Rozprawy doktorskie na temat „Pollen”

Orientador: Simone de Pádua Teixeira
Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia
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Resumo: Dentre os diversos tipos de agrupamento polínico, encontrados em 42 famílias de angiospermas, as políades são de interesse especial, pois são registradas para apenas quatro destas famílias e sua ocorrência pode ser associada a uma redução no número de grãos de pólen por antera em uma espécie. Em Leguminosae, a maior em número de espécies e a mais amplamente distribuída dentre as quatro famílias com políades, essas estruturas ocorrem na subfamília Mimosoideae. Este trabalho apresenta dados sobre a origem, o desenvolvimento e a diversidade morfológica das políades, em nível estrutural e ultraestrutural (Capítulo 1); sobre a origem do adesivo polínico em Calliandra brevipes, substância encontrada tipicamente em políades de espécies do gênero; além de dados sobre a origem e desenvolvimento da políade nesta espécie (Capítulo 2, já publicado); a morfologia e fertilidade polínica em espécies poliembriônicas de Inga (Capítulo 3); e um estudo aprofundado da morfologia incomum das políades em Parkia, em nível estrutural e ultraestrutural (Capítulo 4). As políades são estruturas peculiares e ainda muito pouco estudadas, e o presente trabalho vem prover dados essenciais para a compreensão da origem e morfologia destas estruturas, e de sua funcionalidade na reprodução de espécies da subfamília Mimosoideae em Leguminosae. Para um entendimento mais completo acerca da função, valor adaptativo e seleção dessas estruturas, com ocorrência tão restrita a determinados grupos de plantas, estudos acerca da fisiologia do pólen, interação pólen-pistilo e de viabilidade de embriões formados após a fertilização dos óvulos, são requeridos
Abstract: Among all different types of pollen aggregation, reported for 42 angiosperm families, polyads are of great interest, because they are reported for only four of these families and it is associated to a reduction on number of pollen grains per anther in a species. Among those four families, Leguminosae stands out because it is the most species-rich family and widely spread. In Leguminosae, polyads often occur in the subfamily Mimosoideae. This study highlighted new information on the origin, development and morphological diversity of the polyads, employing anatomic and ultrastructural analyses (Chapter 1); origin of pollen adhesive in Calliandra brevipes, sticky substance tipically found in Calliandra polyads, in addition to data on polyad origin and development (Chapter 2, already published); polyad morphology and fertility in polyembrionic species of Inga (Chapter 3); and a meticulous analysis of the peculiar morphology of Parkia polyads (Chapter 4). Polyads are peculiar and still not well-known structures, and this study aims to contribute with essential data for its origin and morphology understanding, and its functionality in the reproduction of species comprised by subfamily Mimosoideae, in Leguminosae. For a more complete understanding on the function, adaptive value and selection of these structures, that are restricted to certain groups of plants, studies are required on the physiology of pollen, pollen-pistil interaction and viability of embryos formed after fertilization of the ovules
Doutorado
Biologia Vegetal
Doutora em Biologia Vegetal

Orientador: Eduardo Custódio Gasparino
Coorientador: Andréa Onofre de Araújo
Banca: Maria Amélia Vitorino da Cruz-Barros
Banca: Vania Gonçalves Lourenço Esteves
Resumo: A subtribo Gloxiniinae é composta por 21 gêneros e cerca de 160 espécies. No Brasil, Gloxiniinae possui 16 espécies, distribuídas em oito gêneros, sendo três endêmicos, geralmente encontrados em afloramentos rochosos de cerrados, campos rupestres ou florestas de galeria. Foram estudados os grãos de pólen de dez espécies brasileiras de Gloxiniinae (Gesneriaceae) pertencentes aos gêneros: Chautemsia A.O.Araujo & V.C.Souza (1 sp.), Gloxinia L'Hér. (3 spp.), Goyazia Taub. (2 spp.), Mandirola Decne. (3 spp.) e Seemannia Regel (1 sp.) com o objetivo de contribuir para a caracterização taxônomica do grupo e uma melhor delimitação dos gêneros e/ou espécies, com enfoque para as populações do complexo Mandirola-Goyazia, pois os dois gêneros e as espécies incluídas nesse complexo não aparecem bem delimitados em estudos taxonômicos e trabalhos de filogenia, e essa dificuldade pode ser explicada por apresentarem distribuição simpátrica, morfologia floral e fenologia muito semelhantes. Os grãos de pólen foram acetolisados, medidos, fotografados em microscópia óptica, microscopia eletrônica de varredura e transmissão e descritos qualitativamente. Os dados quantitativos foram analisados através de estatísticas descritiva e multivariada. Para as espécies brasileiras de Gloxiniinae analisadas, foram observadas variações entre os grãos de pólen principalmente quanto ao âmbito, forma, comprimento, largura e extremidades dos colpos, presença ou não de margem, tipo de endoabertura e tipo de orname... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Gloxiniinae have 21 genera and about 160 species. In Brazil, Gloxiniinae has 16 species, distributed in eight genera, three of which are endemic, generally found in rock outcrops of cerrado, rupestrian fields or gallery forests. We studied the pollen grains of ten Brazilian Gloxiniinae (Gesneriaceae) belonging to the genera: Chautemsia A.O.Araujo & V.C.Souza (1 sp.), Gloxinia L'Hér. (3 spp.), Goyazia Taub. (2 spp.), Mandirola Decne. (3 spp.) and Seemannia Regel (1 sp.) with the aim of contributing to the taxonomic characterization of the group and a better delimitation of the genera and/or species, focusing on the Mandirola-Goyazia complex populations. The species of this complex are not well delimited in taxonomic studies and phylogeny works, and this difficulty can be explained by the sympatric distribution, and the floral morphology and phenology very similar. The pollen grains were acetolysed, measured, photographed under light microscopy, scanning and transmission electron microscopy and described qualitatively. The quantitative data were analyzed by descriptive and multivariate statistics. We observed for the Brazilian Gloxiniinae species variations on the amb, shape, length and width colpi, colpi end, margo, endoaperture and ornamentation. For the 36 natural populations of Mandirola and Goyazia, qualitative data such as number and type of apertures, endoaperture, margo, ornamentaion and exine utrastructure are very similar, but we identify differences in amb, shape, le... (Complete abstract click electronic access below)
Mestre

