHPLC-MS/MS) was established. Good linear relationships were obtained for 16 PGRs with correlation coefficients (R) above 0.9980. The limits of detection (LODs) of 16 PGRs in cucumber were in the range of 0.01-1.10 μg · kg(-1). Reproducibility of the method was evaluated by intra-day and inter-day precisions with relative standard deviations (RSDs), which were less than 14.4%. We successfully applied this methodology to analyze 16 PGRs in 8 different kinds of fruits and vegetables. The recoveries from samples spiked with 16 PGRs were from 80.5% to 119.2%, with relative standard deviations less than 15.0%. Copyright © 2014 Elsevier B.V. All rights reserved.

  9. Buzz pollination in eight bumblebee-pollinated Pedicularis species: does it involve vibration-induced triboelectric charging of pollen grains?

    Science.gov (United States)

    Corbet, Sarah A; Huang, Shuang-Quan

    2014-12-01

    Buzz pollination involves explosive pollen release in response to vibration, usually by bees. The mechanism of pollen release is poorly understood, and it is not clear which component of vibration (acceleration, frequency, displacement or velocity) is critical; the role of buzz frequency has been particularly controversial. This study proposes a novel hypothesis that explosive pollen release results from vibration-induced triboelectric charging. If it does, pollen release is expected to depend on achievement of a critical threshold velocity. Eight sympatric buzz-pollinated species of Pedicularis that share bumblebee pollinator species were studied, giving a rare opportunity to compare sonication behaviour of a shared pollinator on different plant species. Reconsidering previous experimental studies, it is argued that they establish the critical role of the velocity component of vibration in pollen release, and that when displacement is constrained by body size bees can achieve the critical velocity by adjusting frequency. It was shown that workers of Bombus friseanus assorted themselves among Pedicularis species by body size, and that bees adjusted their buzz/wingbeat frequency ratio, which is taken as an index of the velocity component, to a value that corresponds with the galea length and pollen grain volume of each species of Pedicularis. Sonication behaviour of B. friseanus differs among Pedicularis species, not only because worker bees assort themselves among plant species by body size, but also because bees of a given size adjust the buzz frequency to achieve a vibration velocity corresponding to the floral traits of each plant species. These findings, and the floral traits that characterize these and other buzz-pollinated species, are compatible with the hypothesis of vibration-induced triboelectric charging of pollen grains. © The Author 2014. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For

  10. In vitro Pollen Grain Germination and Tube Growth of Ten Iranian Jujube (Ziziphus jujuba Cultivars

    Directory of Open Access Journals (Sweden)

    Hossein ROUHAKHSH

    2014-06-01

    Full Text Available Jujube (Ziziphus jujuba is a species particularly prone to erratic fruit set. Several causes such as pollen germination and tube growth involve in this behaviour. Thus, the present research aimed to evaluate and compare of pollen grains germination and tube growth of ten Iranian jujube cultivars on in vitro condition. A factorial trial based on completely randomized design with five replications was carried out. The pollen grains were collected from un-opened-flowers of Al-Ghour’, ‘Bardaskan’, ‘Doroh’, ‘Gazik’, ‘Ghom’, ‘Giouk’, ‘Kangan’, ‘Kalkestan’, ‘Magham Sari’ and ‘Noghab’ cultivars at balloon stage. This study showed that there were significant differences among the cultivars in all measured factors. The highest percentage of pollen grains germination was observed for ‘Gazik’, followed by ‘Bardaskan’, while the lowest was in ‘Al-Ghour’. The percentage of pollen grains germination increased with the increasing time of incubation period up to 36 h. Also, flowering times are found to be effective in germination of pollen grains, which 1 flash had highest percentage of germination of pollen grains than in comparison to other flowering times. The results also showed that the mean time germination varied from 24.52-25.92 h, mean hourly germination from 0.67-1.55, hourly germination speed from 0.64-1.48 and coefficient of velocity of germination of pollen grains from 0.058-0.061. The length of pollen tube was found between 44.4 and 624.8 µm. These data demonstrated that cultivar is the main factor determining pollen grains germination and tube growth in jujube, which this important information can be useful for selection of superior desirable jujube genotypes for bringing to commercial cultivation.

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

    Directory of Open Access Journals (Sweden)

    Douglas André Steinmacher

    2011-01-01

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

  12. Ecology of flowers and morphology of pollen grains of selected Narcissus varieties (Narcissus pseudonarcissus x Narcissus poëticus

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    Mirosława Chwil

    2012-12-01

    Full Text Available The investigations carried out in the years 2004-2005 covered five varieties of Narcissus (Narcissus pseudonarcissus L. x Narcissus poëticus L.: 'Fire Bird', 'Hardy', 'Ivory Yellow', 'Pomona' and 'The Sun'. Longevity of a flower and the flowering period of the studied Narcissus varieties determined, flower elements were compared, as well as the anatomic structure of ovary and nectary and the morphology of pollen grains. Pollen grains of 'Hardy' and 'The Sun' var. were observed in a scanning electron microscope. The flowering period of 'The Sun' plants appeared to be the longest, while the shortest in the case of 'Fire Bird' and 'Ivory Yellow'. Each perianth of the studied taxons was characterized by a different corolla appendage, from slightly corrugated ('Pomona' to greatly curled, with the notches getting inside and giving impression of a few whort in this part of the perianth ('Ivory Yellow', 'Hardy'. Monosulcate pollen grains with regards to 9 size was numbered among medium ('Pomona', 'The Sun' and large ('Fire Bird', 'Hardy', 'Ivory Yellow'. Their shape was assumed as circular elongated (prolato-spheroides in polar view and flattened (oblatum and slightly flat (suboboblatum in equatorial view. The highest pollen vitality was shown by 'Hardy' variety (92%, whereas for 'The Sun' it proved to be the lowest (22%. In the narcissus flowers, septal nectaries are situated in the upper part of the ovary.

  13. Relationships between airborne pollen grains, wind direction and land cover using GIS and circular statistics.

    Science.gov (United States)

    Maya-Manzano, J M; Sadyś, M; Tormo-Molina, R; Fernández-Rodríguez, S; Oteros, J; Silva-Palacios, I; Gonzalo-Garijo, A

    2017-04-15

    Airborne bio-aerosol content (mainly pollen and spores) depends on the surrounding vegetation and weather conditions, particularly wind direction. In order to understand this issue, maps of the main land cover in influence areas of 10km in radius surrounding pollen traps were created. Atmospheric content of the most abundant 14 pollen types was analysed in relation to the predominant wind directions measured in three localities of SW of Iberian Peninsula, from March 2011 to March 2014. Three Hirst type traps were used for aerobiological monitoring. The surface area for each land cover category was calculated and wind direction analysis was approached by using circular statistics. This method could be helpful for estimating the potential risk of exposure to various pollen types. Thus, the main land cover was different for each monitoring location, being irrigated crops, pastures and hardwood forests the main categories among 11 types described. Comparison of the pollen content with the predominant winds and land cover shows that the atmospheric pollen concentration is related to some source areas identified in the inventory. The study found that some pollen types (e.g. Plantago, Fraxinus-Phillyrea, Alnus) come from local sources but other pollen types (e.g. Quercus) are mostly coming from longer distances. As main conclusions, airborne particle concentrations can be effectively split by addressing wind with circular statistics. By combining circular statistics and GIS method with aerobiological data, we have created a useful tool for understanding pollen origin. Some pollen loads can be explained by immediate surrounding landscape and observed wind patterns for most of the time. However, other factors like medium or long-distance transport or even pollen trap location within a city, may occasionally affect the pollen load recorded using an air sampler. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Effects of air pollutants: effect of sulfur dioxide on germination of the pollen grains of pears

    Energy Technology Data Exchange (ETDEWEB)

    Matsuoka, Y.; Koyasu, H.; Udagawa, O.; Ishiwata, H.; Ohno, T.

    1967-01-01

    Pear pollen was exposed to 5 ppm and 0.3 ppm sulfur dioxide for 1 hour, both before and immediately after bedding on a sugar-agar plate. The pollen exposed before bedding showed no effect. Pollen exposed to 5 ppm SO/sub 2/ after bedding showed a strong germination and tube elongation inhibition; at 0.3 ppM, the inhibition was not as extreme as at 5 ppm.

  15. Bee Pollen

    Science.gov (United States)

    Bee Pollen Extract, Buckwheat Pollen, Extrait de Pollen d’Abeille, Honeybee Pollen, Honey Bee Pollen, Maize Pollen, Pine Pollen, Polen de Abeja, Pollen, Pollen d'Abeille, Pollen d’Abeille de Miel, Pollen de ...

  16. 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.

    Directory of Open Access Journals (Sweden)

    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.

  17. Brassinosteroids promote development of rice pollen grains and seeds by triggering expression of Carbon Starved Anther, a MYB domain protein.

    Science.gov (United States)

    Zhu, Xiaolei; Liang, Wanqi; Cui, Xiao; Chen, Mingjiao; Yin, Changsong; Luo, Zhijing; Zhu, Jiaying; Lucas, William J; Wang, Zhiyong; Zhang, Dabing

    2015-05-01

    Transport of photoassimilates from leaf tissues (source regions) to the sink organs is essential for plant development. Here, we show that a phytohormone, the brassinosteroids (BRs) promotes pollen and seed development in rice by directly promoting expression of Carbon Starved Anther (CSA) which encodes a MYB domain protein. Over-expression of the BR-synthesis gene D11 or a BR-signaling factor OsBZR1 results in higher sugar accumulation in developing anthers and seeds, as well as higher grain yield compared with control non-transgenic plants. Conversely, knockdown of D11 or OsBZR1 expression causes defective pollen maturation and reduced seed size and weight, with less accumulation of starch in comparison with the control. Mechanically, OsBZR1 directly promotes CSA expression and CSA directly triggers expression of sugar partitioning and metabolic genes during pollen and seed development. These findings provide insight into how BRs enhance plant reproduction and grain yield in an important agricultural crop. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

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

    Directory of Open Access Journals (Sweden)

    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.

  19. Effect of collection time on the viability of banana pollen grains ...

    African Journals Online (AJOL)

    % H3BO3, 0.01% KNO3, 0.03% Ca(NO3)2.4H2O, and 0.02% MgSO4.7H2O, solidified with 0.8% agar, adjusted to different pH. The pollen viability was evaluated by staining with 2,3,5-triphenyltetrazolium chloride (TTC). The highest pollen ...

  20. When did C4 Photosynthesis originate: New evidence from δ13C analysis of single grass-pollen grains

    Science.gov (United States)

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

    2009-12-01

    C4 grasses account for >20% of global primary productivity and dominate tropical, subtropical, and warm-temperate grassland ecosystems. Thus it is vital to understand when and why C4 photosynthesis first evolved in the grass family (Poaceae). However, because of limitations of most proxies, the origin of C4 grasses remains ambiguous. Grass pollen is morphologically indistinct below the family level, making pollen analysis a crude instrument for studying C4-grass evolution. Previous studies have investigated the timing of C4 evolution using molecular tools and δ13C records from n-alkanes, ungulate teeth, and paleosols, but they yield disparate results. Molecular clocks suggest that C4 grasses first evolved between 27 and 36 Ma (million years before present), coincident with the Oligocene decline in pCO2 from >1000 to <500 ppm. In contrast, δ13C-based approaches do not detect the presence of C4 grasses until the middle Miocene, indicating that they were previously uncommon or absent on the landscape. To investigate when C4 photosynthesis first appeared in the grass family, we utilized Single Pollen Isotope Ratio AnaLysis (SPIRAL), a technique that reliably distinguishes C4 from C3 grass pollen via δ13C. We analyzed 837 single grains of grass pollen from eight lacustrine geological samples (~100 grains/sample) from France and Spain spanning the earliest Oligocene to middle Miocene. To distinguish C3/C4 ratios, we used an optimal threshold value of -19.2‰ adjusted for small (~1‰) temporal variations in atmospheric δ13C. Initial results provide unequivocal evidence of C4 grass pollen in all samples (24-57% C4 grass pollen ±9.2% on average) lending further credence to the molecular data, which posits that C4 grasses appeared as early as the Late Eocene, which is a plausible outcome when considering alternate schemes of dating phylogenetic trees. A C4 origin prior to pCO2 reaching its lowest levels of the Cenozoic at the Oligocene/Miocene boundary indicates that

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

    Directory of Open Access Journals (Sweden)

    Iris Heidmann

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

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    Віталій Миколайович Гришко

    2016-05-01

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

  4. pollen grain morphology of three species and a variety of ocimum ...

    African Journals Online (AJOL)

    MR PRINCE

    extensively used in perfumery, flavouring and pharmaceutical products (Khosla, 1993). Many species of Ocimum have been grown by local people as medicinal plants, culinary herbs and insect controlling agents (Grayer et al., 1996). Pollen characteristics have been used consid- erably in the taxonomy of angiosperms and ...

  5. 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

    Directory of Open Access Journals (Sweden)

    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

  6. A flash-lamp based device for fluorescence detection and identification of individual pollen grains

    Science.gov (United States)

    Kiselev, Denis; Bonacina, Luigi; Wolf, Jean-Pierre

    2013-03-01

    We present a novel optical aerosol particle detector based on Xe flash lamp excitation and spectrally resolved fluorescence acquisition. We demonstrate its performances on three natural pollens acquiring in real-time scattering intensity at two wavelengths, sub-microsecond time-resolved scattering traces of the particles' passage in the focus, and UV-excited fluorescence spectra. We show that the device gives access to a rather specific detection of the bioaerosol particles.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. SEM observations of pollen grains, fruits and seeds of the Pieniny Mountains (South Poland endemic species Erysimum pieninicum (Zapał. Pawł. (Brassicaceae

    Directory of Open Access Journals (Sweden)

    Irmina Maciejewska

    2011-01-01

    Full Text Available Erysimum pieninicum (Zapał. Pawł. (Brassicaceae is an endemic species, growing only in Pieniny Mts. The aim of the presented work was to investigate its pollen morphology as well as its ultrastructural traits of pericarp and seed-coat. Pollen grains of this species were of small size, 3-zonocolpate with reticulate ornamentation. The external siliqua surface was of rugose sculpture, covered by numerous, stellate hairs. The internal surface of the fruit was naked and characterized by striate sculpture. The seed-coat ornamentation of E. pieninicum was of blister type.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. A Proteomics Approach to Discover Drought Tolerance Proteins in Wheat Pollen Grain at Meiosis Stage.

    Science.gov (United States)

    Fotovat, Reza; Alikhani, Mehdi; Valizadeh, Mostafa; Mirzaei, Mehdi; Salekdeh, Ghasem H

    2017-01-01

    Plants reproductive phase, when grain yield and consequently farmers' investment is most in jeopardy, is considered as the most sensitive stage to drought stress. In this study, we aimed to explore the proteomic response of wheat anther at meiosis stage in a drought tolerant, Darab, and susceptible, Shiraz, wheat genotypes. Wheat plants were exposed to drought stress at meiosis stage for four days under controlled environmental conditions. Then, anthers from both genotypes were sampled, and their proteomes were examined via quantitative proteomics analysis. Our results demonstrated that short-term stress at meiosis stage reduced plant seed-setting compared to well-watered plants. This reduction was more pronounced in the susceptible genotype, Shiraz, by 51%, compared to the drought tolerant Darab by 14.3%. Proteome analysis revealed that 60 protein spots were drought responsive, out of which 44 were identified using a mass spectrometer. We observed a dramatic up-regulation of several heat shock proteins, as well as induction of Bet v I allergen family proteins, peroxiredoxin-5, and glutathione transferase with similar abundance in both genotypes. However, the abundance of proteins such as several stress response related proteins, including glutaredoxin, proteasome subunit alpha type 5, and ribosomal proteins showed a different response to drought stress in two genotypes. The differential abundance of proteins in two genotypes may suggest mechanisms by which tolerant genotype cope with drought stress. To the best of our knowledge, this is the first proteome analysis of plant reproductive tissue response to drought stress in wheat and could broaden our insight into plant adaptation to drought stress. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  11. Airborne pollen content of Kuşadası

    OpenAIRE

    TOSUNOĞLU, Aycan; YENİGÜN, Ayşe; BIÇAKÇI, Adem; ELİAÇIK, Kayı

    2013-01-01

    Atmospheric pollen grains of Kuşadası were captured using Durham samplers and investigated in 2005. The total number of pollen grains and the pollen grains/cm2 were calculated from slides that were changed weekly. During the study period a total of 12,980 pollen grains/cm2 belonging to 44 identified taxa and unidentified pollen grains were recorded at 2 stations. At the first station (S1), 7346 pollen grains were counted per cm2, while only 5634 pollen grains were counted at the second statio...

  12. The compounding effects of high pollen limitation, selfing rates and inbreeding depression leave a New Zealand tree with few viable offspring.

    Science.gov (United States)

    Van Etten, Megan L; Tate, Jennifer A; Anderson, Sandra H; Kelly, Dave; Ladley, Jenny J; Merrett, Merilyn F; Peterson, Paul G; Robertson, Alastair W

    2015-10-01

    Interactions between species are especially sensitive to environmental changes. The interaction between plants and pollinators is of particular interest given the potential current global decline in pollinators. Reduced pollinator services can be compensated for in some plant species by self-pollination. However, if inbreeding depression is high, selfed progeny could die prior to reaching adulthood, leading to cryptic recruitment failure. To examine this scenario, pollinator abundance, pollen limitation, selfing rates and inbreeding depression were examined in 12 populations of varying disturbance levels in Sophora microphylla (Fabaceae), an endemic New Zealand tree species. High pollen limitation was found in all populations (average of 58 % reduction in seed production, nine populations), together with high selfing rates (61 % of offspring selfed, six populations) and high inbreeding depression (selfed offspring 86 % less fit, six populations). Pollen limitation was associated with lower visitation rates by the two endemic bird pollinators. The results suggest that for these populations, over half of the seeds produced are genetically doomed. This reduction in the fitness of progeny due to reduced pollinator service is probably important to population dynamics of other New Zealand species. More broadly, the results suggest that measures of seed production or seedling densities may be a gross overestimate of the effective offspring production. This could lead to cryptic recruitment failure, i.e. a decline in successful reproduction despite high progeny production. Given the global extent of pollinator declines, cryptic recruitment failure may be widespread. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Horse chestnut pollen quality

    Directory of Open Access Journals (Sweden)

    Ćalić Dušica

    2017-01-01

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

  14. Identification of plant families associated with the predators Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) and Hippodamia convergens Guérin-Menéville (Coleoptera: Coccinelidae) using pollen grain as a natural marker.

    Science.gov (United States)

    Medeiros, M A; Ribeiro, P A; Morais, H C; Castelo Branco, M; Sujii, E R; Salgado-Laboriau, M L

    2010-05-01

    The predators Hippodamia convergens Guérin-Menéville (Coleoptera: Coccinelidae) and Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae), are frequently observed on vegetable crops, especially on tomato plants, as well as on flowers of several plants around crop fields. It is well known that when predators feed on pollen and nectar they can increase their longevity and reproductive capacity. The objective of this work was to identify plants that could be a pollen source for H. convergens and C. externa in order to develop strategies to attract and keep these predators in vegetable fields like the tomato crop. Adults of C. externa (53 individuals) and H. convergens (43 individuals) were collected in fields from 2004-2005 at Embrapa Hortaliças, Brasília, Federal District. The insects were processed by the acetolysis method and pollen from them was extracted and identified. A total of 11335 grains of pollen belonging to 21 families were extracted from C. externa. A total of 46 pollen grains belonging to ten families were extracted from H. convergens. The Poaceae family was the most abundant one for C. externa while Asteraceae was the commonest pollen for H. convergens. The importance of pollen from different plant species as a food resource for each predator species gives an indication of the importance of plant community structure inside and around crop fields for the establishment of these predator populations and to enhance conservation biological control.

  15. Reevaluation of pollen quantitation by an automatic pollen counter.

    Science.gov (United States)

    Muradil, Mutarifu; Okamoto, Yoshitaka; Yonekura, Syuji; Chazono, Hideaki; Hisamitsu, Minako; Horiguchi, Shigetoshi; Hanazawa, Toyoyuki; Takahashi, Yukie; Yokota, Kunihiko; Okumura, Satoshi

    2010-01-01

    Accurate and detailed pollen monitoring is useful for selection of medication and for allergen avoidance in patients with allergic rhinitis. Burkard and Durham pollen samplers are commonly used, but are labor and time intensive. In contrast, automatic pollen counters allow simple real-time pollen counting; however, these instruments have difficulty in distinguishing pollen from small nonpollen airborne particles. Misidentification and underestimation rates for an automatic pollen counter were examined to improve the accuracy of the pollen count. The characteristics of the automatic pollen counter were determined in a chamber study with exposure to cedar pollens or soil grains. The cedar pollen counts were monitored in 2006 and 2007, and compared with those from a Durham sampler. The pollen counts from the automatic counter showed a good correlation (r > 0.7) with those from the Durham sampler when pollen dispersal was high, but a poor correlation (r pollen dispersal was low. The new correction method, which took into account the misidentification and underestimation, improved this correlation to r > 0.7 during the pollen season. The accuracy of automatic pollen counting can be improved using a correction to include rates of underestimation and misidentification in a particular geographical area.

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

    Directory of Open Access Journals (Sweden)

    Leon Mejnartowicz

    2014-01-01

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

  17. 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.

  18. 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

    Directory of Open Access Journals (Sweden)

    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.

  19. Pollen viability in Quercus robur L.

    Directory of Open Access Journals (Sweden)

    Batos Branislava

    2017-01-01

    Full Text Available The variability of viability (germination rate and the length of pollen tubes of fresh pedunculate oak (Quercus robur L. pollen grains was studied in vitro on a medium containing 15% sucrose. Spatial variability was studied by sampling fresh pollen grains from a total of thirteen trees at four different sites in the area of Belgrade (Košutnjak, Banovo Brdo, Ada Ciganlija and Bojčin Forest in a single year (2011. In order to assess temporal variability and determine the effects of climate change on a small time scale, we studied the viability of the pollen grains collected from one tree at the Banovo Brdo site in six different years (2004, 2005, 2006, 2007, 2011 and 2012. Interindividual variability was tested on the pollen grains sampled from eight trees at Ada Ciganlija in 2004. The percentage values of the pollen grain germination rate and the pollen tube length showed no statistically significant differences between the sites. However, the studied characteristics of the pollen grain viability (germination rate and pollen tube length showed statistically significant differences in both temporal (between the pollen collection years and interindividual variability. This type of research makes a valuable contribution to pedunculate oak breeding programs through the identification of trees with stable production and a good quality of pollen. Furthermore, it can be important in defining the patterns of spatial, temporal and individual variability of pollen grain viability under the influence of climate factors, which are showing compelling changing trends from year to year.

  20. Catálogo sistemático dos pólens das plantas arbóreas do Brasil meridional XV - Myrtaceae Catalogue of southern brazilian pollen grains

    Directory of Open Access Journals (Sweden)

    Ortrud Monika Barth

    1972-01-01

    Full Text Available Na presente parte do nosso Catálogo Palinológico analisamos a morfologia dos grãos de polén de 140 espécies de Mirtáceas ocorrentes no Estado de Santa Catarina. O estudo dos grãos de polén destas Mirtáceas permitiu agrupar as espécies estudadas em grupos polínicos, segundo as propriedades das aberturas e da estrutura das exinas. Não foi possível separar nem as espécies nem os gêneros em bases da respectiva morfologia polínica. Desta maneira os grupos polínicos são heterogêneos tanto quanto aos gêneros compreendidos, quanto à ocorrência ecológica das espécies.At the present part of our Pollen Catalogue, it is studied the pollen grain morphology of 140 species of Myrtaceae from Santa Catarina State. The study of these pollen grains allow us the composition of pollinic groups according to the characteristic of the apertures and the structure of the exines. It was not possible to differentiate neither species nor genera according to the pollen grain morphology. The pollinic groups ar not homogeneous in relation to the studied genera and the ecological occurrence of the species.

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

    Directory of Open Access Journals (Sweden)

    Silvia Nietsche

    2009-04-01

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

  2. Atmospheric pollen count in Monterrey, Mexico.

    Science.gov (United States)

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

    2010-01-01

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

  3. Número de anteras por flor, grãos de pólen por antera e capacidade germinativa do pólen de diferentes cultivares de macieiras Number of anthers per flower, pollen grains per anther and pollen germination capacity of different cultivars of apple trees

    Directory of Open Access Journals (Sweden)

    Celso Lopes de Albuquerque Junior

    2010-12-01

    Full Text Available O objetivo deste trabalho foi avaliar o número de anteras por flor, grãos de pólen por antera e capacidade germinativa do pólen de diferentes cultivares de macieiras. O trabalho foi executado no Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal da Universidade Federal de Santa Catarina, e as coletas a campo foram realizadas na Epagri/Estação Experimental de Caçador-SC, em outubro de 2005. Foram utilizadas as seguintes cultivares comerciais de macieira desenvolvidas no Brasil: Primícia, Princesa, Fred Hough, Catarina, Baronesa, Lisgala, Suprema, Condessa, Daiane, Duquesa, Imperatriz e Joaquina. As cultivares de macieira Condessa, Princesa, Eva, Duquesa, Imperatriz, Gala, Fred Hough, Daiane, Baronesa e Suprema produzem pólen em quantidade suficiente e com boa capacidade germinativa. A cv. Condessa, embora apresente alta capacidade germinativa de pólen, produz menos anteras e grãos de pólen por antera que as demais. A cv. Princesa é a que apresenta o melhor perfil como polinizadora, por conjugar número de anteras/flor, número de grãos de pólen/antera e capacidade germinativa do pólen mais satisfatórios.The objective of this study was to evaluate the number of anthers per flower, the number of pollen grains per anther and the pollen germination capacity of different cultivars of apple trees. The study was performed at the Physiology and Plant Genetics Laboratory of Federal University of Santa Catarina. The field collecting were performed at Epagri / Caçador Experimental Station, in Santa Catarina State during October, 2005. It was used the following apple cultivars developed in Brazil: Primícia, Princesa, Fred Hough, Catarina, Baronesa, Lisgala, Suprema, Condessa, Daiane, Duquesa, Imperatriz and Joaquina. It was concluded that the apple cultivars Condessa, Princesa, Eva, Duquesa, Imperatriz, Gala, Fred Hough, Daiane, Baronesa and Suprema produce pollen grains of satisfactory quantity and of good germination

  4. Pollen morphology of the Alangiaceae

    NARCIS (Netherlands)

    Reitsma, Tj.

    1970-01-01

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

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

    Science.gov (United States)

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

    2016-04-01

    In lake sediments where terrestrial macrofossils are rare or absent, AMS radiocarbon dating of pollen concentrates represents an important alternative solution for developing a robust and high resolution chronology suitable for Bayesian modelling of age-depth relationships. Here we report an application of the dense media separation approach (Vandergoes and Prior, Radiocarbon 45:479-492, 2003) to Holocene lake sediments from karstic Lake Sidi Ali, Morocco (33° 03'N, 05° 00'W; 2,080 m a.s.l.). Paired dates on terrestrial (macrofossil) and aquatic (ostracod) samples, and dating of bulk sediment surface material at the site indicate varying reservoir effects of up to 900 yr and highlight the need to date terrestrial carbon sources. Dating of pollen concentrates is a viable approach at Lake Sidi Ali, as pollen concentrations are high (~200,000 grains/cc), and pollen assemblages typically contain only minor percentages (depending on the size of predominant pollen grains) was used to further concentrate the pollen grains, and the samples were freeze dried to determine the dry weight of material. The results show that the highest purity of pollen is sample dependent and may typically be achieved in the fractions precipitating at 1.4-1.2 s.g. With sieving, terrestrial pollen purity of ~50-80% can be achieved, offering a considerable improvement in terms of terrestrial carbon content over bulk sediment. These values reflect the challenge in some samples of fully separating pollen grains from common aquatic algae, e.g. Pediastrum and Botryococcus. From sediment samples of ~15 g dry weight, it was possible to achieve pollen concentrates of 0.5-5 mg, with C content typically ~50% by weight. Samples with as little as 70-200 μg C were successfully measured with 0.5-1% error on the 14C age determination. This application of the pollen concentrate dating approach reinforces the importance of microscopic inspection of the residues during the separation and sieving stages. Sample

  6. Contribution to EPMA to airbone pollen analysis

    OpenAIRE

    Guimarães, Fernanda M. G.; Duque, L.; Ribeiro, H.; Sousa, R.; Abreu, I.

    2012-01-01

    As a component of aerosol, pollen is found in suspension with other mineralogical and anthropogenic particles that can adhere to the pollen wall. The aim of this study was to determine possible alterations that pollen grains suffer under different meteorological conditions in the coastal city of Porto, Portugal. For this study, 2 airborne pollen types were taken into account: Poaceae and Alnus spp sampled in July 2010 and February 2011, respectively. Quantitative analysis and X-ra...

  7. Pollen morphology and taxonomy in the Loganiaceae

    NARCIS (Netherlands)

    Punt, W.; Leenhouts, P.W.

    1967-01-01

    The Loganiaceae is a heterogeneous, eurypalynous family with colpate, colporate or porate pollen grains (Erdtman 1952). Some years ago Dr. Leeuwenberg, specialist in the taxonomy of African Loganiaceae, asked the senior author to undertake an investigation of the pollen grains of that family.

  8. In vitro pollen germination, pollen tube growth and longevity in some ...

    African Journals Online (AJOL)

    Jane

    2011-08-03

    Aug 3, 2011 ... and data were analyzed with SAS software. Significant differences were observed among the ... of culture medium in pollen grain germination and the best storage conditions for different species of ... pollen viability and the in vitro culture method to deter- mine pollen germination rate in 'Longquan No.

  9. Forecasting Models for Sugi (Cryptomeria japonica D. Don) Pollen Count Showing an Alternate Dispersal Rhythm

    OpenAIRE

    Yukiko Ito; Reiko Hattori; Hiroki Mase; Masako Watanabe; Itaru Shiotani

    2008-01-01

    Background: Pollen information is indispensable for allergic individuals and clinicians. This study aimed to develop forecasting models for the total annual count of airborne pollen grains based on data monitored over the last 20 years at the Mie Chuo Medical Center, Tsu, Mie, Japan. Methods: Airborne pollen grains were collected using a Durham sampler. Total annual pollen count and pollen count from October to December (OD pollen count) of the previous year were transformed to logarithms....

  10. Morfologia do pólen anemófilo e alergisante no Brasil: Casuarinaceae, Salicaceae, Moraceae, Ulmaceae e Urticaceae (I Morphology of the anemophilous and allergenic pollen grains in Brazil

    Directory of Open Access Journals (Sweden)

    Ortrud Monika Barth

    1975-01-01

    Full Text Available Foi iniciado um catálogo da morfologia policlínica das epécies anemófilas e das causadoras de alergias, ocorrentes no Brasil. Nesta primeira parte foram examinados os grãos de pólen das Angiospermas consideradas menos evoluídas, correspondendo às seguintes Famílias: Casuarinaceae, Salicaceae, Moraceae, Ulmaceae e Urticaceae. O catálogo seguirá a ordem filogenética dos vegetais superiores.A catalogue of pollen morphology from the anemophilous species in Brazil, specially the allergenic ones, is beginning with this paper. In this first article the pollen grain morphology of the less developed angiosperm families, like Casuarinaceae, Salicaceae, Moraceae and Urticaceae has been examined. The catalogue will follow the phyllogenetic lines of the plant families.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Pollen associated microbiome and its relationship to pollution and allergens

    OpenAIRE

    Obersteiner, Andrea

    2017-01-01

    In the past decades the prevalence of pollen-related respiratory allergies has increased rapidly. Causative agents are mostly airborne pollen grains of trees and grasses. The allergenic potential of these pollen grains depends on the amount of produced allergenic proteins (Bet v 1, Phl p 5) and non-allergenic adjuvant compounds, so called PALMs (pollen-associated lipid mediators). These compounds also play a role in the defense mechanisms of plants against biotic and abiotic stress. The f...

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

    Science.gov (United States)

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

    2015-11-01

    Pea (Pisum sativum L.) is a major legume crop grown in a semi-arid climate in Western Canada, where heat stress affects pollination, seed set and yield. Seed set and pod growth characteristics, along with in vitro percentage pollen germination, pollen tube growth and pollen surface composition, were measured in two pea cultivars (CDC Golden and CDC Sage) subjected to five maximum temperature regimes ranging from 24 to 36 °C. Heat stress reduced percentage pollen germination, pollen tube length, pod length, seed number per pod, and the seed-ovule ratio. Percentage pollen germination of CDC Sage was greater than CDC Golden at 36 °C. No visible morphological differences in pollen grains or the pollen surface were observed between the heat and control-treated pea. However, pollen wall (intine) thickness increased due to heat stress. Mid-infrared attenuated total reflectance (MIR-ATR) spectra revealed that the chemical composition (lipid, proteins and carbohydrates) of each cultivar's pollen grains responded differently to heat stress. The lipid region of the pollen coat and exine of CDC Sage was more stable compared with CDC Golden at 36 °C. Secondary derivatives of ATR spectra indicated the presence of two lipid types, with different amounts present in pollen grains from each cultivar. © 2015 John Wiley & Sons Ltd.

  14. Aerodynamics of saccate pollen and its implications for wind pollination.

    Science.gov (United States)

    Schwendemann, Andrew B; Wang, George; Mertz, Meredith L; McWilliams, Ryan T; Thatcher, Scott L; Osborn, Jeffrey M

    2007-08-01

    Pollen grains of many wind-pollinated plants contain 1-3 air-filled bladders, or sacci. Sacci are thought to help orient the pollen grain in the pollination droplet. Sacci also increase surface area of the pollen grain, yet add minimal mass, thereby increasing dispersal distance; however, this aerodynamic hypothesis has not been tested in a published study. Using scanning electron and transmission electron microscopy, mathematical modeling, and the saccate pollen of three extant conifers with structurally different pollen grains (Pinus, Falcatifolium, Dacrydium), we developed a computational model to investigate pollen flight. The model calculates terminal settling velocity based on structural characters of the pollen grain, including lengths, widths, and depths of the main body and sacci; angle of saccus rotation; and thicknesses of the saccus wall, endoreticulations, intine, and exine. The settling speeds predicted by the model were empirically validated by stroboscopic photography. This study is the first to quantitatively demonstrate the adaptive significance of sacci for the aerodynamics of wind pollination. Modeling pollen both with and without sacci indicated that sacci can reduce pollen settling speeds, thereby increasing dispersal distance, with the exception of pollen grains having robust endoreticulations and those with thick saccus walls. Furthermore, because the mathematical model is based on structural characters and error propagation methods show that the model yields valid results when sample sizes are small, the flight dynamics of fossil pollen can be investigated. Several fossils were studied, including bisaccate (Pinus, Pteruchus, Caytonanthus), monosaccate (Gothania), and nonsaccate (Monoletes) pollen types.

  15. Pollen features of hazelnut (Corylus avellana L. from different habitats

    Directory of Open Access Journals (Sweden)

    Natalia Nikolaieva

    2014-04-01

    Full Text Available The aim of this work was to study general morphological characteristics of pollen grains of Corylus avellana L. Seven samples of pollen were investigated. Samples were collected from different habitats in Ukraine – from botanical gardens (Kyiv, Kamianets-Podilskyi and natural habitats (Kyiv region, Kamianets-Podilskyi, and Sumy region. We studied such morphological traits of pollen grains as length of polar and equatorial axes, diameter of pores, and shape of the pollen grain (elongation index. Analysis of morphological characters of pollen was carried out using electron microscope. Comparison of data was performed with the data of the base polleninfo.org. During research the differences in these parameters were marked. Pollen grains of C. avellana are generally isopolar, from suboblate to oblate or oblate-spheroidal, and contain 3 pores. The article contains an attempt to explain the size variations noted for the pollen collected from different habitats.

  16. Airborne Pollen Concentration in Kütahya

    OpenAIRE

    BIÇAKCI, Adem

    1999-01-01

    The airborne pollen cocentration in the atmosphere of Kütahya was determined by gravimetry with a Durham sampler in 1996. During this study, 23 taxa of arboreal and 14 taxa of herbaceous pollen grains were collected and identified. Pollen from the following taxa were also found to be prevalent in the atmosphere of Kütahya: Pinus L., Cupressaceae, Platanus orientalis L., Quercus L., Oleaceae, Gramineae, Urticaceae, Chenopodiaceae/ Amaranthaceae, Compositae and Plantago L. The effects of meteor...

  17. Transgenic lilies via pollen mediated transformation

    NARCIS (Netherlands)

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

    1997-01-01

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

  18. Characterization of pollen by vibrational spectroscopy.

    Science.gov (United States)

    Zimmermann, Boris

    2010-12-01

    Classification, discrimination, and biochemical assignment of vibrational spectra of pollen samples belonging to 43 different species of the order Pinales has been made using three different vibrational techniques. The comparative study of transmission (KBr pellet) and attenuated total reflection (ATR) Fourier transform infrared (FT-IR) and FT-Raman spectroscopies was based on substantial variability of pollen grain size, shape, and relative biochemical composition. Depending on the penetration depth of the probe light, vibrational techniques acquire predominant information either on pollen grain walls (FT-Raman and ATR-FT-IR) or intracellular material (transmission FT-IR). Compared with the other two methods, transmission FT-IR obtains more comprehensive information and as a result achieves superior spectral identification and discrimination of pollen. The results strongly indicate that biochemical similarities of pollen grains belonging to the same plant genus or family lead to similar features in corresponding vibrational spectra. The exploitation of that property in aerobiological monitoring was demonstrated by simple and rapid pollen identification based on relatively small spectral libraries, with the same (or better) taxonomic resolution as that provided by optical microscopy. Therefore, the clear correlation between vibrational spectra and pollen grain morphology, biochemistry, and taxonomy is obtained, while successful pollen identification illustrates the practicability of such an approach in environmental studies.

  19. Pollen development in Annona cherimola Mill. (Annonaceae. Implications for the evolution of aggregated pollen

    Directory of Open Access Journals (Sweden)

    Hormaza Jose I

    2009-10-01

    Full Text Available Abstract Background In most flowering plants, pollen is dispersed as monads. However, aggregated pollen shedding in groups of four or more pollen grains has arisen independently several times during angiosperm evolution. The reasons behind this phenomenon are largely unknown. In this study, we followed pollen development in Annona cherimola, a basal angiosperm species that releases pollen in groups of four, to investigate how pollen ontogeny may explain the rise and establishment of this character. We followed pollen development using immunolocalization and cytochemical characterization of changes occurring from anther differentiation to pollen dehiscence. Results Our results show that, following tetrad formation, a delay in the dissolution of the pollen mother cell wall and tapetal chamber is a key event that holds the four microspores together in a confined tapetal chamber, allowing them to rotate and then bind through the aperture sites through small pectin bridges, followed by joint sporopollenin deposition. Conclusion Pollen grouping could be the result of relatively minor ontogenetic changes beneficial for pollen transfer or/and protection from desiccation. Comparison of these events with those recorded in the recent pollen developmental mutants in Arabidopsis indicates that several failures during tetrad dissolution may convert to a common recurring phenotype that has evolved independently several times, whenever this grouping conferred advantages for pollen transfer.

  20. Pollen development in Annona cherimola Mill. (Annonaceae). Implications for the evolution of aggregated pollen.

    Science.gov (United States)

    Lora, Jorge; Testillano, Pilar S; Risueño, Maria C; Hormaza, Jose I; Herrero, Maria

    2009-10-29

    In most flowering plants, pollen is dispersed as monads. However, aggregated pollen shedding in groups of four or more pollen grains has arisen independently several times during angiosperm evolution. The reasons behind this phenomenon are largely unknown. In this study, we followed pollen development in Annona cherimola, a basal angiosperm species that releases pollen in groups of four, to investigate how pollen ontogeny may explain the rise and establishment of this character. We followed pollen development using immunolocalization and cytochemical characterization of changes occurring from anther differentiation to pollen dehiscence. Our results show that, following tetrad formation, a delay in the dissolution of the pollen mother cell wall and tapetal chamber is a key event that holds the four microspores together in a confined tapetal chamber, allowing them to rotate and then bind through the aperture sites through small pectin bridges, followed by joint sporopollenin deposition. Pollen grouping could be the result of relatively minor ontogenetic changes beneficial for pollen transfer or/and protection from desiccation. Comparison of these events with those recorded in the recent pollen developmental mutants in Arabidopsis indicates that several failures during tetrad dissolution may convert to a common recurring phenotype that has evolved independently several times, whenever this grouping conferred advantages for pollen transfer.

  1. Pollen Contents Of Commercial Honeys Of Opi, Nsukka, Enugu ...

    African Journals Online (AJOL)

    The composition of the contributing plant species shows that the honey samples were multifloral honeys derived from a wide range of nectar and pollen sources. Also, pollen types of trees and shrubs of entomophilous plants were predominant in the samples. The qualitative and quantitative composition of pollen grains in ...

  2. Allergénicité des Granules Cytoplasmiques de Pollen

    OpenAIRE

    Abou Chakra, Oussama

    2009-01-01

    Grass pollen is one of the most important aeroallergen vectors in Europe. It highly contributes to respiratory allergic diseases such as asthma or allergic rhinitis. In contact to water or airborne pollutants, pollen grains can release microparticles or pollen cytoplasmic granules. Because of their size (

  3. Pollen morphology of the genus Begonia in Africa

    NARCIS (Netherlands)

    Berg, van den R.G.

    1985-01-01

    The morphology of the pollen grains of African Begonias is described, leading to the recognition of 15 pollen types. These pollen types are assumed to constitute natural units produced by evolution and the main purpose of this study has been to reconstruct the course

  4. Phenology and pollen studies of some species of Annonaceae in ...

    African Journals Online (AJOL)

    Phenology and pollen studies were investigated in some species of Annonaceae in Nigeria to help in providing pollen data and record of flowering patterns of the species studied. Phenological data for flowering and fruiting were tracked once a week for both rainy and dry seasons. Pollen grains from fresh anthers of the ...

  5. The importance of the stationary and individual pollen monitoring for the diagnostic of pollen allergy

    Directory of Open Access Journals (Sweden)

    Dorota Myszkowska

    2012-12-01

    Full Text Available The aim of the study was to evaluate pollen seasons of selected taxa with particular reference to allergic taxa such as birch (Betula sp., grasses (Poaceae, mugwort (Artemisia sp. in Cracow in 2003 and 2004 (project number 3 PO5D 034 24 funded by the State Committee for Scientific Research. Pollen concentrations obtained using the stationary Burkard trap and personal Partrap FA 52 were compared. The volumetric method was used in the study. Average daily concentrations (pollen grains × m-3 were obtained by counting pollen grains every hour along 4 longitudinal transects and applying an appropriate conversion factor. Duration of the pollen season was determined using the 95% method. Variations in annual totals of pollen grains (birch and mugwort, in start dates (especially for grasses and in the season duration (birch and grasses were found. The comparison of pollen concentrations obtained using the stationary and personal traps at the same place showed non statistically significant correlation for all the studied taxa and statistically significant correlations for birch, mugwort and grasses (Spearman rank correlation. However, the statistically significant differences between the concentrations obtained using Burkard and Partrap carried by patients (Wilcoxon's test were noted. Very low concentrations of pollen grains measured indoor (work, flats and the influence of the local plants growing in separate place (courtyard of the Allergology Department on the pollen concentration were found.

  6. Pollen morphology of the dichapetalaceae with special reference to evolutionary trends and mutual relationships of pollen types

    NARCIS (Netherlands)

    Punt, W.

    Pollen grains of all three genera of Dichapetalaceae (Dichapetalum, Stephanopodium and Tapura) comprising about 150 species have been studied. Twenty-nine pollen types were recognized and the family has to be considered eurypalynous. A key to the pollen types is added. Based on evolutionary trends

  7. 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)

  8. 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. ...

  9. Ragweed pollen in the air of Szczecin.

    Science.gov (United States)

    Puc, Małgorzata

    2004-01-01

    The aim of the study was to analyse the ragweed (Ambrosia) pollination in Szczecin (western Poland) in the years 2000-2002. Measurements were performed by the volumetric and gravimetric method. Pollen seasons were defined as the periods of 90 % of the total catch. Ragweed pollen is known as a very potent aeroallergen. In recent years ragweed appeared in Europe in hitherto unknown localities, and the number of people allergic to the allergens of this plant has been gradually increasing. In the period of the study a strong tendency towards increasing ragweed pollen counts in the air of Szczecin was noted. Of the three years studied, the lowest concentration of ragweed pollen observed in 2000 equalled a few pollen grains in 1 m(3) per 24 h. In 2001, the highest airborne concentration of 30 grains in 1 m(3) per 24 h was noted at the end of August. The annual pollen count of ragweed in 2002 was 3 times higher than in 2001. The pollen season started in the second decade of August and lasted until the beginning of September. The highest airborne concentration of 98 grains in 1 m(3) per 24 h was noted at the beginning of September on a sunny day with strong wind. The pollen count of ragweed was found to depend on the weather conditions, especially on wind speed and relative humidity, diversity of local flora and long distance transportation.

  10. Pollen morphology and variability of Tulipa hungarica Borb | Ćalić ...

    African Journals Online (AJOL)

    Pollen morphology of the endemic species Tulipa hungarica Borb was investigated with the goal of diversity protection and conservation. Morphology of pollen was evaluated using a scanning electron microscopy. Pollen grain was monosulcate with perforate striate exine surface. Also, pollen of T. hungarica showed ...

  11. Saccharomyces cerevisiae Fermentation Effects on Pollen: Archaeological Implications

    Directory of Open Access Journals (Sweden)

    Crystal A. Dozier

    2016-03-01

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

  12. Types of Pollen Dispersal Units in Orchids, and their Consequences for Germination and Fertilization

    Science.gov (United States)

    Pacini, Ettore; Hesse, Michael

    2002-01-01

    The various pollen dispersal units (PDU) found in orchids are discussed together with possible evolutionary trends and the consequences for germination and fertilization. Orchids with monad and tetrad pollen form more complex dispersal units by means of pollenkitt, elastoviscin, a callosic wall, common walls or a combination of these. Evolutionary trends include (1) from pollenkitt to elastoviscin; (2) from monad to tetrads and multiples of tetrads; (3) from partially dehydrated (30 %) pollen; and (4) from monad pollen to PDUs with many pollen grains. The biological consequences concern both male and female reproductive systems. Some features of the male side are present in all orchids irrespective of the pollen dispersal unit, whereas other characters are found only in orchids with pollinia; the same applies for the female counterpart. Pollen grains of orchids with pollinia germinate at least 24 h after pollination because the pollen grains/tetrads must swell and make space for the growth of pollen tubes. PMID:12102520

  13. Analysis of airborne pollen fall in Balikesir, Turkey, 1996-1997.

    Science.gov (United States)

    Bicakci, A; Akyalcin, H

    2000-01-01

    In this study, pollen grains were identified by use of Durham sampler in the atmosphere of Balikesir in 1996 and 1997. During these two years, a total of 17,256 pollen grains per cm(2) were recorded. A total of 8,576 pollen grains per cm(2) were identified in 1996 and a total of 8,680 pollen grains per cm(2) in 1997. Pollen fall in the years 1996-1997 comprised grains belonging to 50 taxa and unidentified pollen grains. Of these 50 taxa, 30 belonged to arboreal and 20 to non-arboreal plants. Total pollen grains consisted of 70.92% grains from arboreal plants, 24.87% grains from non-arboreal plants and 4.21% unidentified pollen grains. In the region investigated, Pinus spp., Cupressaceae/Taxaceae, Gramineae, Platanus spp., Quercus spp., Olea spp., Salix spp., Urticaceae, Moraceae, Plantago spp., Chenopodiaceae/Amaranthaceae, Ailanthus spp., Juglans spp., Carpinus spp. and Rosaceae released the greatest amounts of pollens. During the study period, the pollen fall reached its highest level in May.

  14. Aerodynamics and pollen ultrastructure in Ephedra.

    Science.gov (United States)

    Bolinder, Kristina; Niklas, Karl J; Rydin, Catarina

    2015-03-01

    Pollen dispersal is affected by the terminal settling velocity (Ut) of the grains, which is determined by their size, bulk density, and by atmospheric conditions. The likelihood that wind-dispersed pollen is captured by ovulate organs is influenced by the aerodynamic environment created around and by ovulate organs. We investigated pollen ultrastructure and Ut of Ephedra foeminea (purported to be entomophilous), and simulated the capture efficiency of its ovules. Results were compared with those from previously studied anemophilous Ephedra species.• Ut was determined using stroboscopic photography of pollen in free fall. The acceleration field around an "average" ovule was calculated, and inflight behavior of pollen grains was predicted using computer simulations. Pollen morphology and ultrastructure were investigated using SEM and STEM.• Pollen wall ultrastructure was correlated with Ut in Ephedra. The relative proportion and amount of granules in the infratectum determine pollen bulk densities, and (together with overall size) determine Ut and thus dispersal capability. Computer simulations failed to reveal any functional traits favoring anemophilous pollen capture in E. foeminea.• The fast Ut and dense ultrastructure of E. foeminea pollen are consistent with functional traits that distinguish entomophilous species from anemophilous species. In anemophilous Ephedra species, ovulate organs create an aerodynamic microenvironment that directs airborne pollen to the pollination drops. In E. foeminea, no such microenvironment is created. Ephedroid palynomorphs from the Cretaceous share the ultrastructural characteristics of E. foeminea, and at least some may, therefore, have been produced by insect-pollinated plants. © 2015 Botanical Society of America, Inc.

  15. MONITORING THE ALLERGENIC POLLEN FROM THE AIRPLANCTON IN 2000

    Directory of Open Access Journals (Sweden)

    Nicoleta Ianovici

    2003-01-01

    Full Text Available This study is intended to determine the annual dissemination means of the pollen grains in the Timisoara’s atmosphere for the year 2000. In this study we present a pollenic calendar for the mentioned region. In the investigated area, the season with maximum pollen concentration was late summer-fall (August. In the first months of the monitoring period, prevailed the pollen coming from anemophile trees and in the last months the pollen coming from anemophile herbaceous plants. Ambrosia, Poaceae, Urtica and Artemisia gave the highest pollen quantities identified in the airplancton. During the studied year, there were identified 23 pollen types. The most important anemophile taxa were: wooden magnoliates (14, herbaceous magnoliates (6, liliates (1 and pinnates (2. The monitoring supplied us with valuable information regarding the dissemination of some anthropophile species (Ambrosia whose pollen is known as a strong allergen.

  16. Pollen load composition and size in the leafcutting bee Megachile rotundata (Hymenoptera: Megachilidae)

    OpenAIRE

    O'Neill, Ruth; O'Neill, Kevin

    2011-01-01

    International audience; We examined how the species composition and volumes of pollen loads of Megachile rotundata varied seasonally and among females of different body sizes. Alfalfa and mustards (Brassicaceae) made up, on average, 88-95% of the pollen load volumes in each of three seasonal samples; in total, the 300 females sampled carried ten different pollen types. Because of variation in pollen grain size among plant species, estimates of the contribution of different species to pollen l...

  17. Ragweed pollen collected along high-traffic roads shows a higher allergenicity than pollen sampled in vegetated areas.

    Science.gov (United States)

    Ghiani, A; Aina, R; Asero, R; Bellotto, E; Citterio, S

    2012-07-01

    Pollutants may affect pollen allergenicity and thus the prevalence of allergies. Although a few studies are available in literature, the connection between pollution and the allergenic potential of pollen has yet to be clearly defined. The objective of this study was to evaluate the effect of traffic-related pollution on the allergenicity of ragweed (Ambrosia artemisiifolia L.) pollen through a field-based experiment. Mature pollen grains were collected from ragweed plants grown along main roadsides and in vegetated areas of Po river plain. The percentage of sub-pollen particle-releasing grains (SPPGs) was evaluated immediately after sampling by microscope and image analysis. Immunochemistry and LC-MS/MS were applied to assess the whole allergenicity and the allergen pattern characterizing the different pollen samples. No statistical difference was detected in the percentage of SPPGs among pollen samples. Specifically, after hydration, the mean percentage was very low (pollen collected along high-traffic roads showed a higher whole allergenicity than pollen from low-traffic roads and vegetated areas which showed a reactivity similar to that of the commercial pollen 'Allergon', used as a standard. The detected higher allergenicity levels were attributed to both quantitative and qualitative differences in allergen pattern. Our findings show that pollen collected at different sites contains different amount and number of allergens and suggest that traffic-related pollution enhances ragweed pollen allergenicity, which may contribute to the increasing prevalence of ragweed allergy in Lombardy plain. © 2012 John Wiley & Sons A/S.

  18. Pollen morphology of the Onobrychis sect. Heliobrychis in Iran

    Directory of Open Access Journals (Sweden)

    Roya Karamian

    2010-01-01

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

  19. QUANTITATIVE AND QUALITATIVE STUDY OF THE ATMOSPHERIC POLLEN IN 2001

    Directory of Open Access Journals (Sweden)

    Nicoleta IANOVICI

    2004-01-01

    Full Text Available This study is intended to emphasize the annual dynamics of the pollen grains of the SW Romanian airplancton. In the investigated area, for the year 2001, the maximum pollen quantity was reached in March and August. During the studied year, 24 pollen types were collected and identified. In Timisoara, the most important anemophile taxa belong to wooden magnoliates (14, herbaceous magnoliates (6, liliates (2 and pinnates (2. Responsible for the greatest pollen quantities are Poaceae (18.32%, Ambrosia (14.89%, Artemisia (9.54%, Urtica (7.67%, Betula (4.87%, Populus (4.68%. In this study we present the pollenic calendar with weekly dynamics.

  20. Fluctuation of birch (Betula L. pollen seasons in Poland

    Directory of Open Access Journals (Sweden)

    Małgorzata Puc

    2015-12-01

    Full Text Available Birch pollen grains are one of the most important groups of atmospheric biological particles that induce allergic processes. The fluctuation pattern of birch pollen seasons in selected cities of Poland is presented. Measurements were performed by the volumetric method (Burkard and Lanzoni 2000 pollen samplers. The distributions of the data were not normal (Shapiro–Wilk test and statistical error risk was estimated at a significance level of α = 0.05. Pollen season was defined as the period in which 95% of the annual total catch occurred. The linear trend for the selected features of the pollen season, skewness, kurtosis and coefficient of variation (V% were also analyzed. During the 12–14 years of study, the beginnings of birch pollen seasons were observed 7–14 days earlier, the ends were noted 5–10 days earlier, and the days with maximum values occurred 7–14 days earlier compared to the long-term data. The left-skewed distribution of the pollen season starts in most sampling sites confirms the short-lasting occurrence of pollen in the air. The threat of birch pollen allergens was high during the pollen seasons. If vegetation is highly diverse, flowering and pollen release are extended in time, spread over different weeks and occur at different times of the day. Flowering time and pollen release are affected by insolation, convection currents, wind, and turbulence. Therefore, pollen seasons are characterized by great inter-annual variability.

  1. 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.

  2. Immersion freezing of birch pollen washing water

    Science.gov (United States)

    Augustin, S.; Wex, H.; Niedermeier, D.; Pummer, B.; Grothe, H.; Hartmann, S.; Tomsche, L.; Clauss, T.; Voigtländer, J.; Ignatius, K.; Stratmann, F.

    2013-11-01

    Birch pollen grains are known to be ice nucleating active biological particles. The ice nucleating activity has previously been tracked down to biological macromolecules that can be easily extracted from the pollen grains in water. In the present study, we investigated the immersion freezing behavior of these ice nucleating active (INA) macromolecules. Therefore we measured the frozen fractions of particles generated from birch pollen washing water as a function of temperature at the Leipzig Aerosol Cloud Interaction Simulator (LACIS). Two different birch pollen samples were considered, with one originating from Sweden and one from the Czech Republic. For the Czech and Swedish birch pollen samples, freezing was observed to start at -19 and -17 °C, respectively. The fraction of frozen droplets increased for both samples down to -24 °C. Further cooling did not increase the frozen fractions any more. Instead, a plateau formed at frozen fractions below 1. This fact could be used to determine the amount of INA macromolecules in the droplets examined here, which in turn allowed for the determination of nucleation rates for single INA macromolecules. The main differences between the Swedish birch pollen and the Czech birch pollen were obvious in the temperature range between -17 and -24 °C. In this range, a second plateau region could be seen for Swedish birch pollen. As we assume INA macromolecules to be the reason for the ice nucleation, we concluded that birch pollen is able to produce at least two different types of INA macromolecules. We were able to derive parameterizations for the heterogeneous nucleation rates for both INA macromolecule types, using two different methods: a simple exponential fit and the Soccer ball model. With these parameterization methods we were able to describe the ice nucleation behavior of single INA macromolecules from both the Czech and the Swedish birch pollen.

  3. Factors affecting quantity of pollen dispersal of spray cut chrysanthemum (Chrysanthemum morifolium).

    Science.gov (United States)

    Wang, Xiao-Guang; Wang, Hai-Bin; Chen, Fa-Di; Jiang, Jia-Fu; Fang, Wei-Min; Liao, Yuan; Teng, Nian-Jun

    2014-01-06

    Spray cut chrysanthemum is a vital flower with high ornamental value and popularity in the world. However, the excessive quantity of pollen dispersal of most spray cut chrysanthemum is an adverse factor during its flowering stage, and can significantly reduce its ornamental value and quickly shorten its vase life. More seriously, excessive pollen grains in the air are usually harmful to people, especially for those with pollen allergies. Therefore, in order to obtain some valuable information for developing spray cut chrysanthemum with less-dispersed or non-dispersed pollen in the future breeding programs, we here investigated the factors affecting quantity of pollen dispersal of spray cut chrysanthemum with four cultivars, i.e. 'Qx-097', 'Noa', 'Qx-115', and 'Kingfisher', that have different quantity of pollen dispersal. 'Qx-097' with high quantity of pollen dispersal has 819 pollen grains per anther, 196.4 disk florets per inflorescence and over 800,000 pollen grains per inflorescence. The corresponding data for 'Noa' with low quantity of pollen dispersal are 406, 175.4 and over 350,000, respectively; and 219, 144.2 and nearly 160,000 for 'Qx-115' without pollen dispersal, respectively. 'Kingfisher' without pollen dispersal has 202.8 disk florets per inflorescence, but its anther has no pollen grains. In addition, 'Qx-097' has a very high degree of anther cracking that nearly causes a complete dispersal of pollen grains from its anthers. 'Noa' has a moderate degree of anther cracking, and pollen grains in its anthers are not completely dispersed. However, the anthers of 'Qx-115' and 'Kingfisher' do not crack at all. Furthermore, microsporogenesis and pollen development are normal in 'Qx-097', whereas many microspores or pollen degenerate in 'Noa', most of them abort in 'Qx-115', and all of them degrade in 'Kingfisher'. These results suggest that quantity of pollen dispersal in spray cut chrysanthemum are mainly determined by pollen quantity per anther, and

  4. First annual register of allergenic pollen in Talca, Chile.

    Science.gov (United States)

    Mardones, P; Grau, M; Araya, J; Córdova, A; Pereira, I; Peñailillo, P; Silva, R; Moraga, A; Aguilera-Insunza, R; Yepes-Nuñez, J J; Palomo, I

    2013-01-01

    There are no data on atmospheric pollen in Talca. In the present work, our aim is to describe the amount of pollen grain in the atmosphere of the city of Talca likely to cause pollinosis of its inhabitants. A volumetric Hirst sampler (Burkard seven-day recording device) was used to study pollen levels. It was placed in the centre of Talca from May 2007 to April 2008. The highest airborne presence of pollen, as measured in weekly averages, was Platanus acerifolia with a maximum weekly daily average of 203 grains/m³ registered during September and October. The second highest was Acer pseudoplatanus with a maximum weekly daily average of 116 grains/m³. Populus spp. had a maximum weekly daily average 103 grains/m³. Olea europaea reached 19 grains/m³ in November. Grasses presented high levels of pollen counts with a maximum weekly daily average of 27 grains/m³ from the end of August until the end of January. Pollens of Plantago spp. Rumex acetosella and Chenopodium spp. had a similar distribution and were present from October to April with maximum weekly daily average of 7 grains/m³, 7 grains/m³ and 3 grains/m³ respectively. Significant concentrations of Ambrosia artemisiifolia were detected from February until April. The population of Talca was exposed to high concentrations of allergenic pollen, such as P. acerifolia, A. pseudoplatanus, and grasses in the months of August through November. The detection of O. europaea and A. artemisiifolia is important as these are emergent pollens in the city of Talca. Aerobiological monitoring will provide the community with reliable information about the level of allergenic pollens, improving treatment and quality of life of patients with respiratory allergy. Copyright © 2011 SEICAP. Published by Elsevier Espana. All rights reserved.

  5. A combinatorial morphospace for angiosperm pollen

    Science.gov (United States)

    Mander, Luke

    2016-04-01

    The morphology of angiosperm (flowering plant) pollen is extraordinarily diverse. This diversity results from variations in the morphology of discrete anatomical components. These components include the overall shape of a pollen grain, the stratification of the exine, the number and form of any apertures, the type of dispersal unit, and the nature of any surface ornamentation. Different angiosperm pollen morphotypes reflect different combinations of these discrete components. In this talk, I ask the following question: given the anatomical components of angiosperm pollen that are known to exist in the plant kingdom, how many unique biologically plausible combinations of these components are there? I explore this question from the perspective of enumerative combinatorics using an algorithm I have written in the Python programming language. This algorithm (1) calculates the number of combinations of these components; (2) enumerates those combinations; and (3) graphically displays those combinations. The result is a combinatorial morphospace that reflects an underlying notion that the process of morphogenesis in angiosperm pollen can be thought of as an n choose k counting problem. I compare the morphology of extant and fossil angiosperm pollen grains to this morphospace, and suggest that from a combinatorial point of view angiosperm pollen is not as diverse as it could be, which may be a result of developmental constraints.

  6. Pollen as atmospheric cloud condensation nuclei

    Science.gov (United States)

    Steiner, Allison L.; Brooks, Sarah D.; Deng, Chunhua; Thornton, Daniel C. O.; Pendleton, Michael W.; Bryant, Vaughn

    2015-05-01

    Anemophilous (wind-dispersed) pollen grains are emitted in large quantities by vegetation in the midlatitudes for reproduction. Pollen grains are coarse particles (5-150 µm) that can rupture when wet to form submicron subpollen particles (SPP) that may have a climatic role. Laboratory CCN experiments of six fresh pollen samples show that SPP activate as CCN at a range of sizes, requiring supersaturations from 0.81 (± 0.07)% for 50 nm particles, 0.26 (± 0.03)% for 100 nm particles, and 0.12 (± 0.00)% for 200 nm particles. Compositional analyses indicate that SPP contain carbohydrates and proteins. The SPP contribution to global CCN is uncertain but could be important depending on pollen concentrations outside the surface layer and the number of SPP generated from a single pollen grain. The production of hygroscopic SPP from pollen represents a novel, biologically driven cloud formation pathway that may influence cloud optical properties and lifetimes, thereby influencing climate.

  7. Plant Sterol Diversity in Pollen from Angiosperms.

    Science.gov (United States)

    Villette, Claire; Berna, Anne; Compagnon, Vincent; Schaller, Hubert

    2015-08-01

    Here we have examined the composition of free sterols and steryl esters of pollen from selected angiosperm species, as a first step towards a comprehensive analysis of sterol biogenesis in the male gametophyte. We detected four major sterol structural groups: cycloartenol derivatives bearing a 9β,19-cyclopropyl group, sterols with a double bond at C-7(8), sterols with a double bond at C-5(6), and stanols. All these groups were unequally distributed among species. However, the distribution of sterols as free sterols or as steryl esters in pollen grains indicated that free sterols were mostly Δ(5)-sterols and that steryl esters were predominantly 9β,19-cyclopropyl sterols. In order to link the sterol composition of a pollen grain at anthesis with the requirement for membrane lipid constituents of the pollen tube, we germinated pollen grains from Nicotiana tabacum, a model plant in reproductive biology. In the presence of radiolabelled mevalonic acid and in a time course series of measurements, we showed that cycloeucalenol was identified as the major neosynthesized sterol. Furthermore, the inhibition of cycloeucalenol neosynthesis by squalestatin was in full agreement with a de novo biogenesis and an apparent truncated pathway in the pollen tube.

  8. 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

  9. Mesoscale atmospheric transport of ragweed pollen allergens from infected to uninfected areas.

    Science.gov (United States)

    Grewling, Ł; Bogawski, P; Jenerowicz, D; Czarnecka-Operacz, M; Šikoparija, B; Skjøth, C A; Smith, M

    2016-10-01

    Allergenic ragweed (Ambrosia spp.) pollen grains, after being released from anthers, can be dispersed by air masses far from their source. However, the action of air temperature, humidity and solar radiation on pollen grains in the atmosphere could impact on the ability of long distance transported (LDT) pollen to maintain allergenic potency. Here, we report that the major allergen of Ambrosia artemisiifolia pollen (Amb a 1) collected in ambient air during episodes of LDT still have immunoreactive properties. The amount of Amb a 1 found in LDT ragweed pollen grains was not constant and varied between episodes. In addition to allergens in pollen sized particles, we detected reactive Amb a 1 in subpollen sized respirable particles. These findings suggest that ragweed pollen grains have the potential to cause allergic reactions, not only in the heavily infested areas but, due to LDT episodes, also in the regions unaffected by ragweed populations.

  10. Mesoscale atmospheric transport of ragweed pollen allergens from infected to uninfected areas

    Science.gov (United States)

    Grewling, Ł.; Bogawski, P.; Jenerowicz, D.; Czarnecka-Operacz, M.; Šikoparija, B.; Skjøth, C. A.; Smith, M.

    2016-10-01

    Allergenic ragweed ( Ambrosia spp.) pollen grains, after being released from anthers, can be dispersed by air masses far from their source. However, the action of air temperature, humidity and solar radiation on pollen grains in the atmosphere could impact on the ability of long distance transported (LDT) pollen to maintain allergenic potency. Here, we report that the major allergen of Ambrosia artemisiifolia pollen (Amb a 1) collected in ambient air during episodes of LDT still have immunoreactive properties. The amount of Amb a 1 found in LDT ragweed pollen grains was not constant and varied between episodes. In addition to allergens in pollen sized particles, we detected reactive Amb a 1 in subpollen sized respirable particles. These findings suggest that ragweed pollen grains have the potential to cause allergic reactions, not only in the heavily infested areas but, due to LDT episodes, also in the regions unaffected by ragweed populations.

  11. A combinatorial approach to angiosperm pollen morphology.

    Science.gov (United States)

    Mander, Luke

    2016-11-30

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

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Trends and threshold exceedances analysis of airborne pollen concentrations in Metropolitan Santiago Chile.

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    Richard Toro A

    Full Text Available Pollen is one of the primary causes of allergic rhinoconjunctivitis in urban centers. In the present study, the concentrations of 39 different pollens in the Santiago de Chile metropolitan area over the period 2009-2013 are characterized. The pollen was monitored daily using Burkard volumetric equipment. The contribution of each type of pollen and the corresponding time trends are evaluated. The concentrations of the pollens are compared with the established threshold levels for the protection of human health. The results show that the total amount of pollen grains originating from trees, grasses, weeds and indeterminate sources throughout the period of the study was 258,496 grains m-3, with an annual average of 51,699 ± 3,906 grains m-3 year-1. The primary source of pollen is Platanus orientalis, which produces 61.8% of the analyzed pollen. Grass pollen is the third primary component of the analyzed pollen, with a contribution of 5.82%. Among the weeds, the presence of Urticacea (3.74% is remarkable. The pollination pattern of the trees is monophasic, and the grasses have a biphasic pattern. The trends indicate that the total pollen and tree pollen do not present a time trend that is statistically significant throughout the period of the study, whereas the grass pollen and weed pollen concentrations in the environment present a statistically significant decreasing trend. The cause of this decrease is unclear. The pollen load has doubled over the past decade. When the observed concentrations of the pollens were compared with the corresponding threshold levels, the results indicated that over the period of the study, the pollen concentrations were at moderate, high and very high levels for an average of 293 days per year. Systematic counts of the pollen grains are an essential method for diagnosing and treating patients with pollinosis and for developing forestation and urban planning strategies.

  14. Glutathione synthesis is essential for pollen germination in vitro

    Science.gov (United States)

    2011-01-01

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

  15. Pollen clumping and wind dispersal in an invasive angiosperm.

    Science.gov (United States)

    Martin, Michael D; Chamecki, Marcelo; Brush, Grace S; Meneveau, Charles; Parlange, Marc B

    2009-09-01

    Pollen dispersal is a fundamental aspect of plant reproductive biology that maintains connectivity between spatially separated populations. Pollen clumping, a characteristic feature of insect-pollinated plants, is generally assumed to be a detriment to wind pollination because clumps disperse shorter distances than do solitary pollen grains. Yet pollen clumps have been observed in dispersion studies of some widely distributed wind-pollinated species. We used Ambrosia artemisiifolia (common ragweed; Asteraceae), a successful invasive angiosperm, to investigate the effect of clumping on wind dispersal of pollen under natural conditions in a large field. Results of simultaneous measurements of clump size both in pollen shedding from male flowers and airborne pollen being dispersed in the atmosphere are combined with a transport model to show that rather than being detrimental, clumps may actually be advantageous for wind pollination. Initial clumps can pollinate the parent population, while smaller clumps that arise from breakup of larger clumps can cross-pollinate distant populations.

  16. Forecasting models for sugi (Cryptomeria japonica D. Don) pollen count showing an alternate dispersal rhythm.

    Science.gov (United States)

    Ito, Yukiko; Hattori, Reiko; Mase, Hiroki; Watanabe, Masako; Shiotani, Itaru

    2008-12-01

    Pollen information is indispensable for allergic individuals and clinicians. This study aimed to develop forecasting models for the total annual count of airborne pollen grains based on data monitored over the last 20 years at the Mie Chuo Medical Center, Tsu, Mie, Japan. Airborne pollen grains were collected using a Durham sampler. Total annual pollen count and pollen count from October to December (OD pollen count) of the previous year were transformed to logarithms. Regression analysis of the total pollen count was performed using variables such as the OD pollen count and the maximum temperature for mid-July of the previous year. Time series analysis revealed an alternate rhythm of the series of total pollen count. The alternate rhythm consisted of a cyclic alternation of an "on" year (high pollen count) and an "off" year (low pollen count). This rhythm was used as a dummy variable in regression equations. Of the three models involving the OD pollen count, a multiple regression equation that included the alternate rhythm variable and the interaction of this rhythm with OD pollen count showed a high coefficient of determination (0.844). Of the three models involving the maximum temperature for mid-July, those including the alternate rhythm variable and the interaction of this rhythm with maximum temperature had the highest coefficient of determination (0.925). An alternate pollen dispersal rhythm represented by a dummy variable in the multiple regression analysis plays a key role in improving forecasting models for the total annual sugi pollen count.

  17. Investigating atmospheric transport of Ambrosia pollen from the Pannonian Plain towards the Balkan region with DEHM-Pollen

    Science.gov (United States)

    Ambelas Skjoth, C.

    2009-04-01

    The pollen grains of Ambrosia spp. are considered to be important aeroallergens. The threshold value for clinical symptoms for ragweed pollen grains for the majority of sensitised patients is below 20 grains/m3. Ambrosia pollen appears to induce asthma about twice as often as other pollen. Each ragweed plant produces millions of pollen grains that are small (18-22 μm) and suitable for long-range transport when conditions are favourable. In this study we use DEHM-Pollen to investigate if the Pannonian Plain could be the source area for observed episodes of Ambrosia pollen in the Balkans. A possible Ambrosia pollen inventory for various regions in the Pannonian Plain was constructed using detailed land cover data from Serbia, Hungary, Austria, Croatia, Bosnia-Herzegovina, Slovakia, Romania and Czech Republic in combination with measurements of the annual load of Ambrosia pollen in the source areas. A simple unified pollen release model (SUPREME) was calibrated against daily measurements from Novi Sad in Serbia and implemented in DEHM-Pollen with the Ambrosia pollen inventory. Model simulations was then performed with DEHM-Pollen for the months August and September 2007 and compared with measurements from stations outside the Pannonian Plain. The simulations several times indicate regional scale transport from the Pannonian Plain towards the Balkan region including the 26th - 27th of August and the 1st and 2nd September. During these episode air masses passed over parts of Bosnia and Herzegovina, Southern Serbia, Albania and Macedonia. The verifying measurements at Skopje (Macedonia) show episodes of elevated Ambrosia pollen concentration the 26th -27th of August and for the 1st and 2nd of September. The model experiments with DEHM-Pollen strongly indicate that the Pannonian Plain alone can be a source to significant Ambrosia pollen concentrations in the Balkans. The methods and the model results look promising with respect to future numerical forecasting of Ambrosia

  18. Effects of pollen load size on seed paternity in wild radish: the roles of pollen competition and mate choice.

    Science.gov (United States)

    Marshall, Diane L; Shaner, Marieken G M; Oliva, Jon-Paul

    2007-08-01

    For sexual selection to be important in plants, it must occur at pollen load sizes typical of field populations. However, studies of the impact of pollen load size on pollen competition have given mixed results, perhaps because so few of these studies directly examined the outcome of mating when pollen load size was varied. We asked whether seed paternity after mixed pollination of wild radish was affected by pollen load sizes ranging from 22 to 220 pollen grains per stigma. We examined the seed siring abilities of 12 pollen donors across 11 maternal plants. Seed paternity was statistically indistinguishable across the pollen load sizes even though, overall, the pollen donors sired different numbers of seeds. This lack of effect of pollen load size on seed paternity may have occurred because fruit abortion and early abortion or failure of fertilization of seeds increased as load size decreased. Thus, failures of fruits and seeds sired by poorer pollen donors may keep seed paternity constant across pollen load sizes.

  19. Pollen dispersal in sugar beet production fields.

    Science.gov (United States)

    Darmency, Henri; Klein, Etienne K; De Garanbé, Thierry Gestat; Gouyon, Pierre-Henri; Richard-Molard, Marc; Muchembled, Claude

    2009-04-01

    Pollen-mediated gene flow has important implications for biodiversity conservation and for breeders and farmers' activities. In sugar beet production fields, a few sugar beet bolters can produce pollen as well as be fertilized by wild and weed beet. Since the crop, the wild beets, and the weed beets are the same species and intercross freely, the question of pollen flow is an important issue to determine the potential dispersal of transgenes from field to field and to wild habitats. We report here an experiment to describe pollen dispersal from a small herbicide-resistant sugar beet source towards male sterile target plants located along radiating lines up to 1,200 m away. Individual dispersal functions were inferred from statistical analyses and compared. Pollen limitation, as expected in root-production fields, was confirmed at all the distances from the pollen source. The number of resistant seeds produced by bait plants best fitted a fat-tailed probability distribution curve of pollen grains (power-law) dependent on the distance from the pollen source. A literature survey confirmed that power-law function could fit in most cases. The b coefficient was lower than 2. The number of fertilized flowers by background (herbicide-susceptible) pollen grains was uniform across the whole field. Airborne pollen had a fertilization impact equivalent to that of one adjacent bolter. The individual dispersal function from different pollen sources can be integrated to provide the pollen cloud composition for a given target plant, thus allowing modeling of gene flow in a field, inter-fields in a small region, and also in seed-production area. Long-distance pollen flow is not negligible and could play an important role in rapid transgene dispersal from crop to wild and weed beets in the landscape. The removing of any bolting, herbicide-resistant sugar beet should be compulsory to prevent the occurrence of herbicide-resistant weed beet, thus preventing gene flow to wild

  20. Pollen morphology of the Euphorbiaceae with special reference to taxonomy

    NARCIS (Netherlands)

    Punt, W.

    1962-01-01

    In the present study pollen morphology of the Euphorbeaceae is treated as an additional character in taxonomy. Besides the greater part of the genera occurring in the system of PAX and K. HOFFMANN (1931), most of the genera published after 1931 are studied. The pollen grains have been described with

  1. 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

  2. Pollen flow in the distylous Palicourea fendleri (Rubiaceae): an experimental test of the Disassortative Pollen Flow Hypothesis.

    Science.gov (United States)

    Lau, Pablo; Bosque, Carlos

    2003-05-01

    The Disassortative Pollen Flow Hypothesis proposed by Darwin postulates that the relative position of anthers and stigmas in distylous flowers enhances pollen flow between flowers of different morphs (legitimate pollination), in comparison to flow between flowers of the same morph (illegitimate pollination). In order to test this hypothesis, we measured pollen transport, mediated by a trained Copper-rumped Hummingbird (Amazilia tobaci), between flowers of the distylous Palicourea fendleri under laboratory conditions. In individual tests, we offered to the hummingbird a pollen donor flower and two emasculated recipient flowers in a controlled sequence. After each foraging bout, we counted the number of pollen grains transported from the donor flower to the stigmas of both recipient flowers. In agreement with Darwin's hypothesis, we found that hummingbirds transport pollen of "pin" flowers in significantly higher numbers to legitimate "thrum" stigmas, even if previously visiting a "pin" flower. However, "thrum" pollen was deposited in greater numbers on illegitimate "thrum" stigmas. We interpret this asymmetry largely as the consequence of floral morphology; pollen flow was greater between anthers and stigmas that exhibit greater spatial matching. In P. fendleri, the position of floral organs along the corolla tube does not always precisely correspond. In our experimental system, the probability that the pollinator extracts a pollen grain from the anther and the probability of self-pollination were both dependent on the type of floral morph. We discuss the relevance of the latter findings in relation to other studies of pollen flow in heterostylous species.

  3. A Multiscale Vibrational Spectroscopic Approach for Identification and Biochemical Characterization of Pollen.

    Science.gov (United States)

    Bağcıoğlu, Murat; Zimmermann, Boris; Kohler, Achim

    2015-01-01

    Analysis of pollen grains reveals valuable information on biology, ecology, forensics, climate change, insect migration, food sources and aeroallergens. Vibrational (infrared and Raman) spectroscopies offer chemical characterization of pollen via identifiable spectral features without any sample pretreatment. We have compared the level of chemical information that can be obtained by different multiscale vibrational spectroscopic techniques. Pollen from 15 different species of Pinales (conifers) were measured by seven infrared and Raman methodologies. In order to obtain infrared spectra, both reflectance and transmission measurements were performed on ground and intact pollen grains (bulk measurements), in addition, infrared spectra were obtained by microspectroscopy of multigrain and single pollen grain measurements. For Raman microspectroscopy measurements, spectra were obtained from the same pollen grains by focusing two different substructures of pollen grain. The spectral data from the seven methodologies were integrated into one data model by the Consensus Principal Component Analysis, in order to obtain the relations between the molecular signatures traced by different techniques. The vibrational spectroscopy enabled biochemical characterization of pollen and detection of phylogenetic variation. The spectral differences were clearly connected to specific chemical constituents, such as lipids, carbohydrates, carotenoids and sporopollenins. The extensive differences between pollen of Cedrus and the rest of Pinaceae family were unambiguously connected with molecular composition of sporopollenins in pollen grain wall, while pollen of Picea has apparently higher concentration of carotenoids than the rest of the family. It is shown that vibrational methodologies have great potential for systematic collection of data on ecosystems and that the obtained phylogenetic variation can be well explained by the biochemical composition of pollen. Out of the seven tested

  4. Grass pollen, aeroallergens, and clinical symptoms in Ciudad Real, Spain.

    Science.gov (United States)

    Feo Brito, F; Mur Gimeno, P; Carnés, J; Fernández-Caldas, E; Lara, P; Alonso, A M; García, R; Guerra, F

    2010-01-01

    In allergic individuals, onset of symptoms is related to atmospheric pollen grain counts and aeroallergen concentrations. However, this relationship is not always clear. To analyze the correlation between grass pollen grain and aeroallergen concentrations in Ciudad Real, Spain, during the year 2004 and establish their association with symptoms in patients with allergic asthma, rhinitis, or both. Two different samplers were used to assess allergen exposure: a Burkard spore trap to collect pollen grains and a high-volume air sampler to collect airborne particles. Individual filters were extracted daily in phosphate-buffered serum and analyzed by enzyme-linked immunosorbent assay based on serum containing high titers of specific immunoglobulin (Ig) E to grasses. The study population comprised 27 grass-allergic patients whose symptoms and medication were recorded daily. Grass pollens were detected between April 28 and July 18. There was a positive correlation between pollen grain counts and symptoms (r = 0.62; P > .001). Grass aeroallergens were detected not only during the grass pollination period, but also before and after this period. There was also a very significant correlation between aeroallergen levels and symptoms (r = 0.76; P < .0001). The threshold level for grass pollen was 35 grains/m3. Grass-related allergenic activity is present throughout the year, demonstrating the existence of aeroallergens outside the pollen season. Symptoms in allergic patients may be related to airborne particle concentrations. This fact should be taken into account in the clinical follow-up and management of allergic patients.

  5. Variation in pollen-donor composition among pollinators in an entomophilous tree species, Castanea crenata, revealed by single-pollen genotyping.

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    Yoichi Hasegawa

    Full Text Available In plants, reproductive success is largely determined by the composition of pollen (i.e., self-pollen and outcross-pollen from near and distant pollen-donors transported as a result of pollinator foraging behavior (e.g., pollen carryover. However, little evidence is available on how and to what extent the pollen carryover affects the pollen-donor composition and on which insect taxa are effective outcross-pollen transporters under field conditions. In this study, we explored roles of foraging behavior of insect pollinators on pollen-donor composition and subsequent reproductive success in a woody plant.We performed paternity analyses based on microsatellite genotyping of individual pollen grains found on diurnal pollinators (i.e., bumblebee, small bee, fly, small beetle, and honeybee visiting Castanea crenata trees.The outcross-pollen rate was highest in bumblebees (66%, followed by small bees (35%, flies (31%, and small beetles (18%. The effective number of pollen donors, representing pollen carryover, was greater in bumblebees (9.71 than in flies (3.40, small bees (3.32, and small beetles (3.06. The high percentages of pollen from outside the plot on bumblebees (65.4% and flies (71.2% compared to small bees (35.3% and small beetles (13.5% demonstrated their longer pollen dispersal distances.All of the diurnal insects carried outcross-pollen grains for long distances via pollen carryover. This fact suggests that a wide range of insect taxa are potential outcross-pollen transporters for the self-incompatible C. crenata.

  6. Variation in pollen-donor composition among pollinators in an entomophilous tree species, Castanea crenata, revealed by single-pollen genotyping.

    Science.gov (United States)

    Hasegawa, Yoichi; Suyama, Yoshihisa; Seiwa, Kenji

    2015-01-01

    In plants, reproductive success is largely determined by the composition of pollen (i.e., self-pollen and outcross-pollen from near and distant pollen-donors) transported as a result of pollinator foraging behavior (e.g., pollen carryover). However, little evidence is available on how and to what extent the pollen carryover affects the pollen-donor composition and on which insect taxa are effective outcross-pollen transporters under field conditions. In this study, we explored roles of foraging behavior of insect pollinators on pollen-donor composition and subsequent reproductive success in a woody plant. We performed paternity analyses based on microsatellite genotyping of individual pollen grains found on diurnal pollinators (i.e., bumblebee, small bee, fly, small beetle, and honeybee) visiting Castanea crenata trees. The outcross-pollen rate was highest in bumblebees (66%), followed by small bees (35%), flies (31%), and small beetles (18%). The effective number of pollen donors, representing pollen carryover, was greater in bumblebees (9.71) than in flies (3.40), small bees (3.32), and small beetles (3.06). The high percentages of pollen from outside the plot on bumblebees (65.4%) and flies (71.2%) compared to small bees (35.3%) and small beetles (13.5%) demonstrated their longer pollen dispersal distances. All of the diurnal insects carried outcross-pollen grains for long distances via pollen carryover. This fact suggests that a wide range of insect taxa are potential outcross-pollen transporters for the self-incompatible C. crenata.

  7. Allergy to Parietaria officinalis pollen.

    Science.gov (United States)

    Cvitanović, S

    1999-03-01

    Parietaria pollen allergens (officinalis, judaica, lusitanica, creatica) are one of the most common causes of pollinosis in the Mediterranean (Spain, France, Italy, and Croatia). Parietaria has very long period of pollination, often reaching peaks of more than 500 grains/m3 of air at the beginning of June, and very strong allergenic properties. There is a significantly positive correlation for the newcomers between the intensity of the skin test reaction and concentration of specific serum IgE with the length of residence in the area, whereas autochthonous patients show a negative correlation between the age and intensity of hypersensitivity. This suggests that the environment encountered at birth may have a decisive role in the development of allergic respiratory diseases. Due to structurally similar pollen antigens in different Parietaria species, they are all equally useful in diagnosis and treatment of allergy, regardless of the pollen species to which the patient is sensitive or the prevalent species in the area. In our hands, specific immunotherapy with subcutaneous injections of partially purified, characterized, and standardized pollen extract of Parietaria allergen proved effective. It was possible to define an optimal maintenance dose of antigen per injection. During (years of) therapy, we observed an initial increase in total serum IgE concentration and increase in allergen-specific serum IgG blocking antibodies, decrease in allergen-specific serum IgE concentration and amount of histamine released from peripheral blood leukocytes challenged in vitro with the allergen, as well as in symptom and additional medication scores.

  8. Pyrrolizidine alkaloids in pollen and pollen products.

    Science.gov (United States)

    Kempf, Michael; Heil, Sandra; Hasslauer, Iris; Schmidt, Lukas; von der Ohe, Katharina; Theuring, Claudine; Reinhard, Annika; Schreier, Peter; Beuerle, Till

    2010-02-01

    Recently, 1,2-dehydropyrrolizidine alkaloid (PA) ester alkaloids, found predominantly as their N-oxides (PANOs, pyrrolizidine N-oxides), have been reported in both honey and in pollen obtained directly from PA plants and pollen loads collected by bees, raising the possibility of health risks for consumers of these products. We confirm these findings in regard to floral pollen, using pollen collected directly from flowers of the known PA plants Senecio jacobaea, S. vernalis, Echium vulgare and pollinia of Phalaenopsis hybrids, and we extend analyses of 1,2-unsaturated PAs and 1,2-unsaturated PANOs to include bee-pollen products currently being sold in supermarkets and on the Internet as food supplements. PA content of floral pollen ranged from 0.5 to 5 mg/g. The highest values were observed in pollen obtained from Senecio species. Up to 95% of the PAs are found as PANOs. Detailed studies with S. vernalis revealed unique PA patterns in pollen and flowers. While seneciphylline was the most prominent PA in S. vernalis pollen, the flowers were dominated by senecionine. To analyze trace amounts of 1,2-unsaturated PAs in pollen products, our previously elaborated method consisting of strong cation exchange-SPE, two reduction steps followed by silylation and subsequent capillary high-resolution GC-MS using SIM mode was applied. In total, 55 commercially available pollen products were analyzed. Seventeen (31%) samples contained 1,2-unsaturated PAs in the range from 1.08 to 16.35 microg/g, calculated as retronecine equivalents. The 1,2-unsaturated PA content of pollen products is expressed in terms of a single sum parameter and no background information such as foraged plants, pollen analysis, etc. was needed to analyze the samples. The detection limit of overall procedure and the reliable quantitation limit were 0.003 and 0.01 microg/g, respectively.

  9. 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

  10. Pollen calendar of Lublin, 1995-2000

    Directory of Open Access Journals (Sweden)

    Krystyna Piotrowska

    2012-12-01

    Full Text Available The measurements of pollen fall were carried out in Lublin in 1995 - 2000 years by the gravimetric method. The modified Durham sampler was applied, located at 9 m above ground level. On the base of results 6 year observations - the pollen calendar for Lublin was prepared. The following 15 plant taxa were taken under consideration: Alnus, Corylus, Cupressaceae, Populus, Fraxinus, Betula, Quercus, Pinaceae, Poaceae, Rumex, Plantago, Urtica, Chenopodiaceae, Artemisia and Ambrosia. The anemophilous plants' pollen season in Lublin began in half of February and lasted till half of September. First appeared pollen grains of decidous tress' and shrubs, then the coniferous. High values of pollen fall of these plants were noted till the end of May. Start of grass pollen season was recorded from the half of May, and at the latter part of this month, also other herbaceous plants. The highest concentrations of pollen were found in April and May when trees and shrubs pollinated. The highest annual totals were marked for plants of the following taxa: Betula, Poaceae, Pinaceae, Alnus, Urtica.

  11. Interpretation of floodplain pollen in alluvial sediments from an Arid Region*1

    Science.gov (United States)

    Solomon, Allen M.; Blasing, T. J.; Solomon, J. A.

    1982-07-01

    Pollen was collected from modern alluvium and from the atmosphere to document the nature and amount of paleoenvironmental information reflected by alluvial pollen chronologies. Results indicate that pollen in alluvium is a homogeneous mixture derived almost entirely from the floodplain itself. The few pollen grains derived from nonfloodplain plant communities and preserved in alluvial sediments are so well mixed that their frequencies no longer reflect the geographic distribution of the specific plant communities in which they originated. In contrast, the abundance of alluvial pollen grains, derived from the major floodplain taxa (Chenopodiineae, Ambrosia type), varies with summer and winter climate. This annual variation is preserved in alluvial pollen assemblages through a combination of processes within sedimentation basins involving discontinuous deposition events and mechanical pollen degradation. The high-frequency, wide-amplitude pollen variance in alluvial pollen assemblages contrasts with the low-frequency, narrow-amplitude pollen variance in sediments of lakes and ponds. The slight geographic variance in alluvial pollen assemblages, in contrast to the large variance in soil pollen, allows use of alluvial pollen to infer climate throughout the watershed in which pollen is sampled.