Estudiar els productes d’ Apis mellifera derivats dels recursos botànics (mel, melat, pol·len i pròpoli), és útil per a caracteritzar i posar en valor els productes de l’ abella d’ un territori i per a comprendre les interaccions planta-pol·linitzador. La melisopalinologia té com a objectius la determinació geogràfica i botànica dels productes apícoles, basant-se en la presencia de tipus pol·línics (TP). El primer objectiu de la present tesi ha estat determinar quines plantes són útils per a A. mellifera a Catalunya, a través d’una revisió bibliogràfica i d’observacions in situ s’ha elaborat una llista de 424 tàxons útils, de 114 famílies. Per a l’estudi melissopalinològic de les 51 mels i els 26 pròpolis analitzats en aquesta tesi es va elaborar una palinoteca de referència en base als TP dels tàxons d’interès apícola de Catalunya. Com a resultat de l’anàlisi melissopalinològica, s’ha determinat l’origen geogràfic i botànic de les mels i els pròpolis, i s’han identificat 156 TP de 74 famílies. A través de l’anàlisi de l’espectre pol·línic de les mels, s’ han tipificat diferents tipus de mels, tant multiflorals com monoflorals, de diferents zones geogràfiques i de diferents anys. A més, l’anàlisi estadística ha mostrat l’existència de diferències significatives entre les mels urbanes i la resta de mels. A les mels no urbanes s’han identificat 131 TP. Tot i que els més freqüents són autòctons (Brassicaceae T., Coronilla T., Quercus perennifolio, Rubus T., Salix sp. y Ulex T.), l’aparició d’espècies invasores (com Ailanthus altissima) mostra la seva utilitat com a recurs apícola, i indica que cal tenir en compte a aquest tipus d’espècies a l’hora d’establir l’origen geogràfic i botànic de les mels d’ un territori. També, destacar l’elevada presència i percentatges de TP com Cistus monspeliensis, Hedera helix, Rhamnus sp. i Salix sp., que podrien servir com a indicadors per a la tipificació geogràfica de mels de Catalunya. Per altra banda, es veu reflectida la importància per a A. mellifera dels ecosistemes de tipus matollar i herbaci, així com, que les abelles de ruscs situats a la perifèria de nuclis urbans s’ endinsen a les ciutats per alimentar-se, mentres que les de ruscs urbans poden allunyar-se de la ciutat. En les mels urbanes, procedents de Barcelona i Viladecans, s’han identificat 89 TP, tant ornamentals com silvestres. L’ aparició dels TP Cercis, Phoenix, Schinus, Agave, Ailanthus altissima, Eucalyptus sp. i Sophora sp., fan palesa la marcada influència de tàxons exòtics. D’altra banda, l’aparició d’un alt percentatge de tàxons arvenses indica que A. mellifera els visita, i reflecteix la importància de minimitzar l’ús d’ herbicides, i la d’adequar sòls amb aquest tipus de vegetació en ciutats. Referent als pròpolis, l’espectre pol·línic reflecteix la variabilitat de paisatges i vegetació de Catalunya. Es van analitzar 26 mostres que van permetre la determinació de 135 TP, dels quals els més freqüents van ser Asparagus sp., Brassicaceae T., Hedera helix, Quercus perennifoli y Rosmarinus officinalis. A més, les diferències observades en els pròpolis de Catalunya en funció del seu color i textura, podrien estar relacionades amb l’origen botànic de les resines procedents de Pinus sp., Quercus sp, Castanea sativa i Populus sp. Comparant les mostres de pròpolis i mel d’un mateix lloc, s’observa que la riquesa i la diversitat pol·línica és major en pròpolis que en mels i, encara que hi ha relació entre els seus espectres pol·línics, els tipus pol·línics difereixen en un 64,4%. Per això, l’estudi de l’espectre pol·línic de tots dos productes aporta una informació més precisa sobre la vegetació circumdant dels abellars, complementant i millorant la determinació de l’origen geogràfic de mels, sobretot, d’ aquelles amb una diversitat pol·línica molt baixa.
Estudiar los productos de Apis mellifera derivados de recursos botánicos (miel, mielato, polen y propóleo), es útil para caracterizar y valorar los productos de la abeja de un territorio y para comprender las interacciones planta-polinizador. La melisopalinología tiene como objetivos la determinación geográfica y botánica de los productos apícolas, basándose en la presencia de tipos polínicos (TP). El primer objetivo de la presente tesis ha sido determinar qué plantas son útiles para A. mellifera en Catalunya, a través de una revisión bibliográfica y de observaciones in situ se ha elaborado una relación de 424 taxones útiles, de 114 familias Para el estudio melisopalinológico de las 51 mieles y 26 propóleos analizados en esta tesis se elaboró una palinoteca de referencia en base a los TP de los taxones de interés apícola de Catalunya. Como resultado del análisis melisopalinológico, se ha determinado el origen geográfico y botánico de mieles y propóleos, y se han identificado 156 TP de 74 familias. A través del análisis del espectro polínico de las mieles, se han tipificado distintos tipos de mieles, tanto multiflorales como monoflorales, de diferentes zonas geográficas y distintos años. Además, el análisis estadístico ha mostrado la existencia de diferencias significativas entre las mieles urbanas y el resto de mieles. En las mieles no urbanas, se han identificado 131 TP. Aunque los más frecuentes son autóctonos (Brassicaceae T., Coronilla T., Quercus perennifolio, Rubus T., Salix sp. y Ulex T.) la aparición de especies invasoras (como Ailanthus altissima) muestra su utilidad como recurso apícola, e indica que hay que tener en cuenta a este tipo de especies al establecer el origen geográfico y botánico de las mieles de un territorio. También, destacar la elevada presencia y porcentajes de TP como Cistus monspeliensis, Hedera helix, Rhamnus sp. y Salix sp., que podrían servir como indicadores para la tipificación geográfica de mieles de Catalunya. Por otro lado, se ve reflejada la importancia para A. mellifera de los ecosistemas de tipo matorral y herbáceo, así como que las abejas de la periferia de núcleos urbanos se adentran en las ciudades para alimentarse, mientras que las de colmenas urbanas pueden alejarse de la ciudad. En las mieles urbanas, de Barcelona y Viladecans, se han identificado 89 TP, tanto ornamentales como silvestres. La aparición de los TP Cercis, Phoenix, Schinus, Agave, Ailanthus altissima, Eucalyptus sp. y Sophora sp., hacen patente la marcada influencia taxones exóticos. Por otro lado, la aparición de un alto porcentaje de taxones arvenses indica que A. mellifera los visita, y refleja la importancia de minimizar el uso de herbicidas, y la de adecuar suelos con este tipo de vegetación en ciudades. Referente a los propóleos, el espectro polínico refleja la variabilidad de paisajes y vegetación de Catalunya. Se analizaron 26 muestras que permitieron la determinación de 135 TP, de los cuales los más frecuentes fueron Asparagus sp., Brassicaceae T., Hedera helix, Quercus perennifolio y Rosmarinus officinalis. Además, las diferencias observadas en los propóleos de Catalunya en función de su color y textura, podrían estar relacionadas con el origen botánico de las resinas procedentes de Pinus sp., Quercus sp, Castanea sativa y Populus sp. Comparando las muestras de propóleo y miel de un mismo lugar, se observa que la riqueza y la diversidad polínica es mayor en propóleos que en mieles y, aunque existe relación entre sus espectros polínicos difieren en un 64.4%. Por ello, el estudio del espectro polínico de ambos productos aporta una información más precisa sobre la vegetación circundante de los colmenares, complementando y mejorando la determinación del origen geográfico de mieles, sobre todo, aquellas con una diversidad polínica muy baja.
The study of Apis mellifera products derived from botanical resources (honey, honeydew honey, corbicular pollen, and propolis) is useful to assess the quality of bee products in a territory and to better understand plant-pollinator interactions. The main objectives of Melissopalynology are the determination of the geographical and botanical origin of bee products, based on the presence of nectariferous and/or polliniferous pollen types (PT). The first objective of this thesis was to determine which plants are useful to A. mellifera in Catalonia, through a literature review as well as on-site observations has been obtained a list of 424 useful taxa from 114 families. For the melissopalynological study of the 51 honeys and 26 propolis analyzed in this thesis, a reference palinotheque was elaborated based on the list of the pollen types (PT) from the taxa with beekeeping interest in Catalonia. As a result of the melissopalynological analysis, the geographical and botanical origin of the honeys and propolis have been determined, and 156 pollen types of 74 families identified. Through the analysis of the pollen spectrum of honeys, different types of honey have been typified, both multifloral and monofloral, from different geographical areas and from different years. In addition, the statistical analysis has demonstrated the existence of significant differences between urban honey and other honey. In non-urban honeys 131 PT were identified. Although the most frequent are native (Brassicaceae T., Coronilla T., Quercus deciduous, Rubus T., Salix sp., and Ulex T.), the appearance of invasive species (such as Ailanthus altissima) shows it’s as apicultural resource, and indicates that this type of species must be taken into account when establishing the geographical and botanical origin of honeys from a given territory. Also, the high presence and percentages of PT such as Cistus monspeliensis, Hedera helix, Rhamnus sp. and Salix sp. could serve as indicators for the geographical classification of honey from Catalonia. On the other side, it has been reflected the importance for A. mellifera of shrubland and herbaceous ecosystems, as well as that honeybees located on the periphery of urban centers enter the cities to feed, and that bees from urban beehives can move outside the city. In the urban honeys from Barcelona and Viladecans, 89 PT were identified, both ornamental and wild. The presence of Cercis, Phoenix, Schinus, Agave, Ailanthus altissima, Eucalyptus sp. and Sophora sp. reveal the marked influence of exotic taxa. On the other hand, the appearance of a high percentage of PT of weed taxa indicates that A. mellifera visits them, and reflects the importance of minimizing the use of herbicides and of implementing soils with this type of vegetation in cities. Regarding propolis, the pollen spectrum reflects the variability of landscapes and vegetation in Catalonia. 26 samples were analyzed, and 135 PT determined, of which the most frequent being Asparagus sp., Brassicaceae T., Hedera helix, Quercus deciduous and Rosmarinus officinalis. Furthermore, the differences observed in the propolis of Catalonia, on the basis of their color and texture, could be related to the botanical origin of the resins from Pinus sp., Quercus sp, Castanea sativa, and Populus sp. Comparing the samples of propolis and honey from the same place, it was observed that the richness and diversity of pollen is greater in propolis than in honey and, although there is a relationship between their pollen spectra, the pollen types differ by 64.4%. Therefore, the study of the pollen spectrum of both products provides more precise information about the surrounding vegetation of the beehives, complementing and improving the determination of the geographical origin of honey, especially those with a very low pollen diversity.