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

    Science.gov (United States)

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

    2014-05-01

    Pectin is a complex polysaccharide and an integral part of the primary plant cell wall and middle lamella, contributing to cell wall mechanical strength and cell adhesion. To understand the structure-function relationships of pectin in the cell wall, a set of transgenic potato lines with altered pectin composition was analysed. The expression of genes encoding enzymes involved in pectin acetylation, degradation of the rhamnogalacturonan backbone and type and length of neutral side chains, arabinan and galactan in particular, has been altered. Upon crossing of different transgenic lines, some transgenes were not transmitted to the next generation when these lines were used as a pollen donor, suggesting male sterility. Viability of mature pollen was severely decreased in potato lines with reduced pectic arabinan, but not in lines with altered galactan side chains. Anthers and pollen of different developmental stages were microscopically examined to study the phenotype in more detail. Scanning electron microscopy of flowers showed collapsed pollen grains in mature anthers and in earlier stages cytoplasmic protrusions at the site of the of kin pore, eventually leading to bursting of the pollen grain and leaking of the cytoplasm. This phenomenon is only observed after the microspores are released and the tapetum starts to degenerate. Timing of the phenotype indicates a role for pectic arabinan side chains during remodelling of the cell wall when the pollen grain is maturing and dehydrating. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  13. Pollen count of selected taxa in the atmosphere of Lublin using two monitoring methods.

    Science.gov (United States)

    Piotrowska, Krystyna; Weryszko-Chmielewska, Elzbieta

    2003-01-01

    In 1997-1998, annual variations in the concentration of pollen in the atmosphere of Lublin, Poland, were analysed by the volumetric and gravimetric methods. To determine the concentration of pollen, a volumetric VST-trap was used, whereas for pollen fall - a gravimetric Durham trap. The following taxa were chosen for pollen analysis: Alnus, Corylus, Populus, Betula, Poaceae, Rumex, Plantago, Urtica, Chenopodiaceae and Artemisia. It was found that the length of pollen season, as well as pollen count increase and decrease tendencies determined by the two methods, were similar. Maximum concentrations of pollen grains occurred on the same dates for arboreous plants, Artemisia and Poaceae in 1997. In the case of other herbal plants, the maximum dates might be different, yet abundant occurrence of pollen grains was registered at the same time.

  14. AIRBORNE POLLEN CONTENT OF TAVŞANLI, KÜTAHYA (TURKEY

    Directory of Open Access Journals (Sweden)

    Sevcan CELENK

    2016-12-01

    Full Text Available A qualitative and quantitative evaluation of pollen fall in the atmosphere of Tavşanlı (Kütahya is presented in this study. A continuous aerobiological survey of the atmosphere of Tavşanlı was carried out from beginning of January 2003 to end of December 2004 by means of the gravimetric method using Durham apparatus. Weekly pollen grains in per cm2 were calculated. During two years, a total of 17 079 pollen grains/ cm2 which belong to 52 taxa, 25 of total belong to arboreal plants (AP and 27 of total non-arboreal (NAP plants and unidentified pollen grains were recorded. 11 630 and 5 449 pollen grains were recorded in the years 2003 and 2004 respectively. Total pollen grains consist of 88.46 % AP, 9.67 % NAP plants and 1.87% unidentified pollen grains. Pinus sp., Cupressaceae/Taxaceae, Quercus sp., Gramineae, Platanus sp., Salix sp. Moraceae and Oleaceae were responsible for the greatest amounts of pollens in the investigated region. 67.48 % of total pollen grains appeared during May.

  15. Estimates of common ragweed pollen emission and dispersion over Europe using RegCM-pollen model

    Science.gov (United States)

    Liu, L.; Solmon, F.; Vautard, R.; Hamaoui-Laguel, L.; Torma, Cs. Zs.; Giorgi, F.

    2015-11-01

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

  16. Visualization of plastid movement in the pollen tube of Arabidopsis thaliana

    OpenAIRE

    Fujiwara, Makoto T.; Yoshioka, Yasushi; Hirano, Tomonari; Kazama, Yusuke; Abe, Tomoko; Hayashi, Kensuke; Itoh, Ryuuichi D.

    2012-01-01

    Organelle dynamics in the plant male gametophyte has received attention for its importance in pollen tube growth and cytoplasmic inheritance. We recently revealed the dynamic behaviors of plastids in living Arabidopsis pollen grains and tubes, using an inherent promoter-driven FtsZ1–green fluorescent protein (GFP) fusion. Here, we further monitored the movement of pollen tube plastids with an actin1 promoter-driven, stroma-targeted yellow fluorescent protein (YFP). In elongating pollen tubes,...

  17. Optimization of conditions for in vitro pollen germination and pollen ...

    African Journals Online (AJOL)

    Pollen germination and pollen tube growth might have a significant effect on fruit and seed production. This study was conducted to investigate the best medium for pollen germination and pollen tube growth of date palm male. Significant differences in percentages of pollen germination and pollen tube growth were ...

  18. Pollen morphology of some Geranium subgenus Robertium species of Iran

    Directory of Open Access Journals (Sweden)

    M. Keshavarzi

    2016-06-01

    Full Text Available Geranium (Geraniaceae comprises more than 23 annual or perennial species in Iran. There is no study in Iran with pollen morphology emphasize. The main aim of this study is to find diagnostic pollen characters in studied species. Totally 40 accessions of five species (G. albanum, G. molle, G. purpureum, G. mascatense and G. pusillum were collected. Pollen grains were studied by use of light and Scanning electron microscopy. To reveal the species relationships different multivariate statistical methods were used. The pollen grains were monad, isopolar, radially symmetric and of spheroid, prolate-spheroid or oblate-spheroid classes. The main ornamentation type was clavate, however reticulate but striate was also observed. All sections are clearly separated by their pollen features except of Batrachioidea which show confusion with Ruberta. Species relationship is discussed.

  19. Airborne pollen spectrum and hay fever type prevalence in Vinnitsa, central Ukraine

    Directory of Open Access Journals (Sweden)

    Victoria Valeriivna Rodinkova

    2015-12-01

    Full Text Available The article deals with the main pollen spectrum in relation to patients’ sensitivity determined in the ambient air of Vinnitsa city located in central Ukraine. The study performed by gravimetric sampling in the years 1999–2000 and by volumetric sampling in the years 2009–2014 showed that Urtica, Betula, Pinus, Alnus, Fraxinus, Ambrosia, Artemisia, Juglans, Carpinus, Populus, Quercus, Acer, Salix, Poaceae, Amarathaceae, and Polygonaceae pollen grains are prevalent among the airborne allergen types in the urban atmosphere. The principal pollen types remain the same but over time their quantities have changed. The relative abundance of Carpinus and Amaranthaceae airborne pollen decreased while the fraction of Urtica pollen increased in the last decade. From 50 to 69 pollen types were determined in the ambient air depending on the season. From 24 to 27 pollen types represented woody plants and from 22 to 46 pollen types belonged to the herbaceous plants. A considerable decrease in herbal pollen types is noted in the Vinnitsa air at present. It was shown that children were sensitive to weed pollen grains, including ragweed, mugwort, and grass, while adults were more sensitive to tree and grass pollen grains. Further studies of the pollen spectrum in the ambient air of this city are required in order to control the hay fever symptoms.

  20. Variation patterns of pollen production in palm flowers

    DEFF Research Database (Denmark)

    Alapetite, Elodie; Barfod, Anders; Albert, Beatrice

    2016-01-01

    in polyandrous species ranges from 8-9 to several hundreds. It is often heard that the more stamens are produced, the more pollen is produced, particularly in the case of the so-called “pollen flowers”, i.e. flowers in which pollen is the main food resource for floral visitors. However, the correlation between...... 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...

  1. Ecological features of flowers and the amount of pollen released in Corylus avellana (L. and Alnus glutinosa (L. Gaertn.

    Directory of Open Access Journals (Sweden)

    Krystyna Piotrowska

    2012-12-01

    Full Text Available Hazel and alder bloom as one of the first plants in climatic conditions of Poland. In the present study, detailed observations were made of the structure of flowers of Corylus avellana L. and Alnus glutinosa (L. Gaertn. Pollen yield of the abovementioned species was determined. The number of pollen grains in the theca, anther, flower and inflorescence was calculated. A comparison was made of the number of pollen grains of these taxa recorded during the atmospheric pollen seasons analysed over a period of 8 years in the conditions of Lublin. The study demonstrates that pollen yield of the common hazel inflorescence was 66 mg, whereas for black alder it was 120 mg. It was found that the number of pollen grains produced by the alder inflorescence was 2.2 times higher than by the hazel inflorescence. The atmospheric pollen season of the studied plant taxa was recorded at similar dates, but alder pollen was in much larger concentrations.

  2. Antioxidant properties of pollen

    OpenAIRE

    Aličić, Damir; Šubarić, Drago; Jašić, Midhat; Pašalić, Hatidža; Ačkar, Đurđica

    2014-01-01

    Today, bee pollen is commonly used in folk medicine and its pharmacy effects have not yet been scientifically proven. The composition and chemistry of bee pollen are not yet standardized nor defined in pharmacopoeia, and may vary due to its botanical and geographical origin, the plant species, environmental conditions, age and status of plants. Because of this, the type of bee pollen depends on the available bee pasture and types of plant species visited by bees. Bee pollen contains nutrition...

  3. Pollen morphology of the Polish species of the genus Ribes L.

    Directory of Open Access Journals (Sweden)

    Dorota Wrońska-Pilarek

    2014-01-01

    Full Text Available This paper presents results of studies on pollen morphology of 6 Polish species of the genus Ribes L. (family Grossulariaceae. Observations were carried out with LM and SEM. Pollen diagnoses were illustrated by series of microphotographs. Grains of examined species are small to medium-sized and prolate spheroidal or subprolate in shape, rarely prolate. They represent three pollen classes: zonocolporate, pantoaperturate and pantoporate. Three types of ectoapertures have been observed: colpi, pori and colpoids. Endoapertures are pori, in number (4- 6-7-8 (-14 per grain. Ornamentation is psilate or fossulate, with the exception of the ectoaperture areas, which are granulate. According to the author, the polarity or apolarity, type of pollen class and ectoaperture, number of endopori and ratio of exine thickness to grain diameter are the main diagnostic features of the pollen grains of the native species of Ribes. The key to Polish species, basing on the morphological characters of grains is given too.

  4. Pollen reference collection digitization

    NARCIS (Netherlands)

    Ercan, F.E.Z.|info:eu-repo/dai/nl/41250085X; Donders, T.H.|info:eu-repo/dai/nl/290469872; Bijl, P.K.|info:eu-repo/dai/nl/314028110; Wagner, F.|info:eu-repo/dai/nl/173870783

    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

  5. Pollen Grains, Random Walks and Einstein

    Indian Academy of Sciences (India)

    wnian motion show us how the most profound physics and mathematics can emerge from simple, direct obser- vation of natural phenomena. Ideas related to Brownian motion and random walks appear today in mathematics, all the natural sciences, engineering, linguistics, finance, economics, and even the social sciences.

  6. Pollen Grains, Random Walks and Einstein

    Indian Academy of Sciences (India)

    dard, Moles of hydrogen. oxy- gen and water, respectively weigh 2.32 and 18 grams. and. NA. • the number of molecules in one mole, named in honour of. Avogadro. is about 6 x 1023 , In particular. note that measuring. NA tells us that one hydrogen atom (and ...... motor proteins in celIs, the analysis of DNA sequences,.

  7. Managing Viable Knowledge

    NARCIS (Netherlands)

    Achterbergh, J.M.I.M.; Vriens, D.J.

    2002-01-01

    In this paper, Beer's Viable System Model (VSM) is applied to knowledge management. Based on the VSM, domains of knowledge are identified that an organization should possess to maintain its viability. The logic of the VSM is also used to support the diagnosis, design and implementation of the

  8. 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.

  9. Comparative studies of allergenic extracts prepared from freshly collected, dried, or dried and defatted pollen.

    Science.gov (United States)

    González Romano, M L; Berrens, L

    1995-01-01

    Fresh pollen samples of Parietaria judaica, Betula pubescens, Dactylis glomerata and Olea europaea were collected and aliquot portions of these pollens were stored after drying in hot air, while other portions were dried and then defatted with diethylether. The different pollen materials were extracted with aqueous media to obtain the non-dialyzable allergenic protein constituents. Review of the production data, together with comparative analyses of the UV-absorption spectra and of IgE binding potencies did not reveal appreciable differences in allergen composition among extracts of fresh, dried, or dried and defatted pollen materials. However, microscopic examination showed the fresh pollen to be no longer viable.

  10. Pollen morphology of the Polish species of the genus Sorbus L.

    Directory of Open Access Journals (Sweden)

    Leszek Bednorz

    2011-01-01

    Full Text Available This paper presents the results of the study on pollen morphology of five Polish species of the genus Sorbus L. (S. aria (L. Crantz, S. aucuparia L. Emend. Hedl., S. chamaemespilus (L. Crantz, S. intermedia (Ehrh. Pers. and S. torminalis (L. Crantz. Observations were carried out with light and scanning microscopes. Investigated pollen grains were small or medium size, most often subprolate or prolate spheroidal in outline. Exine of medium thickness, consisted of two layers. Mainly 3-zonocolporate or sometimes 4-zonocolporate (S. chamaemespilus and S. torminalis grains were noted. Usually striatae type of sculpture was observed, except the grains of S. intermedia, which were characterized by intermediate type of sculpture, with the features both striate and regulate ornamentation. Pollen morphology of the investigated Sorbus species corresponds with their systematic classification. It is relatively easy to separate pollen grains of the following subgenera: Sorbus, Chamaemespilus and Torminaria. Only subgenus Aria includes grains of different morphology and therefore it is impossible to determine the diagnostic features of this subgenus. Pollen morphology does not confirm a close relationship between S. aria and S. intermedia. It is possible to distinguished pollen grains of all the analysed native species. However, there are no important differences in pollen morphology between the subspecies of Sorbus aucuparia. The key for Polish Sorbus species, based on pollen grain characters is given too.

  11. Regulatory Networks in Pollen Development under Cold Stress

    OpenAIRE

    Kamal Dev Sharma; Harsh eNayyar

    2016-01-01

    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 endog...

  12. Genomic expression profiling of mature soybean (Glycine max pollen

    Directory of Open Access Journals (Sweden)

    Singh Mohan B

    2009-03-01

    Full Text Available Abstract Background Pollen, the male partner in the reproduction of flowering plants, comprises either two or three cells at maturity. The current knowledge of the pollen transcriptome is limited to the model plant systems Arabidopsis thaliana and Oryza sativa which have tri-cellular pollen grains at maturity. Comparative studies on pollen of other genera, particularly crop plants, are needed to understand the pollen gene networks that are subject to functional and evolutionary conservation. In this study, we used the Affymetrix Soybean GeneChip® to perform transcriptional profiling on mature bi-cellular soybean pollen. Results Compared to the sporophyte transcriptome, the soybean pollen transcriptome revealed a restricted and unique repertoire of genes, with a significantly greater proportion of specifically expressed genes than is found in the sporophyte tissue. Comparative analysis shows that, among the 37,500 soybean transcripts addressed in this study, 10,299 transcripts (27.46% are expressed in pollen. Of the pollen-expressed sequences, about 9,489 (92.13% are also expressed in sporophytic tissues, and 810 (7.87% are selectively expressed in pollen. Overall, the soybean pollen transcriptome shows an enrichment of transcription factors (mostly zinc finger family proteins, signal recognition receptors, transporters, heat shock-related proteins and members of the ubiquitin proteasome proteolytic pathway. Conclusion This is the first report of a soybean pollen transcriptional profile. These data extend our current knowledge regarding regulatory pathways that govern the gene regulation and development of pollen. A comparison between transcription factors up-regulated in soybean and those in Arabidopsis revealed some divergence in the numbers and kinds of regulatory proteins expressed in both species.

  13. Comparative pollen morphological analysis in the subgenera Passiflora and Decaloba.

    Science.gov (United States)

    Soares, Taliane L; Jesus, Onildo N; Souza, Everton H; Rossi, Mônica L; Oliveira, Eder J

    2017-10-16

    The genus Passiflora is the most diversified of the Passifloraceae, and its palynology presents wide morphological variability. The objective of the study was to evaluate the pollen morphology of 18 Passiflora species in order to identify informative pollinic characteristics to contribute to the taxonomic classification of the genus. The morphology of the pollen grains and the exine structure were investigated using light microscopy and scanning electron microscopy. Differences in the pollen morphology were found in the studied species, mainly in terms of shape, pollen aperture and ornamentation pattern of the exine. Most of the species belonging to the subgenus Passiflora presented ornamented 6-syncolpate pollen grains with an oblate-spheroidal shape and an exine with large lumens. In the subgenus Decaloba the pollen grains were 6-colporate, 12-colpate and 12-colporate, with subprolate to prolate-spheroidal shape, as well as an exine with smaller lumen size and few ornamented. The pollen morphology of the species of the subgenera Passiflora and Decaloba has shown palynological characteristics that have specific diagnostic value, thus allowing a better understanding of the taxonomy of the genus Passiflora.

  14. 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.

  15. Air-spore in Cartagena, Spain: viable and non-viable sampling methods.

    Science.gov (United States)

    Elvira-Rendueles, Belen; Moreno, Jose; Garcia-Sanchez, Antonio; Vergara, Nuria; Martinez-Garcia, Maria Jose; Moreno-Grau, Stella

    2013-01-01

    In the presented study the airborne fungal spores of the semiarid city of Cartagena, Spain, are identified and quantified by means of viable or non-viable sampling methods. Airborne fungal samples were collected simultaneously using a filtration method and a pollen and particle sampler based on the Hirst methodology. This information is very useful for elucidating geographical patterns of hay fever and asthma. The qualitative results showed that when the non-viable methodology was employed, Cladosporium, Ustilago, and Alternaria were the most abundant spores identified in the atmosphere of Cartagena, while the viable methodology showed that the most abundant taxa were: Cladosporium, Penicillium, Aspergillus and Alternaria. The quantitative results of airborne fungal spores identified by the Hirst-type air sampler (non-viable method), showed that Deuteromycetes represented 74% of total annual spore counts, Cladosporium being the major component of the fungal spectrum (62.2%), followed by Alternaria (5.3%), and Stemphylium (1.3%). The Basidiomycetes group represented 18.9% of total annual spore counts, Ustilago (7.1%) being the most representative taxon of this group and the second most abundant spore type. Ascomycetes accounted for 6.9%, Nectria (2.3%) being the principal taxon. Oomycetes (0.2%) and Zygomycestes and Myxomycestes (0.06%) were scarce. The prevailing species define our bioaerosol as typical of dry air. The viable methodology was better at identifying small hyaline spores and allowed for the discrimination of the genus of some spore types. However, non-viable methods revealed the richness of fungal types present in the bioaerosol. Thus, the use of both methodologies provides a more comprehensive characterization of the spore profile.

  16. The occurrence of Ambrosia pollen in the atmosphere of Northwest Turkey: investigation of possible source regions

    Science.gov (United States)

    Celenk, Sevcan; Malyer, Hulusi

    2017-08-01

    Ambrosia pollen was first reported as an important allergen in North America at the end of the nineteenth century, and many European countries have recently reported its increasing significance for pollen allergy. The aims of this study were to determine whether the highly allergenic Ambrosia pollen recorded during the studied period could be the result of long-distance transport (LDT) and to identify the potential sources of Ambrosia pollen grains. The study investigates Ambrosia pollen episodes during the peak term of six yearly periods between 2010 and 2015 by examining source regions in Ambrosia pollen in Bursa, Turkey. A volumetric trap was used for collecting the pollen samples, and the back-trajectory model was used to identify a potential source of atmospheric Ambrosia pollen. The days when pollen levels exceeded 30 P m-3 were computed, and clusters were shown on the figures. The study indicates that the Ambrosia pollen grains recorded during the episode in Bursa were not produced by local sources but transported long distances from potential source regions around the Azov Sea in Russia and Ukraine, Black Sea region of Turkey, Romania, and Bulgaria. Note that atmospheric concentrations of Ambrosia pollen exceeded the clinical threshold during 28 days during the investigation period. Taking into consideration the high allergenicity of Ambrosia pollen, the present findings suggest that the number of ragweed-sensitized individuals might increase in the near future in the region.

  17. Interpretation of floodplain pollen in alluvial sediments from an arid region

    Energy Technology Data Exchange (ETDEWEB)

    Solomon, A.M.; Blasing, T.J.; Solomon, J.A.

    1982-01-01

    Pollen was collected from modern alluvium and from the atmosphere to document the nature and amount of paleoenvironmental information reflected by alluvial pollen chronologies. Results indicate that pollen in alluvium is a homogeneous mixture derived almost entirely from the floodplain itself. The few pollen grains derived from nonfloodplain plant communities and preserved in alluvial sediments are so well mixed that their frequencies no longer reflect the geographic distribution of the specific plant communities in which they originated. In contrast, the abundance of alluvial pollen grains, derived from the major floodplain taxa (Chenopodiineae, Ambrosia type), varies with summer and winter climate. This annual variation is preserved in alluvial pollen assemblages through a combination of processes within sedimentation basins involving discontinuous deposition events and mechanical pollen degradation. The high-frequency, wide-amplitude pollen variance in sediments of lakes and ponds. The slight geographic variance in alluvial pollen assemblages, in contrast to the large variance in soil pollen, allows use of alluvial pollen to infer climate throughout the watershed in which pollen is sampled.

  18. Assessment of pollen reward and pollen availability in Solanum stramoniifolium and Solanum paniculatum for buzz-pollinating carpenter bees.

    Science.gov (United States)

    Burkart, A; Schlindwein, C; Lunau, K

    2014-03-01

    The two widespread tropical Solanum species S. paniculatum and S. stramoniifolium are highly dependent on the visits of large bees that pollinate the flowers while buzzing them. Both Solanum species do not offer nectar reward; the rewarding of bees is thus solely dependent on the availability of pollen. Flower visitors are unable to visually assess the amount of pollen, because the pollen is hidden in poricidal anthers. In this study we ask whether and how the amount of pollen determines the attractiveness of flowers for bees. The number of pollen grains in anthers of S. stramoniifolium was seven times higher than in S. paniculatum. By contrast, the handling time per five flowers for carpenter bees visiting S. paniculatum was 3.5 times shorter than of those visiting S. stramoniifolium. As a result foraging carpenter bees collected a similar number of pollen grains per unit time on flowers of both species. Experimental manipulation of pollen availability by gluing the anther pores showed that the carpenter bees were unable to detect the availability of pollen by means of chemical cues before landing and without buzzing. Our study shows that the efficiency of pollen collecting on S. paniculatum is based on large inflorescences with short between-flower search times and short handling time of individual flowers, whereas that of S. stramoniifolium relies on a large amount of pollen per flower. Interestingly, large carpenter bees are able to adjust their foraging behaviour to drastically different strategies of pollen reward in otherwise very similar plant species. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

  19. Poaceae Pollen From Southern Brazil: Distinguishing Grasslands (Campos From Forests by Analyzing a Diverse Range of Poaceae Species

    Directory of Open Access Journals (Sweden)

    Jefferson Nunes Radaeski

    2016-12-01

    Full Text Available This aim of this study was to distinguish grasslands from forests in southern Brazil by analyzing Poaceae pollen grains. Through light microscopy analysis, we measured the size of the pollen grain, pore, and annulus from 68 species of Rio Grande do Sul. Measurements were recorded of 10 forest species and 58 grassland species, representing all tribes of the Poaceae in Rio Grande do Sul. We measured the polar, equatorial, pore, and annulus diameter. Results of statistical tests showed that arboreous forest species have larger pollen grain sizes than grassland and herbaceous forest species, and in particular there are strongly significant differences between arboreous and grassland species. Discriminant analysis identified three distinct groups representing each vegetation type. Through the pollen measurements we established three pollen types: larger grains (>46 µm, from the Bambuseae pollen type, medium-sized grains (46–22µm, from herbaceous pollen type, and small grains (<22 µm, from grassland pollen type. The results of our compiled Poaceae pollen dataset may be applied to the fossil pollen of Quaternary sediments.

  20. Modern pollen deposition in Long Island Sound

    Science.gov (United States)

    Beuning, Kristina R.M.; Fransen, Lindsey; Nakityo, Berna; Mecray, Ellen L.; Bucholtz ten Brink, Marilyn R.

    2000-01-01

    Palynological analyses of 20 surface sediment samples collected from Long Island Sound show a pollen assemblage dominated by Carya, Betula, Pinus, Quercus, Tsuga, and Ambrosia, as is consistent with the regional vegetation. No trends in relative abundance of these pollen types occur either from west to east or associated with modern riverine inputs throughout the basin. Despite the large-scale, long-term removal of fine-grained sediment from winnowed portions of the eastern Sound, the composition of the pollen and spore component of the sedimentary matrix conforms to a basin-wide homogeneous signal. These results strongly support the use of select regional palynological boundaries as chronostratigraphic tools to provide a framework for interpretation of the late glacial and Holocene history of the Long Island Sound basin sediments.

  1. Annexin5 plays a vital role in Arabidopsis pollen development via Ca2+-dependent membrane trafficking.

    Directory of Open Access Journals (Sweden)

    Jingen Zhu

    Full Text Available The regulation of pollen development and pollen tube growth is a complicated biological process that is crucial for sexual reproduction in flowering plants. Annexins are widely distributed from protists to higher eukaryotes and play multiple roles in numerous cellular events by acting as a putative "linker" between Ca2+ signaling, the actin cytoskeleton and the membrane, which are required for pollen development and pollen tube growth. Our recent report suggested that downregulation of the function of Arabidopsis annexin 5 (Ann5 in transgenic Ann5-RNAi lines caused severely sterile pollen grains. However, little is known about the underlying mechanisms of the function of Ann5 in pollen. This study demonstrated that Ann5 associates with phospholipid membrane and this association is stimulated by Ca2+ in vitro. Brefeldin A (BFA interferes with endomembrane trafficking and inhibits pollen germination and pollen tube growth. Both pollen germination and pollen tube growth of Ann5-overexpressing plants showed increased resistance to BFA treatment, and this effect was regulated by calcium. Overexpression of Ann5 promoted Ca2+-dependent cytoplasmic streaming in pollen tubes in vivo in response to BFA. Lactrunculin (LatB significantly prohibited pollen germination and tube growth by binding with high affinity to monomeric actin and preferentially targeting dynamic actin filament arrays and preventing actin polymerization. Overexpression of Ann5 did not affect pollen germination or pollen tube growth in response to LatB compared with wild-type, although Ann5 interacts with actin filaments in a manner similar to some animal annexins. In addition, the sterile pollen phenotype could be only partially rescued by Ann5 mutants at Ca2+-binding sites when compared to the complete recovery by wild-type Ann5. These data demonstrated that Ann5 is involved in pollen development, germination and pollen tube growth through the promotion of endomembrane trafficking

  2. 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

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    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

  3. 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...

  4. [Juniper pollen monitoring by Burkard sampler in Galveston, Texas, USA and Japanese cedar pollen counting in Fukuoka, Japan -- introduction of Pan American Aerobiology Association protocol counting technique].

    Science.gov (United States)

    Kishikawa, Reiko; M-Horiuti, Terumi; Togawa, Akihisa; Kondoh, Yasuto; Janzy, Paul D; Goldblum, Randal M; Kotoh, Eiko; Shimoda, Teruhumi; Shoji, Shunsuke; Nishima, Sankei; Brooks, Edward G

    2004-06-01

    We have monitored Juniper pollen which caused winter allergy symptoms by Burkard sampler in Galveston, Texas. We identified and counted Juniper pollen grains by PAAA protocol which was a comprehensive guideline for the operation of Hirst-Type suction bioaerosol sampler, (original of Burkard sampler) in the USA. In Galveston we were able to detect the Mountain Cedar (Juniperus ashei) pollen from December to of January, and Eastern Red Cedar (Juniperus virginiana) which has cross reactivity to MC from almost middle of January to February. There is no MC vegetation in Galveston. We found the pollen grains were transported from west at Edward Plateau in West Texas where it was thickly wooded. Then, we tried to monitor Japanese Cedar (JC) pollen grains in Fukuoka, Japan according with the same method. We found the significant positive correlation between the pollen counts using one single longitudinal traverse counting technique in the PAAA protocol and the JC pollen counting on the whole of Melinex tape per 24 hours (R2=0.9212, p=0.0001), and the gravitational method that is Durham sampler's pollen counting in 2002 (R2=0.489, p=0.0001), and in 2003 (R2=0.948, p=0.0001) respectively. We suggested that we can use the PAAA protocol for airborne pollen investigation in Japan by Burkard sampler.

  5. Poaceae, Secale spp. and Artemisia spp. pollen in the air at two sites of different degrees of urbanisation.

    Science.gov (United States)

    Kruczek, Aleksandra; Puc, Małgorzata; Wolski, Tomasz

    2017-03-21

    Among herbal plants, most cases of allergic reactions, like seasonal inflammation of nasal mucosa, conjunctivitis and pollen asthma, are related to the allergens from grass pollen. As the blossoming and pollination of rye is known to start the pollen season of grasses, information about the airborne rye pollen count permits alerting the people allergic to certain allergens contained in rye pollen. An important cause of allergy is also the pollen from wormwood, blossoming in late summer, as its two main allergens produce cross-reactions with many other plant allergens. The aim of the study was to evaluate the risk of allergic reactions in persons with pollinosis on the basis of the pollen calendar, analysis of concentrations of pollen grains of grass and rye, and comparison of diurnal pattern of airborne pollen grain concentrations at two sites with different degrees of urbanisation (Gudowo in the country and the city of Szczecin) in 2012-2014. The concentration of pollen was measured by the volume method. Length of the pollination season was determined by the method of 98%, assuming that the beginning and the end of the pollen season are the days on which 1% and 99% of the annual sum of pollen appeared. The first pollen grains to appear in the air are those produced by rye, followed by those produced by grass and wormwood. The pollen seasons of grasses and wormwood started about one week earlier in Gudowo than in Szczecin, while the pollen season of rye started at almost the same time in the country and in the city. Airborne pollen counts of grasses, rye and wormwood were much higher in the country than in the city. The differences most probably result from the different floristic composition at these two sites and reflect the local contribution of the taxa studied in the country. The risk of allergy caused by the pollen of the taxa analysed was much higher in Gudowo (in the country), than in Szczecin city.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    Taliane Leila Soares

    2013-12-01

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

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

    Directory of Open Access Journals (Sweden)

    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.;

  9. A comparative analysis of the distribution and composition of lipidic constituents and associated enzymes in pollen and stigma of sunflower.

    Science.gov (United States)

    Shakya, Rashmi; Bhatla, Satish Chander

    2010-06-01

    Spatial distribution and compositional analyses of the lipidic constituents in pollen and stigma of sunflower (Helianthus annuus L. cv. Morden) were conducted using ultrastructural, histochemical, and biochemical analysis. Detection of secretions at the base of stigmatic papillae and neutral lipid accumulations on the surface of stigmatic papillae and between adjacent pseudopapillae demonstrates the semidry nature of stigma surface in sunflower. Pollen coat is richer in lipids (8%) than stigma (2.2%) on fresh weight basis. Nile Red-fluorescing neutral lipids are preferentially localized in the pollen coat. Neutral esters and triacylglycerols (TAGs) are the major lipidic constituents in pollen grains and stigma, respectively. Lignoceric acid (24:0) and cis-11-eicosenoic acid (20:1) are specifically expressed only in the pollen coat. Similar long-chain fatty acids have earlier been demonstrated to play a significant role during the initial signaling mechanism leading to hydration of pollen grains on the stigma surface. Lipase (EC 3.1.1.3) activity is expressed both in pollen grains and stigma. Stigma exhibits a better expression of acyl-ester hydrolase (EC 3.1.1.1) activity than that of observed in both the pollen fractions. Expression of two acyl-ester hydrolases (41 and 38 kDa) has been found to be specific to pollen coat. Specific expression of lignoceric acid (24:0) in pollen coat and localization of lipase in pollen and stigma have been discussed to assign possible roles that they might play during pollen-stigma interaction.

  10. Interspecific variation in pollen-ovule ratio is negatively correlated with pollen transfer efficiency in a natural community.

    Science.gov (United States)

    Gong, Y-B; Huang, S-Q

    2014-07-01

    The pollination efficiency hypothesis has long been proposed as an explanation for interspecific variation in pollen-ovule (P:O) ratios. However, no empirical study on P:O ratios has directly and quantitatively measured pollen transfer efficiency (PE). Here, we use a PE index, defined as the proportion of pollen grains removed from anthers that are subsequently deposited on conspecific stigmas, as a direct and quantitative measure of PE. We investigated P:O ratios, pollen removal and pollen deposition in 26 plant species in an alpine meadow, over three consecutive years. Our community survey showed that nearly 5% of removed pollen was successfully deposited on conspecific stigmas. The PE index ranged from 0.01% up to 78.56% among species, and correlated negatively with the P:O ratio across years. This correlation was not changed by controlling for phylogenetic relationships among species, suggesting that the interspecific variation in P:O ratios can be attributed to the probability of pollen grains reaching a stigma. The results indicate that the pollination efficiency hypothesis can help to explain interspecific variation in P:O ratios. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Pollen tube growth: where does the energy come from?

    Science.gov (United States)

    Selinski, Jennifer; Scheibe, Renate

    2014-01-01

    This review focuses on the energy metabolism during pollen maturation and tube growth and updates current knowledge. Pollen tube growth is essential for male reproductive success and extremely fast. Therefore, pollen development and tube growth are high energy-demanding processes. During the last years, various publications (including research papers and reviews) emphasize the importance of mitochondrial respiration and fermentation during male gametogenesis and pollen tube elongation. These pathways obviously contribute to satisfy the high energy demand, and there are many studies which suggest that respiration and fermentation are the only pathways to generate the needed energy. Here, we review data which show for the first time that in addition plastidial glycolysis and the balancing of the ATP/NAD(P)H ratio (by malate valves and NAD(+) biosynthesis) contribute to satisfy the energy demand during pollen development. Although the importance of energy generation by plastids was discounted during the last years (possibly due to the controversial opinion about their existence in pollen grains and pollen tubes), the available data underline their prime role during pollen maturation and tube growth.

  13. Analysis of airborne pollen concentrations in Zagreb, Croatia, 2002.

    Science.gov (United States)

    Peternel, Renata; Culig, Josip; Mitić, Bozena; Vukusić, Ivan; Sostar, Zvonimir

    2003-01-01

    Employing the volumetric method by use of a Hirst sampler, a total of 71,286 pollen grains, as many as 94.20% of them allergenic, were recorded in the air samples from the city of Zagreb during the 2002 pollen season. Among identified pollen of 35 plant species/genera/families, 23 were allergenic: Taxus/Juniperus, Alnus sp., Fraxinus sp., Betula sp., Corylus sp., Poaceae, Urticaceae, Artemisia sp., Ambrosia sp., Carpinus sp., Castanea sp., Chenopodiaceae, Salix sp., Populus sp., Ulmus sp., Juglans sp., Quercus sp., Platanus sp., Fagus sp., Plantago sp., Pinus sp., Picea sp. and Abies sp. The pollen of these plants also cause the majority of pollinosis in Europe. Study results and the pollen calendar designed for the 2002 pollen season for the City of Zagreb provide useful data for allergologists to reach an accurate diagnosis. The calendar also provides timely information on airborne pollen types and air concentrations for individuals with pollen hypersensitivity, thus allowing them to adjust their daily activities so as to minimize their contact with allergens and improve their quality of life both at home and at work.

  14. Ragweed (Ambrosia pollen in aeroplankton of Upper Silesia

    Directory of Open Access Journals (Sweden)

    Kazimiera Chłopek

    2012-12-01

    Full Text Available The work contains the analysis of Ambrosia pollen producing seasons in the atmosphere of Upper Silesia in the years 1998 - 2004. The research was carried out applying a volumetric method (Burkard pollen sampler in Sosnowiec and the gravimetric method, for comparative purposes, in Sosnowiec, Będzin, Czeladź and Katowice. The highest pollen concentration in the research years was found in Sosnowiec and in 1999 in Czeladź. The ambrosia pollen in aeroplankton was noticed in the first ten days of August until the middle of October. The maximum pollen concentrations were from 16 August to 21 September. The highest pollen concentration was found in 1999 and 2002 (222 and 127 grains per 1m3 per 24h on September 4th, the lowest concentration in 2001. Two genera - Ambrosia artemisiifolia and A. psilostachya - can be found over an area of Upper Silesia. They constitute the main source of pollen in aeroplankton, but its transportation from distant areas cannot be excluded. The pollen of these plants can be transported by the wind from neighbouring countries (the Czech Republic, Slovakia, Ukraine, Hungary.

  15. Factors affecting quantity of pollen dispersal of spray cut chrysanthemum (Chrysanthemum morifolium)

    OpenAIRE

    Wang, Xiao-Guang; Wang, Hai-Bin; Chen, Fa-Di; Jiang, Jia-Fu; Fang, Wei-Min; Liao, Yuan; Teng, Nian-Jun

    2014-01-01

    Background Spray cut chrysanthemum is a vital flower with high ornamental value and popularity in the world. However, the excessive quantity of pollen dispersal of most spray cut chrysanthemum is an adverse factor during its flowering stage, and can significantly reduce its ornamental value and quickly shorten its vase life. More seriously, excessive pollen grains in the air are usually harmful to people, especially for those with pollen allergies. Therefore, in order to obtain some valuable ...

  16. [Pollen dispersion of Cryptomeria japonica and Cupressaceae in Ito city during 10 years].

    Science.gov (United States)

    Fujii, Mayumi; Okazaki, Kenji; Makiyama, Kiyoshi; Hisamatsu, Kenichi

    2012-01-01

    For a period of 10 years, ending in 2010, the authors investigated atmospheric pollen dispersion of Cryptomeria japonica and Cupressaceae in Ito City. We expect this investigation useful in treating patients with pollen allergy. We set up a Durham sampler on a rooftop of the three-story building in Ito City and counted atmospheric pollen day by day. The results and the local weather conditions were treated statistically on the computer program Microsoft Excel. During the 10 years, in average, initial pollen was observed at January 3; pollen began to release was observed at February 6; final pollen was observed at May 12. The spring seasonal total pollen counts was 5683 grain/cm2. This pollen counts and the previous early winter seasonal pollen counts were correlated statistically. The pollen counts were related with the local weather conditions significantly. The investigations of the atmospheric pollen dispersion of Cryptomeria japonica and Cupressaceae and the weather conditions in the local area are useful to treat patients with the pollen allergy.

  17. Influence of pollen quality on ovarian development in honeybee workers (Apis mellifera scutellata).

    Science.gov (United States)

    Human, H; Nicolson, S W; Strauss, K; Pirk, C W W; Dietemann, V

    2007-07-01

    Protein-rich diets are known to promote ovarian and egg development in workers of the honeybee, Apis mellifera, even in the presence of a queen. Since the main source of protein for honeybees is pollen, its quality and digestibility might be important dietary factors determining reproductive capacity. We have compared the effect of two types of pollen-sunflower, Helianthus annuus, and aloe, Aloe greatheadii var davyana-on ovarian development in A. mellifera scutellata workers. Under queenright conditions in the field, worker bees exhibited greater ovarian development when feeding on aloe pollen than on sunflower pollen. In their midgut, we observed higher extraction efficiency for aloe (80%) than for sunflower (69%) pollen. This may be attributed to the morphology and size of the two kinds of pollen grains and explains, together with the high protein content of aloe pollen (32% dry mass in bee-collected pollen) compared to sunflower pollen (15%), why aloe pollen promoted higher ovarian development. However, in the laboratory workers sustained on aloe pollen had significantly less-developed ovaries and higher mortality than those fed sunflower pollen. These detrimental effects may be due to an unbalanced protein:carbohydrate ratio. We discuss the effects of unbalanced diets on the physiology and ecology of honeybee reproduction.

  18. MARIS plays important roles in Arabidopsis pollen tube and root hair growth.

    Science.gov (United States)

    Liao, Hong-Ze; Zhu, Meng-Meng; Cui, Hong-Hui; Du, Xin-Yu; Tang, Yu; Chen, Li-Qun; Ye, De; Zhang, Xue-Qin

    2016-11-01

    In flowering plants, male gametes are delivered to female gametes for double fertilization through pollen tubes. Therefore, pollen tube growth is crucial for double fertilization. Despite its importance to sexual reproduction, genetic mechanisms of pollen tube growth remain poorly understood. In this study, we characterized the receptor-like cytoplasmic protein kinase (RLCK) gene, MARIS (MRI) that plays critical roles in pollen tube growth. MRI is preferentially expressed in pollen grains, pollen tubes and roots. Mutation in MRI by a Ds insertion led to a burst of pollen tubes after pollen germination. Pollen-rescue assay by pollen and pollen tube-specific expression of MRI in the mri-4 mutant showed that loss of MRI function also severely affected root hair elongation. MRI protein interacted with the protein kinase OXIDATIVE SIGNAL INDUCIBLE1 (OXI1) in the in vitro and in vivo assays, which functions in plant defence and root hair development, and was phosphorylated by OXI1 in vitro. Our results suggest that MRI plays important roles in pollen tube growth and may function in root hair elongation through interaction with OXI1. © 2016 Institute of Botany, Chinese Academy of Sciences.

  19. Efficient and sensitive identification and quantification of airborne pollen using next-generation DNA sequencing.

    Science.gov (United States)

    Kraaijeveld, Ken; de Weger, Letty A; Ventayol García, Marina; Buermans, Henk; Frank, Jeroen; Hiemstra, Pieter S; den Dunnen, Johan T

    2015-01-01

    Pollen monitoring is an important and widely used tool in allergy research and creation of awareness in pollen-allergic patients. Current pollen monitoring methods are microscope-based, labour intensive and cannot identify pollen to the genus level in some relevant allergenic plant groups. Therefore, a more efficient, cost-effective and sensitive method is needed. Here, we present a method for identification and quantification of airborne pollen using DNA sequencing. Pollen is collected from ambient air using standard techniques. DNA is extracted from the collected pollen, and a fragment of the chloroplast gene trnL is amplified using PCR. The PCR product is subsequently sequenced on a next-generation sequencing platform (Ion Torrent). Amplicon molecules are sequenced individually, allowing identification of different sequences from a mixed sample. We show that this method provides an accurate qualitative and quantitative view of the species composition of samples of airborne pollen grains. We also show that it correctly identifies the individual grass genera present in a mixed sample of grass pollen, which cannot be achieved using microscopic pollen identification. We conclude that our method is more efficient and sensitive than current pollen monitoring techniques and therefore has the potential to increase the throughput of pollen monitoring. © 2014 John Wiley & Sons Ltd.

  20. Co-occurrence of Artemisia and Ambrosia pollen seasons against the background of the synoptic situations in Poland

    Science.gov (United States)

    Stępalska, Danuta; Myszkowska, Dorota; Katarzyna, Leśkiewicz; Katarzyna, Piotrowicz; Katarzyna, Borycka; Kazimiera, Chłopek; Łukasz, Grewling; Idalia, Kasprzyk; Barbara, Majkowska-Wojciechowska; Małgorzata, Malkiewicz; Małgorzata, Nowak; Krystyna, Piotrowska-Weryszko; Małgorzata, Puc; Elżbieta, Weryszko-Chmielewska

    2017-04-01

    The Asteraceae family is one of the largest families, comprising 67 genera and 264 species in Poland. However, only a few genera, including Artemisia and Ambrosia are potential allergenic sources. The aim of the study was to estimate how often and to what degree Artemisia and Ambrosia pollen seasons co-occur intensifying human health risk, and how synoptic situations influence frequency of days with high pollen concentrations of both taxa. Artemisia and Ambrosia pollen data were collected, using the volumetric method, at 8 sites in Poland. Daily concentrations of Artemisia pollen equal to 30 grains or more and Ambrosia pollen equal to 10 grains or more were accepted as high values. Concentrations of more than 10 pollen grains were defined as high in the case of Ambrosia because its allergenicity is considered higher. High concentrations were confronted with synoptic situations. Analysis was performed on the basis of two calendars on circulation types of atmosphere in Poland (Niedźwiedź, 2006, 2015). Co-occurrence of Artemisia and Ambrosia pollen seasons is being found most often, when Ambrosia pollen season starts in the first half of August. If it happens in the last 10 days of August high pollen concentrations of Artemisia and Ambrosia do not occur at the same days. At three sites (Sosnowiec, Rzeszów, Lublin) high Ambrosia pollen concentrations during the Artemisia pollen season appear more often than in other sites under question. The high Artemisia pollen concentrations occur, when continental or polar maritime old air masses inflow into Poland. The impact of air masses on high Ambrosia pollen concentrations depends on site localizations. It is likely, that in the south-eastern part of Poland high Ambrosia pollen concentrations result from the pollen transport from east-south-south-westerly directions and the local sources. Co-occurrence of both taxa pollen seasons depends on the air masses inflow and appears more often in a south-eastern part of Poland.