Orientador: Eduardo Custódio Gasparino
Coorientador: Alain Chautems
Banca: Cynthia Fernandes Pinto da Luz
Banca: Claudia Barbieri Ferreira Mendonça
Resumo: Palinotaxonomia em Espécies Brasileiras do complexo Codonanthe- Codonanthopsis (Gesneriaceae) e gêneros relacionados - Será estudada a morfologia dos grãos de pólen de 25 espécies brasileiras dos gêneros Codonanthe (Mart.) Hanst., Codonanthopsis Mansf., Nematanthus Schrad. e Paradrymonia Hanst., distribuídas em sua maioria em dois biomas, Amazônia e Mata Atlântica. O objetivo deste trabalho é contribuir com a caracterização palinológica, em busca de dados morfológicos que possam melhor definir as espécies estudadas, auxiliando dessa forma, o melhor entendimento das relações de parentesco entre os gêneros e na compreensão da distinção florística entre os respectivos biomas. Os grãos de pólen foram acetolisados, medidos e fotografados sob microscopia de luz, microscopia eletrônica de varredura e transmissão. Os dados quantitativos receberam tratamento estatístico e descritivos, adequado ao tamanho das amostras e foram submetidos a uma análise multivariada identificando caracteres polínicos importantes na distinção das espécies. Os resultados obtidos com este estudo confirma a diversidade polínica para a Gesneriaceae, como já relatado na literatura. Os caracteres que mais contribuíram para distinção entre os gêneros, que auxiliarão trabalhos evolutivos futuros, foram a ornamentação dos grãos de pólen e as características de abertura. As espécies de Codonanthe e Codonanthopsis apresentam ornamentação predominantemente microrreticulada, diferente de Paradrymonia e Nematanthus com ... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Palynotaxonomy in Brazilian species of Codonanthe-Codonanthopsis complex (Gesneriaceae) and related genera - The morphology of the pollen grains of 25 Brazilian species Codonanthe (Mart.) Hanst., Codonanthopsis Mansf., Nematanthus Schrad. and Paradrymonia Hanst., distributed mostly in two biomes, the Amazon rainforest and Atlantic Forest. The objective of this study is to contribute with the palynological characterization, in search of morphological data that can better define the studied species, a, thus helping, the better understanding of kinship relations between the genera and in the understanding of the floristic distinction between the respective biomes. The pollen grains were acetolysed, measured and photographed under light microscopy, scanning electron microscopy and transmission. The quantitative data were submitted to a multivariate analysis, identifying pollen characters that were important for the species classification. The results obtained with this study confirm the pollen diversity for the Gesneriaceae, as already reported in the literature. The characters that contributed the most to distinguish between the genera, which will help future evolutionary works, were the ornamentation of the pollen grains and the aperture characteristics. The species of Codonanthe and Codonanthopsis present predominantly microreticulate ornamentation, different from Paradrymonia and Nematanthus with pollen grains mostly reticulate. For Paradrymonia, there were no variations in the ornamentation of the apocolpium and mesocolpium of its pollen grains; in Nematanthus we can see a variation in the pattern of ornamentation between the apocolpium and mesocolpium regions (from microreticulate, reticulate to foveolate). Pollen grains with colpate aperture were described for Codonanthopsis, and for Paradrymonia pollen grains colp... (Complete abstract click electronic access below)
Mestre

Thesis (M.S.)--University of California, San Diego, 2008.
Title from first page of PDF file (viewed July 25, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 28-29).

Current predictions of pollen levels rely strictly on historical Averages, regardless of environmental factors that might affect the timing of pollen release by different plants. For this thesis, the goal was to develop a statistical model that will accurately forecast pollen levels by correlating those daily counts to atmospheric and meteorological conditions. This project used ARIMA modeling on IBM’s SPSS Statistics 24 of daily pollen count information for multiple allergenic pollens in the Sarasota County, Florida area over a 11-year period. The pollen species in question for this project are oak and cypress trees, grass, and ragweed pollens; and Alternaria and Cladosporium mold spores. The total pollen counts for weeds, grass, trees, and overall total are also included in the 11 years of data. The atmospheric variables used to predict pollen levels are high temperature, low temperature, average temperature, precipitation, humidity, wind direction, and wind speed for daily observations over the 11-year period. Results for these models showed that maximum temperature, precipitation, humidity, and wind direction were the driving predictors behind the pollen counts in Sarasota, Florida. The analysis of the pollination periods also showed that there were phenological changes according to the specific species. The models and phenological changes are specific to the Sarasota, Florida area, and would serve as a framework for studying other pollination regions.

Thesis (Ph. D.)--University of Missouri-Columbia, 2008.
The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 4, 2009) Vita. Includes bibliographical references.

Identification and mapping of genes expressed in pollen and during pollen-pistil interaction in maize The subject of my Ph.D. work was the study of the genomic organization of genes involved in pollen development and function. The first topic was the construction of a functional pollen map of genetic factors controlling the above mentioned processes in maize. A complete panel of oat maize addition lines was exploited to map 1000 maize pollen EST contigs. This large scale mapping revealed that pollen genes are distributed among the ten maize chromosomes and provided evidence for duplication of many genes. Then a positional cloning approach was performed, in order to isolate and characterize Gametophyte Factor 1, a gene responsible of cross-sterility in maize. This gene was previously mapped on chromosome 4, bin 4.02. In order to generate a high-resolution map of the region, we generated a large segregating population of 3000 individuals, phenotypically and molecularly characterized. We placed additional molecular markers obtained from maize genomic and BAC-ends sequences derived from clones sequencing and we created a high-resolution map of the Ga1 region, delimiting a genetic region of 1.03 cM encompassing Ga1. The analysis of the public physical map has led to the identification of a single BAC contig. At the same time, the exploitation of rice-maize synteny has been pursued to identify a region on rice chromosome 11, syntenic to the maize interval flanking Ga1.

La fertilité du pollen de mil (Pennisetum typhoïdes) a été étudiée à l’état frais et après conservation. Plusieurs tests de fertilité ont été utilisés : le colorant d’ALEXANDER, la coloration au diacétate de fluorescéine, la germination in vivo et le taux de grenaison. A l’exception du premier, les corrélations entre les tests pris deux à deux sont positives et très hautement significatives. Le pollen de mil reste fertile environ 12 jours en conditions ambiantes. De nombreux échantillons ont été stockés à 3-5°C et 26-30%, 52-56% ou 70-75% d’humidité relative. En stockage, la fertilité du pollen peut persister pendant plus d’un an au mieux. La fertilité du pollen peut persister pendant plus d’un an au mieux. La fertilité pollinique est influencée par le génotype et les conditions de croissance de la plante émettrice du pollen, par la méthode de récolte, et par l’hygrométrie de stockage. Les mécanismes de la mort du pollen ont été étudiés d’après les courbes de mortalité pollinique et comparaisons entre les résultats de différents tests de fertilité. L’utilité de la conservation de la fertilité du pollen pour l’amélioration des plantes et pour la gestion des ressources génétiques est discutée
The fertility of the pollen of pearl millet (Pennisetum typhoïdes) was studied fresh and after conservation. Several pollen fertility tests were used: Alexander’s stain, fluorescein diacétate staining, in vivo germination and seed set. Except for the first of these tests, the correlation between pairs of tests was positive and very highly significant. Pearl millet pollen stayed fertile for about 12 days in ambient conditions. Many pollen samples were stored at 3-5°C in 26-30%, 25-56% or 70-75% relative humidity. In storage, at best, pollen fertility persisted for over a year. Pollen fertility was influenced by genotype and the growth conditions of the pollen source plants, by harvesting methods, and by storage hygrometry. The mechanisms underlying pollen mortality were studied by examining death curves and by comparing the results of different fertility tests. The usefulness of the conservation of pollen fertility is discussed in relation to plant improvement and genetic resources management

Co-flowering plants within communities typically share pollinators which can lead to the deposition of pollen grains from varying species onto stigmas; or heterospecific pollen transfer (HPT). It has been shown that HPT can have varying effects on plant reproductive success. These effects can range from an 80% reduction on seed production to no effect. However, to date, there are no studies that have evaluated the causes underlying variability of these effects. We investigated this variability through a greenhouse experiment. Hand-pollinations were conducted with a mix of conspecific and heterospecific pollen and a control (conspecific pollen only). We used six pollen recipient and four species as donors for the heterospecific pollen (5 treatments total) We conducted hand-pollinations on a minimum of 10 plants per species (584 total pollinations). After pollination seed set data was recorded for each treatment and the amount of conspecific and heterospecific pollen on stigmas was recorded. We evaluated if the effects of HPT can be explained by the recipient species, the donor species or the interaction between donor and recipient. The results show high variability in the magnitude of HPT(2-93) but this variability is not a result of donor characteristics or even recipient characteristics but a result of the interactions between donors and recipients (df=20, α=.05, p=0.015). We will further investigate if the interaction can be explained by stigma/pollen size ratio, degree of co-flowering, or phylogenetic distance between donor and recipient species. This study will contribute to advance our understanding of how co-flowering plant communities interact amongst themselves after pollination.