  1. Regulatory networks in pollen development under cold stress

    Directory of Open Access Journals (Sweden)

    Kamal Dev Sharma

    2016-03-01

    Full Text Available Cold stress modifies anthers’ metabolic pathways to induce pollen sterility. Cold-tolerant plants, unlike the susceptible ones, produce high proportion of viable pollen. Anthers in susceptible plants, when exposed to cold stress, increase abscisic acid (ABA metabolism and reduce ABA catabolism. Increased ABA negatively regulates expression of tapetum cell wall bound invertase and monosaccharide transport genes resulting in distorted carbohydrate pool in anther. Cold-stress also reduces endogenous levels of the bioactive gibberellins (GAs, GA4 and GA7, in susceptible anthers by repression of the GA biosynthesis genes. Here we discuss recent findings on mechanisms of cold susceptibility in anthers which determine pollen sterility. We also discuss differences in regulatory pathways between cold-stressed anthers of susceptible and tolerant plants that decide pollen sterility or viability.

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

    Science.gov (United States)

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

  3. 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

  4. Molecular changes during pollen germination can be monitored by Raman microspectroscopy.

    Science.gov (United States)

    Schulte, Franziska; Panne, Ulrich; Kneipp, Janina

    2010-08-01

    The processes associated with pollen germination were studied in vitro for two tree species, Salix caprea and Fraxinus excelsior under different nutrient conditions. The results provide evidence of changes in chemical composition of the pollen grains during germination. From the comparison of spectra of the pollen grain body and the growing pollen tube, it can be concluded that there are major chemical differences between these two morphological units. Comparison of germinated and ungerminated pollen grains reveals alterations in the metabolism. Composition of the germinating pollen grain and its morphological units depends on the plant species, but also on the nutrient conditions. The results suggest species-specific utilization of metabolite storage, and potential alterations of the pollen outer coat. Furthermore, discharge of molecules into the nutrient medium may depend on the nutrient conditions in the germination experiments. This has implications for further experiments on dynamic processes in pollen and related plant materials. (c) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Examination of climatological wind patterns and simulated pollen dispersion in a complex island environment.

    Science.gov (United States)

    Viner, Brian J; Arritt, Raymond W; Westgate, Mark E

    2017-03-29

    Complex terrain creates small-scale circulations which affect pollen dispersion but may be missed by meteorological observing networks and coarse-grid meteorological models. On volcanic islands, these circulations result from differing rates of surface heating between land and sea as well as rugged terrain. We simulated the transport of bentgrass, ryegrass, and maize pollen from 30 sources within the agricultural regions of the Hawaiian island Kaua'i during climatological conditions spanning season conditions and the La Niña, El Niño, and neutral phases of the El Niño-Southern Oscillation. Both pollen size and source location had major effects on predicted dispersion over and near the island. Three patterns of pollen dispersion were identified in response to prevailing wind conditions: southwest winds transported pollen inland, funneling pollen grains through valleys; east winds transported pollen over the ocean, with dispersive tails for the smallest pollen grains following the mean wind and extending as far as the island of Ni'ihau 35 km away; and northeast winds moved pollen inland counter to the prevailing flow due to a sea breeze circulation that formed over the source region. These results are the first to predict the interactions between complex island terrain and local climatology on grass pollen dispersion. They demonstrate how numerical modeling can provide guidance for field trials by illustrating the common flow regimes present in complex terrain, allowing field trials to focus on areas where successful sampling is more likely to occur.

  6. Examination of climatological wind patterns and simulated pollen dispersion in a complex island environment

    Science.gov (United States)

    Viner, Brian J.; Arritt, Raymond W.; Westgate, Mark E.

    2017-08-01

    Complex terrain creates small-scale circulations which affect pollen dispersion but may be missed by meteorological observing networks and coarse-grid meteorological models. On volcanic islands, these circulations result from differing rates of surface heating between land and sea as well as rugged terrain. We simulated the transport of bentgrass, ryegrass, and maize pollen from 30 sources within the agricultural regions of the Hawaiian island Kaua'i during climatological conditions spanning season conditions and the La Niña, El Niño, and neutral phases of the El Niño-Southern Oscillation. Both pollen size and source location had major effects on predicted dispersion over and near the island. Three patterns of pollen dispersion were identified in response to prevailing wind conditions: southwest winds transported pollen inland, funneling pollen grains through valleys; east winds transported pollen over the ocean, with dispersive tails for the smallest pollen grains following the mean wind and extending as far as the island of Ni'ihau 35 km away; and northeast winds moved pollen inland counter to the prevailing flow due to a sea breeze circulation that formed over the source region. These results are the first to predict the interactions between complex island terrain and local climatology on grass pollen dispersion. They demonstrate how numerical modeling can provide guidance for field trials by illustrating the common flow regimes present in complex terrain, allowing field trials to focus on areas where successful sampling is more likely to occur.

  7. Evolutionary trends in the morphology and harmomegathy of the pollen of the genus Guioa (Sapindaceae-Cupanieae)

    NARCIS (Netherlands)

    Ham, van der R.W.J.M.; Heuven, van B.J.

    1989-01-01

    A pollen morphological survey of the genus Guioa is presented. Based on a study of the harmomegathy in relation to morphological series, evolutionary trends are postulated: 1. wide ectoapertures → narrow ectoapertures 2. grain parasyncolporate → grain colporate 3. grain parasyncolporate → grain

  8. Fullerene-based symmetry in Hibiscus rosa-sinensis pollen.

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    Kleber Andrade

    Full Text Available 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.

  9. 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.

  10. [Ambrosia pollen under high surveillance].

    Science.gov (United States)

    Thibaudon, M; Lachasse, C

    2004-11-01

    The pollinic season of ambrosia in 2003 present strong disturbances due to the meteorology of the end of this summer. The areas with the allergenic risk are concentrated on the area of Rhône-Alpes (more than 40 days with a risk equal to or higher than 3) and on the peripheral areas: the area Centre Auvergne with Saint Etienne, Clermont-Ferrand and Montlucon with approximately 10 days with a the allergenic risk equal to or higher than 3; the Saône-Savoie area with the towns of Macon and Grenoble with about twenty days with a allergenic risk equal to or higher than 3 and Dijon, Châlon-sur-Saône with 6 days with a allergic risk equal to or higher than 3; the Mediterranean area with the towns of Avignon and Aix-in-Provence presenting ten days with allergenic risk equal to or higher than 3, Marseille and Toulon with 7 days with a allergenic risk equal to or higher than 3. The allergic risk related to the ambrosia in 2003 had peaks overall less high, but the season is spread out and had during until September 20. The daily peaks for the Rhône-Dauphiné-Drôme area were noted between 6 h and 8 h or 8 h and 10 h, for 2003. On the peripheral areas, we remark a diversity of the daily peaks (Châlon-sur-Saône between 18 h and 20 h). Are these pollens local grains or immigrants grains? On Lyon I (Gerland), the follow-up of the data of the ambrosia since 1987 permit to remark a stagnation of the number of days with an allergic risk, despite a reduction of the number of pollens.

  11. Exine ultrastructure of in situ pollen from the cycadalean cone Androstrobus prisma Thomas et Harris 1960 from the Jurassic of England

    NARCIS (Netherlands)

    Zavialova, N.; van Konijnenburg-van Cittert, J.H.A.|info:eu-repo/dai/nl/140562044

    2012-01-01

    Pollen grains extracted from the cycad pollen cone Androstrobus prisma Thomas et Harris 1960 from the Bajocian of Yorkshire were studied by means of LM, SEM and TEM. The species is characterized by rounded-oval, inaperturate pollen with an indistinctly verrucate surface and predominantly homogeneous

  12. Use of maize pollen by adult Chrysoperla carnea (Neuroptera: Chrysopidae) and fate of Cry proteins in Bt-transgenic varieties.

    Science.gov (United States)

    Li, Yunhe; Meissle, Michael; Romeis, Jörg

    2010-02-01

    We investigated the use of maize pollen as food by adult Chrysoperla carnea under laboratory and field conditions. Exposure of the insects to insecticidal Cry proteins from Bacillus thuringiensis (Bt) contained in pollen of transgenic maize was also assessed. Female C. carnea were most abundant in a maize field when the majority of plants were flowering and fresh pollen was abundant. Field-collected females contained an average of approximately 5000 maize pollen grains in their gut at the peak of pollen shedding. Comparable numbers were found in females fed ad libitum maize pollen in the laboratory. Maize pollen is readily used by C. carnea adults. When provided with a carbohydrate source, it allowed the insects to reach their full reproductive potential. Maize pollen was digested mainly in the insect's mid- and hindgut. When Bt maize pollen passed though the gut of C. carnea, 61% of Cry1Ab (event Bt176) and 79% of Cry3Bb1 (event MON 88017) was digested. The results demonstrate that maize pollen is a suitable food source for C. carnea. Even though the pollen grains are not fully digested, the insects are exposed to transgenic insecticidal proteins that are contained in the pollen. Copyright 2009 Elsevier Ltd. All rights reserved.

  13. Flowering phenology and potential pollen emission of three Artemisia species in relation to airborne pollen data in Poznań (Western Poland).

    Science.gov (United States)

    Bogawski, Paweł; Grewling, Łukasz; Frątczak, Agata

    Artemisia pollen is an important allergen in Europe. In Poznań (Western Poland), three Artemisia species, A. vulgaris, A. campestris and A. absinthium, are widely distributed. However, the contributions of these species to the total airborne pollen are unknown. The aim of the study was to determine the flowering phenology and pollen production of the three abovementioned species and to construct a model of potential Artemisia pollen emission in the study area. Phenological observations were conducted in 2012 at six sites in Poznań using a BBCH phenological scale. Pollen production was estimated by counting the pollen grains per flower and recalculating the totals per inflorescence, plant and population in the study area. Airborne pollen concentrations were obtained using a Hirst-type volumetric trap located in the study area. Artemisia vulgaris began to flower the earliest, followed by A. absinthium and then A. campestris. The flowering of A. vulgaris corresponded to the first peak in the airborne pollen level, and the flowering of A. campestris coincided with the second pollen peak. The highest amounts of pollen per single plant were produced by A. vulgaris and A. absinthium. A. campestris produced considerably less pollen, however, due to its common occurrence, it contributed markedly (30 %) to the summation of total of recorded pollen. A. vulgaris is the most important pollen source in Poznań, but the roles of two other Artemisia species cannot be ignored. In particular, A. campestris should be considered as an important pollen contributor and likely might be one of the main causes of allergic reactions during late summer.

  14. Characteristics of Pollen from Transgenic Lines of Apple Carrying the Exogenous CpTI Gene

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    Shi Xiaoxin

    2015-07-01

    Full Text Available It is fundamental for gene transformation and ecosystem hazard evaluation to study the pollen characteristics of transgenic plants. In this research, the characteristics of pollen from 7- or 8-year-old transgenic apple plants carrying an exogenous CpTI gene were analyzed. The results showed that there was no significant difference in terms of size, morphology, or exine ornamentation between the pollen of the transgenic plants and the non-transgenic control. However, the transgenic plants had more abnormal pollen grains. Of the 13 transgenic lines tested, 12 had a significantly lower amount of pollen and six exhibited a significantly lower germination rate when cultured in vitro. The pollen viability of three transgenic lines was determined, with two showing significantly lower viability than the control. The transgenic Gala apple pollen grains germinated normally via controlled pollination on Fuji apple stigmas. However, the pollen tubes extended relatively slowly during the middle and late development stages, and another 8 h were needed to reach the ovules compared with the control. The gibberellic acid concentration in transgenic Gala apple flowers was lower than in the non-transgenic control during all development stages tested. The abscisic acid concentration in the transgenic flowers was lower during the pink stage, and higher during the ball and fully open stages. Microscopic observation of the anther structure showed no difference. The tapetum of the pollen sac wall in transgenic plants decomposed late and affected pollen grain development, which could be one of the reasons for the lower number of pollen grains and poor viability in the transgenic plants.

  15. Anemophilous plant pollen in spring specific honeys from the Rzeszów area

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    Katarzyna Ceglińska

    2012-12-01

    Full Text Available The present study comprises pollen analyses of 23 samples of spring specific honeys collected from apiaries situated in 12 communes in the Rzeszów area during the 2005-2006 apicultural season. Forty two pollen taxa were identified in the examined material, of which 31 nectariferous and 11 non-nectariferous anemophilous plants. Among the nectariferous plants, the highest pollen frequency was found for Brassicaceae (others (95.7%, Rubus type (91.3% and Prunus type (86.9%. The presence of anemophilous pollen grains was recorded in all the samples, with Poaceae reaching the highest frequency (69.8%. The frequency of over 50% was characteristic of Quercus and Rumex, while the lowest frequency (less than 10% was recorded for Cerealia, Corylus avellana and Humulus lupulus. The highest participation was found for Quercus, whose pollen grains constituted as much as 80% of anemophilous pollen grains in a single sample. The lowest participation (below 3% was found for Rumex, Pinus and Artemisia. Among all the taxa of pollen grains found in a single sample, Poaceae pollen reached the highest share of anemophilous pollen in a sample of honey from fruit trees (10%, whereas Quercus pollen in one honey from Brassica napus (7.8% and in one honey from Acer (4.5%. The pollen share of the remaining anemophilous taxa in the examined honeys ranged between 0.2% and 2.9%. The identified anemophilous taxa belong to 10 botanical families. In 19 out of 23 examined samples of honeys, small indicators of honeydew were discovered.

  16. Are the genera Hallea and Mitragyna (Rubiaceae-Coptosapelteae) pollen morphologically distinct?

    OpenAIRE

    Huysmans, S.; Robbrecht, E.; Smets, E.

    1994-01-01

    Recent literature is controversial as regards the segregation of Hallea and Mitragyna, and pretends that the two genera show pollen morphological differences. In the present study the pollen morphology of all ten species of the complex is described on the basis of light and scanning electron microscopy (including examination of broken grains, which were obtained with a technique never applied in palynology, viz. shaking with glass beads). The two genera have 3-zonocolporate grains with compou...

  17. 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.

  18. Pollen Ingestion by Chrysoperla externa (Hagen) Adults in a Diversified Organic Agroecosystem.

    Science.gov (United States)

    Andrade, K A; Aguiar-Menezes, E L; Gonçalves-Esteves, V; Mendonça, C B F; Vieira, G R M; Melo, S J; Magalhães, J L A; Melo, G J B

    2018-02-01

    Chrysoperla externa (Hagen) larvae prey on pest insects and mites in agroecosystems, and adults mainly feed on pollen, nectar, and honeydew. Therefore, preserving this lacewing in crop systems depends on having plants that provide these resources. The objectives of this research were to identify pollen grains ingested by Ch. externa adults collected in a diversified organic agroecosystem and to evaluate whether there is a difference in the amount of ingested pollen grains between males and females. The adults of Ch. externa were collected in four different crops during 13 months in Seropédica, state of Rio de Janeiro, Brazil, using a collecting net. The adults were killed and underwent acetolysis, in order to recover the pollen in the gut. A total of 37,441 pollen grains from 19 Angiospermae families were found, besides 16 Pteridophyte spores. Among the recognized pollen grains, those of Poaceae were the majority, both in frequency of occurrence (87.5%) and in quantity (33496), and were found and recovered in every month of collection. Females and males ingested, respectively, 71.9 and 28.1% of the total number of Angiospermae pollen grains consumed by both sexes. The highest number of Poaceae pollens was obtained from the females (72.1% of the total number of Poaceae pollen, recovered from females + males). Taken as a whole, this study showed that adults of Ch. externa find possibilities to maintain throughout the year, in different crops, but the main source of pollen to males and females was Poaceae plants.

  19. Variation in ragweed (Ambrosia artemisiifolia L.) pollen concentration in central Croatia, 2002-2003.

    Science.gov (United States)

    Peternel, Renata; Culig, Josip; Srnec, Lidija; Mitić, Bozena; Vukusić, Ivan; Hrga, Ivana

    2005-01-01

    The aim of the study was to determine the onset, duration and termination of the ragweed pollen season; intradiurnal, daily and monthly pollen variation, and possible differences in the occurrence and concentration of ragweed pollen according to sampling sites between 2002 and 2003. The study was conducted at three sampling sites in central Croatia over two pollen seasons (2002 and 2003) using the volumetric method of sampling (Hirst type sampler). In 2003, the ragweed pollen season was by 43 % longer and the percentage proportion of ragweed pollen by 3.4 % greater in comparison with 2002. The total ragweed pollen count and number of days with ragweed pollen concentration greater than 30 pollen grains per m (3) air showed a declining tendency from East to West in both seasons. The intradiurnal peak concentration occurred between 10.00-14.00. The air concentration of ragweed pollen decreased with temperature decline and precipitation. Results of the study provided useful information to individuals allergic to ragweed pollen thereby allowing them to adjust their outdoor activities to avoid contact with the allergen.

  20. Fifteen years' record of airborne allergenic pollen and meteorological parameters in Thessaloniki, Greece

    Science.gov (United States)

    Gioulekas, Dimitrios; Balafoutis, Christos; Damialis, Athanasios; Papakosta, Despoina; Gioulekas, George; Patakas, Dimitrios

    . A pollen calendar has been constructed for the area of Thessaloniki and relationships between pollen transport and meteorological parameters have been assessed. Daily airborne pollen records were collected over a 15-year period (1987-2001), using a Burkard continuous volumetric pollen trap, located in the centre of the city. Sixteen allergenic pollen types were identified. Simultaneously, daily records of five main meteorological parameters (mean air temperature, relative humidity, rainfall, sunshine, wind speed) were made, and then correlated with fluctuations of the airborne pollen concentrations. For the first time in Greece, a pollen calendar has been constructed for 16 pollen types, from which it appears that 24.9% of the total pollen recorded belong to Cupressaceae, 20.8% to Quercus spp., 13.6% to Urticaceae, 9.1% to Oleaceae, 8.9% to Pinaceae, 6.3% to Poaceae, 5.4% to Platanaceae, 3.0% to Corylus spp., 2.5% to Chenopodiaceae and 1.4% to Populus spp. The percentages of Betula spp., Asteraceae (Artemisia spp. and Ambrosia spp.), Salix spp., Ulmaceae and Alnus spp. were each lower than 1%. A positive correlation between pollen transport and both mean temperature and sunshine was observed, whereas usually no correlation was found between pollen and relative humidity or rainfall. Finally, wind speed was generally found to have a significant positive correlation with the concentrations of 8 pollen types. For the first time in the area of Thessaloniki, and more generally in Greece, 15-year allergenic pollen records have been collected and meteorological parameters have been recorded. The airborne pollen concentration is strongly influenced by mean air temperature and sunshine duration. The highest concentrations of pollen grains are observed during spring (May).

  1. On the Relationship between Pollen Size and Genome Size

    Directory of Open Access Journals (Sweden)

    Charles A. Knight

    2010-01-01

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

  2. The Pannonian plain as a source of Ambrosia pollen in the Balkans

    Science.gov (United States)

    Šikoparija, B.; Smith, M.; Skjøth, C. A.; Radišić, P.; Milkovska, S.; Šimić, S.; Brandt, J.

    2009-05-01

    This study aims to find likely sources of Ambrosia pollen recorded during 2007 at five pollen-monitoring sites in central Europe: Novi Sad, Ruma, Negotin and Nis (Serbia) and Skopje (Macedonia). Ambrosia plants start flowering early in the morning and so Ambrosia pollen grains recorded during the day are likely to be from a local source. Conversely, Ambrosia pollen grains recorded at night or very early in the morning may have arrived via long-range transport. Ambrosia pollen counts were analysed in an attempt to find possible sources of the pollen and to identify Ambrosia pollen episodes suitable for further investigation using back-trajectory analysis. Diurnal variations and the magnitude of Ambrosia pollen counts during the 2007 Ambrosia pollen season showed that Novi Sad and Ruma (Pannonian Plain) and to a lesser degree Negotin (Balkans) were located near to sources of Ambrosia pollen. Mean bi-hourly Ambrosia pollen concentrations peaked during the middle of the day, and concentrations at these sites were notably higher than at Nis and Skopje. Three episodes were selected for further analysis using back-trajectory analysis. Back-trajectories showed that air masses brought Ambrosia pollen from the north to Nis and, on one occasion, to Skopje (Balkans) during the night and early morning after passing to the east of Novi Sad and Ruma during the previous day. The results of this study identified the southern part of the Pannonian Plain around Novi Sad and Ruma as being a potential source region for Ambrosia pollen recorded at Nis and Skopje in the Balkans.

  3. Effect of morphactin (IT 3456 on pollen germination and pollen tube growth in four species of Angiospermae

    Directory of Open Access Journals (Sweden)

    Barbara Gabara

    2014-01-01

    Full Text Available The action of morphactin in 10, 100 and 1000 ppm on pollen germination and tube growth was studied in four species: Antirrhinum majus, Campanula rapunculoides, Eschscholtzia californica and Narcissus poeticus. Pollen grains showed different sensitivity to particular concentrations of morphactin. Although the concentration of 1000 ppm inhibited completely pollen germination in A. majus and C. rapunculoides, it was not sufficient to suppress this process in E. californica and N. poeticus. Morphactin has a different effect on the percentage of germinated and ruptured pollen, tube length and its rate of growth. This effect was either inhibitory, neutral or stimulatory, depending on the morphactin concentration, the time of culture and species studied. The action of morphactin on the germination process is discussed.

  4. Morphological characterization of pollens from three Apiaceae species and their ingestion by twelve-spotted lady beetle (Coleoptera: Coccinellidae).

    Science.gov (United States)

    D'Ávila, V A; Aguiar-Menezes, E L; Gonçalves-Esteves, V; Mendonça, C B F; Pereira, R N; Santos, T M

    2016-04-19

    Larvae and adults of certain species of predator lady beetles feed on pollen, guaranteeing their survival, and at times, reproduction in the absence of preferred prey. Palynology, therefore, may contribute in the investigation of botanical families visited by these predators in order to obtain this floral resource. There are records of the visitation of Apiaceae flowers by Coleomegilla maculata DeGeer, 1775 (Coleoptera, Coccinellidae), but not the ingestion of their pollen grains by this lady beetle. The external morphology of pollen grains of three Apiaceae aromatic species (Anethum graveolens L., Coriandrum sativum L., Foeniculum vulgare Mill.) was characterized, and it was evaluated the ingestion of these pollens by fourth instar larvae and adults of C. maculata upon confinement along with flowers of these Apiaceae for 24 and 48 hours. The pollen grains of those species presented similar external morphology. In the two times of exposure, the larvae ingested the same amount of pollen from the three Apiaceae species, and the amount of C. sativum pollen ingested was the same between larvae and adults. The amount of A. graveolens pollen grains ingested by the adults was significantly greater than the pollens of C. sativum and F. vulgare, in 24 hours, with the opposite occurring in 48 hours. In the first 24 hours, the adults ingested more A. graveolens pollen than the larvae, with the opposite occurring with F. vulgare. There was no significant difference in the amount of Apiaceae pollen ingested between larvae and adults in 48 hours. The results suggest that the pollen-eating habits of certain aphidophagous lady beetles may be crucial in their preservation within agro-ecosystems.

  5. Morphological characterization of pollens from three Apiaceae species and their ingestion by twelve-spotted lady beetle (Coleoptera: Coccinellidae

    Directory of Open Access Journals (Sweden)

    V. A. D’Ávila

    Full Text Available Abstract Larvae and adults of certain species of predator lady beetles feed on pollen, guaranteeing their survival, and at times, reproduction in the absence of preferred prey. Palynology, therefore, may contribute in the investigation of botanical families visited by these predators in order to obtain this floral resource. There are records of the visitation of Apiaceae flowers by Coleomegilla maculata DeGeer, 1775 (Coleoptera, Coccinellidae, but not the ingestion of their pollen grains by this lady beetle. The external morphology of pollen grains of three Apiaceae aromatic species (Anethum graveolens L., Coriandrum sativum L., Foeniculum vulgare Mill. was characterized, and it was evaluated the ingestion of these pollens by fourth instar larvae and adults of C. maculata upon confinement along with flowers of these Apiaceae for 24 and 48 hours. The pollen grains of those species presented similar external morphology. In the two times of exposure, the larvae ingested the same amount of pollen from the three Apiaceae species, and the amount of C. sativum pollen ingested was the same between larvae and adults. The amount of A. graveolens pollen grains ingested by the adults was significantly greater than the pollens of C. sativum and F. vulgare, in 24 hours, with the opposite occurring in 48 hours. In the first 24 hours, the adults ingested more A. graveolens pollen than the larvae, with the opposite occurring with F. vulgare. There was no significant difference in the amount of Apiaceae pollen ingested between larvae and adults in 48 hours. The results suggest that the pollen-eating habits of certain aphidophagous lady beetles may be crucial in their preservation within agro-ecosystems.

  6. Skin prick test reactivity in allergic rhinitis patients to airborne pollens.

    Science.gov (United States)

    Erkara, Ismuhan Potoglu; Cingi, Cemal; Ayranci, Unal; Gurbuz, Kezban Melek; Pehlivan, Sevil; Tokur, Suleyman

    2009-04-01

    The aim was to investigate the impact of atmospheric pollen in determining allergic rhinitis. It was conducted with 130 patients with allergic rhinitis in three different sites in Eskisehir, Turkey, in 2000-2001, using a gravimetric method with a Durham sampler. Skin prick test results, the symptoms of patients and their findings all confirmed the presence of allergic reactions to pollen allergens in the patients observed. During the period, a total of 47,082 pollen grains/cm(2) belonging to 45 taxa were recorded. Of the total pollen grains, 81.0% were arboreal and 18% non-arboreal. The majority of the investigated pollen grains were from Pinaceae, Salix spp., Chenopodiaceae/Amaranthaceae, Cupressaceae and Poaceae. Pollen concentrations reached the highest level in May (54.36%). The pollen allergens provoking severe sensitization were grasscereal mixtures (58.5%), followed by arboreals (33.8%). All patients (100.0%) were sensitive to grass. This study emphasizes the significance of determining the types and concentrations of pollen with a view to comparing changes in highly concentrated allergens.

  7. 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

  8. The long-range transport of Pinaceae pollen: an example in Kraków (southern Poland).

    Science.gov (United States)

    Szczepanek, Kazimierz; Myszkowska, Dorota; Worobiec, Elżbieta; Piotrowicz, Katarzyna; Ziemianin, Monika; Bielec-Bąkowska, Zuzanna

    2017-01-01

    High Pinaceae pollen concentrations in the air and on the surface of puddles before the main pollen season started were observed in Kraków (southern Poland) in May 2013. The paper presents the results of detailed studies of the composition and source of the "yellow rain" in 2013, and as a comparison, the Pinaceae pollen concentrations and samples collected from the ground surface in 2014 were considered. The air samples were collected using the volumetric method (Hirst-type device), while pollen grains sampled from the ground surface were processed using a modified Erdtman acetolysis method. Finally, all samples were studied using a light microscope. In 2013, the period of higher Abies, Picea and Pinus pollen concentrations was observed from the 5 to 12 of May, earlier than the main pollen season occurred. The presence of rainfall on the 12 and 13 of May 2013 caused the pollen deposition on the ground surface, where the prevalence of Pinaceae pollen was found. The synoptic situation and the analysis of the back-trajectories and air mass advection at the beginning of May 2013 indicated that Pinaceae pollen grains could have been transported from Ukraine, Romania, Hungary and Slovakia. In contrast, Pinaceae pollen grains deposited on the ground surface as a "yellow" film in May 2014, originated from local sources.

  9. 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

  10. PHOTOPERIOD-INDUCED POLLEN ABORTION IN PGMS RICE

    African Journals Online (AJOL)

    user

    2013-11-20

    Nov 20, 2013 ... day length treatment and after every four days, the next row was included in the treatment. .... At post ripening stage, three tillers with full grown panicles were ... with 1% I/K, no pollen grains were noticed (Figure 3a and b).

  11. In situ Gymnosperm pollen from the Middle Jurassic of Yorkshire

    NARCIS (Netherlands)

    Konijnenburg-van Cittert, van Johanna H.A.

    1971-01-01

    In this paper the morphology of pollen grains yielded by male Gymnosperm fructifications from the Jurassic flora of Yorkshire is studied and discussed. Several new male fructifications were found and described: Hastystrobus gen. nov. was erected for male cones yielding the Eucommiidites type of

  12. 100 years of Einstein's Theory of Brownian Motion: From Pollen ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 10; Issue 11. 100 years of Einstein's Theory of Brownian Motion: From Pollen Grains to Protein Trains – 2. Debashish Chowdhury. General Article Volume 10 Issue 11 November 2005 pp 42-54 ...

  13. 100 years of Einstein's Theory of Brownian Motion: from Pollen ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 10; Issue 9. 100 Years of Einstein's Theory of Brownian Motion: from Pollen Grains to Protein Trains – 1. Debashish Chowdhury. General Article Volume 10 Issue 9 September 2005 pp 63-78 ...

  14. Pollen Dimorphism of Several Members of Nymphaeaceae and Nelumbonaceae: An Index of Geographical and Ecological Variation

    Directory of Open Access Journals (Sweden)

    Somnath BHOWMIK

    2012-08-01

    Full Text Available Pollen morphology of five Nymphaea (Nymphaeaceae species, growing in Tripura, India were analysed using Scanning Electron Microscopy. Pollen grains of Nymphaea are dimorphic (ellipsoidal and spheroidal. The exine pattern also varies among the species. The variation as reported in the present study in terms of exine pattern of the studied species suggests the feasibility of applying the data in the identification of the genus of Nymphaea. The difference in exine patterns with the earlier reports may be interpreted as reflections of genetic variations possibly due to mutational changes effected by ecological conditions. The present pollen dimorphism may be attributed by introgression of populations. The variability in pollen morphology, including size variation and morphological differences, is often associated with hybrids among angiosperm groups. The examinations of percentages of aborted grains, generally considered a good indicator of hybridity. The occurrence of monosulcate pollens in Nelumbo nucifera along with dominant tricolpate pollens may be considered as aberrant pollens because of very low percentage of occurrence of monosulcate pollens. The ecological and geographical variations in pollen morphology could be an index of the genetic impact of the environment on the plant. Thus the present difference in terms of exine pattern could be useful to separate them at varietal level.

  15. Suspendable macromolecules are responsible for ice nucleation activity of birch and conifer pollen

    Directory of Open Access Journals (Sweden)

    B. G. Pummer

    2012-03-01

    Full Text Available The ice nucleation of bioaerosols (bacteria, pollen, spores, etc. is a topic of growing interest, since their impact on ice cloud formation and thus on radiative forcing, an important parameter in global climate, is not yet fully understood. Here we show that pollen of different species strongly differ in their ice nucleation behaviour. The average freezing temperatures in laboratory experiments range from 240 to 255 K. As the most efficient nuclei (silver birch, Scots pine and common juniper pollen have a distribution area up to the Northern timberline, their ice nucleation activity might be a cryoprotective mechanism. Far more intriguingly, it has turned out that water, which has been in contact with pollen and then been separated from the bodies, nucleates as good as the pollen grains themselves. The ice nuclei have to be easily-suspendable macromolecules located on the pollen. Once extracted, they can be distributed further through the atmosphere than the heavy pollen grains and so presumably augment the impact of pollen on ice cloud formation even in the upper troposphere. Our experiments lead to the conclusion that pollen ice nuclei, in contrast to bacterial and fungal ice nucleating proteins, are non-proteinaceous compounds.

  16. Turbulence-induced resonance vibrations cause pollen release in wind-pollinated Plantago lanceolata L. (Plantaginaceae)

    Science.gov (United States)

    Timerman, David; Greene, David F.; Urzay, Javier; Ackerman, Josef D.

    2014-01-01

    In wind pollination, the release of pollen from anthers into airflows determines the quantity and timing of pollen available for pollination. Despite the ecological and evolutionary importance of pollen release, wind–stamen interactions are poorly understood, as are the specific forces that deliver pollen grains into airflows. We present empirical evidence that atmospheric turbulence acts directly on stamens in the cosmopolitan, wind-pollinated weed, Plantago lanceolata, causing resonant vibrations that release episodic bursts of pollen grains. In laboratory experiments, we show that stamens have mechanical properties corresponding to theoretically predicted ranges for turbulence-driven resonant vibrations. The mechanical excitation of stamens at their characteristic resonance frequency caused them to resonate, shedding pollen vigorously. The characteristic natural frequency of the stamens increased over time with each shedding episode due to the reduction in anther mass, which increased the mechanical energy required to trigger subsequent episodes. Field observations of a natural population under turbulent wind conditions were consistent with these laboratory results and demonstrated that pollen is released from resonating stamens excited by small eddies whose turnover periods are similar to the characteristic resonance frequency measured in the laboratory. Turbulence-driven vibration of stamens at resonance may be a primary mechanism for pollen shedding in wind-pollinated angiosperms. The capacity to release pollen in wind can be viewed as a primary factor distinguishing animal- from wind-pollinated plants, and selection on traits such as the damping ratio and flexural rigidity may be of consequence in evolutionary transitions between pollination systems. PMID:25297315

  17. Foraging behavior affects pollen removal and deposition in Impatiens capensis (Balsaminaceae).

    Science.gov (United States)

    Young, Helen J; Dunning, Dan W; Hasseln, Kyle W von

    2007-07-01

    Flowers of most plant species are visited by a variety of animals. Some of these visitors are effective pollinators while others remove resources without transferring pollen. Studies comparing the effectiveness of different visitors as pollinators often compare taxa without considering variation in behavior within a taxon. Wilson and Thomson (Ecology 72: 1503-1507, 1991) documented the effects of honey bees and bumble bees on the pollination dynamics of Impatiens capensis. They found that pollen-collecting honey bees removed large numbers of pollen grains from anthers but deposited little of it on stigmas; bumble bees, which sought nectar, removed less pollen but deposited more of it on stigmas. It is unclear whether the low pollen transfer efficiencies of honey bees are explained by their morphology or by their pollen-collecting behavior. We repeated the work of Wilson and Thomson at a site where honey bees were foraging for nectar, not pollen. We measured the quantity of pollen remaining in anthers, the number of pollen grains deposited on stigmas, and seed production after single visits by honey bees and bumble bees. The differences between the taxa disappeared when they were foraging in a similar manner. Our results clearly demonstrate the importance of foraging behavior on the pollination effectiveness of floral visitors.

  18. Comparison of modern pollen distribution between northern and southern South China Sea

    Science.gov (United States)

    Luo, C.; Chen, M.; Xiang, R.; Liu, J.; Zhang, L.; Lu, J.

    2013-12-01

    To understand pollen transport mechanic and terrigenous area is the base to explain pollen data correctly in Southern South China Sea (Fig.1). Based on Palynology analyzing the following preliminary conclusions are listed. 1. Air pollen differences between northern and southern South China Sea 15 air pollen samples were collected from northern part of the South China Sea from August to September 2011. 13 air pollen samples were collected from southern South China Sea in December 2011. It was found that the air pollen are different between northern and southern part of South China Sea: the pollen types in the north are more abundant than in the south, Ulmaceae, Monolete spore, Cyperaceae, Euphorbiaceae, Rubiaceae, Artemisia, Chenopodiaceae, Rosaceae, Labiatae occur only in the north, they do not occur or is just sporadic in the south. The total pollen number and concentration in the north is 10 times of the south, one of the reasons may be that the sampling season in the north is autumn with more flowering plants, the sampling season in the south is winter, with fewer flowering plants; the second reason might be that pollen and spore in autumn and winter are mainly spread by the winter wind, thus they reduce from north to south. 2. Pollen differences of the surface sediments between northern and southern South China Sea 14 samples were collected from surface sediments in the northern part of the South China Sea from August to October, 2011. 12 samples were collected from surface sediments in the southern part of the South China Sea from year 1997 to 2002. The differences of pollen characteristics from the surface sediments between northern and southern part of South China Sea are: pollen types and quantities in the north are richer than in south. There are Trilete spores (35-100%), Pinus (3-65%) in northern of SCS, with pollen concentration of 33-1031grain/g. There are only a small amount of Trilete-spore and Pinus pollen in southern of SCS. Pollen concentration in

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

    Directory of Open Access Journals (Sweden)

    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.

  20. Evaluation of pollen production in Bromus catharticus Vahl and Guadua trinii (Nees Nees ex Rupr. (Poaceae for interpretation of fossil data

    Directory of Open Access Journals (Sweden)

    Jefferson Nunes Radaeski

    2016-12-01

    Full Text Available We evaluated pollen production per anther, per flower, and per spikelet of the grassland species Bromus catharticus and the forest taxon Guadua trinii (Poaceae, which have divergent pollination syndrome. We collected ten anthers of each taxon to determine differences in pollen production based on pollination system. Anthers were macerated and pollen grains were counted in a Neubauer chamber. Pollen morphology was observed using optical and scanning electron microscopy to establish relationships between pollen grain production and morphology. The anemophilous species Bromus catharticus (2,556,000 pollen grains/spikelet has twice the pollen production per anther and per spikelet compared to Guadua trinii (1,716,000 pollen grains/spikelet, a species that requires biotic assistance for pollination. Pollen grain size is inversely proportional to production. Microechinate ornamentation, which is not expected to occur in anemophilous species, was observed on pollen of both taxa. Our results indicate that the frequency of forest Poaceae in the quaternary records may be underestimated while frequency of grassland taxa may be overestimated, leading to misrepresentation of the respective flora in this period.

  1. RELATIONSHIP BETWEEN RECENT POLLEN DEPOSITION AND AIRBORNE POLLEN CONCENTRATION

    NARCIS (Netherlands)

    SPIEKSMA, FTM; NIKKELS, BH; BOTTEMA, S

    In the reconstruction of past or recent vegetation the study of deposited pollen plays an important role. As reference value, very often the pollen content of moss polsters (''moss cushions'') is assessed to estimate the pollen deposition (''influx'') from the air. Recently, the data from

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Science.gov (United States)

    Emer, Carine; Vaughan, Ian P.; Hiscock, Simon; Memmott, Jane

    2015-01-01

    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. PMID:26633170

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

    Science.gov (United States)

    Emer, Carine; Vaughan, Ian P; Hiscock, Simon; Memmott, Jane

    2015-01-01

    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.

  5. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  7. [Clustering Sugi-pollen dispersal patterns for the past 26 years].

    Science.gov (United States)

    Ito, Yukiko

    2014-05-01

    Pollinosis caused by the pollen of Sugi (Cryptopmeria japonica) trees is the most significant allergic disease occurring in the spring in Japan. For pollinosis patients and medical staff, it is important to know when the pollen dispersion would reach maximum or when the pollen count would decrease as well as knowing what would the total density of pollen grains be. These sorts of information could be useful for the purpose of disease prevention and deciding on the therapeutic regimen. In this study, we presented the sugi-dispersal patterns and cited several examples of the dispersal pattern. Airborne pollen grains were collected using a Durham sampler. Total annual pollen counts/cm2 were examined. The sugi-dispersal patterns were classified into several groups by cluster analysis using variables of ten days pollen counts distribution from February to April for the past 26 years. (1987-2012). The annual pollen count revealed an alternate rhythm consisting of an "on" year (high pollen count) and an "off" year (low pollen count). The results of the cluster analysis showed eleven off-years classified as one group (group 1), and fifteen on-years classified into three groups (groups 2A, 2B, and 2C). The dispersal pattern in group 1 was almost symmetrical with the pollen count rapidly decreasing until late-March. On the other hand, the patterns in group 2 were asymmetrical. In group 2A and 2B a high rate of dispersion was indicated after maximum dispersion, whereas in group 2C the high rate of dispersion was indicated before maximum dispersion. In group 2A, a major dispersion of almost 3000 grains was noted in late-March, and immediately proceeded to the cypress (Chamaecyparis) pollen season without any decrease seen in pollen dispersion. The periods of dispersion of over 10 pollen grains/cm2 per day were 38, 47, 47 and 51 days in groups 1, 2A, 2B and 2C, respectively. That in group 2 was significantly longer than that in group 1, but there was no significant differences

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

    Directory of Open Access Journals (Sweden)

    Ortrud M. Barth

    2010-12-01

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

  9. 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...

  10. Relation between Poaceae pollen concentrations and meteorological factors during 2000–2010 in Timisoara, Romania

    Directory of Open Access Journals (Sweden)

    Nicoleta Ianovici

    2015-12-01

    Full Text Available This paper presents the results of Poaceae pollen seasons from 2000–2010 in Timisoara, Romania. Airborne Poaceae pollen concentrations was high. An increasing trend in the annual totals was observed. The longest pollen season was recorded in the year 2000. The period in which the Poaceae pollen count exceeded the threshold value of 30 grains/m3 lasted from 9 to 46 days. The present study analyzed the dynamics of pollen seasons in relation to meteorological factors. On the basis of Spearman’s correlation test, the strongest positive correlation was found between the Poaceae pollen counts and temperature; and sunshine hours. Daily average relative humidity, atmospheric pressure and precipitation had a negative effect. A multiple regression analysis was applied to determine how much of the total variance in Poaceae pollen counts can be explained by meteorological parameters. The coefficient of determination ranged from 0.245 to 0.460. Our data illustrate the contrasting effects of temperature, wind, relative humidity and rainfall on the concentration of pollen in the air. The optimum conditions for Poaceae pollen release occur during late spring and early summer. The Poaceae pollen remains one of the major aeroallergens in Timisoara area.

  11. Ragweed (Ambrosia L. pollen in aeroplankton of Lublin (Poland and Lviv (Ukraine

    Directory of Open Access Journals (Sweden)

    Krystyna Piotrowska-Weryszko

    2013-10-01

    Full Text Available In Europe Ambrosia is included in invasive species. Its pollen contains very strong allergens that can be the cause of pollinosis at the turn of summer and autumn. The aim of the present study was to compare Ambrosia pollen concentrations in the air of Lublin and Lviv and to analyse the effect of weather conditions on Ambrosia pollen content in the air. The study was carried out in 2011 and 2012. In Lublin the volumetric method was applied using a Lanzoni VPPS 2000 trap, whereas in Lviv the gravimetric method was applied using a Durham trap. To make the results comparable, the data obtained by the gravimetric method were properly counted and expressed as the number of pollen grains per 1 m3 of air. This research shows that the Ambrosia pollen season started about a month earlier in Lviv and lasted longer than in Lublin. In Lviv ragweed pollen was recorded from the beginning of July, while in Lublin from the second week of August. The pollen season in both cities ended on different days of October. The seasonal peaks in both years and the annual pollen count in 2011 were much higher in Lublin than in Lviv. In both cities air temperature was the most important meteorological factor affecting pollen concentrations. During the pollen season in Lublin, the wind was predominantly from NE and E directions, whereas in Lviv from N and SE.

  12. Airborne Pollen Records of Shomolu Local Government Area in Lagos State

    Directory of Open Access Journals (Sweden)

    Tiwalade A. ADENIYI

    2014-12-01

    Full Text Available Data on the prevalence of pollen in the atmosphere is limited and almost non-existent for Lagos State and Nigeria. Pollen grains are known to be highly allergenic and thus they are potential causes of respiratory diseases. To investigate airborne incidence of pollen, so as to construct a pollen calendar and contribute to current trends in the development of aeropalynology/allergy study in Nigeria, three highly populated locations in Shomolu Local Government areas of Lagos State: University of Lagos, Bariga and Gbagada, were sampled. Aero-samplers were harvested monthly from January 2013 to December 2013. After acetolysis treatment and analysis, the total pollen count was 4393, belonging to 38 pollen taxa and 29 families. The main taxa include Poaceae, Cyperaceae, Amaranthaceae, Ludwigia and Alchornea. Monthly pollen counts were highest in October and lowest in June. Almost three-quarters of the total pollen content came from grasses and weeds. This composition reflects the ornamental and grassland flora of the town, as well as the natural vegetation surrounding the urban area. The total pollen concentration correlates positively with the temperature and negatively with the wind, rainfall and relative humidity, which was similar in the dominant taxa Amaranthaceae and Alchornea. Dominant taxa Cyperaceae and Ludwigia have significant positive correlation with wheezing cough. Results from this work will form the basis for a forecast service required to inform and educate the general public and allergy sufferers about pollen distribution in Lagos State.

  13. Hybridizing pines with diluted pollen

    Science.gov (United States)

    Robert Z. Callaham

    1967-01-01

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

  14. 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

  15. 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.

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

    Science.gov (United States)

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

    2010-01-01

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

  17. Catálogo sistemático dos pólens das plantas arbóreas do Brasil Meridional: XII - Palmae Catalogue of Brazilian pollen grains

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    Ortrud Monika Barth

    1971-01-01

    Full Text Available Foi estudada a morfologia polínica de sete espécies de palmeiras que ocorrem na floresta subtropical latifoliada do Brasil meridional, dando-se especial ênfase à estratificação das exinas em relação ao aspecto da superfície. A presença de nexina 1 no gênero Butia e a falta desta camada nos deamis gêneros estudados, está de acôrdo com as grandes divisões toxonômicas destas família, bem como a ocorrência ecológica das espécies.The pollinic morphology of seven palm-tree species which occur in the subtropical ombrophilous forest in southern Brazil have been examined. Emphasis have been put in the study of the exine stratification in relation to the superficial aspect of the pollen. The presence of nexine 1 in Butia and the lack of this layer in the other genera, agrees with the taxonomic sub-division of the family, as well as with the ecological distribution of the species here studied.

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

    Directory of Open Access Journals (Sweden)

    Antônio Vander Pereira

    2006-03-01

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

  19. The Long Distance Transport of Airborne Ambrosia Pollen to the UK and the Netherlands from Central and South Europe

    OpenAIRE

    Weger, L.A.; Pashley, C.H.; Šikoparija, B.; Skjøth, C.; Kasprzyk, I.; Grewling, Ł.; Thibaudon, M.; Magyar, D.; Smith, Matt

    2016-01-01

    The invasive alien species Ambrosia artemisiifolia (common or short ragweed) is increasing its range in Europe. In the UK and the Netherlands, airborne concentrations of Ambrosia pollen are usually low. However, more than 30 Ambrosia pollen grains per cubic metre of air (above the level capable to trigger allergic symptoms) were recorded in Leicester (UK) and Leiden (NL) on 4 and 5 September 2014. The aims of this study were to determine whether the highly allergenic Ambrosia pollen recorded ...

  20. 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

  1. Heterospecific pollen deposition: does diversity alter the consequences?

    Science.gov (United States)

    Arceo-Gómez, Gerardo; Ashman, Tia-Lynn

    2011-11-01

    • In natural communities, plants can receive pollen from multiple heterospecifics as well as conspecifics. However, studies on the effects of interspecific pollen transfer have focused on interactions between species pairs. The potential exists for diverse interactions among heterospecific pollen (HP) grains on the stigma, and for these to affect plant reproduction, alone or in combination with conspecific pollen (CP) loss, but these interactions have not yet been explored. • We used hand-pollinations to simulate increasing community diversity and CP loss on Mimulus guttatus stigmas. We used pollen mixes of one to three heterospecific donors to determine how species composition and CP load size affect seed production and to characterize the mechanisms underlying fertilization failure. • Heterospecific pollen deposition reduced M. guttatus seed production and while the effect increased with the number of heterospecific donors, the strength depended on species composition and was independent of conspecific load size. Different types of interactions (additive and synergistic) are hypothesized to underlie the diverse effects on M. guttatus reproductive success. • Our results suggest that an increase in the diversity of heterospecific donors will not always lead to a greater decrease in fitness because multispecies effects depend on the interacting species. © 2011 The Authors. New Phytologist © 2011 New Phytologist Trust.

  2. Localization of actin in pollen tubes of Ornithogalum virens L.

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    Małgorzata Stępka

    2014-01-01

    Full Text Available The germinating pollen grain (in vivo on the stigma or in vitro in germination medium forms a pollen tube which transports the vegetative nucleus and generative cell/two sperm cells participating in the process of double fertilization. The growth of the tube and the transport of organelles and the cells occur due to two major motor systems existing in the pollen tubes of higher plants: the tubuline-dynein/kinesin and the actin-myosin system. In pollen tubes of Ornithogalum virens the actin filaments were labelled with TRITC-phalloidin (2 µg/ml in the PIPES buffer and the 10% sucrose, without the fixative and DMSO. Omission of the fixative and permeabilizing agent (DMSO allowed better preservation of the structure, and the "fluorescence" of actin was observed in living pollen tubes. Observations in CLSM (confocal laser scanning microscope showed that actin is distributed in the vicinity of the cell membrane. This could support the view that actin filaments and the plasmalemma form the pollen tube cortex along which the cytoplasmic movement of organelles, and cell transport occurs.

  3. Exposure to Japanese cedar pollen in early life and subsequent sensitization to Japanese cedar pollen.

    Science.gov (United States)

    Ozasa, K; Dejima, K; Hama, T; Watanabe, Y; Takenaka, H

    2000-01-01

    The effect of exposure to Japanese cedar pollen (JCP) in early life on subsequent sensitization to it was evaluated. Specific IgE antibody to JCP was examined in 440-504 school children in a rural town each year during 1995-98. The amount of dispersed pollen measured by a Durham sampler widely ranged from 165 to 5941 grains/cm2/year during this period. The amount had been measured during the period of 1982-91 in which these children were born, and it also widely ranged from 148 to 8566 grains/cm2/year. Children born during November to January, who were exposed to JCP within 6 months of age, increased at the risk of sensitization to JCP, especially severe sensitization, relative to those born in the other months. Age-adjusted prevalence rate ratio (RR) of having a JCP-IgE > or = 15 U/ml (control; pollen during the period of 2-6 months after birth and the prevalence of sensitization to JCP.

  4. Angiosperm-like pollen and Afropollis from the Middle Triassic (Anisian) of the Germanic Basin (Northern Switzerland)

    Science.gov (United States)

    Hochuli, Peter A.; Feist-Burkhardt, Susanne

    2013-01-01

    Here we report on angiosperm-like pollen and Afropollis from the Anisian (Middle Triassic, 247.2–242.0 Ma) of a mid-latitudinal site in Northern Switzerland. Small monosulcate pollen grains with typical reticulate (semitectate) sculpture, columellate structure of the sexine and thin nexine show close similarities to early angiosperm pollen known from the Early Cretaceous. However, they differ in their extremely thin inner layer (nexine). Six different pollen types (I–VI) are differentiated based on size, reticulation pattern, and exine structure. The described pollen grains show all the essential features of angiosperm pollen. However, considering the lack of a continuous record throughout the lower part of the Mesozoic and the comparison with the oldest Cretaceous finds we suggest an affinity to an angiosperm stem group. Together with the previously published records from the Middle Triassic of the Barents Sea area the angiosperm-like pollen grains reflect a considerable diversity of the parent plants during the Middle Triassic. Sedimentological evidence and associated palynofloras also suggest a remarkable ecological range for these plants. Associated with these grains we found pollen comparable to the genus Afropollis. Representatives of this genus are commonly recorded in Lower Cretaceous sediments of low latitudes, but until now had no record from the lower part of the Mesozoic. PMID:24106492

  5. Angiosperm-like pollen and Afropollis from the Middle Triassic (Anisian) of the Germanic Basin (Northern Switzerland).

    Science.gov (United States)

    Hochuli, Peter A; Feist-Burkhardt, Susanne

    2013-01-01

    Here we report on angiosperm-like pollen and Afropollis from the Anisian (Middle Triassic, 247.2-242.0 Ma) of a mid-latitudinal site in Northern Switzerland. Small monosulcate pollen grains with typical reticulate (semitectate) sculpture, columellate structure of the sexine and thin nexine show close similarities to early angiosperm pollen known from the Early Cretaceous. However, they differ in their extremely thin inner layer (nexine). Six different pollen types (I-VI) are differentiated based on size, reticulation pattern, and exine structure. The described pollen grains show all the essential features of angiosperm pollen. However, considering the lack of a continuous record throughout the lower part of the Mesozoic and the comparison with the oldest Cretaceous finds we suggest an affinity to an angiosperm stem group. Together with the previously published records from the Middle Triassic of the Barents Sea area the angiosperm-like pollen grains reflect a considerable diversity of the parent plants during the Middle Triassic. Sedimentological evidence and associated palynofloras also suggest a remarkable ecological range for these plants. Associated with these grains we found pollen comparable to the genus Afropollis. Representatives of this genus are commonly recorded in Lower Cretaceous sediments of low latitudes, but until now had no record from the lower part of the Mesozoic.

  6. Pollen waste and unrelated traits in a fig-fig wasp symbiosis : a new behaviour suggesting a host shift

    NARCIS (Netherlands)

    Michaloud, G; Bossu-Dupriez, N; Chevolot, M; Lasbleiz, C

    In a fig-fig wasp symbiosis, we have discovered that male fig pollinators (Alfonsiella fimbriata Waterston) bite into the dehiscent anthers of Ficus natalensis leprieuri Miq., thus scattering the pollen grains throughout the syconium. Female pollinators are the only ones to transfer pollen to

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    Benjamin Eggs

    Full Text Available 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.

  9. Identification and persistence of Pinus pollen DNA on cotton fabrics: A forensic application.

    Science.gov (United States)

    Schield, Cassandra; Campelli, Cassandra; Sycalik, Jennifer; Randle, Christopher; Hughes-Stamm, Sheree; Gangitano, David

    2016-01-01

    Advances in plant genomics have had an impact on the field of forensic botany. However, the use of pollen DNA profiling in forensic investigations has yet to be applied. Five volunteers wore a jacket with Pinus echinata pollen-containing cotton swatches for a 14-day period. Pollen decay was evaluated at days 0, 3, 6, 9 and 14 by microscopy. Pollen grains were then transferred to slides using a portable forensic vacuum handle. Ten single grains per swatch were isolated for DNA analysis. DNA was extracted using a high throughput extraction method. A nine-locus short tandem repeat (STR) multiplex system, including previously published primers from Pinus taeda, was developed. DNA was amplified by PCR using fluorescent dyes and analyzed by capillary electrophoresis. Pollen counts from cotton swatches in a 14-day period exhibited an exponential decay from 100% to 17%. The success rate of PCR amplification was 81.2%. Complete and partial STR profiles were generated from 250 pollen grains analyzed (44% and 37%, respectively). Due to the limited amount of DNA, drop-in events were observed (1.87%). However, the rate of contamination with pollen from other pine individuals originating from environmental sources was 4.4%. In conclusion, this study has shown that pollen can be a stable source of forensic DNA evidence, as a proof-of-principle, and that may persist on cotton clothing for at least 14 days of wear. This method can be applied in forensic cases where pollen grains larger than 10 μm (e.g., from herbs or trees) may be transferred to clothing (worn by suspect or victim) by primary contact. Copyright © 2015 The Chartered Society of Forensic Sciences. Published by Elsevier Ireland Ltd. All rights reserved.

  10. Influence of wind velocity on pollen concentration in urban canopy layer

    Science.gov (United States)

    Pospisil, J.; Jícha, M.

    2009-09-01

    POLLEN RELEASE Temperature is the basic parameter for prediction of the beginning of the pollen season and identification days with good potential for pollen release. Different approaches are used for determination of the start of the pollen season: i) the sum of daily pollen counts = x criterion (Arnold 2002), ii) the mean temperature method during pre-defined period (Sparks, 2000), iii) the temperature sum method (Jones 1992). Another parameters influencing pollen release are: day light length, morning temperature gradient, relative humidity. The mentioned parameters enable to create the "statistical” model for determination of timing of pollen potential release. But, the correct determination of pollen release timing is only the first step to correct prediction of pollen concentration in air. The above mentioned collection of parameters isn't complete for correct pollen production prediction without inclusion of the actual wind velocity. The wind velocity directly influences the pollen release rate from mother plant and subsequently transport of pollen grains. From this reason, influence of wind conditions has to be considered as exactly as possible in complex prediction models. WIND VELOCITY AND POLLEN CONCENTRATION Results of in-situ measurements were used for carried out analysis of the relation between wind velocity and pollen concentration in an urban canopy layer. The mean daily wind velocities and the mean daily pollen concentrations were used as the input data describing the pollen season 2005 in an inner part of the city of Brno (pop. 400 000). The mean daily pollen concentrations were matched to corresponding mean daily wind velocity and depicted in graphs. This procedure was done for all locally monitored aeroallergens, namely Alnus, Ambrosia, Betula, Artemis, Corylus, Fraxinus, Poaceae and Quercus. Only days with significant pollen concentration (above 10% of maximal pollen season concentration) were considered for detail analysis. Clear

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

    Directory of Open Access Journals (Sweden)

    Babić Vojka

    2017-01-01

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

  12. Phenology of flowering and pollen release of selected herbaceous plants in Szczecin and Gudowo (Western Pomerania and the risk of pollen allergy

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    Aleksandra Kruczek

    2012-12-01

    Full Text Available This paper presents the course of the pollen season of selected allergenic taxa (Secale spp., Rumex spp., Plantago spp., Urtica spp., Artemisia spp., Chenopodiaceae and Poaceae in Szczecin (2009 and Gudowo (Western Pomerania, Poland (2009–2010, and also the flowering pattern of Chenopodium album, Artemisia vulgaris and Secale spp. Pollen deposition was studied by the gravimetric method using a Durham sampler. In 2010 the flowering period of the studied taxa was shorter than in 2009 and its onset was observed later; the maximum values of daily pollen deposition were lower. Pollen grains of most of the taxa studied appeared in the atmosphere of the city earlier than in the rural area, but in the rural area significantly higher values of daily deposition were recorded. The effect of weather conditions on pollen fall in Szczecin in 2009 was analysed. Statistically significant positive correlations with pollen deposition were found only with maximum, minimum, and mean air temperature, dew point and maximum wind speed, while a negative correlation was found with precipitation and – only for Rumex pollen grains – with air humidity and pressure.

  13. Identification of plant families associated with the predators Chrysoperla externa (Hagen (Neuroptera: Chrysopidae and Hippodamia convergens Guérin-Menéville (Coleoptera: Coccinelidae using pollen grain as a natural marker Identificação de famílias de plantas associadas aos predadores Chrysoperla externa (Hagen (Neuroptera: Chrysopidae e Hippodamia convergens Guérin-Menéville (Coleoptera: Coccinelidae usando o pólen como marcador natural

    Directory of Open Access Journals (Sweden)

    MA Medeiros

    2010-05-01

    Full Text Available The predators Hippodamia convergens Guérin-Menéville (Coleoptera: Coccinelidae and Chrysoperla externa (Hagen (Neuroptera: Chrysopidae, are frequently observed on vegetable crops, especially on tomato plants, as well as on flowers of several plants around crop fields. It is well known that when predators feed on pollen and nectar they can increase their longevity and reproductive capacity. The objective of this work was to identify plants that could be a pollen source for H. convergens and C. externa in order to develop strategies to attract and keep these predators in vegetable fields like the tomato crop. Adults of C. externa (53 individuals and H. convergens (43 individuals were collected in fields from 2004-2005 at Embrapa Hortaliças, Brasília, Federal District. The insects were processed by the acetolysis method and pollen from them was extracted and identified. A total of 11335 grains of pollen belonging to 21 families were extracted from C. externa. A total of 46 pollen grains belonging to ten families were extracted from H. convergens. The Poaceae family was the most abundant one for C. externa while Asteraceae was the commonest pollen for H. convergens. The importance of pollen from different plant species as a food resource for each predator species gives an indication of the importance of plant community structure inside and around crop fields for the establishment of these predator populations and to enhance conservation biological control.Os predadores Chrysoperla externa (Hagen (Neuroptera: Chrysopidae e Hippodamia convergens Guérin-Menéville (Coleoptera: Coccinelidae são frequentemente observados em cultivos de hortaliças, especialmente tomateiros, bem como sobre flores de diversas plantas próximas aos cultivos. Sabe-se que os predadores, quando se alimentam de pólen e néctar, aumentam a sua longevidade e a sua capacidade reprodutiva. O objetivo deste trabalho foi identificar as plantas que poderiam servir de fonte de p

  14. Correlation between meteorological conditions and Parietaria pollen concentration in Alassio, north-west Italy.

    Science.gov (United States)

    Crimi, P; Macrina, G; Folli, C; Bertoluzzo, L; Brichetto, L; Caviglia, I; Fiorina, A

    2004-09-01

    The pollen grains in the atmosphere in different geographical areas differ according to the species present, the pollination seasons and pollen grain concentrations, but possibly the greatest contributors to this variability are the meteorological conditions. The aim of our research is to establish a possible correlation between Parietaria pollen concentration and meteorological conditions during the period from 1991 to 1995 in the town of Alassio (north-west Italy). As far as vegetation is concerned, the Mediterranean climatic conditions support the blooming of extensive grasslands in the environment surrounding the town; these grasslands mainly comprise Urticaceae and shrubs. The study demonstrates that the most influential parameters affecting the Urticaceae grain concentration upsurge are the absence of rainfall, a maximum daily temperature of about 21 degrees C, and a diurnal temperature range of about 5 degrees C. Moreover, our aeropalinological study indicates that this last parameter has the greatest influence on Urticaceae pollination. In fact, an increase in diurnal temperature range could be responsible for a dehydration of pollens resulting in a loss in mass. This grain lightness and volatility would ultimately permit atmospheric dispersion if there is a significant wind speed. On the other hand, days with rain or high relative humidity make pollens heavier, preventing them from flying long distances and therefore partially explaining the decline in airbone pollen concentration.

  15. Pollen morphology of Quercus (subgenus Quercus, section Quercus in Iran and its systematic implication

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    Parisa Panahi

    2012-03-01

    Full Text Available For the first time, pollen morphology of 9 (4 spp. and 5 subspp. taxa representing lobed leaved oaks of Iran in the family of Fagaceae has been examined and illustrated using light microscopy and scanning electron microscopy of acetolysed material. Detailed pollen morphological characteristics are given for Quercus section. The pollen grains are single, isopolar, radially symmetrical, tricolpate, tricolporoidate or tricolporate. Pollens were studied to show all possible characteristics like shape, size, apertures, wall thickness, etc., with special reference to the specific features of each pollen type such as structural, sculptural and suprasculptural patterns. There is considerable variation in pollen morphology between taxa so that, three types of pollen shape, five types of structural pattern, two types of sculptural pattern, five types of suprasculptural pattern and three types of perfora distribution are defined. Furthermore, the relationship between pollen morphology and taxonomy is discussed. Overall, pollen characters are shown to be a useful and informative tool for assessing taxonomic position within Quercus section in Iran.

  16. Pollen--tiny and ephemeral but not forgotten: New ideas on their ecology and evolution.

    Science.gov (United States)

    Williams, Joseph H; Mazer, Susan J

    2016-03-01

    Ecologists and evolutionary biologists have been interested in the functional biology of pollen since the discovery in the 1800s that pollen grains encompass tiny plants (male gametophytes) that develop and produce sperm cells. After the discovery of double fertilization in flowering plants, botanists in the early 1900s were quick to explore the effects of temperature and maternal nutrients on pollen performance, while evolutionary biologists began studying the nature of haploid selection and pollen competition. A series of technical and theoretic developments have subsequently, but usually separately, expanded our knowledge of the nature of pollen performance and how it evolves. Today, there is a tremendous diversity of interests that touch on pollen performance, ranging from the ecological setting on the stigma, structural and physiological aspects of pollen germination and tube growth, the form of pollen competition and its role in sexual selection in plants, virus transmission, mating system evolution, and inbreeding depression. Given the explosion of technical knowledge of pollen cell biology, computer modeling, and new methods to deal with diversity in a phylogenetic context, we are now more than ever poised for a new era of research that includes complex functional traits that limit or enhance the evolution of these deceptively simple organisms. © 2016 Botanical Society of America.

  17. Ecological features of Ambrosia artemisiifolia L. flowers and characteristics of Ambrosia L. pollen seasons in the condition of Lublin (Poland in the years 2001-2008

    Directory of Open Access Journals (Sweden)

    Elżbieta Weryszko-Chmielewska

    2012-12-01

    Full Text Available In the study, the biology of fl owering of Ambrosia artemisiifolia L. was investigated and the pattern of the Ambrosia pollen seasons in Lublin in the years 2001-2008 was characterised. The structure of male and female A. artemisiifolia flowers was observed in cultivated plants under controlled conditions in the 2000 vegetative season. The number of pollen grains produced by the stamen, flower, inflorescence and plant was determined. It was shown that in A. artemisiifolia flowers nonfunctional pistils occurred with a reduced ovary, performing the role of a pollen presenter. The pistils found in female flowers differed significantly in their morphological features from the pistils in male flowers. It was calculated that one stamrn produced an average of 3 375 pollen grains, whereas one flower 16 875. A plant which produces 20 racemes may release over 420 million pollen grains into the atmosphere. The Ambrosia pollen seasons in particular years had different patterns. In some years, the days of maximum concentration were in the second half of August, in other years in the first half of September. Over the 8-year period, the maximum daily concentration had a mean value of 116 pollen grains in m3 (31-311. Annual total concentrations of Ambrosia pollen grains ranged between 194 and 1200 grains, and it was 523 grains on the average. The pollen seasons were characterised by the occurrence of several-day-long interruptions in the presence of airborne pollen in the atmosphere of Lublin, which may indicate the long-distance transport of Ambrosia pollen.

  18. 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.

  19. Composição do meio de cultura e condições ambientais para germinação de grãos de pólen de porta-enxertos de pereira Medium composition and environmental conditions for the germination of pollen grains of pear rootsocks

    Directory of Open Access Journals (Sweden)

    Edvan Alves Chagas

    2010-02-01

    Full Text Available Visando a dar suporte a trabalhos de melhoramento genético para porta-enxertos de pera e ajuste de protocolo de germinação de pólen para fins de polinização intra e interespécies, objetivou-se ajustar os componentes básicos do meio de cultura e as condições ambientais para a realização de testes de germinação in vitro e viabilidade de grãos de pólen dos porta-enxertos para pereiras 'Taiwan Nashi-C' (Pyrus calleryana e 'Taiwan Mamenashi' (P. betulaefolia. O pólen utilizado foi obtido de anteras provenientes de flores em estádio de balão. Em seguida, com auxílio de um pincel n°2, os grãos de pólen foram espalhados sobre a superfície de placas de Petri, contendo 20ml de meio de cultura de acordo com os seguintes experimentos: 1 concentrações de sacarose (0, 30, 60 e 90g L-1 e agar (4, 6, 8 e 10g L-1; 2 concentrações de nitrato de cálcio (0, 200, 400 e 800mg L-1 e ácido bórico (0, 400, 800 e 1200mg L-1; 3 valores de pH (4,0; 4,5; 5,0; 5,5; 6,0 e 6,5; 4 temperaturas (20; 25; 30 e 35; e 5 tempo de emissão do tubo polínico (1, 2, 3, 4, 5, 6 e 12 horas após a inoculação, os quais foram montados de forma sequencial. A utilização de 10g L-1 de agar e 90g L-1 de sacarose para o porta-enxerto 'Taiwan Mamenashi' e 47,78g L-1 para 'Taiwan Nashi-C', com 795 a 838mg L-1 de ácido bórico, na ausência de nitrato de cálcio, pH entre 5,2 e 5,8 e temperatura de 28°C, proporcionou as melhores condições de germinação de grãos de grãos. A porcentagem máxima de polens germinados é obtida com oito horas após a inoculação para 'Taiwan Nashi-C' e com 12 horas para 'Taiwan Mamenashi'.In order to support the works with genetic improvement for pear rootstocks and adjust the pollen germination protocol for intra and inter species polinization, this study aimed to adjust the culture medium basic compounds and environmental conditions for the realization of in vitro pears pollen grains germination and viability tests of

  20. Effect of nitrogen dioxide and sulfur dioxide on viability and morphology of oak pollen.

    Science.gov (United States)

    Ouyang, Yuhui; Xu, Zhaojun; Fan, Erzhong; Li, Ying; Zhang, Luo

    2016-01-01

    Nitrogen dioxide (NO2) and sulfur dioxide (SO2) generated by excessive coal combustion and motor vehicle emissions are major air pollutants in the large cities of China. The objective of our study was to determine the effects of the exposure of oak pollens (Quercusmongolica) to several concentrations of NO2 or SO2. Pollen grains were exposed to 0.5 ppm to 5.0 ppm NO2 or SO2 for 4 hours and assessed for morphological damage by field emission scanning electron microscopy and for viability using the trypan blue stain. Morphological changes in pollen grains were also examined after contact with acid solutions at pH 4.0 to pH 7.0. Exposure to NO2 or SO2 significantly damaged pollen grains at all concentrations investigated, compared to exposure to air; with exposure to concentrations of 0.5 ppm to 2 ppm resulting in fissures or complete breaks in the exine and a concentration of 5 ppm resulting in complete breakdown and release of pollen cytoplasmic granules. Significantly greater amounts of pollen grain were damaged after exposure to SO2 (15.5-20.4%) than after exposure to NO2 (7.1-14.7%). Similarly, exposure to NO2 or SO2 significantly decreased the viability of pollen grains, compared with exposure to air; with SO2 being slightly more detrimental than NO2. Exposure to acid solutions also induced pollen damage, which appeared to be pH-dependent (from 24.6% at pH 6.0 to 55.8% at pH 4.0; compared to 3.8% at pH 7.0). Short-term exposure of oak pollen to high concentrations of SO2 or NO2 significantly increases their fragility and disruption, leading to subsequent release of pollen cytoplasmic granules into the atmosphere. These results suggest that heightened air pollution during the oak pollen season may possibly increase the incidence of allergic airway disease in sensitized individuals by facilitating the bioavailability of airborne pollen allergens. © 2015 ARS-AAOA, LLC.

  1. Links between early pollen development and aperture pattern in monocots.

    Science.gov (United States)

    Nadot, S; Forchioni, A; Penet, L; Sannier, J; Ressayre, A

    2006-08-01

    Although the pollen grains produced in monocots are predominantly monosulcate (or monoporate), other aperture types are also found within this taxonomic group, such as the trichotomosulcate, inaperturate, zonaperturate, di-, or triaperturate types. The aperture pattern is determined during the young-tetrad stage of pollen development and it is known that some features of microsporogenesis can constrain the aperture type. For example, trichotomosulcate pollen is always associated with simultaneous cytokinesis, a condition considered as derived in the monocots. Our observations of the microsporogenesis pathway in a range of monocot species show that this pathway is surprisingly variable. Our results, however preliminary, reveal that variation in microsporogenesis concerns not only cytokinesis but also callose deposition among the microspores and shape of the tetrads. The role played by these features in aperture pattern determination is discussed.

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

    Science.gov (United States)

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

    2013-10-15

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

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

    Directory of Open Access Journals (Sweden)

    Elżbieta Weryszko-Chmielewska

    2017-06-01

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

  4. 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.

  5. Successful expression in pollen of various plant species of in vitro synthesized mRNA introduced by particle bombardment.

    Science.gov (United States)

    Tanaka, T; Nishihara, M; Seki, M; Sakamoto, A; Tanaka, K; Irifune, K; Morikawa, H

    1995-05-01

    Gold particles coated with beta-glucuronidase (GUS) mRNA with a 5' cap structure that had been synthesized in vitro were introduced, by use of a pneumatic particle gun, into pollen grains of lily (Lilium longiflorum), freesia (Freesia refracta) and tulip (Tulipa gesneriana). A fluorometric assay for the GUS activity indicated that in vitro synthesized GUS mRNA introduced into these pollen cells by particle bombardment was successfully expressed. GUS activity in extracts of the bombarded lily pollen became detectable fluorometrically within 30 min after bombardment, peaked at 6 h, then gradually decreased. This activity changed as a function of the developmental stage of the pollen cell of lily.

  6. The dangerous liaison between pollens and pollution in respiratory allergy.

    Science.gov (United States)

    Schiavoni, Giovanna; D'Amato, Gennaro; Afferni, Claudia

    2017-03-01

    To recapitulate the more recent epidemiologic studies on the association of air pollution with respiratory allergic diseases prevalence and to discuss the main limitations of current approaches used to establish a link between pollinosis and pollution. Through the use of PubMed, we conducted a broad literature review in the following areas: epidemiology of respiratory allergic diseases, effect of pollution and climate changes on pollen grains, and immunomodulatory properties of pollen substances. Studies on short- and long-term exposure to air pollutants, such as gaseous and particulate materials, on allergic sensitization, and on exacerbation of asthma symptoms were considered. Trend in respiratory allergic disease prevalence has increased worldwide during the last 3 decades. Although recent epidemiologic studies on a possible association of this phenomenon with increasing pollution are controversial, botanic studies suggest a clear effect of several pollutants combined to climatic changes on the increased expression of allergenic proteins in several pollen grains. The current literature suggests the need for considering both pollen allergen and pollutant contents for epidemiologic evaluation of environmental determinants in respiratory allergies. We propose that a measure of allergenic potential of pollens, indicative of the increase in allergenicity of a polluted pollen, may be considered as a new risk indicator for respiratory health in urban areas. Because public greens are located in strict proximity to the anthropogenic sources of pollution, the identification of novel more reliable parameters for risk assessment in respiratory allergic diseases is an essential need for public health management and primary prevention area. Copyright © 2017 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  7. Numerical simulation of birch pollen dispersion with an operational weather forecast system.

    Science.gov (United States)

    Vogel, Heike; Pauling, Andreas; Vogel, Bernhard

    2008-11-01

    We included a parameterisation of the emissions of pollen grains into the comprehensive model system COSMO-ART. In addition, a detailed density distribution of birch trees within Switzerland was derived. Based on these new developments, we carried out numerical simulations of the dispersion of pollen grains for an episode that occurred in April 2006 over Switzerland and the adjacent regions. Since COSMO-ART is based on the operational forecast model of the German Weather Service, we are presenting a feasibility study of daily pollen forecast based on methods which have been developed during the last two decades for the treatment of anthropogenic aerosol. A comparison of the model results and very detailed pollen counts documents the current possibilities and the shortcomings of the method and gives hints for necessary improvements.

  8. [Allergy, pollen and the environment].

    Science.gov (United States)

    Terán, Luis Manuel; Haselbarth-López, Michelle Marie Margarete; Quiroz-García, David Leonor

    2009-01-01

    Allergic respiratory diseases such asthma and allergic rhinitis are a health problem throughout the world. In Mexico City, pollens are an important cause of allergic respiratory disease. Both, the geographic location- and the vegetation surrounding this City favor the distribution of pollens leading to respiratory disease in susceptible patients. Aerobiological studies have shown that during the mild dry winter there is a large amount of pollens in the environment with tree pollens being the most abundant of all. The most frequent tree pollens found in Mexico City include Fraxinus, Cupressaseae, Alnus, Liquidambar, Callistemon, Pinus, and Casuarina. In contrast, grass- and weed pollens predominate during the summer (rainy season) including Compositae, Cheno-Am, Ambrosia and Gramineae. An additional health problem in Mexico City is the air pollution that exerts a direct effect on individuals. This in turn increases pollen allergenicity by disrupting them leading to the release of their particles which then penetrate the human airways causing disease. Thus, the polluted environment along with global warming which is also known to increase pollen quantities by inducing longer pollen seasons may represent a health risk to Mexico City inhabitants.

  9. Comparative Pollen Morphological Analysis and Its Systematic Implications on Three European Oak (Quercus L., Fagaceae) Species and Their Spontaneous Hybrids.

    Science.gov (United States)

    Wrońska-Pilarek, Dorota; Danielewicz, Władysław; Bocianowski, Jan; Maliński, Tomasz; Janyszek, Magdalena

    2016-01-01

    Pollen morphology of three parental Quercus species (Q. robur L., Q. petraea (Matt) Liebl, Q. pubescens Willd.) and two spontaneous hybrids of these species (Q. ×calvescens Vuk. = Q. petraea × Q. pubescens and Q. ×rosacea Bechst. = Q. robur × Q. petraea) was investigated in this study. The pollen originated from 18 natural oak sites and 67 individuals (oak trees). Each individual was represented by 30 pollen grains. In total, 2010 pollen grains were measured. They were analysed for nine quantitative and four qualitative features. Pollen size and shape were important features to diagnosing Quercus parental species and hybrids. On the basis of exine ornamentation, it was possible to identify only Q. pubescens, while the remaining species and hybrids did not differ significantly with respect to this feature. The determination of the diagnostic value of endoaperture features requires further palynological studies. On the basis of pollen size and shape Q. robur × Q. petraea was clearly separated. Grouping of 67 oak trees on the basis of pollen grain features has shown that individuals from different as well as same taxa occurred in the same groups. Likewise, with respect to natural sites, oak trees originating from the same places as well as from geographically distant ones, grouped together. Pollen morphological features allow to distinguish a part of the studied Quercus taxa. Therefore, it can be used as an auxiliary feature in the taxonomy.

  10. Comparative Pollen Morphological Analysis and Its Systematic Implications on Three European Oak (Quercus L., Fagaceae Species and Their Spontaneous Hybrids.

    Directory of Open Access Journals (Sweden)

    Dorota Wrońska-Pilarek

    Full Text Available Pollen morphology of three parental Quercus species (Q. robur L., Q. petraea (Matt Liebl, Q. pubescens Willd. and two spontaneous hybrids of these species (Q. ×calvescens Vuk. = Q. petraea × Q. pubescens and Q. ×rosacea Bechst. = Q. robur × Q. petraea was investigated in this study. The pollen originated from 18 natural oak sites and 67 individuals (oak trees. Each individual was represented by 30 pollen grains. In total, 2010 pollen grains were measured. They were analysed for nine quantitative and four qualitative features. Pollen size and shape were important features to diagnosing Quercus parental species and hybrids. On the basis of exine ornamentation, it was possible to identify only Q. pubescens, while the remaining species and hybrids did not differ significantly with respect to this feature. The determination of the diagnostic value of endoaperture features requires further palynological studies. On the basis of pollen size and shape Q. robur × Q. petraea was clearly separated. Grouping of 67 oak trees on the basis of pollen grain features has shown that individuals from different as well as same taxa occurred in the same groups. Likewise, with respect to natural sites, oak trees originating from the same places as well as from geographically distant ones, grouped together. Pollen morphological features allow to distinguish a part of the studied Quercus taxa. Therefore, it can be used as an auxiliary feature in the taxonomy.

  11. Pollen morphology of Nothofagus (Nothofagaceae, Fagales and its phylogenetic significance

    Directory of Open Access Journals (Sweden)

    Fernández Damián Andrés

    2016-12-01

    Full Text Available Nothofagaceae (southern beeches are a relatively small flowering plant family of trees confined to the Southern Hemisphere. The fossil record of the family is abundant and it has been widely used as a test case for the classic hypothesis that Antarctica, Patagonia, Australia and New Zealand were once joined together. Although the phylogenetic relationships in Nothofagus appear to be well supported, the evolution of some pollen morphological traits remains elusive, largely because of the lack of ultrastructural analyses. Here we describe the pollen morphology of all extant South American species of Nothofagus, using scanning electron microscopy (SEM, transmission electron microscopy (TEM and light microscopy (LM, and reconstruct ancestral character states using a well-supported phylogenetic tree of the family. Our results indicate that the main differences between pollen of subgenera Fuscospora (pollen type fusca a and Nothofagus (pollen type fusca b are related to the size of microspines (distinguishable or not in optical section, and the thickening of colpi margins (thickened inwards, or thickened both inwards and outwards. In particular, Nothofagus alessandrii, the only extant South American species of subgenus Fuscospora, presents distinctive pollen features that have not been observed in any other species of the genus (i.e. a large granular infratectum and spongy apertural endexine. Species of subgenus Lophozonia are characterized by having the largest pollen grains, with polygonal outline in polar view, microspines distinguishable in optical section, long and non-thickened colpi, and a thin endexine. The reconstruction of character states for the node corresponding to the common ancestor to genus Nothofagus leads us to conclude that the ancestral form of Nothofagaceae should have had: equatorial diameter < 40 μm, circular outline in polar view, microspines distinguishable in optical section, short colpi thickened inwards, and a thin

  12. Current glimpse of airborne allergenic pollen in Indian subcontinent

    Directory of Open Access Journals (Sweden)

    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.

  13. Meiotic aberrations during 2n pollen formation in Begonia.

    Science.gov (United States)

    Dewitte, A; Eeckhaut, T; Van Huylenbroeck, J; Van Bockstaele, E

    2010-02-01

    Unreduced gametes are the driving force for the polyploidization of plants in nature, and are also an important tool for ploidy breeding. The final heterozygosity of a 2n pollen grain depends on the cytological mechanism behind 2n pollen formation. In this study, chromosome pairing and chromosome segregation during the microsporogenesis of seven Begonia genotypes were analysed using fluorescent chromosome staining on (squashed) pollen mother cells. Among the seven genotypes, five genotypes produce 2n pollen (B. 'Bubbles', B. 'Florence Rita', B. 'Orococo', B. 'Tamo' and B276) and two genotypes produce only normal n pollen (B. fischeri and B243). All 2n pollen producers showed a mechanism equivalent to first division restitution (FDR), in which chromosomes did not segregate during meiosis I but only during meiosis II. This FDR was the result of (a) an irregular chromosome pairing in B. 'Tamo', (b) stickiness of chromosomes associated with numerous chromosome bridges in B. 'Florence Rita' and B276, and (c) a combination of irregular chromosome pairing and stickiness of chromosomes in B. 'Bubbles'. The exact mechanism of the nuclear restitution in B. 'Orococo' could not be determined. Other mechanisms, such as early asymmetric cytokinesis, omission of meiosis II, parallel or tripolar spindle formation, were rather uncommon. Unpaired chromosomes (univalents) were observed in all genotypes, but they had moved to one of the poles by the end of anaphase I or II. Only B. 'Tamo' formed a high number of micronuclei. Consequently, this genotype formed a large number of malformed pollen. Obviously, chromosome behaviour during meiosis in Begonia is very dynamic, which may have important consequences for chromosome evolution and biodiversity within the genus.

  14. Pollen Dimorphism of Several Members of Nymphaeaceae and Nelumbonaceae: An Index of Geographical and Ecological Variation

    OpenAIRE

    Somnath BHOWMIK; Badal Kumar DATTA

    2012-01-01

    Pollen morphology of five Nymphaea (Nymphaeaceae) species, growing in Tripura, India were analysed using Scanning Electron Microscopy. Pollen grains of Nymphaea are dimorphic (ellipsoidal and spheroidal). The exine pattern also varies among the species. The variation as reported in the present study in terms of exine pattern of the studied species suggests the feasibility of applying the data in the identification of the genus of Nymphaea. The difference in exine patterns with the earlier rep...

  15. Callose plug deposition patterns vary in pollen tubes of Arabidopsis thaliana ecotypes and tomato species

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    Qin Peng

    2012-10-01

    Full Text Available Abstract Background The pollen grain contains the male gametophyte that extends a pollen tube that grows through female tissues in order to deliver sperm to the embryo sac for double fertilization. Growing pollen tubes form periodic callose plugs that are thought to block off the older parts of the tube and maintain the cytoplasm near the growing tip. The morphology of callose plugs and the patterns of their deposition were previously shown to vary among species, but variation within a species had not been examined. We therefore systematically examined callose plug deposition in Arabidopsis thaliana ecotypes, tested for heritability using reciprocal crosses between ecotypes that had differing deposition patterns, and investigated the relationship between callose plugs and pollen tube growth rate. We also surveyed callose plug deposition patterns in different species of tomato. Results We used in vitro grown pollen tubes of 14 different A. thaliana ecotypes and measured the distance from the pollen grain pore to the first callose plug (termed first interval. This distance varied among Arabidopsis ecotypes and in some cases even within an ecotype. Pollen tubes without a callose plug were shorter than those with a callose plug, and tubes with a callose plug near the grain were, on average, longer than those with the first callose plug farther from the grain. Variations in the first callose plug position were also observed between different species of tomato. Conclusions We showed that the position of the first callose plug varied among Arabidopsis ecotypes and in tomato species, and that callose plug deposition patterns were heritable. These findings lay a foundation for mapping genes that regulate callose plug deposition or that determine pollen tube length or growth rate.

  16. [Description and value of the Microvision system for pollen analysis].

    Science.gov (United States)

    Thibaudon, M; Lachasse, C

    2004-09-01

    Currently, two techniques of analysis are classically used by the aerobiological networks: the technique of the 12 vertical lines allow to follow the evolution by bi-hourly periods of pollination, but the segmentation of the sample doesn't allow to visualise pollen clouds of short duration; the technique of 2 or 3 horizontal lines allow to follow the daily evolution, but only the daily totals are recorded. The MICROVISION system adapted by the RNSA to the pollen analysis allow to keep the horizontal method, which is faster and continue, and to record automatically in the database the hourly or bi-hourly data. So each pollen is recorded by its coordinates with a precision of 1 micron (1.8 seconds). First, we realised a cartography of the impaction of the pollen grains on the strip, in order to locate the more representative horizontal lines. Secondly, the coupling of the microscope with the Microvision system and the software of data acquiring elaborated by the RNSA allow to propose a more reliable and faster procedure for pollen analysis.

  17. Pollen morphology of Rhizophora L. in Peninsular Malaysia

    Science.gov (United States)

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

    2013-11-01

    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.

  18. 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.

  19. Trisetum paniceum (wild oats) pollen counts and aeroallergens in the ambient air of Madrid, Spain.

    Science.gov (United States)

    Cabrera, M; Martínez-Cócera, C; Fernández-Caldas, E; Carnés Sánchez, J; Boluda, L; Tejada, J; Subiza, J L; Subiza, J; Jerez, M

    2002-06-01

    Madrid has a short but intensive grass pollen season, in which 79% of the total grass pollen load is released from the middle of May to the middle of June. The main objectives of this study were to quantify Trisetum paniceum (wild oats) aeroallergen in the atmosphere in Madrid from February to December 1996 and to correlate the aeroallergen concentrations with grass pollen counts. Two different samplers were used to assess allergen exposure; a Burkard spore trap was used to collect pollen grains and a high-volume air sampler to collect airborne particles. A total of 182 air filters were collected and extracted in 1 ml of PBS and analysed by ELISA inhibition, using pooled sera from highly allergic individuals. T. paniceum aeroallergens were detected not only during the grass pollen season, but also before and after. Wild oat allergens had two main peaks of 1 and 1.9 microg/m(3), occurring in late May and July, respectively. The time series analysis established the existence of lags between the two main variables pollen counts and aeroallergen activity. Analysis of the data by the Spearman rank test and linear regression showed a weak correlation between grass allergenic activity and grass pollen counts (Spearman's rho = 0.29). Data obtained from time series analysis demonstrated that grass allergenic activity correlated strongly with current and 5-week-old grass pollen grain counts (r(2) = 0.73). Wild oats allergenic activity was detected during the entire year and not only during the pollen season. This fact is an important aspect to be considered in the clinical follow-up and treatment of grass pollen-sensitised patients in Madrid. Copyright 2002 S. Karger AG, Basel

  20. Examining Ambrosia pollen episodes at Poznań (Poland) using back-trajectory analysis

    Science.gov (United States)

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

    2007-03-01

    The pollen grains of Ambrosia spp. are considered to be important aeroallergens in parts of southern and central Europe. Back-trajectories have been analysed with the aim of finding the likely sources of Ambrosia pollen grains that arrived at Poznań (Poland). Temporal variations in Ambrosia pollen at Poznań from 1995-2005 were examined in order to identify Ambrosia pollen episodes suitable for further investigation using back-trajectory analysis. The trajectories were calculated using the transport model within the Lagrangian air pollution model, ACDEP (Atmospheric Chemistry and Deposition). Analysis identified two separate populations in Ambrosia pollen episodes, those that peaked in the early morning between 4 a.m. and 8 a.m., and those that peaked in the afternoon between 2 p.m. and 6 p.m.. Six Ambrosia pollen episodes between 2001 and 2005 were examined using back-trajectory analysis. The results showed that Ambrosia pollen episodes that peaked in the early morning usually arrived at Poznań from a southerly direction after passing over southern Poland, the Czech Republic, Slovakia and Hungary, whereas air masses that brought Ambrosia pollen to Poznań during the afternoon arrived from a more easterly direction and predominantly stayed within the borders of Poland. Back-trajectory analysis has shown that there is a possibility that long-range transport brings Ambrosia pollen to Poznań from southern Poland, the Czech Republic, Slovakia and Hungary. There is also a likelihood that Ambrosia is present in Poland, as shown by the arrival of pollen during the afternoon that originated primarily from within the country.

  1. 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.

  2. Analysis of airborne ragweed (Ambrosia artemisiifolia L. pollen in Timisoara, 2004

    Directory of Open Access Journals (Sweden)

    Nicoleta IANOVICI

    2007-05-01

    Full Text Available Ambrosia artemisiifolia (ragweed is an annual, herbaceous, with high invasive potential, wind-pollinated plant that is important allergenic weed belonging to the Asteraceae plant family. Allergenic airpollen can interact with other components of environmental global change in a synergic way increasing the risks to public health. Analysis of the pollen count was performed on the basis of the data collected in Timişoara in the season of 2004. Airborne ragweed pollen concentrations, measured continuously with a volumetric method are compared with respect to both their quantitative and seasonal aspects. A weekly programmed Hirst spore-trap was used to sample airborne pollen grains, calibrated to handle a flow of 10 L/min of air, which roughly corresponds to a human breathing rhythm. In Timisoara the Lanzoni model was used. The daily quantities of pollen are expressed as numbers of pollen grains per cubic meter of air per day (PG/m3.The pollen seasons show 3 main parts: tree season (February–April, grass season (May–July, weed season (July–October. In September 65,71% of the total aeropollen concentration is due to Ambrosia. The highest concentration of ragweed pollen was 220 PG/m3.Ambrosia artemisiifolia have a pronounced invasive character. Since 1910, having been spread all over the country, it has become the most common weed in Romania. There is an urgent need to organize interventions to stop ragweed expansion and to clear the areas already polluted.