Le pollen des Graminées est l'un des principaux vecteurs d'allergènes. Il contribue à l'apparition des allergies respiratoires comme l'asthme et la rhinite allergique. En contact avec l'eau de pluie ou des polluants atmosphériques, le pollen peut libérer des microparticules (<5 !m) dites granules cytoplasmiques de pollen. À cause de leur taille, ces granules peuvent pénétrer plus profondément dans l'appareil respiratoire que le pollen entier et induire ainsi des réactions allergiques. L'objectif de ce travail est de caractériser l'allergénicité de ces granules selon 3 volets : épidémiologique, expérimental et analytique. Les résultats de l'étude épidémiologique mettent évidence un effet éventuel des granules dans la survenue des allergies respiratoires, et plus particulièrement de l'asthme. Dans la partie expérimentale, les résultats obtenus permettent de montrer que les granules induisent des réactions allergiques, humorales et cellulaires ainsi que des réponses inflammatoires, comparables au pollen entier, chez le rat Brown Norway, le modèle animal d'allergie ici utilisé. Enfin, la partie analytique permet de conclure que l'allergénicité des granules dépend à la fois de leur contenu en allergènes hydrosolubles et non-hydrosolubles.

The eastern Mediterranean area is a region of high archaeological importance, it is also a region where climate has been a force interacting with humans in shaping the landscape and vegetation history. Variations in pollen content and composition in various climate archives (e.g. lake sediments and peat sections) are widely used to reconstruct vegetation changes and human impact in the Quaternary environments. Pollen sampling has been conducted throughout the Peloponnese peninsula but there is a lack of regional synthesis of these locally based studies. The aims of the thesis are partly to show how pollen data may be used in a regional analysis on Late Pleistocene and Holocene vegetation changes, partly to assemble all published pollen data from Peloponnese peninsula in a database. The question formulations are; i) how may a database with pollen dataserve as a basis for interpretations of regional vegetation changes on Peloponnese?, ii) what are the possibilities of using classification of pollen and distinguish between driving factors behind the historic vegetation changes? The constructed database facilitates further research regarding pollen records at Peloponnese. Pollen recordsmay show important patterns in landscape changes during Late Pleistocene and Holocene but using pollen records at a regional scale need comparisons between coring sites which may be troublesome due to different approaches, different species investigated and varied calculation of pollen sum. In order to distinguish between driving forces and actors affecting the vegetation, pollen data may be used both in detail but also in using groups and classifications of the pollen included.

The control of pollen viability and release is of major commercial importance in the development of crops for hybrid seed production and selective breeding. It has been shown that key transcription factors in Arabidopsis particularly MALE STERILITY1 (MS1), are functionally conserved in rice (Li et al., 2011), therefore extending this comparative analysis and controlling fertility in temperate cereals, such as barley, is the long term goal of this project. Although anther and pollen development of barley seems morphologically similar to Arabidopsis, the genes involved and how they are regulated are currently unknown. Arabidopsis MS1 is a tapetum specific transcription factor which is expressed exclusively from the tetrad stage to early microspores release. Identification and accurate staging of barley anther development is essential for expression analysis and functional characterisation of genes involved in pollen development. Therefore, a complete morphological study of barley development was conducted. External characteristics have been described in parallel to anther development in order to predict anther stages by the observation of external stages phenotypic traits. Characterization of the barley orthologue of MS1 (HvMS1) has been conducted. Recently a new grass genome has been released, Brachypodium distachyion. This new resource has been used to aid primers design alongside the rice OsPTC1 sequence, the orthologue of MS1 (Li et al., 2011). Genome sequencing has indicated that the Brachypodium genus is more closely related to wheat and barley than it is to rice, Due to the close relationship between Brachypodium and barley, this new grass has been used as intermediary to identify the OsPTC1 orthologue in barley as well as downstream MS1 targets. A highly similar sequence to OsPTC1 was found in Brachypodium, Bradi4g31760. This new gene, as a result of its similarities to OsPTC1, was considered as its putative orthologue gene in Brachypodium. Therefore, the most conserved areas between OsPTC1-Bradi4g31760 were used for primers design to successfully amplify equivalent gene in barley (HvMS1). The characterization of this barley gene showed a similar expression pattern to the MS1 putative orthologue in Arabidopsis of tapetum specific expression. In addition, RNAi silencing of this gene has revealed that it is essential for the normal development of pollen, with a lack of viable pollen produced in the putative HvMS1 silenced transgenic lines.

Previously published descriptions of the pollen morphology of the Palmae are reviewed and discussed. The earliest macro fossil records for palms are summarised, while a more detailed review is given of the fossil records of palmlike pollen. Selected literature relating to pollen sharing some similarities to palm pollen in other monocotyledonous families are briefly reviewed, and the fossil pollen records for these families are examined. A brief chronological account of earlier systematic treatments of the palms is provided, as well as an outline of the systematic treatment of the family used in the present account. The pollen morphology of 1150 collections, representing 765 species of palms,f rom all but seveno f the currentlyr ecognisedg enera,h asb eene xamýined, as well as dispersedp alm-likef ossil pollen from the middle Eoceneo f the Isle of Wight, and of Java. Iii silit pollen of fossil palm flowers from the Messel oil shales (Germany)a re describedP. ost meiotic tetrad stageh asb eens tudiedf or representatives peciesin all subfamiliese xceptingt he PhytelephantoideaeP.o llen morphologyo f both recenta nd fossil pollen is describedf rom light, scanning electrona nd, selectivelyf rom transmissione lectronm icroscopy,w hile tetrad resultsa re from light and scanninge lectronm icroscopy.F ull detailso f preparation methods,t erminologya nd databaseus sedf or pollen morphological,f ossil and tetrad studies are given. Seventeena perturet ypes,p lus numerouss ubtypesa, nd twelve exine types with numerous subtypes are identified. The aperture types are shown to be broadly separablein to two groupsw hich are associatedw ith either simultaneous (tetrahedralt etrads)o r successive(t etragonalt etrads)m icros porogenessi. In generalt heset wo groups supportp resents ystematico pinion regardingt he subfamilies.S uccessivem eiosisi s dominanti n subfamiliesC alamoideaea nd Nypoideaew hile, with somer are exceptionss, imultaneousm eiosisp redominates in the remainingf our subfamiliesC: oryphoideaeC, eroxyloideaeA, recoideaea nd PhytelephantoideaeP.o llenu ltrastructurei s treatedi n detail only for simple tectate exines where it is important for further definition. Six types and a number of subtypesa re described.T he systematicd istributionso f aperturea nd exine types are summarisedA. trend towardsl arger pollen is noted, with the smallest pollen occurring in the least specialised subfamily, the Coryphoideae, while very large-sized pollen are characteristic of subfamily Phytelephantoideae. Monosulcate, disulcate and zonosulcate pollen are described from fossil material and closest affinities with recent palms suggested. Pollen morphology of recent palms is summarised and discussed, and compared with pollen of selected monocotyledonous families. The bearing of pollen data on recent palm systematics is considered at various levels from subfamily to species. Angiosperm pollen evolution is re-considered and evolutionary pathways for palm pollen aperture types and exine types are suggested. In the light of recent pollen morphology for the family the fossil record of palm pollen is re-evaluated. Some widely accepted affinities are challenged while previously unconsidered affinities are suggested, particularly for the mid- Cretaceous. The need is emphasized for future fossil pollen studies to look critically for pre Late Cretaceous palm-like monosulcates, which would be more informative of the early history of the family than the apparently highly evolved, easily recognisable Spini. -onocolpiles of the Late Cretaceous. Palaeogeography, environment and distribution of fossil records and depositional environment are discussed. Probable evolutionary pathways of pollen morphology, including pollen tetrad data which suggests imultaneousra thert han successivem eiosisa s the plesiomorphics tate,o ffer further evidencet hat the palmsa re indeeda n ancient group, and support the hypothesis that the palms may have originated in South America and Africa (West Gondwana)in the Late Jurassic or early Cretaceous, prior to the complete separation of these continents.

Le pollen des Graminées est l'un des principaux vecteurs d'allergènes. Il contribue à l'apparition des allergies respiratoires comme l'asthme et la rhinite allergique. En contact avec l'eau de pluie ou des polluants atmosphériques, le pollen peut libérer des microparticules (<5 μm) dites granules cytoplasmiques de pollen. À cause de leur taille, ces granules peuvent pénétrer plus profondément dans l'appareil respiratoire que le pollen entier et induire ainsi des réactions allergiques. L'objectif de ce travail est de caractériser l'allergénicité de ces granules selon 3 volets : épidémiologique, expérimental et analytique. Les résultats de l'étude épidémiologique mettent évidence un effet éventuel des granules dans la survenue des allergies respiratoires, et plus particulièrement de l'asthme. Dans la partie expérimentale, les résultats obtenus permettent de montrer que les granules induisent des réactions allergiques, humorales et cellulaires ainsi que des réponses inflammatoires, comparables au pollen entier, chez le rat Brown Norway, le modèle animal d'allergie ici utilisé. Enfin, la partie analytique permet de conclure que l'allergénicité des granules dépend à 1 fois de leur contenu en allergènes hydrosolubles et non-hydrosolubles
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 (<5 μm), granules may penetrate deeper into the lungs than pollen grains and so, can induce stronger allergie responses. The aim of this study was to characterized allergic potential of pollen cytoplasmic granules along 3 axes: epidemiological, experimental and analytical. Results of the epidemiological study involve a possible effect of granules in the onset of allergic reparatory diseases, in particular asthma. In experimental part, the results show that granules induced allergic - both humoral and cellular - and inflammatory responses. These results are compared with whole pollen, on a good animal model of allergy, the Brown Norway rat. Finally, according to the results of the analytical study, both water-soluble and water-insoluble allergens of granules contribute to the allergenicity of these microparticules

Ephedra (Gnetales) is a gymnosperm genus with a long evolutionary history; the first dispersed pollen grains with affinity to the group are known already from the Permian. This thesis focuses on the evolutionary history of the group and different aspects of its pollination mechanisms. Despite the limited number of extant species of the genus (50-60), and a low morphological and genetic divergence among species, there is variation in pollination syndrome in the genus. The prevailing state in Ephedra, and most gymnosperms, is wind pollination. It is therefore surprising that one species, E. foeminea, is insect-pollinated. Together with co-workers I documented the pollination syndromes of E. foeminea and a sympatric species, E. distachya, based on long term field experiments in north-eastern Greece and aerodynamic investigations and calculations. Placing the results into an evolutionary framework reveals that the insect-pollinated species E. foeminea is sister to the remaining (mostly wind-pollinated) genus, and indicates that insect pollination is the ancestral state in the Gnetales. During the course of evolution of the group there has been a shift to wind pollination, which may have played a crucial role for the diversification of the crown group in the Paleogene. Pollination biology is often correlated with the morphology of the pollen such that pollen grains of anemophilous plants are small with a smooth surface, whereas pollen grains of entomophilous plants are larger with an ornamented surface and a covering of pollenkitt. The pollen morphology of Ephedra can be broadly divided into two types: an ancestral type with an unbranched pseudosulcus between each pair of plicae, and a derived type with a branched pseudosulcus between each pair of plicae. Further, the pollen morphology and ultrastructure of the pollen wall in Ephedra are to some degree correlated with the pollination syndrome and capability of long distance dispersal. Pollen of E. foeminea has a denser ultrastructure, as a result a higher settling velocity and is therefore capable of flying shorter distances than does pollen of the anemophilous E. distachya, and other investigated anemophilous species that show a more spacious ultrastructure of the pollen grain. These results can be useful in the reconstruction of the pollination mechanism of extinct taxa of the Ephedra-lineage in the future.

This study focuses on saving multi-million-dollar losses caused by rust diseases of wheat. Genetic diversity assessment in a panel of landraces through phenotypic assays and genotyping with markers linked with known adult plant stem rust resistance genes revealed the presence of Sr55 and Sr58 individually and in combination. Sr2 and Sr57 were present in two and five landraces, respectively. Genotypes carrying putatively new sources for adult plant stem rust resistance were identified. Two consistent QTL; QSr.sun-5BL and QSr.sun- 7BL were identified from a pre-Green Revolution winter wheat landrace Aus27959. Based on physical position of QSr.sun-5BL in Chinese Spring (NRG v1.0), this QTL was shown to be different from the chromosome 5B located stem rust resistance gene Sr56. Hence, this QTL represents a new source for stem rust resistance. The uniqueness of QSr.sun-7BL remains to be determined. Genetic analysis of stripe rust resistance at the 4th leaf stage in Australian wheat cultivar Axe indicated the involvement of a single locus. The underlying locus was mapped on chromosome 7A and named as Yr75. Fine mapping of the Yr75-carrying genomic region identified close linkage of kompetitive allele specific PCR (KASP) markers sunKASP_427 (0.4 cM) and sunKASP_430 (0.3 cM). These flanking markers are 1.24 Mb (physical disctance; IWGSC RefSeq v1.0 genome assembly) apart. Scanning electron microscopic (SEM) observations showed significant variation in pollen size. In vitro pollen germination medium was standardized to achieve 70-80% germination in 30-40 minutes. Pollen viability study among a set of 12 wheat genotypes showed the viability of wheat pollen up to five hours under controlled conditions. These experiments demonstrated the conditions for initiating pollen mediated gene editing in wheat.

This thesis aims to understand the mechanisms involved in pollen transport and deposition in cave environments and the influence of different factors on the composition of the pollen assemblage, with special reference to the problem of the Neanderthal ‘Flower burial’ at Shanidar Cave, Kurdish Iraq. Limited systematic taphonomic work has been done in cave environments, with most of the studies on an ad hoc basis. However, the number of interconnected factors acting on pollen transport, deposition and accumulation in this kind of environments implies that models used for open-air sites are inadequate and demonstrates the need for further taphonomic studies. Surface samples from six caves located in the Zagros Mountains of Kurdish Iraq were collected along front-back transects and outside for comparison in order to evaluate the distribution of anemophilous and entomophilous taxa in relation to the sample location. Additional surface samples were collected from Shanidar Cave along a side to side and perimeter transects to better evaluate the pollen distribution. Water, airfall and animal dung samples were also collected to investigate the influence of those factors in pollen transport. Finally, stratigraphic samples collected during the excavation at the site were analysed for pollen and for particle size distribution. Results show that simple sac-like caves with little or no influence of factors such as water, humans and animals are characterised by broadly predictable patterns of pollen distribution with a positive correlation between anemophilous pollen and vicinity to the cave entrance and entomophilous pollen and distance from the cave entrance. Caves with active biotic vectors and/or more complex geomorphology show instead more irregular patterns. Cave SLS203 presents an inverse anemophilous/entomophilous distribution that is likely to be related to its geomorphological complexity (a second entrance at the back of the cave influencing the air circulation) and to the presence of animals. Shanidar Cave presents a very irregular distribution which is likely to reflect a combination of factors such as the mixing of surface sediments caused by the tourists visiting the site, the pollen transported by animals and that moved by the wind. Other factors, such as water input and cave entrance flora, seem not to play an important role in ii Kurdish Iraq, while they appear to strongly influence pollen distribution in caves elsewhere (e.g. Coles, 1988; Simpson, 2006). The stratigraphic samples were sterile or contained few pollen grains, probably because the aeolian nature of the sediments, deposited during stadials, with low pollen deposition and high sediment influx. Finally, clumps of pollen of both anemophilous and entomophilous taxa have been found for different taxa in all the caves. Leroi-Gourhan (1975) had suggested that similar clumps found in the vicinity of Shanidar IV remains were evidence for burial with flowers but their presence on the surface demonstrates that they can occur naturally and that other explanations should be considered. Moreover, the high amount of Lactuceae and the presence of older pollen grains in her samples suggest a strong taphonomic imprint not necessarily resulting from anthropogenic activity.