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

    Directory of Open Access Journals (Sweden)

    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

  4. Survey of airborne pollens in Seoul, Korea.

    Science.gov (United States)

    Park, H S; Chung, D H; Joo, Y J

    1994-02-01

    The daily pollen counts in the air of Seoul, Korea were measured using a rotorod sampler from June 1990 to July 1992. Two distinct pollen periods were noted: tree pollens such as alder, poplar, willow, oak and pine appeared in the spring from March to May, and weed pollens, such as Artemisia spp., Ambrosia spp. and Hop japanese appeared in the autumn from August to September. Various kinds of grass pollen appeared from June to September. The study indicated that there were two pollen peaks in Seoul composed of tree pollens in spring and weed pollens in autumn.

  5. Hedycarya macrofossils and associated Planarpollenites pollen from the early Miocene of New Zealand.

    Science.gov (United States)

    Conran, John G; Bannister, Jennifer M; Mildenhall, Dallas C; Lee, Daphne E

    2016-05-01

    The history of the basal angiosperm family Monimiaceae is based largely on fossil wood and leaf and floral fossils of uncertain affinity. Fossilized leaves with a well-preserved cuticle and Hedycarya-like flowers, including one with in situ pollen tetrads and fruits from an early Miocene lacustrine diatomite deposit in southern New Zealand implies a long record for Hedycarya in New Zealand. The flowers contain pollen grains that are very similar to those of the modern New Zealand species Hedycarya arborea and the Australian H. angustifolia but are considerably smaller. We undertook comparative studies of the leaf, flower and fruit morphology of the newly discovered macrofossils and compared the in situ pollen grains from the flower with dispersed pollen grains from extant species. The leaves are referred to a new, extinct species, Hedycarya pluvisilva Bannister, Conran, Mildenh. & D.E.Lee, (Monimiaceae), and associated with fossilized Hedycarya-like flowers that include in situ pollen and an infructescence of three drupes from the same site. Phylogenetic analysis placed the fossil into Hedycarya, sister to H. angustifolia in a clade with H. arborea and Levieria acuminata. A new name, Planarpollenites fragilis Mildenh., is proposed for dispersed fossil pollen tetrads at the site and those associated with the flower. The fossils are similar to those of modern Australian and New Zealand Hedycarya species, suggesting that the genus and related taxa have been significant components of the rainforests of Australia and the former Zealandian subcontinent for most of the Cenozoic. © 2016 Botanical Society of America.

  6. Risk of exposure to airborne Ambrosia pollen from local and distant sources in Europe - an example from Denmark.

    Science.gov (United States)

    Sommer, Janne; Smith, Matt; Šikoparija, Branko; Kasprzyk, Idalia; Myszkowska, Dorota; Grewling, Łukasz; Skjøth, Carsten A

    2015-01-01

    Ambrosia artemisiifolia L. is a noxious invasive alien species in Europe. It is an important aeroallergen and millions of people are exposed to its pollen. The main aim of this study is to show that atmospheric concentrations of Ambrosia pollen recorded in Denmark can be derived from local or more distant sources. This was achieved by using a combination of pollen measurements, air mass trajectory calculations using the HYPLIT model and mapping all known Ambrosia locations in Denmark and relating them to land cover types. The annual pollen index recorded in Copenhagen during a 15-year period varied from a few pollen grains to more than 100. Since 2005, small quantities of Ambrosia pollen has been observed in the air every year. We have demonstrated, through a combination of Lagrangian back-trajectory calculations and atmospheric pollen measurements, that pollen arrived in Denmark via long-distance transport from centres of Ambrosia infection, such as the Pannonian Plain and Ukraine. Combining observations with results from a local scale dispersion model show that it is possible that Ambrosia pollen could be derived from local sources identified within Denmark. The high allergenic capacity of Ambrosia pollen means that only small amounts of pollen are relevant for allergy sufferers, and just a few plants will be sufficient to produce enough pollen to affect pollen allergy sufferers within a short distance from the source. It is necessary to adopt control measures to restrict Ambrosia numbers. Recommendations for the removal of all Ambrosia plants can effectively reduce the amount of local pollen, as long as the population of Ambrosia plants is small.

  7. Forecasting of the selected features of Poaceae (R. Br.) Barnh., Artemisia L. and Ambrosia L. pollen season in Szczecin, north-western Poland, using Gumbel's distribution.

    Science.gov (United States)

    Puc, Małgorzata; Wolski, Tomasz

    2013-01-01

    The allergenic pollen content of the atmosphere varies according to climate, biogeography and vegetation. Minimisation of the pollen allergy symptoms is related to the possibility of avoidance of large doses of the allergen. Measurements performed in Szczecin over a period of 13 years (2000-2012 inclusive) permitted prediction of theoretical maximum concentrations of pollen grains and their probability for the pollen season of Poaceae, Artemisia and Ambrosia. Moreover, the probabilities were determined of a given date as the beginning of the pollen season, the date of the maximum pollen count, Seasonal Pollen Index value and the number of days with pollen count above threshold values. Aerobiological monitoring was conducted using a Hirst volumetric trap (Lanzoni VPPS). Linear trend with determination coefficient (R(2)) was calculated. Model for long-term forecasting was performed by the method based on Gumbel's distribution. A statistically significant negative correlation was determined between the duration of pollen season of Poaceae and Artemisia and the Seasonal Pollen Index value. Seasonal, total pollen counts of Artemisia and Ambrosia showed a strong and statistically significant decreasing tendency. On the basis of Gumbel's distribution, a model was proposed for Szczecin, allowing prediction of the probabilities of the maximum pollen count values that can appear once in e.g. 5, 10 or 100 years. Short pollen seasons are characterised by a higher intensity of pollination than long ones. Prediction of the maximum pollen count values, dates of the pollen season beginning, and the number of days with pollen count above the threshold, on the basis of Gumbel's distribution, is expected to lead to improvement in the prophylaxis and therapy of persons allergic to pollen.

  8. Evolutionary trends in the morphology and harmomegathy of the pollen of the genus Guioa (Sapindaceae-Cupanieae)

    OpenAIRE

    Ham, van der, E.; Heuven, van, V.J.J.P.

    1989-01-01

    A pollen morphological survey of the genus Guioa is presented. Based on a study of the harmomegathy in relation to morphological series, evolutionary trends are postulated: 1. wide ectoapertures → narrow ectoapertures 2. grain parasyncolporate → grain colporate 3. grain parasyncolporate → grain syncolporate 4. ornamentation rugulate → ornamentation psilate-imperforate. It is suggested that the most ‘primitive’ species of Guioa occur in the southeastern part of the distribution area of the gen...

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

    Science.gov (United States)

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

    2005-01-01

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

  10. 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

  11. 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.

  12. [Prospective study of pollen dispersal prediction and identifying the usefulness of different parameters].

    Science.gov (United States)

    Maeda, Masanori; Maguchi, Shiro; Nakamaru, Yuji; Takagi, Dai; Fukuda, Satoshi

    2006-05-01

    Birch pollen is the major pollen allergen in Hokkaido, Northern Japan. We reported a Betula masting model based on the resource budget model hypothesis. In addition to weather conditions, cumulative hours of sunlight and mean temperature from May to July of the previous year, this model used the amount of annual pollen dispersed in previous and penultimate years as a parameter based on data from 1990 to 2000. We compared the predicted and observed amount of pollen dispersed for 3 years from 2001 to 2003 and evaluated the usefulness of each parameter in this model. Birch pollen was measured using the Durham sampler at the Hokkaido University Graduate School of Medicine Research Institute in Sapporo. The difference between predicted and observed amounts of pollen dispersal was about 200-500 grains cm(-2). The annual pollen dispersed in the previous year was found to be the most useful parameter. This model is useful in predicting whether the amount of birch pollen will be less than average, about average, more than average, or much more than average.

  13. Pollen morphology of members of southern African Boerhavia and Commicarpus (Nyctaginaceae

    Directory of Open Access Journals (Sweden)

    M. Struwig

    2013-01-01

    Full Text Available In southern Africa, Boerhavia L. and Commicarpus Standl. are the most species-rich genera of the Nyctaginaceae. Hitherto, the pollen morphology of only three southern African species of each of these genera has been described. A palynological study of the remaining species is therefore necessary to complete the information for the taxa. The pollen morphology of sixteen species was studied with light, scanning electron and transmission electron microscopy. Pollen grains of Boerhavia and Commicarpus are uniform in shape and sculpturing. Grains are spheroidal and pantoporate, and the tectum tubuliferous and spinulose. Pollen grains of the Boerhavia are 52–91 μm in diameter and those of Commicarpus 52–129 μm. Spinules in both genera are 1–5 μm long. Pore plates have one or two spinules. In both genera the exine is 3.5–11.5 μm thick, the tectum 0.9–3.9 μm thick and the collumellae 0.6–2.8 μm long. Foot layers are 0.9–5.1 μm thick and the endexine is barely visible. Size variation of the pollen grain, pore diameter and exine thickness overlap and cannot be used to distinguish between the two genera or the individual species.

  14. 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

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

    Directory of Open Access Journals (Sweden)

    Maria Goreti Senna Corrêa

    2005-06-01

    II. The frequencies of normal/abnormal PMC found in microsporogenesis point out to the existence of great variation among the species. It should be emphasized the absence of PMC with abnormalities in Monstera deliciosa Adans. microsporogenesis, as well as in Anthurium scandens (Aubl Engl. M I and in Caladium hortulanum Birdsey M II. The number of anomalous PMC in Syngonium podophyllum Schott and Zantedeschia aethiopica Spreng in M I and M IIwas higher than expected. Average frequency of normal tetrads in ten araceous species and viable pollen grains in 17 species were significantly superior to the average frequency of abnormal tetrads and unviable pollen grains, respectively.

  16. Turbulence-induced resonance vibrations cause pollen release in wind-pollinated Plantago lanceolata L. (Plantaginaceae).

    Science.gov (United States)

    Timerman, David; Greene, David F; Urzay, Javier; Ackerman, Josef D

    2014-12-06

    In wind pollination, the release of pollen from anthers into airflows determines the quantity and timing of pollen available for pollination. Despite the ecological and evolutionary importance of pollen release, wind-stamen interactions are poorly understood, as are the specific forces that deliver pollen grains into airflows. We present empirical evidence that atmospheric turbulence acts directly on stamens in the cosmopolitan, wind-pollinated weed, Plantago lanceolata, causing resonant vibrations that release episodic bursts of pollen grains. In laboratory experiments, we show that stamens have mechanical properties corresponding to theoretically predicted ranges for turbulence-driven resonant vibrations. The mechanical excitation of stamens at their characteristic resonance frequency caused them to resonate, shedding pollen vigorously. The characteristic natural frequency of the stamens increased over time with each shedding episode due to the reduction in anther mass, which increased the mechanical energy required to trigger subsequent episodes. Field observations of a natural population under turbulent wind conditions were consistent with these laboratory results and demonstrated that pollen is released from resonating stamens excited by small eddies whose turnover periods are similar to the characteristic resonance frequency measured in the laboratory. Turbulence-driven vibration of stamens at resonance may be a primary mechanism for pollen shedding in wind-pollinated angiosperms. The capacity to release pollen in wind can be viewed as a primary factor distinguishing animal- from wind-pollinated plants, and selection on traits such as the damping ratio and flexural rigidity may be of consequence in evolutionary transitions between pollination systems. © 2014 The Author(s) Published by the Royal Society. All rights reserved.

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

    Science.gov (United States)

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

    2016-05-01

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

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    Cerović Radosav

    2014-01-01

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

  20. 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.

  1. Classification and phylogenetic analysis of Chinese hawthorn assessed by plant and pollen morphology.

    Science.gov (United States)

    Ma, S L Y; Lu, Y M

    2016-09-19

    The Chinese hawthorn (Crataegus pinnatifida Bge. var. major N.E.Br.) is uniquely originated in northern China. The ecological and horticultural importance of Chinese hawthorn is considerable and some varieties are valued for their fruit or medicine extracts. Its taxonomy and phylogeny remain poorly understood. Apart from general plant morphological traits, pollen is an important trait for the classification of plants and their evolutionary origin. However, few studies have investigated the pollen of Chinese hawthorn. Here, an analysis of plant and pollen morphological characteristics was conducted in 57 cultivars from the Shenyang region. Thirty plant morphological characters and nine pollen grain characters were investigated. The plant morphological analysis revealed that the coefficient of variation for 13 traits was >20%, which indicates a high degree of variability. We also found that the pollen grains varied greatly in size, shape (from prolate to perprolate), and exine pattern (striate-perforate predominantly). The number of apertures was typically three. Based on these findings, we suggest that pollen morphology associated with plant morphological traits can be used for classification and phylogenetic analysis of Chinese hawthorn cultivars. In sum, our results provide new insights and constitute a scientific basis for future studies on the classification and evolution of Chinese hawthorn.

  2. Different allergenicity of pollen extracts of three Mediterranean cypress species accounted for cytological observations.

    Science.gov (United States)

    Barberini, S; Della Rocca, G; Danti, R; Zanoni, D; Mori, B; Ariano, R; Mistrello, G

    2015-09-01

    Cypresses play an important role in the urban landscape of the Mediterranean region, releasing a huge amount of allergenic airborne pollen which causes a specific pollinosis in exposed people. The aim of this work is to evaluate, in vivo and in vitro, the potential allergenicity of Cupressus macrocarpa pollen, and to compare it with the allergenicity observed for C. arizonica and C. sempervirens. Pollen extracts of the three species were prepared, to determine their protein profile through SDS PAGE analysis and to evaluate their allergenic potential through EAST inhibition assays and SPT. Pollen grain composition was evaluated using a cytochemical approach with optical microscopy. SDS PAGE, EAST inhibition and SPT indicated the higher allergenic potential of C. arizonica compared to C. sempervirens and C. macrocarpa. No significant differences in allergenic potential were found between the latter two species. Cytochemical observations reveal higher β-glucans and protein content in the intine of C. arizonica during hydration. The higher protein content found in C. arizonica pollen grains extract may be due to higher enzyme activity leading to the movement of β-glucans and pectins from the intine to the partially developed pollen cell wall during hydration. This could explain the higher potential allergenicity of C.arizonica in respect to C. macrocarpa and C. sempervirens.

  3. Viable Syntax: Rethinking Minimalist Architecture

    Directory of Open Access Journals (Sweden)

    Ken Safir

    2010-03-01

    Full Text Available Hauser et al. (2002 suggest that the human language faculty emerged as a genetic innovation in the form of what is called here a ‘keystone factor’—a single, simple, formal mental capability that, interacting with the pre-existing faculties of hominid ancestors, caused a cascade of effects resulting in the language faculty in modern humans. They take Merge to be the keystone factor, but instead it is posited here that Merge is the pre-existing mechanism of thought made viable by a principle that permits relations interpretable at the interfaces to be mapped onto c-command. The simplified minimalist architecture proposed here respects the keystone factor as closely as possible, but is justified on the basis of linguistic analyses it makes available, including a relativized intervention theory applicable across Case, scope, agreement, selection and linearization, a derivation of the A/A’-distinction from Case theory, and predictions such as why in situ wh-interpretation is island-insensitive, but susceptible to intervention effects.

  4. Specialized Bees Fail to Develop on Non-Host Pollen : Do Plants Chemically Protect Their Pollen ?

    OpenAIRE

    Praz, Christophe J.; Müller, Andreas; Dorn, Silvia

    2012-01-01

    Bees require large amounts of pollen for their own reproduction. While several morphological flower traits are known to have evolved to protect plants against excessive pollen harvesting by bees, little is known on how selection to minimize pollen loss acts on the chemical composition of pollen. In this study, we traced the larval development of four solitary bee species, each specialized on a different pollen source, when reared on non-host pollen by transferring unhatched eggs of one specie...

  5. Seasonal and Spatial Variations of Indoor Pollen in a Hospital

    Directory of Open Access Journals (Sweden)

    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.

  6. Group 13 allergens as environmental and immunological markers for grass pollen allergy: studies by immunogold field emission scanning and transmission electron microscopy.

    Science.gov (United States)

    Grote, Monika; Swoboda, Ines; Valenta, Rudolf; Reichelt, Rudolf

    2005-04-01

    Polygalacturonases were recently identified as important grass pollen allergens and designated group 13 allergens. The objective of the present study was to investigate the presence of group 13 grass pollen allergens in different grass species, their release and ultrastructural location in dry and hydrated grass pollen. Nitrocellulose-blotted allergen extracts from 12 wild and cultivated grass genera were probed with a rabbit antiserum raised against purified recombinant timothy grass pollen allergen, Phl p 13. The release kinetics of Phl p 13 from timothy grass pollen hydrated for 0.5 min to 3 h were analyzed by immunoblotting. Phl p 13 was localized in dry and hydrated grass pollen grains by immunogold field emission scanning and transmission electron microscopy. Group 13 allergens were detected in all 12 wild and cultivated grass genera representing the major subfamilies of the Poaceae. Ultrastructurally, the allergen was located in the wall and in the cytoplasm of timothy grass pollen grains. In the cytoplasm, Phl p 13 was associated with polysaccharide particles and as yet undescribed stacks of microtubule-like structures. After hydration in rain water, pollen grains expel cytoplasmic particles of respirable size containing Phl p 13, which becomes detectable in aqueous supernatants already after 0.5 min. Group 13 allergens represent one set of marker allergens which specifically occur in pollen of the major grass subfamilies and are rapidly released in association with respirable particles after pollen hydration. They may be considered as environmental markers for grass pollen exposure and group 13-specific IgE antibodies as immunological markers for genuine grass pollen sensitization. Copyright (c) 2005 S. Karger AG, Basel

  7. Pollen Aquaporins: The Solute Factor.

    Science.gov (United States)

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

    2016-01-01

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

  8. Bumblebees require visual pollen stimuli to initiate and multimodal stimuli to complete a full behavioral sequence in close-range flower orientation.

    Science.gov (United States)

    Wilmsen, Saskia; Gottlieb, Robin; Junker, Robert R; Lunau, Klaus

    2017-03-01

    Flower visits are complex encounters, in which animals are attracted by floral signals, guided toward the site of the first physical contact with a flower, land, and finally take up floral rewards. At close range, signals of stamens and pollen play an important role to facilitate flower handling in bees, yet the pollen stimuli eliciting behavioral responses are poorly known. In this study, we test the response of flower-naive bumblebees ( Bombus terrestris ) toward single and multimodal pollen stimuli as compared to natural dandelion pollen. As artificial pollen stimuli, we used the yellow flavonoid pigment quercetin, the scent compound eugenol, the amino acid proline, the monosaccharide glucose, and the texture of pollen-grain-sized glass pellets as a tactile stimulus. Three test stimuli, dandelion pollen, one out of various uni- and multimodal stimulus combinations, and a solvent control were presented simultaneously to individual bumblebees, whose response was recorded. The results indicate that bumblebees respond in an irreversible sequence of behavioral reactions. Bumblebees approached the visual stimulus quercetin as often as natural dandelion pollen. An additional olfactory stimulus resulted in slightly more frequent landings. The multimodal stimulus combinations including visual, olfactory, gustatory, and tactile stimuli elicited approaches, antennal contacts, and landings as often as natural pollen. Subsequent reactions like proboscis extension, mandible biting, and buzzing were more often but not regularly observed at dandelion pollen. Our study shows that visual signals of pollen are sufficient to trigger initial responses of bumblebees, whereas multimodal pollen stimuli elicit full behavioral response as compared to natural pollen. Our results suggest a major role of pollen cues for the attraction of bees toward flowers and also explain, why many floral guides mimic the visual signals of pollen and anthers, that is, the yellow and UV-absorbing color, to

  9. 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.

  10. The long distance transport (LDT) of Ambrosia pollen from the Pannonian Plain to Scandinavia

    Science.gov (United States)

    Šikoparija, B..; Skjøth, C. A.; Alm Kübler, K.; Dahl, A.; Radišić, P.; Sommer, J.; Grewling, Ł.; Smith, M.

    2012-04-01

    Ragweed (Ambrosia spp.) pollen grains are important aeroallergens that cause seasonal allergic rhinitis and asthma to sensitive individuals. This study describes the conditions required for the LDT of ragweed pollen from the Pannonian Plain (PP) to Sweden on the 27- 28 August 2011, using a combination of daily and bi-hourly pollen count data, the overall synoptic weather situation, 3D analysis of the regional scale orography using Digital Elevation Models, surface meteorological data, satellite observations, and air mas trajectories calculated using the HYSPLIT model. During the episode, high pressure (1024-1028 hPa) situated over European Russia and the Black Sea to the east and deep low pressure (~990 hPa) over the British Isles in the northwest resulted in a general southeast-northwest movement of air, and the occurrence of the jet-effect Kosava wind in the PP. This dry and gusty wind caused ragweed pollen release on the PP and pollen to be transported to the northwest. A foehn wind that governs air movement down leeward slopes into the PP was also active. The 24 and 25 August 2011 were very hot and caused large amounts of ragweed pollen to be released and taken high up in the atmosphere through convection. Such conditions also resulted in high Planetary Boundary Layers over the entire area, conditions that facilitated the transport of pollen over areas of low elevation on the Western Carpathians (i.e. the Moravian Gate or Low Baskid passes) northward into Poland and beyond.

  11. Changes in total soluble proteins and Ca2+ upon cryopreservation of Prunus mume pollen.

    Science.gov (United States)

    Zhang, Y L; Li, B L; Wang, H; Liu, Y

    2012-01-01

    Mei Flowers (Prunus mume) are traditional Chinese ornamental plants. Fifty-one Mei cultivars have been conserved in a pollen cryobank since 2003. We used two-dimensional electrophoresis (2-DE) of total soluble proteins and flow cytometric detection of Ca2+ fluorescence to probe changes in pollen grains before and after cryopreservation. Results indicated that: (1) electrophoresis maps of total soluble proteins before and after cryostorage of pollen from three cultivars were different, even though 70 percent of the protein spots among these three cultivars were matched after cryopreservation. We found some protein spots that changed in all three cultivars; their molecular weights and pI were between 12.6-72.8 kDa and 5.6-7.3, respectively; (2): the geometric mean of Ca2+ fluorescence intensity (GMFI) value of cryopreserved pollen was significantly higher compared with that of fresh pollen in cultivar 'Beijing Yudie'. GMFI increased during pollen germination in our studied cultivars, especially after 0.5 and 1.0 h of culturing. In addition, no positive correlation was found between pollen germination rate and GMFI in the present study.

  12. 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.

  13. Grass Pollen Affects Survival and Development of Larval Anopheles arabiensis (Diptera: Culicidae).

    Science.gov (United States)

    Asmare, Yelfwagash; Hopkins, Richard J; Tekie, Habte; Hill, Sharon R; Ignell, Rickard

    2017-09-01

    Nutrients in breeding sites are critical for the survival and development of malaria mosquitoes, having a direct impact on vectorial capacity. Yet, there is a limited understanding about the natural larval diet and its impact on the individual fitness of mosquitoes. Recent studies have shown that gravid Anopheles arabiensis Patton (Diptera: Culicidae) are attracted by and oviposit in grass-associated habitats. The pollen provided by these grasses is a potential source of nutrients for the larvae. Here, we assess the effect of Typha latifolia L. (Poales: Typhaceae), Echinochloa pyramidalis Lamarck, Pennisetum setaceum Forsskål, and Zea mays L. pollen on larval survival and rate of development in An. arabiensis under laboratory conditions. In addition, we characterize the carbon to nitrogen ratio and the size of pollen grains as a measure of diet quality. Carbon-rich pollen with a small grain size (T. latifolia and P. setaceum; 9.7 ± 0.3 × 103 and 5.5 ± 0.2 × 104 µm3, respectively) resulted in enhanced rates of development of An. arabiensis. In contrast, the larva fed on the nitrogen-rich control diet (TetraMin) was slower to develop, but demonstrated the highest larval survival. Larvae fed on carbon-rich and large-grained Z. mays pollen (4.1 ± 0.2 × 105 µm3) survived at similar levels as those fed on the control diet and also took a longer time to develop compared with larvae fed on the other pollens. While males and females did not appear to develop differently on the different pollen diets, males consistently emerged faster than their female counterparts. These results are discussed in relation to integrated vector management. © The Author 2017. Published by Oxford University Press on behalf of Entomological Society of America.

  14. Non-native Ambrosia pollen in the atmosphere of Rzeszów (SE Poland); evaluation of the effect of weather conditions on daily concentrations and starting dates of the pollen season

    Science.gov (United States)

    Kasprzyk, Idalia

    2008-05-01

    The investigated problem was whether and to what an extent the elements of weather conditions were associated with changes in the concentration of Ambrosia pollen in air. The study was carried out in the years 1997-2004 using the volumetric method. Ragweed did not occur in the flora of the town of Rzeszów and its vicinity, but every year its pollen occurred at concentrations considerably exceeding the threshold values for the allergic response. The pollen seasons usually began from near the end of August to the first part of September. The values of daily concentrations varied greatly: days without pollen grains being frequently noted while single grains occurred long before and after the season. The effect of the elements of weather on changes in the concentration of pollen in the air was slight. Taking into account all meteorological parameters, it can be stated that an increase in the number of pollen grains is connected with increased temperature and higher wind speeds, but negatively correlated with humidity and rainfall. These relationships can usually be explained by the effects of the type of weather taking place over the wider region. The analysis of the results showed that pollen was probably transported from distant regions. The mean angle at which the greatest pollen concentrations were recorded corresponded to the SE wind direction. The analysis of synoptic phenomena during the pollen season confirms the thesis about the long-distance transport from the south, southeast and southwest. A close dependence was also found between the starting date of the season and the sum of maximum temperatures and the sum of differences between the maximum and minimum temperatures.

  15. Physiological influence of silica on germinating pollen as shown by Raman spectroscopy.

    Science.gov (United States)

    Joester, Maike; Seifert, Stephan; Emmerling, Franziska; Kneipp, Janina

    2017-04-01

    The process of silicification in plants and the biochemical effects of silica in plant tissues are largely unknown. To study the molecular changes occurring in growing cells that are exposed to higher than normal concentration of silicic acid, Raman spectra of germinating pollen grains of three species (Pinus nigra, Picea omorika, and Camellia japonica) were analyzed in a multivariate classification approach that takes into account the variation of biochemical composition due to species, plant tissue structure, and germination condition. The results of principal component analyses of the Raman spectra indicate differences in the utilization of stored lipids, a changed mobilization of storage carbohydrates in the pollen grain bodies, and altered composition and/or structure of cellulose of the developing pollen tube cell walls. These biochemical changes vary in the different species. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Grain boundaries

    Energy Technology Data Exchange (ETDEWEB)

    Balluffi, R.W.; Bristowe, P.D.

    1991-01-01

    The present document is a progress report describing the work accomplished to date during the second year of our four-year grant (February 15, 1990--February 14, 1994) to study grain boundaries. The research was focused on the following three major efforts: Study of the atomic structure of grain boundaries by means of x-ray diffraction, transmission electron microscopy and computer modeling; study of short-circuit diffusion along grain boundaries; and development of a Thin-film Deposition/Bonding Apparatus for the manufacture of high purity bicrystals.

  17. Grain boundaries

    Science.gov (United States)

    Balluffi, R. W.; Bristowe, P. D.

    The present document is a progress report describing the work accomplished to date during the second year of our four-year grant (February 15, 1990 to February 14, 1994) to study grain boundaries. The research was focused on the following three major efforts: study of the atomic structure of grain boundaries by means of x-ray diffraction, transmission electron microscopy and computer modeling; study of short-circuit diffusion along grain boundaries; and development of a Thin-film Deposition/Bonding Apparatus for the manufacture of high purity bicrystals.

  18. 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

  19. Static and elevated pollen traps do not provide an accurate assessment of personal pollen exposure.

    Science.gov (United States)

    Penel, V; Calleja, M; Pichot, C; Charpin, D

    2017-03-01

    Background. Volumetric pollen traps are commonly used to assess pollen exposure. These traps are well suited for estimating the regional mean airborne pollen concentration but are likely not to provide an accurate index of personal exposure. In this study, we tested the hypothesis that hair sampling may provide different pollen counts from those from pollen traps, especially when the pollen exposure is diverse. Methods. We compared pollen counts in hair washes to counts provided by stationary volumetric and gravimetric pollen traps in 2 different settings: urban with volunteers living in short distance from one another and from the static trap and suburban in which volunteers live in a scattered environment, quite far from the static trap. Results. Pollen counts in hair washes are in full agreement with trap counts for uniform pollen exposure. In contrast, for diverse pollen exposure, .individual pollen counts in hair washes vary strongly in quantity and taxa composition between individuals and dates. These results demonstrate that the pollen counts method (hair washes vs. stationary pollen traps) may lead to different absolute and relative contributions of taxa to the total pollen count. Conclusions. In a geographic area with a high diversity of environmental exposure to pollen, static pollen traps, in contrast to hair washes, do not provide a reliable estimate of this higher diversity.

  20. Identification of Rad23-4 gene required for pollen development in ...

    African Journals Online (AJOL)

    雨林木风

    2012-05-31

    May 31, 2012 ... Key words: Nucleotide excision repair (NER), rad23-4 gene, anthocyanin, pollen grains, seeds abortion. INTRODUCTION. Plants are ... Rad23 gene in Arabidopsis were purchased from the ABRC. (Arabidopsis Biological ... exposed to enhanced UV-B for 0-6 h daily for one week. After UV-B treatment, the ...

  1. Effect of repetitive mowing on common ragweed (Ambrosia artemisiifolia L.) pollen and seed production.

    Science.gov (United States)

    Simard, Marie-Josée; Benoit, Diane Lyse

    2011-01-01

    Ambrosia artemisiifolia L (common ragweed) is a familiar roadside weed in southern Québec (Canada) that produces large amounts of airborne pollen responsible for multiple rhino-conjunctivitis (hay fever) cases. As roadside weeds are increasingly controlled by mowing alone, the effect of a mowing treatment on pollen production was evaluated. Ambrosia artemisiifolia plants were grown in a greenhouse at 4 densities (1, 3, 6 and 12 plants per 314 cm(2) pot) and either left intact or mowed (10 cm from the ground) when the plants reached 25 cm in height, i.e. twice during the life cycle of this annual plant. Pollen production per male inflorescence was collected in open-top bags and counted. Inflorescence mass, length, location on the plant and date of anthesis onset was noted. Above-ground plant biomass and seed production was also evaluated. Mowed plants produced less pollen per unit of inflorescence length than intact plants. Pollen production per plant was reduced by a factor of 8.84 by the double mowing treatment, while viable seed production per plant was reduced by a factor of 4.66, irrespective of density. Mowing twice has the potential to reduce airborne pollen loads but Ambrosia artemisiifolia seed banks are unlikely to be depleted by this management strategy.

  2. 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

  3. [Methods of cryopreservation of pollen in Fritillaria thunbergii Miq].

    Science.gov (United States)

    Su, X

    1991-07-01

    The effects of cryomethods, cryoprotectants, pollen age and pollen water content on the viability of pollen in Fritillaria thunbergii after cryopreservation were studied. The viability came highest (56.4%) when pollen of the flowering day (20% pollen water content) was treated by step-cooling. Hybridization in the fields showed that cryopreserved pollen could go to seed as well.

  4. National Allergy Bureau Pollen and Mold Report

    Science.gov (United States)

    ... Search AAAAI National Allergy Bureau Pollen and Mold Report Date: March 02, 2018 Location: San Antonio (2), ... 01/2018 ( click here to view ). Our Allergen Report Email Service can automatically email you daily pollen ...

  5. Pollen from Glycine species survive cryogenic exposure.

    Science.gov (United States)

    Tyagi, R K; Hymowitz, T

    2003-01-01

    Pollen of 12 genotypes of the annual soybean and its wild perennial relatives were stored without pre-desiccation at low temperatures (-20 C and -196 C) and tested for their viability in vitro. The influence of cryopreserved pollen on pod set and seed production was also investigated. Cryopreserved pollen of all the genotypes showed germination in vitro. Pollen of annual soybean stored at -20 C retained their viability for 4 months, however, pollen of its wild perennial relatives at same storage conditions failed to germinate in vitro. Flowers pollinated with cryopreserved pollen had similar pod set and number of seeds/pod as those pollinated with fresh pollen. Results of this study suggest that cryopreservation of pollen can be used successfully for soybean breeding, and also offers the possibility of conserving the haploid gene pool of soybean and wild perennial species in a cryobank facility.

  6. Wind-mediated horseweed (Conyza canadensis) gene flow: pollen emission, dispersion, and deposition.

    Science.gov (United States)

    Huang, Haiyan; Ye, Rongjian; Qi, Meilan; Li, Xiangzhen; Miller, David R; Stewart, Charles Neal; DuBois, David W; Wang, Junming

    2015-07-01

    Horseweed (Conyza canadensis) is a problem weed in crop production because of its evolved resistance to glyphosate and other herbicides. Although horseweed is mainly self-pollinating, glyphosate-resistant (GR) horseweed can pollinate glyphosate-susceptible (GS) horseweed. To the best of our knowledge, however, there are no available data on horseweed pollen production, dispersion, and deposition relative to gene flow and the evolution of resistance. To help fill this knowledge gap, a 43-day field study was performed in Champaign, Illinois, USA in 2013 to characterize horseweed atmospheric pollen emission, dispersion, and deposition. Pollen concentration and deposition, coupled with atmospheric data, were measured in a source field (180 m by 46 m) and its surrounding areas up to 1 km downwind horizontally and up to 100 m vertically. The source strength (emission rate) ranged from 0 to 140 pollen grains per plant per second (1170 to 2.1×10(6) per plant per day). For the life of the study, the estimated number of pollen grains generated from this source field was 10.5×10(10) (2.3×10(6) per plant). The release of horseweed pollen was not strongly correlated to meteorological data and may be mainly determined by horseweed physiology. Horseweed pollen reached heights of 80 to100 m, making long-distance transport possible. Normalized (by source data) pollen deposition with distance followed a negative-power exponential curve. Normalized pollen deposition was 2.5% even at 480 m downwind from the source edge. Correlation analysis showed that close to or inside the source field at lower heights (≤3 m) vertical transport was related to vertical wind speed, while horizontal pollen transport was related to horizontal wind speed. High relative humidity prevented pollen transport at greater heights (3-100 m) and longer distances (0-1000 m) from the source. This study can contribute to the understanding of how herbicide-resistance weeds or invasive plants affect ecology

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

    Directory of Open Access Journals (Sweden)

    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

  8. Grain alcohol study: summary

    Energy Technology Data Exchange (ETDEWEB)

    The study has concentrated upon a detailed examination of all considerations involved in the production, use, and marketing of ethyl alcohol (ethanol) as produced from the fermentation of agricultural grains. Each parameter was examined in the light of current energy markets and trends; new sources and technological, and processes for fermentation, the capability of the agricultural industry to support fermentation demand; the optimizaton of value of agricultural crops; and the efficiencies of combining related industries. Ahydrous (200 proof) ethanol makes an excellent blending component for all present automotive fuels and an excellent octane additive for unleaded fuels in proportions up to 35% without requiring modifications to current engines. There is no difference between ethanol produced by fermentation and ethanol produced synthetically from petroleum. The decision to produce ethanol one way or the other is purely economic. The agricultural industry can support a major expansion in the fermentation industry. The residue (distillers grains) from the fermentation of corn for ethanol is an excellent and economical feed for livestock and poultry. A reliable supply of distillers grain can assist in making the large beef feedlot operations more economically viable. The source materials, fuels, products and by-products of an ethanol plant, beef feedlot, gas biodigester plant, municipal waste recovery plant and a steam generated electrical plant are interrelated and mutually beneficial for energy efficiencies and economic gains when co-located. The study concludes that the establishment of such agricultural- environment industrial energy complexes, would provide a broad range of significant benefits to Indiana.

  9. Grain alcohol study: summary

    Energy Technology Data Exchange (ETDEWEB)

    The study has concentrated upon a detailed examination of all considerations involved in the production, use, and marketing of ethyl alcohol (Ethanol) as produced from the fermentation of agricultural grains. Each parameter was examined in the light of current energy markets and trends; new sources and technological, and processes for fermentation, the capability of the agricultural industry to support fermentaton demand; the optimization of value of agricultureal crops; and the efficiencies of combining related industries. Anhydrous (200 proof) ethanol makes an excellent blending component for all present automotive fuels and an excellent octane additive for unleaded fuels in proportions up to 35% without requiring modifications to current engines. There is no difference between ethanol produced by fermentation and ethanol produced synthetically from petroleum. The decision to produce ethanol one way or the other is purely economic. The agricultural industry can support a major expansion in the fermentation industry. The residue (distillers grains) from the fermentation of corn for ethanol is an excellent and economical feed for livestock and poultry. A reliable supply of distillers grains can assist in making the large beef feedlot operations more economically viable. The source materials, fuels, products and by-products of an ethanol plant, beef feedlot, gas biodigester plant, municipal waste recovery plant and a steam generated electrical plant are interrelated and mutually beneficial for energy efficiencies and economic gains when co-located. The study concludes that the establishment of such agricultural-environment industrial energy complexes, would provide a broad range of significant benefits to Indiana.

  10. [The epidemiology of pollen allergy].

    Science.gov (United States)

    Charpin, D; Caillaud, D

    2014-04-01

    The prevalence of seasonal allergic rhinitis can be established through surveys performed in a sample of the general population. These surveys are based on a questionnaire, which could lead to an overestimate of prevalence rates, and on measurements of specific IgE, which need to be interpreted in the light of the responses to the questionnaire. Such surveys are few in France and need to be updated. Risk factors for seasonal allergic rhinitis are genetic, epigenetic and environmental. Relationships between exposure to pollen and health can be documented through ecological and panel surveys. Panel surveys may give information on threshold levels and dose-response relationships. In addition to pollen exposure, global warming and air pollutants act as cofactors. Monitoring of both pollen exposure and its health effects should be encouraged and strengthened. Copyright © 2014 SPLF. Published by Elsevier Masson SAS. All rights reserved.

  11. Effect of Bt-176 maize pollen on first instar larvae of the Peacock butterfly (Inachis io) (Lepidoptera; Nymphalidae).

    Science.gov (United States)

    Felke, Martin; Langenbruch, Gustav-Adolf; Feiertag, Simon; Kassa, Adane

    2010-01-01

    More than 10 years after registration of the first Bt maize cultivar in Europe, there still exists a remarkable lack of data on effects on Lepidoptera which would be necessary for a complete and comprehensive environmental risk assessment. So far only very few European butterfly species have been tested in this aspect. In our study the effect of transgenic Bacillus thuringiensis (Bt) maize pollen (event Bt-176) on the development and survival of neonate larvae of the Peacock butterfly, Inachis io (L.) was for the first time shown. The results of our study suggest that the Peacock butterfly may serve as a model organism for assessing potential side effects of new developed transgenic Bt crops on non-target butterflies in a GMO environmental risk assessment. The study was done under laboratory conditions by exposing larvae of the Peacock butterfly to various pollen doses of transgenic maize event Bt-176 (cv. PACTOL CB) or the conventional isogenic maize (cv. PACTOL) using a no-choice test. Larvae feeding for 48 h on nettle plants (Urtica dioica) that were contaminated with higher pollen concentrations from Bt-176 maize (205 and 388 applied pollen.cm⁻²) suffered a significantly higher mortality rate (68 and 85% respectively) compared to larvae feeding on leaves with no pollen (11%), or feeding on leaves with pollen from conventional maize (6 to 25%). At lower Bt maize pollen doses (23-104 applied pollen.cm⁻²),mortality ranged from 11-25% and there were no apparent differences among treatments. The corresponding LC₅₀-and LC₉₀-values for neonate larvae of the Peacock butterfly were 187 and 448 applied pollen grains.cm⁻² of Bt-176, respectively.Weight of larvae surviving consumption of Bt-176 maize pollen declined between 10 and 81% with increased pollen doses (r = -0.95). The highest weight reduction (81%) corresponded to the highest pollen concentration (388 pollen grains applied.cm⁻²). Ingestion of pollen from the conventional maize hybrid did not

  12. An assessment of the Ambrosia L. pollen threat at a regional scale using the example of the town of Sosnowiec (Silesian Uplands, Poland

    Directory of Open Access Journals (Sweden)

    Kazimiera Chłopek

    2012-12-01

    Full Text Available The investigation of Ambrosia pollen counts in the air of Sosnowiec was carried out from 1998 to 2010 by means of the volumetric method. The pollen season which was determined by means of the 98% method started at the end of July and the beginning of August and lasted until the end of October. The highest Ambrosia pollen count was recorded in 1999 (222 grains x m-3 and the lowest in 2001 (18 grains x m-3. It was stated that the daily count of pollen grains depended on the wind direction and maximum air temperature. The strongest correlations were found with maximum temperature and with a wind direction from the south east. A high negative correlation coefficient was found between the frequency of inflows of air masses from the west and the annual total of pollen grains and the value of the maximum daily count. The closest sites of Ambrosia L. are at a distance of 25-40 kilometres from the sampling point. Significant correlations with the frequency of inflow of air masses can support the conclusion that Ambrosia pollen grains recorded in Sosnowiec were most probably carried not only from local sources but also, at least in part, from distant places.

  13. 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.

  14. 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.

  15. Asthmatic exacerbations and environmental pollen concentration in La Comarca Lagunera (Mexico).

    Science.gov (United States)

    Ordaz, V A; Castaneda, C B; Campos, C L; Rodríguez, V M; Saenz, J G; Ríos, P C

    1998-01-01

    In order to determine the correlation between the concentration of environmental pollen and the frequency of asthmatic exacerbations in La Comarca Lagunera (México), a study in a cohort of a 104 diagnosed patients suffering allergic asthma was carried out monitoring monthly from July '93 to July '95 in order to register the existence of asthmatic exacerbations. Environmental samples were taken weekly during the same period of time through a PST high volume collector (Andersen Samplers Inc). The above mentioned samples were processed under acetolysis technics and the pollen grain count under light microscopy. Linear correlation measures were made between the rates of asthmatic exacerbations and the concentration of pollen grain in m3 of air by means of a statistical computer program SAS. There was a 1469 persons/month follow up ('X 15.5) and the correlation between the rates of asthmatic exacerbations and the concentration of environmental pollen was relevant (r = 0.63, r2 = 0.39, p < 0.01). The correlation increased (r = 0.70, r2 = 0.49 and p < 0.01) when the asthmatic exacerbations associated to infectious disease in the upper respiratory system were restricted. The conclusion reached is that the concentration of environment pollen has influence in the development of asthmatic exacerbations in patients with allergic asthma.

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

    Science.gov (United States)

    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.

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

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-02

    Nov 2, 2009 ... 2Zonguldak Karaelmas University, Faculty of Arts and Sciences, Department of Biology, 67100 İncivez,. Zonguldak,Turkey. ..... Forest Genetic Resources Working Papers, Regional. Updates. Rome, pp. 64-67. Fernando DD, Owens JN, Von Aderkas P (1998). In-vitro fertilization from co-cultured pollen tubes ...

  18. Capturing the surface texture and shape of pollen: a comparison of microscopy techniques.

    Directory of Open Access Journals (Sweden)

    Mayandi Sivaguru

    Full Text Available Research on the comparative morphology of pollen grains depends crucially on the application of appropriate microscopy techniques. Information on the performance of microscopy techniques can be used to inform that choice. We compared the ability of several microscopy techniques to provide information on the shape and surface texture of three pollen types with differing morphologies. These techniques are: widefield, apotome, confocal and two-photon microscopy (reflected light techniques, and brightfield and differential interference contrast microscopy (DIC (transmitted light techniques. We also provide a first view of pollen using super-resolution microscopy. The three pollen types used to contrast the performance of each technique are: Croton hirtus (Euphorbiaceae, Mabea occidentalis (Euphorbiaceae and Agropyron repens (Poaceae. No single microscopy technique provided an adequate picture of both the shape and surface texture of any of the three pollen types investigated here. The wavelength of incident light, photon-collection ability of the optical technique, signal-to-noise ratio, and the thickness and light absorption characteristics of the exine profoundly affect the recovery of morphological information by a given optical microscopy technique. Reflected light techniques, particularly confocal and two-photon microscopy, best capture pollen shape but provide limited information on very fine surface texture. In contrast, transmitted light techniques, particularly differential interference contrast microscopy, can resolve very fine surface texture but provide limited information on shape. Texture comprising sculptural elements that are spaced near the diffraction limit of light (~250 nm; NDL presents an acute challenge to optical microscopy. Super-resolution structured illumination microscopy provides data on the NDL texture of A. repens that is more comparable to textural data from scanning electron microscopy than any other optical

  19. Ragweed pollen observed in Turkey: detection of sources using back trajectory models.

    Science.gov (United States)

    Zemmer, Franziska; Karaca, Ferhat; Ozkaragoz, Fatih

    2012-07-15

    This paper discusses the pollen season and the source apportionment of ragweed (Ambrosia) grains detected in the atmosphere of Istanbul, Turkey. The dynamic migration of this invasive taxon is a serious environmental issue. Ragweed pollen is highly allergenic and causes sensitization in patients at low concentrations. At present, there is no floristic evidence of this taxon in the region. Aerobiological records presented here, though, indicate a local source. Moreover, we argue that ragweed pollen comes from distant sources through air mass movements. The analysis concerns the ragweed season 2007. Pollens were sampled with a Burkard trap and identified at a magnification of 400 ×. Grains were counted on 12 transverse traverses to estimate bi-hourly changes in concentrations. The peak day was on August 28 with 20 grainsm(-3). Ragweed was observed on 22 days during August and September 2007. On all days, except one, the daily average concentration was below 10 grainsm(-3). Diurnal bi-hourly ragweed concentrations reached a maximum at 11:00 EET. Relatively high concentrations were observed between 21:00 and 01:00 EET. This allowed for the assumption of a local and a remote ragweed pollen source. We used HYSPLIT backward trajectory ensembles to identify possible sources on peak day. A frequency analysis of back trajectories covering the entire ragweed season followed. Firstly, possible local sources were the Istanbul Province and Turkish Thrace; secondly, a likely over-regional source was Bulgaria; and lastly, remote sources of ragweed pollen were the Ukraine, the Russian coastal region of the Black Sea and Moldova. This study provides evidence that pollens detected on our receptor site stem from combined local and remote origins. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Pollen limitation is not the rule in nival plants: A study from the European Central Alps.