The researches of this thesis focused on the pollen rain on the city of Florence (Italy) studied through the use of different methods of analysis: gravimetric (moss cushions) and volumetric traps (Hirst type samplers). The comparison between the two types of pollen sampling allowed to evaluate the accumulation time of pollen grains in the mosses, the quantitative/qualitative differences among the pollen data and the local and extra-local contribution to the pollen amounts, focusing in particular on cypress trees and the allergenic component of the pollen rain. Moss cushions operate a continuous sampling over time, collecting pollen grains for a time interval greater than five years. The overall composition of the pollen rain is similar in both the sampling types, with noticeable differences from a quantitative point of view. The greatest local contribution is due to the arboreal component which displayed a strong proximity effect to the pollen values recorded at ground level. This is especially true for the most widespread ornamental trees, although the data interpolations show that pollen accumulation is uneven across the city. Regarding the extra-local contribution, the plants growing on the hills north of the city provide the greatest pollen amount in Florence, especially when the wind blows at a high intensity. The detailed investigation on Cupressaceae pollen grains allowed to estimate their accumulation rate at ground level and the proximity effects of these plants on the pollen record. Cypress tree pollen is the main component of the allergenic pollen rain, although herbaceous plants pollen concentrations are high over the years.
Le ricerche che compongono questa tesi hanno come argomento la pioggia pollinica nella città di Firenze studiata mediante differenti metodologie di analisi: trappole gravimetriche (cuscinetti di muschio) e volumetriche (campionatori di tipo Hirst). Attraverso queste due tipologie di campionamento è stato possibile stimare il tempo di accumulo dei granuli pollinici nei muschi, le differenze quantitative/qualitative ed il contributo locale ed extra-locale sulle quantità di polline, con particolare riferimento ai cipressi ed alla componente allergenica della pioggia pollinica. I cuscinetti di muschio raccolgono la pioggia pollinica in maniera continuativa, accumulando granuli per un intervallo maggiore di cinque anni. La composizione della pioggia pollinica è relativamente simile nelle due metodologie di campionamento, mentre si osservano differenze notevoli da un punto di vista quantitativo. Il maggior contributo locale è dovuto alla componente arborea che mostra un elevato effetto di prossimità sui valori pollinici registrati al suolo. L’interpolazione dei dati ha mostrato che l’accumulo di polline è irregolare dentro la città e confermato una forte correlazione con la presenza degli alberi ornamentali più diffusi in ambito urbano. Per quanto riguarda l’apporto extra-locale, le piante che crescono sulle colline a nord della città forniscono il contributo di polline più elevato, soprattutto quando il vento spira ad intensità elevate. Lo studio sui granuli pollinici di Cupressaceae ha permesso di stimare il loro tasso di accumulo a livello del suolo e l’effetto prossimità di queste piante sulle registrazioni. Il polline di cipresso è la maggiore componente della pioggia pollinica allergenica, sebbene le concentrazioni di polline di piante erbacee siano e si mantengano elevate nel corso degli anni.

L'importance socio-economique du palmier dattier a conduit les scientifiques a developper de nombreuses recherches, fondamentales et appliquees, principalement orientees sur les palmiers femelles ; les palmiers males restent mal connus. Ils constituent une population tres heterogene. Les phoeniciculteurs se basent, pour leur caracterisation et leur distinction sur leur apparence phenotypique afin de les rapprocher des femelles. Dans le but de rechercher des criteres de distinction entre les arbres males, nous avons etudie une collection de dokkars de la station de biskra (algerie). Nous essayons, par une approche multidisciplinaire, de definir et de modeliser un certain nombre de caracterisatiques, morphologiques, chimiques, biochimiques, physiologiques (viabilite) des pollens de phoenix dactylifera. Nos resultats, soumis a differentes techniques d'analyses multivariees (arbre de longueur minimale, classification hierarchique, analyse factorielle des correspondances), ont permis de proposer une classification des pollens etudies. Le caractere multidisciplinaire de nos recherches a permis de definir deux types de criteres, l'un de distinction et l'autre de qualite. C'est sur cette base que pourrait se faire le stockage des pollens dans la future banque de pollens

Orientador: Antonio Baldo Geraldo Martins
Banca: Carlos Ruggiero
Banca: João Alexio Scapare Filho
Resumo: A procura cada vez maior por uma alimentação saudável e balanceada tem levado a um aumento no consumo de frutas e verduras, e a uma maior diversificação pelos consumidores. Em virtude disso, o consumo de frutas exóticas tem aumentado nos últimos anos, destacando-se, entre os produtos comercializados, a pitaya. Por ser uma cultura ainda incipiente no país, há a necessidade de estabelecimento de pesquisas quanto ao seu cultivo para dar suporte aos produtores. Neste sentido, este trabalho foi realizado com o objetivo de realizar a caracterização do ciclo de produção da pitaya vermelha (Hylocereus undatus) na região de Jaboticabal, SP e a frutificação e qualidade de frutos em função da fonte de pólen, do ambiente de cultivo e da época de produção. O experimento foi conduzido em delineamento inteiramente casualizado, em esquema fatorial 3X2X2 (três espécies doadoras de pólen: H. undatus, H. polyrhizus e Selenicereus setaceus, dois ambientes - condução sob tela plástica branca e preta, e duas épocas de polinização: março e abril), com quatro repetições. Observou-se que a emissão de gemas e o florescimento na cultura da pitaya ocorrem com a associação de altas temperaturas e precipitação, havendo constante emissão de botões florais durante os meses de novembro a abril, com pico de florescimento no mês de dezembro. O clone avaliado mostrou-se auto-incompatível, sendo necessária polinização cruzada, com pólen de outras espécies de pitaya para garantir a frutificação. As condições climáticas influenciaram diretamente do desenvolvimento e na qualidade dos frutos obtidos
Abstract: The increasing demand for a healthy and balanced diet has led to an increased on fruits and vegetables expenditure, and greater diversification by the consumer. As a result, consumption of exotic fruits has increased in recent years, especially the dragon fruit. Due of the fact that is a new crop in Brazil country, researches are needed about their cultivation to support their producers. Therefore, this study was conducted with the aim of assess the phenology of red dragon fruit (Hylocereus undatus) on Jaboticabal, Brazil, and the effect of pollen source, environment for cultivation, and time on fruit set and fruit quality. The experimental design was entirely randomized, in a 3 X 2 X 2 (three pollen sources: H. undatus, H. polyrhizus and Selenicereus. setaceus X two environment for cultivation - under plastic screen black or white, X two times of pollination: March and April) factorial arrangement, with 4 replicates. It was observed that the issue of floral buds and the bloom on dragon fruit culture occurs with a combination of high temperatures and rainfall, with constant emission of flower buds during the months from November to April, with peak bloom in December. The clone evaluated demonstrated self-incompatible, requiring cross-pollination with foreign pollen to ensure fruit set. The environmental conditions influences directly on fruit development and quality
Mestre

I compared atmospheric and soil pollen values to determine taphonomic influences on pollen in Southwestern soils. Burkard traps sampled atmospheric pollen for six years from multiple sites in Tucson, Arizona. Tauber and soil samples were collected for two years at Tumamoc Hill (Tucson). Morus, Ambrosia, Gramineae, and Chenopodiaceae-Amaranthus characterize Tucson's airborne pollen. Artemisia, Garrya and summer Pinus pollen are transported from the mountains. Annual pollen capture is similar between Burkard and Tauber samplers. Atmospheric pollen is seasonally variable; annual variability is low. Spatial variability among sites is low. Pollen concentrations vary widely among sites, but taxonomic composition remains constant. Reentrained soil pollen comprises 11% of the airborne pollen. Gramineae and Chenopodiaceae-Amaranthus pollen comprise 90% of the reentrained pollen. Pollen reentrainment varies seasonally. High maximum and minimum temperatures, low dew point and moderate wind speeds are associated with maximum atmospheric pollen concentrations. Winds preceding summer storms cause increased pollen concentrations. Deterioration characterizes pollen from soils. Chenopodiaceae-Amaranthus, Ambrosia, Other Compositae and Graminear are commonly found; Morus is rarely found. Pinus, Sphaeralcea, Boerhaavia and Kallstroemia are present in low numbers. These taxa have thick pollen walls, and they resist destruction. Seasonally collected soil samples have similar pollen spectra. Seasonal airborne pollen variability does not affect the soil pollen spectra. Inoculated soil pollen is well preserved, but pollen is lost rapidly. After one year, pollen concentrations approached background levels for seven of the eight pollen taxa tested. Solidago remained an order of magnitude higher. Pollen morphology may play a role in differential pollen loss. Pollen from the inoculated plots is lost through post-mortem transport. Pollen in soils is time-averaged and exhibits little temporal variability. The average airborne pollen spectra differs from the pollen in the soil. Soil pollen was degraded; inoculated plot pollen was well preserved. I conclude airborne pollen contributes little to the soil pollen of Tumamoc Hill. The soil pollen spectra is affected by selective- or non-deposition of airborne pollen (e.g. Morus), differential pollen destruction, and differential post mortem transport.

The growth of walled cells is due to the cooperation of physical and chemical mechanisms leading to the controlled mechanical deformation of the cells. Plant cells, for example, need to expand the surface area of their cell wall in order to grow in size. This can be done in a uniform manner called diffusive growth or through tip-growth. Tip-growth is characterised by a mechanical deformation that is confined to a specific region of the cell wall, namely its tip. Tip-growth generally leads to tubular cell wall shapes and has been observed in plant cells such as pollen tubes and root hairs but also in fungal hyphae, algae and neuronal growth cones. The pollen tube is a protuberance growing on the pollen grain. As part of plant fertilisation, its purpose is to extend until it reaches the ovule of a host plant and allow for the passage of a sperm cell contained in the pollen grain. This thesis studies how physical principles direct and control the tip-growth of a pollen tube. The three particular phenomena that were addressed concern the effects of elastic forces and short-range electrical potentials on ion diffusion, actin protein aggregation and the viscous flow in growing pollen tubes. A very intriguing phenomenon, observed a decade ago, concerning growing pollen tubes is the oscillation in time of the growth rate, the concentration of signalling molecules such as calcium and the thickness of the cell wall. While the total interaction of the components of such a complex system is hard to asses, I show that a few key elements, when coupled adequately, lead to the steady oscillation similar to that observed experimentally. The growing cell was modelled as a fluid finger in the viscous regime with elastic properties depending on the material delivery to the growing region. The difference between the material delivered and the material required for growth led to the stable oscillation of the growth rate. A se
La croissance de cellules ayant une paroie cellulaire est due \'a la collaboration de processus physiques et chimiques menant \'a une déformation mécanique contrôlée de ces cellules. Les cellules végétales, par exemple, doivent augmenter la surface de leur paroie afin de croître. Ceci peut être accompli de façon uniforme appellée croissance diffuse ou par croissance apicale. La croissance apicale est caractérisée par une déformation mécanique qui est confinée à une région spécifique de la cellule, soit l'apex. La croissance apicale méne générallement à des paroies cellulaires de forme cylindrique. Elle est observée chez des cellules végétales telles que le tube pollinique ou des racines mais aussi chez des algues ou des hyphes fongiques. Le tube pollinique est une protubérance qui croît sur un grain de pollen. Lors de la fertilisation, son rôle est de s'allonger jusqu'à ce qu'il atteigne l'ovule de la plante hôte et de permettre le passage d'une cellule de sperme contenue dans le grain de pollen.Cette thése étudie les principes physiques qui contrôlent la croissance apicale d'une cellule végétale. Elle s'applique plus spécifiquement à la croissance d'un tube pollinique. Les trois systémes particuliers que nous étudierons concernent les effets élastiques et les potentiels électriques sur la diffusion d'ions, l'aggrégation de protéines et le flot visqueux dans les tubes de pollen en croissance. Un premier phénoméne, observé il y a une décennie, est l'oscillation dans le temps de la vitesse de croissance ainsi que de la concentration de calcium et de l'épaisseur de la paroie cellulaire d'un tube pollinique. Bien que les interactions entre toutes les composantes du tube pollinique sont complexes, nous avont démontré que quelles composantes, lorsque couplées de maniére adéquate, produisent l'oscillation stable observée en laboratoire.La c

Master of Science
Department of Agronomy
William T. Schapaugh
Heat and drought stress are common problems for crops grown in Kansas. Rarely do these problems occur separately, more often than not they occur in tandem if not simultaneously. The interaction of heat stress and pollen germination was investigated in order to determine if a physiological screen was a feasible method of determining heat tolerance in soybean [Glycine max (L.) Merr]. Ten soybean lines (Group A) from the 2006 Northern Region Uniform Soybean Tests were analyzed over two years in four locations consisting of irrigated and dryland field environments, with an additional twenty lines (Group B) analyzed in the second year. Pollen was collected from plants and incubated at either 28o, 34o, or 38o C to determine pollen germination for optimal and stress-inducing temperatures. A three-way interaction of entry x incubation temperature x environment was observed, as well as significant differences among entries, incubation temperatures and environments. Average pollen germination for soybean entries ranged from 25% to 38% across three incubation temperatures and four environments in Kansas during 2006 – 07. The average environment effect for pollen germination ranged from 29% (dryland, 2006) to 34% (irrigated, 2007), while the average incubation temperature effect on pollen germination ranged from 25% (38oC) to 44% (28oC). This experiment has shown that increasing incubation temperatures significantly decreases pollen germination in vitro. It has also shown that soybean genotypes differ in pollen germination and that an in vitro screen can be used to characterize these differences. Further studies are needed to establish the relationship between pollen germination, seed set and seed yield in soybean. Work also needs to be completed to determine the proper sample size to adequately characterize differences in pollen germination so that performance differences among genotypes can be used as selection criteria in a plant breeding program.

Honey bees (Apis mellifera) collect and store both honey and pollen in preserved forms. Pollen storage involves the addition of honey or nectar and oral secretions to pollen granules. It is controversial whether the duration of pollen storage alters the palatability or nutritive value of the pollen storage medium. We examined how bees utilize different-aged stored pollen during an extended pollen flow. The deposition of pollen into wax cells and subsequent consumption were monitored daily on 18 brood frames from 6 colonies over an 8d observation period. Despite a greater abundance of older stored pollen cells on brood frames, bees showed a marked preference for the consumption of freshly-stored pollen. Two to four day-old pollen cell contents were significantly more likely to be consumed, while pollen cell contents more than seven days old were eaten at much lower rates. Similar experiments that controlled for cell abundance and spatial effects using cage assays yielded the same result. One day-old stored pollen was consumed approximately three times more often than 10d-old stored pollen, and two times more often than 5d-old stored pollen. These consumption preferences for freshly-stored pollen occurred despite a lack of clear developmental advantages. Young adult workers reared for 7 days on 1d-, 5d-, or 10d-old stored pollen showed no difference in body mass, stored pollen consumption, hindgut fecal material accumulation, or hypopharyngeal gland (HPG) protein titers, suggesting that different-aged pollen stores did not vary in their nutritional value to adult bees. These findings are inconsistent with the hypothesis promoting a period of microbially-mediated, "beebread maturation" that results in greater palatability or nutritive value for aged pollen stores. Rather, stored pollen that is not eaten in the first few days accumulates as excess stores preserved in a less preferred, but nutritionally-similar state.