    Science.gov (United States)

    Wagner, Johanna; Lechleitner, Martin; Hosp, Daniela

    2016-03-01

    Seed output of high-mountain plants in the uppermost life zones is highly variable. One possible reason might be pollen limitation due to inadequate pollinator services. We tested this hypothesis for the insect-pollinated species Cerastium uniflorum, Ranunculus glacialis, and Saxifraga bryoides, which have their distribution center in the subnival and nival zone of the European Central Alps. We recorded insect visitors and determined their impact as pollinators. By analyzing pollination success and seed set following natural and saturating hand pollination, the magnitude of quantitative and qualitative pollen limitation was assessed. Anthomyiid and muscid flies had the highest pollination impact for R. glacialis and S. bryoides and syrphids for C. uniflorum. Natural stigma pollen load was highly variable in individual flowers of all species, but in most cases the number of conspecific pollen grains clearly exceeded the number of ovules to be fertilized. There was also a surplus in germinated pollen grains, whereas the pollen tube to ovule ratio was only sufficient in R. glacialis (2.6 on average) and S. bryoides (1.3), but not in C. uniflorum (0.6). Accordingly, seed to ovule ratio was around 0.8 in R. glacialis, 0.7 in S. bryoides but 0.4 in C. uniflorum. In C. uniflorum, saturating pollination slightly increased seed set. Regression analyses revealed that natural pollination success was more frequently limited by quality than by quantity. Our results do not support the idea of chronic, widespread pollen limitation in the subnival but rather fit into the concept of parental optimism by overinvesting in the number of ovules as an adaptation to variable resource availability. © 2016 Botanical Society of America.

  1. Visual Recognition Software for Binary Classification and Its Application to Spruce Pollen Identification.

    Directory of Open Access Journals (Sweden)

    David K Tcheng

    Full Text Available Discriminating between black and white spruce (Picea mariana and Picea glauca is a difficult palynological classification problem that, if solved, would provide valuable data for paleoclimate reconstructions. We developed an open-source visual recognition software (ARLO, Automated Recognition with Layered Optimization capable of differentiating between these two species at an accuracy on par with human experts. The system applies pattern recognition and machine learning to the analysis of pollen images and discovers general-purpose image features, defined by simple features of lines and grids of pixels taken at different dimensions, size, spacing, and resolution. It adapts to a given problem by searching for the most effective combination of both feature representation and learning strategy. This results in a powerful and flexible framework for image classification. We worked with images acquired using an automated slide scanner. We first applied a hash-based "pollen spotting" model to segment pollen grains from the slide background. We next tested ARLO's ability to reconstruct black to white spruce pollen ratios using artificially constructed slides of known ratios. We then developed a more scalable hash-based method of image analysis that was able to distinguish between the pollen of black and white spruce with an estimated accuracy of 83.61%, comparable to human expert performance. Our results demonstrate the capability of machine learning systems to automate challenging taxonomic classifications in pollen analysis, and our success with simple image representations suggests that our approach is generalizable to many other object recognition problems.

  2. 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.

  3. Development of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) on pollen from Bt-transgenic and conventional maize.

    Science.gov (United States)

    Meissle, Michael; Zünd, Jan; Waldburger, Mario; Romeis, Jörg

    2014-07-31

    Maize (Zea mays) pollen is highly nutritious and can be used by predatory arthropods to supplement or replace a carnivorous diet. We demonstrate that maize pollen can be utilized by larvae of the green lacewing, Chrysoperla carnea (Neuroptera: Chrysopidae) under laboratory conditions. Complete development on maize pollen was not possible, but 25% of neonates reached the third instar. When only one instar was fed with pollen and the other two instars with eggs of Ephestia kuehniella (Lepidoptera: Pyralidae), 58-87% of the larvae reached the pupal stage. The experiments included pollen produced by nine cultivars: three genetically modified (GM) cultivars expressing the Bacillus thuringiensis proteins Cry1Ab or Cry3Bb1, their corresponding non-transformed near-isolines, and three conventional cultivars. Maize cultivars were grown in two batches in a glasshouse. Their pollen differed by up to 59% in total protein content, 25% in C:N ratio, and 14% in grain diameter, but the differences were inconsistent and depended on the batch. Lacewing performance was not affected by maize cultivar. For environmental risk assessment of GM plants, in planta studies must consider the variability among conventional cultivars, individual plants, batches, and environmental conditions when evaluating the ecological significance of differences observed between GM and near-isolines.

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

    Directory of Open Access Journals (Sweden)

    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.

  5. An algorithm and a device for counting airborne pollen automatically using laser optics

    Science.gov (United States)

    Kawashima, Shigeto; Clot, Bernard; Fujita, Toshio; Takahashi, Yuichi; Nakamura, Kimihito

    Airborne pollen is important in relation to the social issues of pollinosis and of the environmental effects of genetically modified plants. Existing methods for pollen counting involve counting and classifying the grains that adhere to a sampling surface, requiring much time and skilled labor. We therefore have developed a method of automatically monitoring pollen, using a laser-optics instrument. In this instrument, the sideways and forward scattering of laser light by each particle is recorded in real time for computer processing. A field experiment was conducted in 2005, comparing our method with that of the older Hirst method. A scatter plot was made of the forward scattering vs. the sideways scattering for each particle. An algorithm was developed to find the optimum rectangular region of the plot for each type of pollen, and a count of points inside this region was taken as the count for that type of pollen. For the three most common types of pollen found in the field test (Urticaceae, Poaceae, and Ambrosia), the daily counts from this algorithm were compared with the daily counts from the Hirst-type (Burkard) sampler. There was a very high correlation (determination coefficient approximately 0.8) between the results of the two methods.

  6. Carbon isotopic composition of Ambrosia and Artemisia pollen: assessment of a C₃-plant paleophysiological indicator.

    Science.gov (United States)

    Nelson, David M

    2012-09-01

    There is limited evidence on how shifts in plant physiological performance influence vegetation variations in the paleorecord. To evaluate δ¹³C of pollen from C₃ plants as an indicator of community-level physiology, small quantities (10-30 grains) of untreated pollen and sporopollenin from herbarium specimens of Ambrosia (A. tomentosa and A. psilostachya) and Artemisia (A. frigida, A. ludoviciana and A. dracunculus), genera abundant in grassland pollen profiles, were isolated by micromanipulation. Their δ¹³C values were measured using a spooling-wire microcombustion device interfaced with an isotope-ratio mass spectrometer. Leaf δ¹³C was also measured. Carbon isotope discrimination (Δ) for untreated pollen, sporopollenin and leaves was compared with historic records of seasonal precipitation amount, vapor pressure deficit and the Palmer Drought Severity Index (PDSI). Each species showed positive correlations between Δ of untreated pollen and sporopollenin. Sporopollenin Δ was most strongly correlated with PDSI. Correlations among leaf Δ and moisture indicators were stronger for Ambrosia than Artemisia. These results suggest that sporopollenin Δ indicates the level of moisture stress in C₃ plants. Therefore, δ¹³C analysis of pollen promises to help address important paleoecological questions, such as how community-level physiology contributes to shifts in vegetation composition. © 2012 The Author. New Phytologist © 2012 New Phytologist Trust.

  7. 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.

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

    Directory of Open Access Journals (Sweden)

    Grzegorz Migdałek

    2014-09-01

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

  9. La longévité du pollen de colza

    Directory of Open Access Journals (Sweden)

    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

  10. A Simple, Inexpensive Pollen Trap

    Science.gov (United States)

    P. E. Hoekstra

    1965-01-01

    Pollen plays a role of vital importance in the sexual reproduction of all plants but it is especially important in forestry. With few exceptions, sexual reproduction is the only link between succeeding generations in the forest. To be sure, vegetative reproduction is important for special purposes, but it will probably not be used on a mass scale in timber...

  11. A last glacial and deglacial pollen record from the northern South China Sea: New insight into coastal-shelf paleoenvironment

    Science.gov (United States)

    Yu, Shaohua; Zheng, Zhuo; Chen, Fang; Jing, Xia; Kershaw, Peter; Moss, Patrick; Peng, Xuechao; Zhang, Xin; Chen, Chixin; Zhou, Yang; Huang, Kangyou; Gan, Huayang

    2017-02-01

    This study presents a marine palynological record of the Asian summer monsoon and sea level change in the Last Glacial Maximum (LGM) and the deglacial period in the northern South China Sea (SCS). A fossil core STD 235 (855 cm in length) and 273 surface sediment samples from the northern SCS were pollen analysed to reconstruct the paleoenvironment of the continental shelf during the last glacial period. Results from fossil pollen show that the main pollen source region fundamentally changed from the LGM to the deglacial period as sea level rapidly rose. The modern marine surface samples show that pollen concentrations in the estuary of the Pearl River are extremely high, and modern pollen assemblages are in good agreement with the regional vegetation. However, wind transport becomes more important in the deeper ocean as the percentages of Pinus, a taxon with very high pollen production and dispersal capacity, is highest in these sediments, which otherwise have very low pollen concentrations. The concentration of total pollen between surface and fossil pollen samples is compared in order to determine the possible vegetation sources areas for the marine core. Pollen concentration as high as >100 grains/g at the LGM suggested that the paleo-shoreline was located within 80 km of the core. Consequently, pollen would mostly have derived from the exposed continental shelf in the northern SCS. By contrast, pollen concentrations were very low due to a much greater transport distance (318 km at present, core STD 235) under higher sea levels, and windblown pollen played a more important role because of the limitation of riverine input into the deep ocean during this highstand period. Such alternation of pollen flux and source distance should be repeated during all glacial-interglacial cycles, reflecting closely sea level and climate dynamics. According to fossil pollen assemblages from Core STD 235, we conclude that wetland and/or grassland communities with sparse subtropical

  12. Organismal versus Environmental Control of the Carbon Isotope Composition of Dicot Angiosperm Pollen: Implications for Paleoenvironmental Reconstruction

    Science.gov (United States)

    King, D. P.; Schubert, B.; Foelber, K.; Jahren, H.

    2011-12-01

    The prevalence and diagenetic resilience of palynomorphs in Proterozoic and Phanerozoic sediments has led researchers to investigate its potential as an environmental proxy based on its stable isotope composition. Towards this, Loader and Hemming (2001), noted that the carbon isotope composition (δ13C) of modern Pinus sylvestris pollen exine correlates with the developmental period temperature (°C) of the pollen (R2=0.68), implying that the δ13C of gymnosperm pollen could be quantitatively utilized as a paleotemperature proxy. However, the majority of pollen-producing organisms during the last ~120 million years have been angiosperms, which are subject to complex internal signaling for reproduction, in addition to environmental triggers. Because these internal signals control the relative proportion of lipids, long-chain fatty acids, and polysaccharides within pollen grains, we hypothesized that the δ13C variability in pollen (δ13Cpollen) from several plants subject to the same external environmental parameters is of the same magnitude as the amount attributed to the environment for gymnosperms. Within growth chambers, the test organism (Brassica rapa) was cultivated under constant light, water, pCO2, and nutrient supply, but exhibited average δ13Cpollen variability = 4.35% within any chamber (n = 6 to 8 plants per chamber). Field experiments were also conducted in which the pollen from the test organism (Hibiscus spp.) was sampled from several botanical gardens within the state of Hawaii. Pollen collected from any one botanical garden exhibited an average δ13Cpollen variability = 4.5% (up to 5 plants per garden). Upon comparing chambers operating at different temperatures (17°C to 32°C), we discovered no correlation (R2=0.01) between the developmental period temperature (°C) and the δ13C of B. rapa pollen; similarly, no correlation was found between the δ13C of Hibiscus pollen and its developmental period temperature (°C) (R2=0.12). This work

  13. 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.

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

    DEFF Research Database (Denmark)

    Jensen, Kaare Hartvig

    2016-01-01

    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...... 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...

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

    Directory of Open Access Journals (Sweden)

    Deirdre Loughnan

    2014-08-01

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

  16. Transmitting tissue ECM distribution and composition, and pollen germinability in Sarcandra glabra and Chloranthus japonicus (Chloranthaceae).

    Science.gov (United States)

    Hristova, Katerina; Lam, Matthew; Feild, Taylor; Sage, Tammy L

    2005-10-01

    and Aims Free-flowing surface exudates at the stigmatic (wet versus dry stigma) and adaxial epidermis at the site of angiospermy in carpels of Chloranthaceous species have been proposed to comprise a continuous extracellular matrix (ECM) operating in pollen tube transmission to the ovary. The aim of this research was to establish the spatial distribution and histo/immunochemical composition of the ECM involved in pollen tube growth in Sarcandra glabra and Chloranthus japonicus (Chloranthaceae). Following confirmation of the pollen tube pathway, the histo/immunochemical make-up of the ECM was determined with histochemistry on fresh tissue to detect cuticle, esterase, proteins, pectins, and lipids and immunolocalization at the level of the TEM on sections from cryofixed/freeze-substituted tissue to detect molecules recognized by antibodies to homogalacturonans (JIM7, 5), arabinogalactan-proteins (JIM13) and cysteine-rich adhesion (SCA). Pollen germinability is low in both species. When grains germinate, they do so on an ECM comprised of an esterase-positive cuticle proper (dry versus wet stigma). Pollen tubes do not track the surface ECM of stigma or adaxial epidermal cells at the site of angiospermy. Instead, tubes grow between stigmatic cells and subsequently along the inner tangential walls of the stigmatic and adaxial carpel cells at the site of angiospermy. Pollen tubes enter the ovary locule at the base of the funiculus. The stigmatic ECM is distinct by virtue of the presence of anti-JIM5 aggregates, lipids, and a protein recognized by anti-SCA. The Chloranthaceae joins a growing number of basal angiosperm taxa whereby pollen tubes germinate on a dry versus wet stigma to subsequently grow intercellularly en route to the ovary thereby challenging traditional views that the archetype pollen tube pathway was composed of the surface of stigma and adaxial epidermal cells covered with a free-flowing exudate.

  17. Pure Quantum Interpretations Are not Viable

    Science.gov (United States)

    Schmelzer, I.

    2011-02-01

    Pure interpretations of quantum theory, which throw away the classical part of the Copenhagen interpretation without adding new structure to its quantum part, are not viable. This is a consequence of a non-uniqueness result for the canonical operators.

  18. Analysis of morphological and molecular composition changes in allergenic Artemisia vulgaris L. pollen under traffic pollution using SEM and FTIR spectroscopy.

    Science.gov (United States)

    Depciuch, J; Kasprzyk, I; Roga, E; Parlinska-Wojtan, M

    2016-11-01

    Nowadays, pollen allergy becomes an increasing problem for human population. Common mugwort (Artemisia vulgaris L.) is one of the major allergenic plants in Europe. In this study, the influence of air pollution caused by traffic on the structure and chemical composition of common mugwort pollen was investigated. Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and curve-fitting analysis of amide I profile was applied to assess the morphological and structural changes of mugwort pollen grains collected from sites with different vehicle pollution levels. Microscopic observations support the conclusion, that the higher the car traffic, the smaller the pollen grains. The obtained results clearly show that air pollution had an impact on different maximum absorbance values of individual functional groups composing the chemical structure of pollen. Moreover, air pollution induced structural changes in macromolecules of mugwort pollen. In pollen collected from the unpolluted site, the content of sporopollenin (850 cm(-1)) was the highest, whereas polysaccharide concentration (1032 cm(-1)) was the lowest. Significant differences were observed in lipids. Pollen collected from the site with heavy traffic had the lowest content of lipids at 1709, 2071, and 2930 cm(-1). The largest differences were observed in the spectra regions corresponding to proteins. In pollen collected from unpolluted site, the highest level of β-sheet (1600 cm(-1)) and α-helix (1650 cm(-1)) was detected. The structural changes in proteins, observed in the second derivative of the FTIR spectrum and in the curve-fitting analysis of amide I profile, could be caused inter alia by air pollutants. Alterations in protein structure and in their content in the pollen may increase the sensitization and subsequent risk of allergy in predisposed people. The obtained results suggest that the changes in chemical composition of pollen may be a good indicator of air quality and

  19. Gelechiidae Moths Are Capable of Chemically Dissolving the Pollen of Their Host Plants: First Documented Sporopollenin Breakdown by an Animal

    Science.gov (United States)

    Luo, Shixiao; Li, Yongquan; Chen, Shi; Zhang, Dianxiang; Renner, Susanne S.

    2011-01-01

    Background Many insects feed on pollen surface lipids and contents accessible through the germination pores. Pollen walls, however, are not broken down because they consist of sporopollenin and are highly resistant to physical and enzymatic damage. Here we report that certain Microlepidoptera chemically dissolve pollen grains with exudates from their mouthparts. Methodology/Principal Findings Field observations and experiments in tropical China revealed that two species of Deltophora (Gelechioidea) are the exclusive pollinators of two species of Phyllanthus (Phyllanthaceae) on which their larvae develop and from which the adults take pollen and nectar. DNA sequences placed the moths and plants phylogenetically and confirmed that larvae were those of the pollinating moths; molecular clock dating suggests that the moth clade is younger than the plant clade. Captive moths with pollen on their mouthparts after 2-3 days of starvation no longer carried intact grains, and SEM photographs showed exine fragments on their proboscises. GC-MS revealed cis-β-ocimene as the dominant volatile in leaves and flowers, but GC-MS analyses of proboscis extracts failed to reveal an obvious sporopollenin-dissolving compound. A candidate is ethanolamine, which occurs in insect hemolymphs and is used to dissolve sporopollenin by palynologists. Conclusions/Significance This is the first report of any insect and indeed any animal chemically dissolving pollen. PMID:21552530

  20. Gelechiidae moths are capable of chemically dissolving the pollen of their host plants: first documented sporopollenin breakdown by an animal.

    Directory of Open Access Journals (Sweden)

    Shixiao Luo

    Full Text Available BACKGROUND: Many insects feed on pollen surface lipids and contents accessible through the germination pores. Pollen walls, however, are not broken down because they consist of sporopollenin and are highly resistant to physical and enzymatic damage. Here we report that certain Microlepidoptera chemically dissolve pollen grains with exudates from their mouthparts. METHODOLOGY/PRINCIPAL FINDINGS: Field observations and experiments in tropical China revealed that two species of Deltophora (Gelechioidea are the exclusive pollinators of two species of Phyllanthus (Phyllanthaceae on which their larvae develop and from which the adults take pollen and nectar. DNA sequences placed the moths and plants phylogenetically and confirmed that larvae were those of the pollinating moths; molecular clock dating suggests that the moth clade is younger than the plant clade. Captive moths with pollen on their mouthparts after 2-3 days of starvation no longer carried intact grains, and SEM photographs showed exine fragments on their proboscises. GC-MS revealed cis-β-ocimene as the dominant volatile in leaves and flowers, but GC-MS analyses of proboscis extracts failed to reveal an obvious sporopollenin-dissolving compound. A candidate is ethanolamine, which occurs in insect hemolymphs and is used to dissolve sporopollenin by palynologists. CONCLUSIONS/SIGNIFICANCE: This is the first report of any insect and indeed any animal chemically dissolving pollen.

  1. Aerobiological study of pollen and mold in Seoul, Korea

    Directory of Open Access Journals (Sweden)

    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.

  2. Charting novel allergens from date palm pollen (Phoenix sylvestris) using homology driven proteomics.

    Science.gov (United States)

    Saha, Bodhisattwa; Bhattacharya, Swati Gupta

    2017-08-08

    Pollen grains from Phoenix sylvestris (date palm), a commonly cultivated tree in India has been found to cause severe allergic diseases in an increasing percentage of hypersensitive individuals. To unearth its allergenic components, pollen protein were profiled by two-dimensional gel electrophoresis followed by immunoblotting with date palm pollen sensitive patient sera. Allergens were identified by MALDI-TOF/TOF employing a layered proteomic approach combining conventional database dependent search and manual de novo sequencing followed by homology-based search as Phoenix sylvestris is unsequenced. Derivatization of tryptic peptides by acetylation has been demonstrated to differentiate the 'b' from the 'y' ions facilitating efficient de novo sequencing. Ten allergenic proteins were identified, out of which six showed homology with known allergens while others were reported for the first time. Amongst these, isoflavone reductase, beta-conglycinin, S-adenosyl methionine synthase, 1, 4 glucan synthase and beta-galactosidase were commonly reported as allergens from coconut pollen and presumably responsible for cross-reactivity. One of the allergens had IgE binding epitope recognized by its glycan moiety. The allergenic potency of date palm pollen has been demonstrated using in vitro tests. The identified allergens can be used to develop vaccines for immunotherapy against date palm pollen allergy. Identification of allergenic proteins from sources harboring them is essential in developing therapeutic interventions. This is the first comprehensive study on the identification of allergens from Phoenix sylvestris (date palm) pollen, one of the major aeroallergens in India using a proteomic approach. Proteomic methods are being increasingly used to identify allergens. However, since many of these proteins arise from species which are un-sequenced, it becomes difficult to interpret those using conventional proteomics. Date palm being an unsequenced species, the Ig

  3. Hollow Pollen Shells to Enhance Drug Delivery

    Science.gov (United States)

    Diego-Taboada, Alberto; Beckett, Stephen T.; Atkin, Stephen L.; Mackenzie, Grahame

    2014-01-01

    Pollen grain and spore shells are natural microcapsules designed to protect the genetic material of the plant from external damage. The shell is made up of two layers, the inner layer (intine), made largely of cellulose, and the outer layer (exine), composed mainly of sporopollenin. The relative proportion of each varies according to the plant species. The structure of sporopollenin has not been fully characterised but different studies suggest the presence of conjugated phenols, which provide antioxidant properties to the microcapsule and UV (ultraviolet) protection to the material inside it. These microcapsule shells have many advantageous properties, such as homogeneity in size, resilience to both alkalis and acids, and the ability to withstand temperatures up to 250 °C. These hollow microcapsules have the ability to encapsulate and release actives in a controlled manner. Their mucoadhesion to intestinal tissues may contribute to the extended contact of the sporopollenin with the intestinal mucosa leading to an increased efficiency of delivery of nutraceuticals and drugs. The hollow microcapsules can be filled with a solution of the active or active in a liquid form by simply mixing both together, and in some cases operating a vacuum. The active payload can be released in the human body depending on pressure on the microcapsule, solubility and/or pH factors. Active release can be controlled by adding a coating on the shell, or co-encapsulation with the active inside the shell. PMID:24638098

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

    Directory of Open Access Journals (Sweden)

    Andrea Obersteiner

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

  5. The long pollen tube journey and in vitro pollen germination of Phalaenopsis orchids.

    Science.gov (United States)

    Chen, Jhun-Chen; Fang, Su-Chiung

    2016-06-01

    Pollen biology in P. aphrodite. Orchids have a distinct reproductive program. Pollination triggers ovule development and differentiation within flowers, and fertilization occurs days to months after pollination. It is unclear how pollen tubes travel through the developing ovaries during ovule development and when pollen tubes arrive at the mature embryo sac to achieve fertilization. Here, we report a robust staining protocol to image and record the timing of pollen germination, progressive growth of pollen tubes in ovaries, and arrival of pollen tubes at embryo sacs in Phalaenopsis aphrodite. The pollen germinated and pollen tubes entered the ovary 3 days after pollination. Pollen tubes continued to grow and filled the entire cavity of the ovary as the ovary elongated and ovules developed. Pollen tubes were found to enter the matured embryo sacs at approximately 60-65 days after pollination in an acropetal manner. Moreover, these temporal changes in developmental events such as growth of pollen tubes and fertilization were associated with expression of molecular markers. In addition, we developed an in vitro pollen germination protocol, which is valuable to enable studies on pollen tube guidance and tip growth regulation in Phalaenopsis orchids and possibly in other orchid species.

  6. Pollen parameters estimates of genetic variability among newly ...

    African Journals Online (AJOL)

    Estimates of some pollen parameters where used to assess the genetic diversity among some newly selected Nigerian Roselle (Hibiscus sabdariffa L.). Standard procedures were used to determine the pollen parameters such as: percentage pollen fertility, percentage pollen sterility, pollen diameters as well as anther ...

  7. 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.

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

    National Research Council Canada - National Science Library

    Obersteiner, Andrea; Gilles, Stefanie; Frank, Ulrike; Beck, Isabelle; Häring, Franziska; Ernst, Dietrich; Rothballer, Michael; Hartmann, Anton; Traidl-Hoffmann, Claudia; Schmid, Michael

    2016-01-01

    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...

  9. 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

  10. Viabilidade polínica como seleção assistida no programa de melhoramento genético de triticale Pollen viability as assisted selection in the triticale genetic breeding program

    Directory of Open Access Journals (Sweden)

    Maira Zanotto

    2009-01-01

    Full Text Available Neste trabalho,objetivou-se analisar a viabilidade de grãos de pólen de 52 genótipos de triticale, oriundos do bloco de cruzamentos do programa de melhoramento genético da Embrapa Trigo do ano de 2005. A coleta das espigas foi realizada quando as plantas se encontravam na fase anterior à antese. As análises citológicas foram realizadas fixando as anteras de uma mesma espiga em fixador Carnoy. Para a análise polínica, as lâminas foram confeccionadas usando-se três anteras da mesma flor, oriundas das regiões basal, mediana e apical de uma espiga, totalizando nove lâminas por genótipo. Para cada lâmina, foram contados cerca de 200 grãos de pólen, classificando-os em duas categorias: 1 normais ou viáveis e 2 anormais. Os dados foram analisados e as médias comparadas pelo teste de Duncan 5%. A análise de variância demonstrou haver diferenças significativas em relação à viabilidade polínica entre os 52 genótipos observados. A grande maioria dos genótipos apresentou viabilidade polínica superior a 90 %. A seleção assistida, via análise citológica de grãos de pólens, é potencialmente útil para um programa de melhoramento genético vegetal, uma vez que cruzamentos feitos entre plantas portadoras de pólens inviáveis resultarão em plantas estéreis e numa menor produção de grãos.The objective of this study was to analyze the pollen grain viability of 52 triticale genotypes from the 2005 crossing block of the Embrapa Wheat breeding program. The spikes were collected prior to anthesis and cytological analyses were performed upon fixing the anthers from the basal, medium, and apical regions of the spike and replicated three times for each sample. For each slide, about 200 pollen grains were analyzed and they were classified into two different groups: 1 normal or viable and 2 non-viable or abnormal. The obtained data were analyzed and the means were compared by the Duncan test at 5% propability. The results of

  11. Pollen and reproductive morphology of Rhigiophyllum and Siphocodo (Campanulaceae: two unique genera of the fynbos vegetation of South Africa

    Directory of Open Access Journals (Sweden)

    W. M. M. Eddie

    2010-07-01

    Full Text Available Pollen grains of Rhigiophyllum squarrosum Hochst., Siphocodon spartioides Turcz. and S. debilis Schltr., are flattened and triangular with pores at the angles. This morphology is radically different from known pollen of the Campanulaceae s.sfr:: the Campanulaceae are treated here as a family separate from the Lobeliaceae, Cyphiaceae, Nemacladaceae, Pentaphragmataceae and Sphenocleaceae (Lammers 1992. As traditionally conceived, the Campanulaceae is very heterogeneous and, in many classifications, these families were treated as subfamilies of a much-enlarged Campanulaceae. The consistently different floral morphology, biochemistry and pollen structure of the Lobeliaceae favours the recognition of this predominantly tropical group as a separate family. The pollen grains of these species are described in comparison with other members of the Campanulaceae. Based on surface characteristics of their pollen grains, we conclude that they represent an early offshoot o f the wahlenbergioid line­age in southern Africa. We suggest that this unique pollen may also be the result of a highly selective regime in the fynbos, associated with specialized pollinators, and base-poor soils, in addition to possible adaptations for ant dispersal and fire. Rhigiophyllum Hochst. and Siphocodon Turcz. are also unique in having free carpel-like structures within the ovary. These shrink to form seed pockets around the seeds and disperse as units when the capsule matures. Data from molecular studies support the contention that these taxa form a sister group to all other wahlenbergioids and that this should be formally recognized in a classification system. We treat Rhigiophyllum and Siphocodon within the Campanulaceae: Wahlenbergioideae, as a separate tribe, the Rhigiophylleae tribus nov., the species of which are distinguishable from other wahlenbergioids by unique angulaperturatc pollen, epipetalous stamens, free carpel-like structures and seed pockets.

  12. 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.

  13. Pollen and reproductive morphology of Rhigiophyllum and Siphocodo (Campanulaceae: two unique genera of the fynbos vegetation of South Africa

    Directory of Open Access Journals (Sweden)

    W. M. M. Eddie

    2010-12-01

    Full Text Available Pollen grains of Rhigiophyllum squarrosum Hochst., Siphocodon spartioides Turcz. and S. debilis Schltr., are flattened and triangular with pores at the angles. This morphology is radically different from known pollen of the Campanulaceae s.sfr:: the Campanulaceae are treated here as a family separate from the Lobeliaceae, Cyphiaceae, Nemacladaceae, Pentaphragmataceae and Sphenocleaceae (Lammers 1992. As traditionally conceived, the Campanulaceae is very heterogeneous and, in many classifications, these families were treated as subfamilies of a much-enlarged Campanulaceae. The consistently different floral morphology, biochemistry and pollen structure of the Lobeliaceae favours the recognition of this predominantly tropical group as a separate family.The pollen grains of these species are described in comparison with other members of the Campanulaceae. Based on surface characteristics of their pollen grains, we conclude that they represent an early offshoot o f the wahlenbergioid line­age in southern Africa. We suggest that this unique pollen may also be the result of a highly selective regime in the fynbos, associated with specialized pollinators, and base-poor soils, in addition to possible adaptations for ant dispersal and fire. Rhigiophyllum Hochst. and Siphocodon Turcz. are also unique in having free carpel-like structures within the ovary. These shrink to form seed pockets around the seeds and disperse as units when the capsule matures. Data from molecular studies support the contention that these taxa form a sister group to all other wahlenbergioids and that this should be formally recognized in a classification system. We treat Rhigiophyllum and Siphocodon within the Campanulaceae: Wahlenbergioideae, as a separate tribe, the Rhigiophylleae tribus nov., the species of which are distinguishable from other wahlenbergioids by unique angulaperturatc pollen, epipetalous stamens, free carpel-like structures and seed pockets.  

  14. The long distance transport of airborne Ambrosia pollen to the UK and the Netherlands from Central and south Europe

    Science.gov (United States)

    de Weger, Letty A.; Pashley, Catherine H.; Šikoparija, Branko; Skjøth, Carsten A.; Kasprzyk, Idalia; Grewling, Łukasz; Thibaudon, Michel; Magyar, Donat; Smith, Matt

    2016-12-01

    The invasive alien species Ambrosia artemisiifolia (common or short ragweed) is increasing its range in Europe. In the UK and the Netherlands, airborne concentrations of Ambrosia pollen are usually low. However, more than 30 Ambrosia pollen grains per cubic metre of air (above the level capable to trigger allergic symptoms) were recorded in Leicester (UK) and Leiden (NL) on 4 and 5 September 2014. The aims of this study were to determine whether the highly allergenic Ambrosia pollen recorded during the episode could be the result of long distance transport, to identify the potential sources of these pollen grains and to describe the conditions that facilitated this possible long distance transport. Airborne Ambrosia pollen data were collected at 10 sites in Europe. Back trajectory and atmospheric dispersion calculations were performed using HYSPLIT_4. Back trajectories calculated at Leicester and Leiden show that higher altitude air masses (1500 m) originated from source areas on the Pannonian Plain and Ukraine. During the episode, air masses veered to the west and passed over the Rhône Valley. Dispersion calculations showed that the atmospheric conditions were suitable for Ambrosia pollen released from the Pannonian Plain and the Rhône Valley to reach the higher levels and enter the airstream moving to northwest Europe where they were deposited at ground level and recorded by monitoring sites. The study indicates that the Ambrosia pollen grains recorded during the episode in Leicester and Leiden were probably not produced by local sources but transported long distances from potential source regions in east Europe, i.e. the Pannonian Plain and Ukraine, as well as the Rhône Valley in France.

  15. 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.

  16. A catalogue of Irish pollen diagrams

    OpenAIRE

    Mitchell, Fraser

    2013-01-01

    PUBLISHED The first Irish pollen diagram was published by Gunnar Erdtman in the Irish Naturalists? Journal in 1927. Since then over 471 pollen diagrams have been produced from locations throughout Ireland from a range of sites and time spans. The data from these pollen diagrams can be used to reconstruct vegetation dynamics over long time scales and so facilitate the investigation of climate change impacts, plant migration and the scale of human induced landscape change. In this paper we ...

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

    Directory of Open Access Journals (Sweden)

    Stephen C McDowell

    2015-04-01

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

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    transgenes were not transmitted to the next generation when these lines were used as a pollen donor, suggesting male sterility. Viability of mature pollen was severely decreased in potato lines with reduced pectic arabinan, but not in lines with altered galactan side chains. Anthers and pollen of different...

  19. [2001 survey of pollen in Wakayama City with a real-time pollen counter].

    Science.gov (United States)

    Seno, Satoshi; Dake, Yoshihiro; Sakoda, Takema; Saito, Yuko; Ikeda, Hiroki; Kitano, Hiroya; Kitajima, Kazutomo; Enomoto, Tadao

    2002-03-01

    Self-care is gradually being recognized as important in the treatment of pollinosis, based up to now on data on airborne pollen. To determine the real-time numbers of airborne pollen would be more useful in self-care, however, so we studied the usefulness of the real-time pollen counter. Between Feb. 2, 2001, and Apr. 26, 2001, 4 types of airborne pollen i.e., Japanese cedar, Japanese cypress, black alder, and beech observed in Wakayama City were counted with a Durham pollen counter and a real-time pollen counter (Yamato Manufacturing Co. Ltd.). Correlation between the 2 pollen counters was r = 0.69 for Japanese cedar in March and r = 0.89 for Japanese cypress in April. A high correlation was observed between outcomes of the 2 pollen counters. The amount of pollen from black alder and beech was less than that from Japanese cedar and cypress. Unexpected peaks were observed not related to the pollen number is apparently due to snow. We have taken measure against snow, so we concluded that the real-time pollen counter was useful in counting the amount of airborne pollen over time.

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

    Directory of Open Access Journals (Sweden)

    Melekber Sulusoglu

    2014-01-01

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

  1. Late Quaternary palynology in marine sediments: a synthesis of the understanding of pollen distribution patterns in the NW African setting.

    NARCIS (Netherlands)

    Hooghiemstra, H.; Lézine, A.M.; Leroy, S.A.G.; Dupont, L.; Marret, F.

    2006-01-01

    Abstract After a review of the first steps in marine palynology, we show that the understanding of the northwest African setting is crucial to evaluate the potential of marine palynological studies elsewhere. We studied distribution patterns of pollen grains in recent marine sediments off NW Africa

  2. DNA damage response in male gametes of Cyrtanthus mackenii during pollen tube growth.

    Science.gov (United States)

    Hirano, Tomonari; Takagi, Keiichi; Hoshino, Yoichiro; Abe, Tomoko

    2013-01-01

    Male gametophytes of plants are exposed to environmental stress and mutagenic agents during the double fertilization process and therefore need to repair the DNA damage in order to transmit the genomic information to the next generation. However, the DNA damage response in male gametes is still unclear. In the present study, we analysed the response to DNA damage in the generative cells of Cyrtanthus mackenii during pollen tube growth. A carbon ion beam, which can induce DNA double-strand breaks (DSBs), was used to irradiate the bicellular pollen, and then the irradiated pollen grains were cultured in a liquid culture medium. The male gametes were isolated from the cultured pollen tubes and used for immunofluorescence analysis. Although inhibitory effects on pollen tube growth were not observed after irradiation, sperm cell formation decreased significantly after high-dose irradiation. After high-dose irradiation, the cell cycle progression of generative cells was arrested at metaphase in pollen mitosis II, and phosphorylated H2AX (γH2AX) foci, an indicator of DSBs, were detected in the majority of the arrested cells. However, these foci were not detected in cells that were past metaphase. Cell cycle progression in irradiated generative cells is regulated by the spindle assembly checkpoint, and modification of the histones surrounding the DSBs was confirmed. These results indicate that during pollen tube growth generative cells can recognize and manage genomic lesions using DNA damage response pathways. In addition, the number of generative cells with γH2AX foci decreased with culture prolongation, suggesting that the DSBs in the generative cells are repaired.

  3. Ornamental Representatives of the Genus Centaurea L. as a Pollen Source for Bee Friendly Gardens

    Directory of Open Access Journals (Sweden)

    Denisow Bożena

    2014-12-01

    Full Text Available The flowering phenology and pollen production of three ornamental Centaurea species were investigated in the years 2009 and 2012-2013. The study objects, Centaurea montana L. = Cyanus montanus (L. Hill, Centaurea mollis Waldst & Kit, and Centaurea dealbata Willd. were cultivated within an area of the UMCS Botanical Garden in Lublin, Poland (51° 14’ N, 22° 34’ E. Under the environmental conditions of SE Poland, the Centaurea species flowered continuously from mid-May to the first week of June. The mass of pollen in anthers was found to be species-related: 3.70 mg (C. montana, 4.02 mg (C. mollis, and 6.01 mg (C. dealbata per 100 anthers. The total pollen yield was related to the mass of pollen produced in flowers and the abundance of blooming. Pollen grains were medium-sized, spheroid (C. dealbata or prolato-spheroid (C. mollis and C. montana in shape, and characterized by high viability (over 80% on average. The pollen provided by the plants of ornamental Centaurea species amounted to 6.0 - 7.9 g per m2 on average. The honeybee was the most frequent visitor of C. dealbata, accounting for 55.2% of the total pollinators, and bumblebee species predominated on the flowers of both C. montana (77.7% and C. mollis (85.6%. Solitary bees and dipterans were also observed on the flowers of all species studied, but C. mollis was avoided by lepidopterans. Ornamental Centaurea species provide pollen reserves that could support communities of invertebrate pollinators, although the period of effective supply fluctuates annually due to changeable periods of blooming.

  4. Ecological features of Ambrosia artemisiifolia L. flowers and characteristics of Ambrosia L. pollen seasons in the condition of Lublin (Poland) in the years 2001-2008

    OpenAIRE

    Elżbieta Weryszko-Chmielewska; Krystyna Piotrowska

    2012-01-01

    In the study, the biology of fl owering of Ambrosia artemisiifolia L. was investigated and the pattern of the Ambrosia pollen seasons in Lublin in the years 2001-2008 was characterised. The structure of male and female A. artemisiifolia flowers was observed in cultivated plants under controlled conditions in the 2000 vegetative season. The number of pollen grains produced by the stamen, flower, inflorescence and plant was determined. It was shown that in A. artemisiifolia flowers nonfunctiona...

  5. Features of ionogenic group composition in polymeric matrix of lily pollen wall.

    Science.gov (United States)

    Meychik, N R; Matveyeva, N P; Nikolaeva, Yu I; Chaikova, A V; Yermakov, I P

    2006-08-01

    The composition of ionogenic groups and ion-exchange capacity were studied in the polymeric matrix of cell walls isolated from the pollen grain and tissues of vegetative organs (leaves and stems) of Lilium longiflorum Thunb. The ion-exchange capacity was evaluated at different pH values and ionic strength of 100 mM. In the two-layered pollen wall and the somatic cell walls four types of ionogenic groups were found: amino groups, two carboxyl groups (represented by residues of uronic and hydroxycinnamic acids), and phenolic OH-groups. The groups of all four types are present in the intine, whereas the exine contains one type of anion-exchange and two types of cation-exchange groups. The contents of each type group and their ionization constants were determined. The qualitative and quantitative compositions of structural polymers of the pollen intine and somatic cell walls are significantly different. It is suggested that hydroxycinnamic acids should be involved in cross-linking of polysaccharide chains in both the intine and somatic cell primary walls, and such cross-links play a crucial role in the structural organization and integrity of the pollen grain wall.

  6. An Arabidopsis F-box protein regulates tapetum degeneration and pollen maturation during anther development.

    Science.gov (United States)

    Kim, Ok-Kyoung; Jung, Jae-Hoon; Park, Chung-Mo

    2010-07-01

    The Arabidopsis anther has a bilateral symmetry with four lobes, each consisting of four distinct layers of somatic cells from the outer to inner side: epidermis, endothecium, middle layer and tapetum. The tapetum is a layer of cells comprising the inner surface of the pollen wall. It plays an important role in anther development by providing enzymes, materials and nutrients required for pollen maturation. Genes and molecular mechanisms underlying tapetum formation and pollen wall biosynthesis have been studied in Arabidopsis. However, tapetum degeneration and anther dehiscence have not been well characterized at the molecular level. Here, we report that an Arabidopsis gene, designated reduced male fertility (RMF), regulates degeneration of tapetum and middle layer during anther development. The Arabidopsis dominant mutant rmf-1D overexpressing the RMF gene exhibited pleiotropic phenotypes, including dwarfed growth with small, dark-green leaves and low male fertility. Tapetum development and subsequent degeneration were impaired in the mutant. Accordingly, pollen maturation was disturbed, reducing the male fertility. In contrast, tapetum degeneration was somewhat accelerated in the RMF RNAi plants. The RMF gene was expressed predominantly in the anther, particularly in the pollen grains. Notably, the RMF protein contains an F-box motif and is localized to the nucleus. It physically interacts with the Arabidopsis-Skp1-like1 protein via the F-box motif. These observations indicate that the RMF gene encodes an F-box protein functioning in tapetum degeneration during anther development.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. Fatores que afetam a germinação do grão de pólen do maracujá: meios de cultura e tipos de agrotóxicos Factors affecting the grain pollen germination of yellow passion fruit: culture medium and agrotoxics

    Directory of Open Access Journals (Sweden)

    Mairon Moura da Silva

    1999-03-01

    Full Text Available Foram conduzidos estudos para seleção de temperatura, meio de cultura e tempo de incubação ideais para germinação de grãos de pólen do maracujá-amarelo (Passiflora edulis f. flavicarpa, com a finalidade de adequar o método de avaliação da interferência de agrotóxicos. A temperatura de 28 + 0,5ºC e o meio com 50 g/L de sacarose; 0,2 g/L de ácido bórico e 1,0 g/L de nitrato de cálcio forneceram as melhores condições para germinação dos grãos de pólen do maracujazeiro. Não detectou-se efeito significativo do tempo de incubação (17 e 48 horas na germinação dos grãos de pólen. A percentagem de germinação dos grãos de pólen não foi prejudicada pelo acaricida Dicofol + Tetradifon e pelos inseticidas Cartap, Fenpropathrin e Abamectin. Os demais agrotóxicos afetaram a germinação dos grãos de pólen. Os inseticidas Malathion, Fenthion, Trichlorfon, Vamidothion, Deltamethrine, Parathion Methyl e o espalhante adesivo N-dodecil benzeno de sulfato de sódio reduziram moderadamente a germinação, enquanto o Ethion e o Lambdacyhalothrin interferiram severamente na germinação dos grãos de pólen.Temperature, culture medium, incubation period and pH for yellow passion fruit (Passiflora edulis f. flavicarpa pollen germination, as well the effect of agrotoxics were studied. Temperature of 28 ± 0.5°C, culture medium with 50 g/L of sacarose, 0.2 g/L of boric acid and 1.0 g/L of calcium nitrate showed better germination of P. edulis f. flavicarpa pollen. No effect of the incubation period (17 and 48 hours was registered for pollen germination of this plant. Percentage of pollen germination of P. edulis f. flavicarpa was not affected by the acaricid Dicofol + Tetradifon and by the insecticides Cartap, Fenpropathrin, and Abamectin. There was a small reduction in pollen germination in the presence of insecticides Malathion, Fenthion, Thrichorfon, Vamidothion, Deltamethrin, Methyl Parathion and the spreader-sticker N

  9. Using Generic Examples to Make Viable Arguments

    Science.gov (United States)

    Adams, Anne E.; Ely, Rob; Yopp, David

    2017-01-01

    The twenty-first century has seen an increased call to train students to craft mathematical arguments. The third of the Common Core's (CCSS) Standards for Mathematical Practice (SMP 3) (CCSSI 2010) calls for all mathematically proficient students to "construct viable arguments" to support the truth of their ideas and to "critique…

  10. The Arabidopsis general transcription factor TFIIB1 (AtTFIIB1) is required for pollen tube growth and endosperm development.