This study investigates the variations in the start and severity of the grass and birch pollen seasons at a network of sites in the United Kingdom. Daily grass and birch pollen concentrations have been monitored during the course of the study (1992-1994) at the University of North London site. Retrospective pollen data of up to 30 years in length at London, Cardiff and Derby has been incorporated into the database, along with between 2 and 7 years of retrospective data from 7 other European Aeroallergen Network(UK) sites. Annual grass and birch pollen concentrations, start of season dates and seasonal severities have been identified and analysed in relation to meteorological conditions and local pollen source areas. Variations have been found at the individual sites from year to year, and between the different sites in the same year. Multiple regression analysis has been used on the long term data sets at London, Cardiff and Derby to produce forecast models to enable the prediction of the start of the season and total seasonal grass and birch pollen concentrations at the 3 sites. Data from the other EAN(UK) sites has been incorporated into these models to assess their use on a regional basis. This research has relevance within many subject areas. The long term data sets on which a large part of the thesis is based are of great interest to Aerobiologists in the identification of long term trends in pollen data. The research has relevance to Quaternary palynologists interested in the influence of the source area on the pollen catch. The influence of climate on the seasonal variation of grass species will be of interest to Agriculturalists, Ecologists and Biogeographers. Finally, through the accurate forecasting of the start and severity of the grass and birch pollen seasons, hayfever sufferers are able to have increased knowledge, and therefore may be able to avoid the amount of medical consultation required by means of prophylactic treatment. The research is unique in that it is the first study to be conducted on the UK pollen databank. It is also unique research in that data sets of this length do not exist anywhere else in Europe and probably the world, and therefore this study poses an important piece of research both on a national and an international level.

Model projections of future climate change require that coupled climate-vegetation models are developed and validated, i.e. these models should be able to reproduce past climate and vegetation change. Records of pollen deposited in lake bottoms and peat bogs can provide the information needed to validate these models. The aim of this thesis was i) to explore the modern relationships between pollen and vegetation in northern and temperate China and estimate pollen productivity of major plant taxa, and ii) to use the results of i) to produce the first reconstruction of plant cover in China over the last 10 000 years for the purpose of climate modelling. A study of the modern pollen-vegetation-climate relationships was performed in northwestern China (Paper I). Pollen productivity for 18 major plants of cultural landscapes in central-eastern China was estimated (Paper II). Based on a synthesis and evaluation of all existing estimates of pollen productivity in the study region, a standard dataset of pollen productivity for 31 plant taxa is proposed (Paper III). This dataset was used to achieve pollen-based REVEALS reconstructions of plant cover over the last 10 000 years in 35 regions of northern and temperate China (Paper IV). The major findings can be summarized as follows. Paper I: Annual precipitation (Pann) is the major climatic factor influencing pollen assemblages, followed by July precipitation (PJul). The shared effect of combinations of two climatic factors explains a larger portion of the variation in pollen data than individual variables. Paper II: Of the 16 reliable pollen productivities estimated, the estimates for 8 taxa are new, Castanea, Cupressaceae, Robinia/Sophora, Anthemis type/Aster type, Cannabis/Humulus, Caryophyllaceae, Cruciferae, and Galium type. Trees have in general larger pollen productivity than herbs. Paper III: Of the total 31 taxa for which estimates of pollen productivity are available in China, 13 taxa have more than 1 value. All or most of these values are similar for Artemisia, Cyperaceae, Larix, Quercus and Pinus. Eight taxa have very variable estimates. Paper IV: The REVEALS plant percentage-cover strongly differs from the pollen percentages, and they provide new important insights on past changes in plant composition and vegetation dynamics.

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Os objetivos dessa pesquisa foram os de estudar a morfologia floral, o ponto de maturidade fisiológica das sementes de Phoenix roebelenii (tamareira-anã) e o período de colheita dos frutos, no qual as sementes apresentem máxima qualidade fisiológica. As flores femininas e masculinas foram esquematizadas com o auxílio de uma câmara clara acoplada ao estereomicroscópio. Os grãos de pólen foram observados e fotografados em microscópio eletrônico de varredura. Os frutos, a partir de sua formação, foram colhidos semanalmente, sendo as determinações feitas em laboratório. Os dados biométricos dos frutos e das sementes foram determinados com auxílio de paquímetro digital. Foram também determinados o teor de água, a matéria verde e a matéria seca dos frutos e das sementes, a porcentagem de germinação e o índice de velocidade de germinação das sementes. As variáveis que apresentaram crescimento em função do tempo foram ajustadas ao modelo logístico e aquelas com tendência decrescente em função do tempo foram ajustadas ao modelo exponencial decrescente. A morfologia das flores masculinas, femininas e dos grãos de pólen de P. roebelenii é bastante homogênea e confiável, podendo ser usada no reconhecimento e identificação dessa espécie, além de fornecer subsídios para estudos da sua biologia floral e reprodutiva. O ponto de maturidade fisiológica das sementes de P. roebelenii ocorreu aos 138 dias após a antese (d.a.a.), podendo o período de colheita ser estendido até os 194 d.a.a.
The objectives of this research were to study the floral morphology and the physiological maturation of Phoenix roebelenii seeds, for the determination of the ideal harvesting time. The pistillate and staminate flowers were schematized with a clear camera coupled to the stereomicroscope, and the pollen grains were documented by means of electronic spin microscope. The fruits, after its formation, were harvested weekly and they were evaluated at laboratory conditions. Biometrical data of the fruits and seeds were obtained. The moisture content, the fresh and dry weight from the fruits and seeds, and the seed germination and the speed of germination index (SGI) were also recorded. The variables which showed growth in function of the time were adjusted to a logistic model and the one's which exhibited a decrescent trend in the function of the time were adjusted to an exponential decrescent model. The morphology of the flowers, and of the pollen grains of P. roebelenii is sufficiently homogeneous and trustworthy, being able to be used for the recognition and identification of this species, besides supplying subsidies studies of its floral and reproductive biology. It was observed that the physiological maturation point of seeds of P.roebelenii occurred at 138 days after anthesis (d.a.a.), and the harvesting period could be extended up to 194 d.a.a.

Chez les organismes pluricellulaires, la diversité morphologique observée à tous les niveaux est frappante, que ce soit au niveau de la taille, des couleurs, ou de la forme des individus, et des différentes parties qui les composent. La sélection naturelle, ainsi que les contraintes développementales, influencent l’évolution de ces différents attributs, sur le court terme comme sur le long terme. Le modèle choisi ici pour étudier l’évolution des formes est le grain de pollen des plantes à fleurs, qui présente une très grande diversité morphologique. Nous nous sommes focalisés sur un caractère morphologique, les apertures, qui sont des structures de la paroi du grain de pollen impliquées dans la survie et la reproduction. Nous avons étudié l’évolution des apertures à grande échelle taxonomique chez les angiospermes, et nous montrons que s’il existe de nombreuses variations, deux types principaux dominent : un pollen à une aperture chez les Monocotylédones et les angiospermes divergeant à la base, et un pollen à trois apertures chez les Eudicotylédones. En étudiant la dominance du pollen à trois apertures, nous avons pu montrer que la stase chez les Eudicotylédones était vraisemblablement due à une sélection stabilisante plutôt qu’à des contraintes développementales. Nous avons également montré, grâce à l’utilisation de mutants de la plante modèle Arabidopsis thaliana, qu’un nombre d’apertures élevé est défavorable face à un stress osmotique, ce qui pourrait suggérer que les pollens triaperturés représentent un bon compromis entre survie et germination. Enfin, nous nous sommes intéressés à un type particulier de pollen possédant de nombreuses apertures, dont nous avons étudié la distribution chez les angiospermes. L’apparition de ce type de pollen est récurrente, mais il n’est que rarement fixé à grande échelle taxonomique, suggérant l’existence d’un mécanisme de sélection interphylétique éliminant ce type de pollen sur le long terme
Multicellular organisms are morphologically very diverse at every scale, regarding size, color, and shape of individuals and of their different parts. Natural selection and developmental constraints influence evolution of these characteristics, on the short term as well as on the long term. The model chosen here to study form evolution is the pollen grain of flowering plants, which is very diversified morphologically. We focused on specific features called apertures, which are structures of the pollen wall involved in survival and reproduction. We studied aperture evolution at large taxonomic scale in angiosperms, and we showed that in spite of variations, two main pollen types dominate: a pollen with one aperture in Monocots and early diverging angiosperms, and a pollen with three apertures in Eudicots. The study of this pattern showed that the stasis of triaperturate pollen in Eudicots is likely due to stabilizing selection rather than developmental constraints. Experiments on Arabidopsis thaliana mutants also revealed that an increase in aperture number was associated with lower resistance to osmotic stress. This result could suggest that triaperturate pollen grains represent a good trade-off between survival and germination. Moreover, we focused on a particular pollen type with many apertures, to determine its distribution in angiosperms. This type of pollen has many origins, however it is seldom fixed at large taxonomical scale, suggesting the intervention of lineage selection, eliminating this pollen type in the long run

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