    Science.gov (United States)

    Zhou, Jing-Jing; Liang, Yan; Niu, Qian-Kun; Chen, Li-Qun; Zhang, Xue-Qin; Ye, De

    2013-05-01

    Pollen tube growth and endosperm development are important for fertilization and seed formation. The genetic mechanism of the processes remains poorly understood. This study reports the functional characterization of AtTFIIB1 in pollen tube growth and endosperm development. AtTFIIB1 shares 86% and 44% similarity with AtTFIIB2 and AtTFIIB3/AtpBRP2, respectively. It is expressed in many tissues including vegetative nuclei and generative cells of pollen grains and pollen tubes, endosperm, and embryos. It is thus different from AtTFIIB2, whose expression is not found in the endosperm and vegetative nucleus of mature pollen, and AtTFIIB3/AtpBRP2, which is expressed mostly in male gametophytes and weakly in seeds. Mutations in AtTFIIB1 caused a drastic retardation of pollen tube growth and endosperm development, as well as impaired pollen tube guidance and reception, leading to disruption of fertilization and seed development. Expression of AtTFIIB2 driven by the AtTFIIB1 promoter could restore the defective pollen tube growth, guidance, and reception completely, but only partially recovered the seed development in attfiib1, whilst expression of AtTFIIB3/AtpBRP2 driven by the AtTFIIB1 promoter could rescue only the defective attfiib1 seeds. All these results suggest that AtTFIIB1 plays important roles in pollen tube growth, guidance, and reception as well as endosperm development and is partially functionally different from AtTFIIB2 and AtTFIIB3/AtpBRP2.

  11. Aperture number influences pollen survival in Arabidopsis mutants

    National Research Council Canada - National Science Library

    Prieu, Charlotte; Matamoro-Vidal, Alexis; Raquin, Christian; Dobritsa, Anna; Mercier, Raphaël; Gouyon, Pierre-Henri; Albert, Béatrice

    2016-01-01

    .... Thus, morphological or structural adaptations might exist to help pollen adjust to sudden volume changes, though little is known about the correlation between pollen morphology and its ability...

  12. A high-resolution angiosperm pollen reference record covering Albian mid-latitude coastal deposits (Lusitanian Basin, Portugal)

    Science.gov (United States)

    Horikx, Maurits; Dinis, Jorge L.; Heimhofer, Ulrich

    2013-04-01

    The Lusitanian Basin in Portugal is one of the most important areas to investigate the rise and radiation of early angiosperms. Here, important micro-, macro- and mesofossil remains including pollen, reproductive organs, fruits and seeds have been found. In this study, a high-resolution Early to Late Albian pollen record from a thick (~160m) coastal succession in the Lusitanian Basin containing mixed carbonate-siliciclastic near-shore deposits is generated. The outcrop is located near the town of Ericeira (São Julião) and exhibits some important new features compared to existing records from the Lusitanian basin. The comparatively proximal depositional setting and high sedimentation rate of the São Julião outcrop is well suited for high-resolution palynological sampling compared to previously studied, more distal outcrops. In addition, the succession covers almost the entire Albian including a thick interval representing Late Albian strata. Dating of the succession was obtained using dinoflagellate cyst biostratigraphy, bulk C-isotope analysis and strontium isotope analysis of low-Mg oysters and rudist shells. The high-resolution pollen record shows a distinct radiation pattern of early angiosperm pollen as well as significant changes in the accompanying palynoflora. During most of the section gymnosperm pollen types such as Classopollis spp., Inaperturopollenites spp. and Exesipollenites spp. are dominant. Angiosperm pollen abundances do not exceed 20%, although angiosperms increase slightly from the Early Albian onwards. Monoaperturate grains of magnoliid or monocot affinity remain the most dominant angiosperm pollen type, both in abundances and diversity. Tricolpate and zonoaperturate pollen grains are also present. In addition, the occurrence of several odd-shaped Dichastopollenites-type pollen types is intriguing. The palynological results indicate a warm and dry climate during most of the Albian, although a rise in the spores over pollen ratio in the

  13. Specialized bees fail to develop on non-host pollen: do plants chemically protect their pollen?

    Science.gov (United States)

    Praz, Christophe J; Müller, Andreas; Dorn, Silvia

    2008-03-01

    Bees require large amounts of pollen for their own reproduction. While several morphological flower traits are known to have evolved to protect plants against excessive pollen harvesting by bees, little is known on how selection to minimize pollen loss acts on the chemical composition of pollen. In this study, we traced the larval development of four solitary bee species, each specialized on a different pollen source, when reared on non-host pollen by transferring unhatched eggs of one species onto the pollen provisions of another species. Pollen diets of Asteraceae and Ranunculus (Ranunculaceae) proved to be inadequate for all bee species tested except those specialized on these plants. Further, pollen of Sinapis (Brassicaceae) and Echium (Boraginaceae) failed to support larval development in one bee species specialized on Campanula (Campanulaceae). Our results strongly suggest that pollen of these four taxonomic groups possess protective properties that hamper digestion and thus challenge the general view of pollen as an easy-to-use protein source for flower visitors.

  14. The coexistence of bicellular and tricellular pollen in Annona cherimola (Annonaceae): Implications for pollen evolution.

    Science.gov (United States)

    Lora, Jorge; Herrero, María; Hormaza, José I

    2009-04-01

    Most angiosperms release bicellular pollen. However, in about one-third of extant angiosperms, the second pollen mitosis occurs before anthesis such that pollen is tricellular upon release. The shift from bicellular to tricellular development has occurred several times independently, but its causes are largely unknown. In this work, we observed the coexistence of both kinds of pollen at anther dehiscence in Annona cherimola, a species that belongs to the basal angiosperm family Annonaceae. Examination of pollen cell number during anther development showed that this coexistence was due to a late mitosis starting shortly before pollen shedding. Both types of pollen germinated equally well over the course of development. Because variable proportions of bicellular and tricellular pollen were observed at different sampling times, we tested the role of temperature by performing field and growth chamber experiments, which showed that higher temperatures near anthesis advanced the time of pollen mitosis II. The results show that selection could favor the production of tricellular pollen under certain environmental circumstances that prime rapid pollen germination and provide evidence of a system in which developmental variation persists, but that can be modified by external factors such as temperature.

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

    Energy Technology Data Exchange (ETDEWEB)

    Demchik, S.M.; Day, T.A. [West Virginia Univ., Morgantown, WV (United States)

    1996-05-01

    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 enhanced{close_quotes}), or 32% ({open_quotes}high enhanced{close_quotes}) ozone depletion levels at Morgantown, WV, USA in mid-March. In the first experiment,pollen production and viability per flower were reduced by {approx}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 {approx}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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Subramanian, N.; Iyer, C.P.A.; Singh, R. (Indian Inst. of Horticultural Research, Bangalore)

    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.

  17. The pollen tube paradigm revisited.

    Science.gov (United States)

    Kroeger, Jens; Geitmann, Anja

    2012-12-01

    The polar growth process characterizing pollen tube elongation has attracted numerous modeling attempts over the past years. While initial models focused on recreating the correct cellular geometry, recent models are increasingly based on experimentally assessed cellular parameters such as the dynamics of signaling processes and the mechanical properties of the cell wall. Recent modeling attempts have therefore substantially gained in biological relevance and predictive power. Different modeling methods are explained and the power and limitations of individual models are compared. Focus is on several recent models that use closed feedback loops in order to generate limit cycles representing the oscillatory behavior observed in growing tubes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Pollen used to produce allergen extracts.

    Science.gov (United States)

    Codina, Rosa; Lockey, Richard F

    2017-02-01

    To review the use of pollen for the production of allergen extracts to diagnose and treat allergic diseases, examine the associated regulations, and highlight candidate areas for improvement. A PubMed search was performed using focused keywords combined with a review of regulatory documents and industry guidelines. The information obtained through literature, documents, and industry was scrutinized and used with personal experience and expertise to write this article. Both genetic and environmental factors affect the allergenic composition of pollen because it is a biologically active pharmaceutical ingredient obtained from nature. The potential effect of airborne contaminants in pollen requires major attention but can be properly addressed through careful collection practices, combined with a proper interpretation of the data on purity obtained for each pollen lot. The regulations associated with pollen used to manufacture allergen extracts in the United States and Europe and the numbers of pollen allergen extracts commercially available in both areas of the world differ. A critical parameter to select the appropriate extracts for diagnosis and allergen immunotherapy is to understand the phenomenon of cross-reactivity among pollen families, genera, and species. Physicians should be aware of the factors responsible for the qualitative and quantitative composition of pollen allergen extracts and the associated regulations to produce suitable extracts to diagnose and treat allergic diseases. Collaboration and cooperation among allergen manufacturing companies and regulatory agencies are necessary. Copyright © 2016 American College of Allergy, Asthma & Immunology. Published by Elsevier Inc. All rights reserved.

  19. Pollen viability and membrane lipid composition

    NARCIS (Netherlands)

    Bilsen, van D.G.J.L.

    1993-01-01

    In this thesis membrane lipid composition is studied in relation to pollen viability during storage. Chapter 1 reviews pollen viability, membranes in the dry state and membrane changes associated with cellular aging. This chapter is followed by a study of age-related changes in phospholipid

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

    Directory of Open Access Journals (Sweden)

    Raquel DL Cardoso

    2009-03-01

    material was stained with acetic carmim at 45%. The chromosome counting was performed in metafasic intact cells and the pollen viability estimated by counting the number of viable and non viable pollen grains. The crossing possibility among cultivars and among cultivars and non commercial accessions was evaluated through the hybridization between the feminine cv. Terra Fame and A8 and masculine genitors, cvs. Cariba and Azteca. All accessions presented fifty chromosomes, indicating that the morphological variation in the capitulum (simple, semidouble and double is not due to the chromosome number mutation or polyploidy. The evaluated accessions displayed high pollen viability, varying from 87.67% to 99.27. The seed formation was 4.46% in the crossings among cultivars, and 50% among cultivar and non commercial accession of gerbera. The genomic compatibility among the accessions, the high pollen viability and the success in the seed formation among commercial and non-commercial accessions, reveal the possibility of hybrid production with new allelic combination and transference of desirable traits from the non-commercial to the commercial accessions.

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

    Directory of Open Access Journals (Sweden)

    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.

  2. The influence of weather conditions on the course of pollen seasons of alder (Alnus spp., hazel (Corylus spp. and birch (Betula spp. in Lublin (2001-2006

    Directory of Open Access Journals (Sweden)

    Agnieszka Dąbrowska

    2012-12-01

    Full Text Available The start and rate of florescence of Alnus, Corylus and Betula are dependent on meteorological conditions. In the present paper we have analysed the effect of mean, maximum and minimum temperature, relative air humidity and precipitation on the onset of the pollen season as well as on its length and annual count of pollen grains in alder, hazel and birch. The measurement of pollen fall was done by the gravimetric methods with the use of Durham sampler. Correlation coefficients were calculated between the determined characteristics of the pollen season and weather conditions. In the six-year research period 2001-2006 it was observed that low temperatures in January produced a delayed start of the pollen season in alder, hazel and birch. The beginning of flowering in these taxa was also influenced by thermal conditions prevailing directly before the season (ca. 10 days. The pollen season of the trees in question tended to be prolonged alongside with the increase in relative air humidity, but it was shortened due to higher temperatures. The volume of alder and hazel pollen release increased together with the rise in relative air humidity and precipitation. The annual counts of birch pollen increased along with rising temperature and decreasing relative air humidity and precipitation in the season.

  3. MICROBIAL QUALITY OF HONEY MIXTURE WITH POLLEN

    Directory of Open Access Journals (Sweden)

    Ján Mareček

    2011-02-01

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

  4. New insights into ragweed pollen allergens.

    Science.gov (United States)

    Bordas-Le Floch, Véronique; Groeme, Rachel; Chabre, Henri; Baron-Bodo, Véronique; Nony, Emmanuel; Mascarell, Laurent; Moingeon, Philippe

    2015-11-01

    Pollen allergens from short ragweed (Ambrosia artemisiifolia) cause severe respiratory allergies in North America and Europe. To date, ten short ragweed pollen allergens belonging to eight protein families, including the recently discovered novel major allergen Amb a 11, have been recorded in the International Union of Immunological Societies (IUIS) allergen database. With evidence that other components may further contribute to short ragweed pollen allergenicity, a better understanding of the allergen repertoire is a requisite for the design of proper diagnostic tools and efficient immunotherapies. This review provides an update on both known as well as novel candidate allergens from short ragweed pollen, identified through a comprehensive characterization of the ragweed pollen transcriptome and proteome.

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

    Science.gov (United States)

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

    2017-04-01

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

  6. Monotone viable trajectories for functional differential inclusions

    Science.gov (United States)

    Haddad, Georges

    This paper is a study on functional differential inclusions with memory which represent the multivalued version of retarded functional differential equations. The main result gives a necessary and sufficient equations. The main result gives a necessary and sufficient condition ensuring the existence of viable trajectories; that means trajectories remaining in a given nonempty closed convex set defined by given constraints the system must satisfy to be viable. Some motivations for this paper can be found in control theory where F( t, φ) = { f( t, φ, u)} uɛU is the set of possible velocities of the system at time t, depending on the past history represented by the function φ and on a control u ranging over a set U of controls. Other motivations can be found in planning procedures in microeconomics and in biological evolutions where problems with memory do effectively appear in a multivalued version. All these models require viability constraints represented by a closed convex set.

  7. Abiotic stress and control of grain number in cereals.

    Science.gov (United States)

    Dolferus, Rudy; Ji, Xuemei; Richards, Richard A

    2011-10-01

    Grain number is the only yield component that is directly associated with increased grain yield in important cereal crops like wheat. Historical yield studies show that increases in grain yield are always accompanied by an increase in grain number. Adverse weather conditions can cause severe fluctuations in grain yield and substantial yield losses in cereal crops. The problem is global and despite its impact on world food production breeding and selection approaches have only met with limited success. A specific period during early reproductive development, the young microspore stage of pollen development, is extremely vulnerable to abiotic stress in self-fertilising cereals (wheat, rice, barley, sorghum). A better understanding of the physiological and molecular processes that lead to stress-induced pollen abortion may provide us with the key to finding solutions for maintaining grain number under abiotic stress conditions. Due to the complexity of the problem, stress-proofing our main cereal crops will be a challenging task and will require joint input from different research disciplines. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  8. Dynamics of storage reserve deposition during Brassica rapa L. pollen and seed development in microgravity

    Science.gov (United States)

    Kuang, A.; Popova, A.; McClure, G.; Musgrave, M. E.

    2005-01-01

    Pollen and seeds share a developmental sequence characterized by intense metabolic activity during reserve deposition before drying to a cryptobiotic form. Neither pollen nor seed development has been well studied in the absence of gravity, despite the importance of these structures in supporting future long-duration manned habitation away from Earth. Using immature seeds (3-15 d postpollination) of Brassica rapa L. cv. Astroplants produced on the STS-87 flight of the space shuttle Columbia, we compared the progress of storage reserve deposition in cotyledon cells during early stages of seed development. Brassica pollen development was studied in flowers produced on plants grown entirely in microgravity on the Mir space station and fixed while on orbit. Cytochemical localization of storage reserves showed differences in starch accumulation between spaceflight and ground control plants in interior layers of the developing seed coat as early as 9 d after pollination. At this age, the embryo is in the cotyledon elongation stage, and there are numerous starch grains in the cotyledon cells in both flight and ground control seeds. In the spaceflight seeds, starch was retained after this stage, while starch grains decreased in size in the ground control seeds. Large and well-developed protein bodies were observed in cotyledon cells of ground control seeds at 15 d postpollination, but their development was delayed in the seeds produced during spaceflight. Like the developing cotyledonary tissues, cells of the anther wall and filaments from the spaceflight plants contained numerous large starch grains, while these were rarely seen in the ground controls. The tapetum remained swollen and persisted to a later developmental stage in the spaceflight plants than in the ground controls, even though most pollen grains appeared normal. These developmental markers indicate that Brassica seeds and pollen produced in microgravity were physiologically younger than those produced in 1 g

  9. Diurnal variations of airborne pollen concentration and the effect of ambient temperature in three sites of Mexico City

    Science.gov (United States)

    Ríos, B.; Torres-Jardón, R.; Ramírez-Arriaga, E.; Martínez-Bernal, A.; Rosas, I.

    2016-05-01

    Pollen is an important cause of allergic respiratory ailments in the Mexico City Metropolitan Area (MCMA). However, very little is known if ambient air temperature correlates with the early blooming of plants observed in other urban areas around the world. A research study was conducted during the dry season of 2012-2013 at three representative sites of the MCMA with different urban characteristics with the aim to understand the relationships between the profusion and diversity of pollen against temperature and other meteorological variables and degree of urbanization. Pollen samples were collected using a Hirst-type trap sampler in the sites: Merced (highly urbanized), Iztapalapa (medium-high urbanized) and Coyoacan (moderately urbanized). Urbanization levels were determined using a composite index based on population density, proportion of surface covered by construction and asphalt, and urban heat island intensity. A set of representative pollen sampling tapes were assayed under a light microscope at magnification of ×1,000 and converted to grains per cubic meter. The most representative pollen types found in the three sites were, regardless of urbanization levels were: Fraxinus, Cupressaceae/Taxodiaceae, Casuarina, Alnus, Myrtaceae, and Pinus. Total pollen concentration was greatest in the moderately urbanized area, although earlier blooming took place at the highly urbanized zone. Total pollen concentration in the medium-high urbanized site has the lowest because the green areas in this zone of MCMA are few. In a diurnal basis, the most abundant pollen types peaked near midday or in the afternoon evening at the three sites. A Spearman test showed a positive correlation among bihourly pollen concentrations, temperature and relative humidity in all sites, but wind speed just correlated in Iztapalapa and Coyoacan. The results obtained suggest that Urban Heat Island Intensity can disturb flowering periods and pollen concentrations, largely in the highly urbanized

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

    Science.gov (United States)

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

    2015-01-01

    The frequency of hybrid formation in angiosperms depends on how and when heterospecific pollen is transferred to the stigma, and on the success of that heterospecific pollen at fertilising ovules. We applied pollen mixtures to stigmas to determine how pollen interactions affect siring success and the frequency of hybrid formation between two species of Mediterranean deceptive orchid. Plants of Orchis italica and O. anthropophora were pollinated with conspecific and heterospecific pollen (first conspecific pollen then heterospecific pollen and vice versa) and molecular analysis was used to check the paternity of the seeds produced. In this pair of Mediterranean orchids, competition between conspecific and heterospecific pollen functions as a post-pollination pre-zygotic barrier limiting the frequency of the formation of hybrids in nature. Flowers pollinated with heterospecific pollen can remain receptive for the arrival of conspecific pollen for a long time. There is always an advantage of conspecific pollen for fruit formation, whether it comes before or after heterospecific pollen, because it overtakes the heterospecific pollen. The conspecific pollen advantage exhibited in O. italica and O. anthropophora is likely to result from the reduced germination of heterospecific pollen or retarded growth of heterospecific pollen tubes in the stigma and ovary. Overall, the results indicate that our hybrid zone represents a phenomenon of little evolutionary consequence, and the conspecific pollen advantage maintains the genetic integrity of the parental species. © 2014 German Botanical Society and The Royal Botanical Society of the Netherlands.

  11. The influence of meteorological conditions on the start of the hazel (Corylus L. pollen season in Lublin, 2001-2009

    Directory of Open Access Journals (Sweden)

    Krystyna Piotrowska

    2012-12-01

    Full Text Available Early spring flowering plants show large differences in the start dates of pollen emission due to high weather variability in the preceding period. In the present study, the influence of meteorological conditions on the start date of the hazel pollen season in Lublin in the years 2001-2009 was investigated. The aeropalynological study was carried out by the volumetric method using a Lanzoni VPPS 2000 sampler. The start of the hazel pollen season was determined using the 98% method. The differences in particular years of the study were over two months. Hazel pollen grains were recorded earliest in 2007, since from 13 January, and latest in 2003, from 18 March. It was found that accumulated 5-day mean temperature before the season affects the onset of the pollen season. As a result of multiple regression analysis, a statistical model was derived, which shows with great accuracy the relationship of the start of the hazel pollen season with total precipitation and the number of winter days.

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

    Directory of Open Access Journals (Sweden)

    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.

  13. Towards numerical forecasting of long-range air transport of birch pollen: theoretical considerations and a feasibility study.

    Science.gov (United States)

    Sofiev, M; Siljamo, P; Ranta, H; Rantio-Lehtimäki, A

    2006-07-01

    This paper considers the feasibility of numerical simulation of large-scale atmospheric transport of allergenic pollen. It is shown that at least small grains, such as birch pollen, can stay in the air for a few days, which leads to a characteristic scale for their transport of approximately 10(3) km. The analytical consideration confirmed the applicability of existing dispersion models to the pollen transport task and provided some reference parameterizations of the key processes, including dry and wet deposition. The results were applied to the Finnish Emergency Dispersion Modelling System (SILAM), which was then used to analyze pollen transport to Finland during spring time in 2002-2004. Solutions of the inverse problems (source apportionment) showed that the main source areas, from which the birch flowering can affect Finnish territory, are the Baltic States, Russia, Germany, Poland, and Sweden-depending on the particular meteorological situation. Actual forecasting of pollen dispersion required a birch forest map of Europe and a unified European model for birch flowering, both of which were nonexistent before this study. A map was compiled from the national forest inventories of Western Europe and satellite images of broadleaf forests. The flowering model was based on the mean climatological dates for the onset of birch forests rather than conditions of any specific year. Utilization of probability forecasting somewhat alleviated the problem, but the development of a European-wide flowering model remains the main obstacle for real-time forecasting of large-scale pollen distribution.

  14. 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.

  15. The capturing of pollens in the atmosphere of La Laguna City, Tenerife, Canary Islands 1990-1995.

    Science.gov (United States)

    García Cobaleda, I; De la Torre Morin, F; García Robaina, J C; Hardisson de la Torre, A

    1997-01-01

    This paper forms part of a Doctorate Thesis, carried out in the Allergy and Immunology Department of the Nuestra Señora de la Candelaria Hospital, Tenerife, entitled "Epidemiology of Pollens on the Island of Tenerife. Allergy to Pollen". This paper deals with the capturing of pollen in the atmosphere of the city of La Laguna, Tenerife, during the period 1990-1995, and demonstrates that the Occidental Islands of the Canarian Archipelago are similar to a miniature continent with a special microclimate and a large amount of vegetation, where all classes of pollen can be found given the large variety of plants and trees including native species. High concentrations of more than 50 grains of pollen per m3 can be found in the air of the Occidental Islands, above all wild grasses, cultivated grasses, weeds, Artemisa vulgaris, Parietaria officinalis and Plantago lanceolata, and in a lowe proportion, Cupressaceae, Pinaceas, Mercurialis and Rumex. We have pollen concentrations very similar to other parts of the continent.

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

    Directory of Open Access Journals (Sweden)

    Alexandre Alonso Alves

    2007-01-01

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

  17. Aerobiological and immunochemical studies on Carica papaya L. pollen: an aeroallergen from India.

    Science.gov (United States)

    Chakraborty, P; Ghosh, D; Chowdhury, I; Roy, I; Chatterjee, S; Chanda, S; Gupta-Bhattacharya, S

    2005-07-01

    Carica papaya L. is a fruit yielding tree, wildly grown or cultivated in the tropics and subtropics. Its pollen grain has been reported to be airborne and cause immunoglobulin E (IgE)-mediated hypersensitivity. To conduct long-term aerobiological study on Carica pollen, along with aeroallergenic particles originating from it and to identify vis-a-vis characterize an important IgE-reactive component present in this pollen. The seasonal and diurnal periodicities of airborne C. papaya pollen were recorded in a 5-year survey using a Burkard volumetric sampler. The allergenic potential was studied by skin prick tests, IgE-enzyme-linked immunosorbent assay (ELISA) and also by aeroallergen immunoblotting. The total pollen extract was fractionated by Sephacryl S-200 column, and out of the eluted five fractions, the maximum IgE-reactive fraction (as found in ELISA inhibition) was resolved into five major subfractions in reverse-phase high-performance liquid chromatography (RP-HPLC). The subfraction with optimum IgE reactivity was studied by activity gel, native and nonreducing sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). The homogeneity of the isolated protein fraction was checked by crossed immunoelectrophoresis with rabbit antisera and IgE reactivity was confirmed by ELISA inhibition and immunoblotting using individual patient sera. The Carica pollen occurred in the air round the year with peaks during January and September-October. Among a patient population of 1000, skin-test results showed 27.8% +1 level and 5.6% +2/+3 level reactions. In aeroallergen immunoblotting of exposed Burkard tape segments, the detected allergen spots showed a significant correlation with airborne pollen count recorded. The pollen extract elicited loss of IgE reactivity when treated with reducing agent-like beta-mercaptoethanol and heat, but showed six IgE-reactive components in nonreducing IgE-immunoblot. The fraction 1 eluted from Sephacryl S-200 column showed

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

    Directory of Open Access Journals (Sweden)

    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.

  19. Brassica oleracea pollen, a new source of occupational allergens

    NARCIS (Netherlands)

    Hermanides, H. K.; Laheÿ-de Boer, A. M.; Zuidmeer, L.; Guikers, C.; van Ree, R.; Knulst, A. C.

    2006-01-01

    BACKGROUND: Vegetable pollen is a rare source of occupational allergens. Occupational allergy has only been described in the case of paprika pollen and tomato pollen. We describe a new source of occupational pollen allergy. AIM: To study the incidence and the impact of broccoli and cauliflower

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

    African Journals Online (AJOL)

    This experiment was designed to study the floral structure, pollen morphology and the potential pollen viability of five Musa genotypes obtained from the Musa field ... Three different types of pollen were encountered viz, big, moderate and small pollens with corresponding big, moderate and small apertures and pores.

  1. (Cocos nucifera) pollens for removal of Cu (II)

    African Journals Online (AJOL)

    GREGO

    determine the suitability of coconut pollen treated with reactive dyes as adsorbents for heavy metals such as copper and zinc, and elucidate the mechanisms of heavy metal adsorption onto the dyed coconut pollen. MATERIALS AND METHODS. Coconut pollens. Coconut pollens utilized for this study were collected from ...

  2. In vitro pollen quantity, viability and germination tests in quince

    African Journals Online (AJOL)

    use

    2011-11-21

    Nov 21, 2011 ... Quince (Cydonia oblonga Mill.) cvs. Ekmek, Eşme, Limon, Ege 2, Ege 22, Ege 25 and Quince-A rootstock pollens were collected in April from the unopened pink balloon-stage flowers on mature trees. The pollen amount was between 20063 pollen/flower ('Ege 25') and 11906 pollen/flower ('Limon').

  3. Alnus as a disturbing factor in pollen diagrams

    NARCIS (Netherlands)

    Janssen, C.R.

    1959-01-01

    It is commonly accepted that percentages of pollen in a pollen diagram do not express the exact composition of forests in earlier times. This inaccuracy is due to several factors, for instance the different quantities of pollen produced by plants, the distance of transport etc. A pollen diagram

  4. In vitro pollen quantity, viability and germination tests in quince ...

    African Journals Online (AJOL)

    Quince (Cydonia oblonga Mill.) cvs. Ekmek, Esme, Limon, Ege 2, Ege 22, Ege 25 and Quince-A rootstock pollens were collected in April from the unopened pink balloon-stage flowers on mature trees. The pollen amount was between 20063 pollen/flower ('Ege 25') and 11906 pollen/flower ('Limon') with hemacytometer.

  5. Comprehensive analysis of tobacco pollen transcriptome unveils common pathways in polar cell expansion and underlying heterochronic shift during spermatogenesis

    Directory of Open Access Journals (Sweden)

    Hafidh Said

    2012-02-01

    Full Text Available Abstract Background Many flowering plants produce bicellular pollen. The two cells of the pollen grain are destined for separate fates in the male gametophyte, which provides a unique opportunity to study genetic interactions that govern guided single-cell polar expansion of the growing pollen tube and the coordinated control of germ cell division and sperm cell fate specification. We applied the Agilent 44 K tobacco gene chip to conduct the first transcriptomic analysis of the tobacco male gametophyte. In addition, we performed a comparative study of the Arabidopsis root-hair trichoblast transcriptome to evaluate genetic factors and common pathways involved in polarized cell-tip expansion. Results Progression of pollen grains from freshly dehisced anthers to pollen tubes 4 h after germination is accompanied with > 5,161 (14.9% gametophyte-specific expressed probes active in at least one of the developmental stages. In contrast, > 18,821 (54.4% probes were preferentially expressed in the sporophyte. Our comparative approach identified a subset of 104 pollen tube-expressed genes that overlap with root-hair trichoblasts. Reverse genetic analysis of selected candidates demonstrated that Cu/Zn superoxide dismutase 1 (CSD1, a WD-40 containing protein (BP130384, and Replication factor C1 (NtRFC1 are among the central regulators of pollen-tube tip growth. Extension of our analysis beyond the second haploid mitosis enabled identification of an opposing-dynamic accumulation of core regulators of cell proliferation and cell fate determinants in accordance with the progression of the germ cell cycle. Conclusions The current study provides a foundation to isolate conserved regulators of cell tip expansion and those that are unique for pollen tube growth to the female gametophyte. A transcriptomic data set is presented as a benchmark for future functional studies using developing pollen as a model. Our results demonstrated previously unknown functions of

  6. Cluster analysis of intradiurnal holm oak pollen cycles at peri-urban and rural sampling sites in southwestern Spain

    Science.gov (United States)

    Hernández-Ceballos, M. A.; García-Mozo, H.; Galán, C.

    2015-08-01

    The impact of regional and local weather and of local topography on intradiurnal variations in airborne pollen levels was assessed by analysing bi-hourly holm oak ( Quercus ilex subsp. ballota (Desf.) Samp.) pollen counts at two sampling stations located 40 km apart, in southwestern Spain (Cordoba city and El Cabril nature reserve) over the period 2010-2011. Pollen grains were captured using Hirst-type volumetric spore traps. Analysis of regional weather conditions was based on the computation of backward trajectories using the HYSPLIT model. Sampling days were selected on the basis of phenological data; rainy days were eliminated, as were days lying outside a given range of percentiles (P95-P5). Analysis of cycles for the study period, as a whole, revealed differences between sampling sites, with peak bi-hourly pollen counts at night in Cordoba and at midday in El Cabril. Differences were also noted in the influence of surface weather conditions (temperature, relative humidity and wind). Cluster analysis of diurnal holm oak pollen cycles revealed the existence of five clusters at each sampling site. Analysis of backward trajectories highlighted specific regional air-flow patterns associated with each site. Findings indicated the contribution of both nearby and distant pollen sources to diurnal cycles. The combined use of cluster analysis and meteorological analysis proved highly suitable for charting the impact of local weather conditions on airborne pollen-count patterns. This method, and the specific tools used here, could be used not only to study diurnal variations in counts for other pollen types and in other biogeographical settings, but also in a number of other research fields involving airborne particle transport modelling, e.g. radionuclide transport in emergency preparedness exercises.

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

    Science.gov (United States)

    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.

  8. The comparison of pollen abundance in air and honey samples

    Directory of Open Access Journals (Sweden)

    Ingrida Šaulienė

    2015-12-01

    Full Text Available Honey as a food has long been used in human nutrition and is still popular. Honey is important because of its therapeutic, prophylactic and strengthening value. Pollen is one of the most decisive components that ensure the quality and type of honey. Modern society becomes more and more sensitive to airborne pollen. Therefore, it is crucial to determine the composition of allergenic plant pollen in natural honey. For this purpose, we studied and compared pollen abundance in honey and air samples collected in Lithuania. Standard methods for pollen investigation in air and honey were used in this study. The botanical diversity of pollen identified in honey and air samples indicates 10 morphotypes: 8 of woody plants and 2 of herbaceous plants, in both the honey and air samples. Salix pollen counts in the honey were found to be highest among airborne pollen from May to September. The anemophilous allergenic pollen constituted 44 % of the total pollen detected in the honey.

  9. Variation in Pollen-Donor Composition among Pollinators in an Entomophilous Tree Species, Castanea crenata, Revealed by Single-Pollen Genotyping

    OpenAIRE

    Yoichi Hasegawa; Yoshihisa Suyama; Kenji Seiwa

    2015-01-01

    Background In plants, reproductive success is largely determined by the composition of pollen (i.e., self-pollen and outcross-pollen from near and distant pollen-donors) transported as a result of pollinator foraging behavior (e.g., pollen carryover). However, little evidence is available on how and to what extent the pollen carryover affects the pollen-donor composition and on which insect taxa are effective outcross-pollen transporters under field conditions. In this study, we explored role...

  10. Bee Pollen: Chemical Composition and Therapeutic Application

    Directory of Open Access Journals (Sweden)

    Katarzyna Komosinska-Vassev

    2015-01-01

    Full Text Available Bee pollen is a valuable apitherapeutic product greatly appreciated by the natural medicine because of its potential medical and nutritional applications. It demonstrates a series of actions such as antifungal, antimicrobial, antiviral, anti-inflammatory, hepatoprotective, anticancer immunostimulating, and local analgesic. Its radical scavenging potential has also been reported. Beneficial properties of bee pollen and the validity for their therapeutic use in various pathological condition have been discussed in this study and with the currently known mechanisms, by which bee pollen modulates burn wound healing process.

  11. Parejas viables que perduran en el tiempo

    OpenAIRE

    Juan José Cuervo Rodríguez

    2013-01-01

    El presente artículo científico presenta resultados del proceso llevado a cabo en el proyecto de investigación docente "Mecanismos de autorregulación en parejas viables que perduran en el tiempo". Se soporta en una mirada compleja de la psicología basada en una epistemología de la construcción. En el ámbito metodológico, se inscribe en los estudios de terapia familiar desde una perspectiva de la comunicación humana como un todo integrado. Participaron nueve parejas. Los criterios de inclusión...

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

    OpenAIRE

    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 (O3) on reactive oxygen species (ROS) and allergen content of ragweed pollen (Ambrosia artemisiifolia). Pollen was exposed to acute O3 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...

  13. Enzymatic isolation of viable human odontoblasts.

    Science.gov (United States)

    Cuffaro, H M; Pääkkönen, V; Tjäderhane, L

    2016-05-01

    To improve an enzymatic method previously used for isolation of rat odontoblasts to isolate viable mature human odontoblasts. Collagenase I, collagenase I/hyaluronidase mixture and hyaluronidase were used to extract mature human odontoblasts from the pulp chamber. Detachment of odontoblasts from dentine was determined with field emission scanning electron microscopy (FESEM) and to analyse the significance of differences in tubular diameter, and the t-test was used. MTT-reaction was used to analyse cell viability, and nonparametric Kruskal-Wallis and Mann-Whitney post hoc tests were used to analyse the data. Immunofluorescent staining of dentine sialoprotein (DSP), aquaporin-4 (AQP4) and matrix metalloproteinase-20 (MMP-20) and quantitative PCR (qPCR) of dentine sialophosphoprotein (DSPP) were used to confirm the odontoblastic nature of the cells. MTT-reaction and FESEM demonstrated collagenase I/hyaluronidase resulted in more effective detachment and higher viability than collagenase I alone. Hyaluronidase alone was not able to detach odontoblasts. Immunofluorescence revealed the typical odontoblastic-morphology with one process, and DSP, AQP4 and MMP-20 were detected. Quantitative PCR of DSPP confirmed that the isolated cells expressed this odontoblast-specific gene. The isolation of viable human odontoblasts was successful. The cells demonstrated morphology typical for odontoblasts and expressed characteristic odontoblast-type genes and proteins. This method will enable new approaches, such as apoptosis analysis, for studies using fully differentiated odontoblasts. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  14. [Pollen morphology of species of genus Senna (Fabales: Fabaceae) in Southeast Ibera, Corrientes, Argentina].

    Science.gov (United States)

    Fernandez-Pacella, Lionel

    2014-06-01

    The system of Ibera lake and marshes in the Province of Corrientes, covers an area of approximately 12 000km2, and is considered one of the most important wetlands in Latin America. Given the wide diversity of tropical communities in this area, it is important to generate new information about the different species of this ecosystem, through pollen morphology, as lake sediments favor the pollen grains conservation. With the aim to promote future research on systematics, vegetation history and melissopalynology of this region, this study attempted to describe the pollen morphology of the well represented genus Senna. For this, we conducted 5-8 days collection trips in Southeast Ibera, on a monthly basis between 2009 and 2011. Based on the plants collected, the literature review and databases from the herbarium of the Botanical Institute of Northeast Argentina, we developed a list of species for the Province of Corrientes. For the pollen morphology, we manually took at least three flower buds per flower in the sampled sites, and for those species not sampled in the field, samples were obtained from the IBONE herbarium. Palynological material preparation was carried out by a modified technique of Erdtman acetolysis. The palynological descriptions considered the polar and equatorial diameter, exine thickness, openings and sculptural elements. Our results showed that Senna genus is euripalynic, composed of 3-colporate pollen grains, small to medium size, radiosymmetric, isopolar, oblates-spheroidals to prolates, subcircular field, subtriangular to triangular and long colpis. We described for the first time, the pollen morphology of 17 species of the genus Senna for this area, and recognized two groups considering endoapertures: lalongates and circular. The list of species belonging to the genus Senna presented here could be considered in restoration and recovery plans. A major constraint for the correct interpretation of the environmental changes impacts in vegetation

  15. 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

  16. Pollen-projektiga Rootsis / Lembit Jakobson

    Index Scriptorium Estoniae

    Jakobson, Lembit

    2009-01-01

    Avastusõppe projektist "Pollen" Eesti (2006-2009) mille eesmärk on kõiki lapsi kaasav uurimisõpe. Kevadisel koolivaheajal tutvus kümmekond Eesti õpetajat uurimisõppega Stockholmi kahes algkoolis

  17. Evolutionarily conserved phenylpropanoid pattern on angiosperm pollen.

    Science.gov (United States)

    Fellenberg, Christin; Vogt, Thomas

    2015-04-01

    The male gametophyte of higher plants appears as a solid box containing the essentials to transmit genetic material to the next generation. These consist of haploid generative cells that are required for reproduction, and an invasive vegetative cell producing the pollen tube, both mechanically protected by a rigid polymer, the pollen wall, and surrounded by a hydrophobic pollen coat. This coat mediates the direct contact to the biotic and abiotic environments. It contains a mixture of compounds required not only for fertilization but also for protection against biotic and abiotic stressors. Among its metabolites, the structural characteristics of two types of phenylpropanoids, hydroxycinnamic acid amides and flavonol glycosides, are highly conserved in Angiosperm pollen. Structural and functional aspects of these compounds will be discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Intraspecific variation in pollen viability, germination and ...

    African Journals Online (AJOL)

    Oleaceae) cultivars 'Koroneiki', 'Mastoidis' and 'Kalamata' was studied with scanning electron microscopy to identify genotype- distinguishing characters that could be employed for morphological cultivar discrimination. Pollen viability and germination ...

  19. Pollen movement between native maize Yucatán and maintenance of genetic diversity

    Directory of Open Access Journals (Sweden)

    Jaime Canul Ku

    2012-09-01

    Full Text Available In Yucatan, Mexico, the cultivation of different native maize populations in the system milpa, promote the interchange of pollen. To evaluate the relationship between the flow of pollen and the dynamics of genetic diversity in 2005 and 2006, a white kernel population and another yellow, both of the Xmejen-nal and Xnuc-nal types, were grown associated with squash. The yellow kernel variety was planted surrounded by the white kernel variety, 540 ears were harvested in 8 directions, from the periphery to the center, and the percentage of yellow grain in the white variety was used as indicator of out crossing rate. For each direction, regression analysis was performed between distance and yellow kernel percentage. The largest out crossing rates in Xmejen-nal (44 % and Xnuc-nal (42 % were obtained in the direction northeast-southwest in 2005; and indirection southeast-northwest in Xmejen-nal (37 % and Xnuc-nal (41 % in 2006. Both direction and intensity of dominant wind determined trajectories of pollen, and the out crossing rate was reduced with the distance to the source of pollen. Genetic interchange is promoted by management and genotype distribution in both time and space, and gene flow among populations promotes intrapopulation diversity.

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Lack of phosphoserine phosphatase activity alters pollen and tapetum development in Arabidopsis thaliana.

    Science.gov (United States)

    Flores-Tornero, M; Anoman, A D; Rosa-Téllez, S; Ros, R

    2015-06-01

    Formation of mature pollen grain, an essential process for the reproduction of higher plants, is affected in lines that are deficient in the enzymes of the phosphorylated pathway of serine biosynthesis (PPSB). Mutants of phosphoserine phosphatase (PSP), the enzyme that catalyses the last step of PPSB, are embryo-lethal. When they are complemented with a construct carrying PSP1 cDNA under the control of the 35S promoter (psp1.1 35S:PSP1), which is poorly expressed in anther tissues, plants display a wild-type phenotype, but are male-sterile. The pollen from the psp1.1 35S:PSP1 lines are shrunken and unviable. Here we report the morphological alterations that appear in the psp1.1 35S:PSP1 lines during microspore development. We show that the pollen wall from these lines presents a normal exine layer, but a shrunken and collapsed shape. Lack of PSP activity also affects oil bodies formation in the tapetosomes of tapetal cells which, in turn, may influence microspore pollen coat formation. All these results highlight the important role of the PPSB in the normal development of microspores in Arabidopsis thaliana. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. Bee Pollen: Chemical Composition and Therapeutic Application

    OpenAIRE

    Katarzyna Komosinska-Vassev; Pawel Olczyk; Justyna Kaźmierczak; Lukasz Mencner; Krystyna Olczyk

    2015-01-01

    Bee pollen is a valuable apitherapeutic product greatly appreciated by the natural medicine because of its potential medical and nutritional applications. It demonstrates a series of actions such as antifungal, antimicrobial, antiviral, anti-inflammatory, hepatoprotective, anticancer immunostimulating, and local analgesic. Its radical scavenging potential has also been reported. Beneficial properties of bee pollen and the validity for their therapeutic use in various pathological condition ha...

  3. Ragweed (Ambrosia) pollen source inventory for Austria.

    Science.gov (United States)

    Karrer, G; Skjøth, C A; Šikoparija, B; Smith, M; Berger, U; Essl, F

    2015-08-01

    This study improves the spatial coverage of top-down Ambrosia pollen source inventories for Europe by expanding the methodology to Austria, a country that is challenging in terms of topography and the distribution of ragweed plants. The inventory combines annual ragweed pollen counts from 19 pollen-monitoring stations in Austria (2004-2013), 657 geographical observations of Ambrosia plants, a Digital Elevation Model (DEM), local knowledge of ragweed ecology and CORINE land cover information from the source area. The highest mean annual ragweed pollen concentrations were generally recorded in the East of Austria where the highest densities of possible growth habitats for Ambrosia were situated. Approximately 99% of all observations of Ambrosia populations were below 745m. The European infection level varies from 0.1% at Freistadt in Northern Austria to 12.8% at Rosalia in Eastern Austria. More top-down Ambrosia pollen source inventories are required for other parts of Europe. A method for constructing top-down pollen source inventories for invasive ragweed plants in Austria, a country that is challenging in terms of topography and ragweed distribution. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

  4. Pollen-related allergy in Europe.

    Science.gov (United States)

    D'Amato, G; Spieksma, F T; Liccardi, G; Jäger, S; Russo, M; Kontou-Fili, K; Nikkels, H; Wüthrich, B; Bonini, S

    1998-06-01

    The increasing mobility of Europeans for business and leisure has led to a need for reliable information about exposure to seasonal airborne allergens during travel abroad. Over the last 10 years or so, aeropalynologic and allergologic studies have progressed to meet this need, and extensive international networks now provide regular pollen and hay-fever forecasts. Europe is a geographically complex continent with a widely diverse climate and a wide spectrum of vegetation. Consequently, pollen calendars differ from one area to another; however, on the whole, pollination starts in spring and ends in autumn. Grass pollen is by far the most frequent cause of pollinosis in Europe. In northern Europe, pollen from species of the family Betulaceae is a major cause of the disorder. In contrast, the mild winters and dry summers of Mediterranean areas favor the production of pollen types that are rarely found in central and northern areas of the continent (e.g., the genera Parietaria, Olea, and Cupressus). Clinical and aerobiologic studies show that the pollen map of Europe is changing also as a result of cultural factors (e.g., importation of plants for urban parklands) and greater international travel (e.g., the expansion of the ragweed genus Ambrosia in France, northern Italy, Austria, and Hungary). Studies on allergen-carrying paucimicronic or submicronic airborne particles, which penetrate deep into the lung, are having a relevant impact on our understanding of pollinosis and its distribution throughout Europe.

  5. 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. PMID:23940803