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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Potencial alelopático de extratos e frações de Neea theifera Oerst. (Nyctaginaceae) sobre sementes e plântulas de Lactuca sativa /

Santos, Valter Henrique Marinho dos. January 2012 (has links)
Orientador: Regildo Márcio Gonçalves da Silva / Banca: Giuseppina Pace Pereira Lima / Banca: Rosana Marta Kolb / Resumo: A alelopatia é um mecanismo de interação bioquímica entre vegetais, considerada uma forma de adaptação química defensiva das plantas. Neste fenômeno, biomoléculas produzidas por uma planta são liberadas para o meio ambiente e influenciam no crescimento e desenvolvimento de plantas vizinhas. Assim, o objetivo deste trabalho foi investigar o potencial alelopático de extratos e frações de folhas de Neea theifera, por meio de bioensaios de pré e pós-emergência. Para tanto, sementes e plântulas de Lactuca sativa foram tratadas com o extrato orgânicos (nhexânico, acetato de etila e metanólico) em diferentes concentrações (5, 10 e 20 mg/mL), e frações do extrato metanólico bruto de Neea theifera, além de um grupo controle negativo (água). O teste de viabilidade nas sementes submetidas aos extratos foi realizado pelo teste do tetrazólio, já o teste de fitotoxicidade foi elucidado pela determinação do índice mitótico. Foi realizada também uma triagem fitoquímica por meio de reações específicas para detecção de possíveis classes químicas dos extratos avaliados, além de avaliar o perfil cromatográfico por meio de cromatografia de camada delgada e reveladores específicos. De acordo com a metodologia adotada e os resultados obtidos foi possível elucidar o potencial alelopático, assim como propor um mecanismo de ação dos aleloquímicos desta espécie / Abstract: Allelopathy is a mechanism of biochemical interaction between plants, considered a form of adaptation of plants. In this phenomenon, biomolecules are produced by a plant and are released into the environment and influence the growth and development of neighboring plants. The objective of this study was to investigate the allelopathic potential of extracts and fractions of leaves Neea thief through bioassays pre-and post-emergence. For this purpose, seeds and seedlings of Lactuca sativa were treated with organic extract (nhexânico, ethyl acetate and methanol) at different concentrations (5, 10 and 20 mg / mL), and fractions of the brute methanol extract Neea theifera, and a negative control (water). The test of viability in seeds subjected to the extracts was carried out by the tetrazolium test, already the test phytotoxicity was elucidated by determining the mitotic index. Was also carried out a phytochemical screening through specific reactions to detect possible chemical classes of extracts assessed, and to evaluate the chromatographic profile by thin layer chromatography and revealing specific. According to the methodology used and the results obtained it was possible to elucidate the allelopathic potential, and to propose a mechanism of action of allelochemicals of this species / Mestre
12

A systematic study of Boerhavia L. and Commicarpus Standl. (Nyctaginaceae) in Southern Africa / Madeleen Struwig

Struwig, Madeleen January 2011 (has links)
The Nyctaginaceae Juss. is a small flowering plant family of about 30 genera and 400 species mainly found in the tropical and subtropical regions of the New World. In Africa, six genera and 49 species occur, and in southern Africa, five genera and 19 species. Boerhavia L. and Commicarpus Standl. are the most species rich genera in southern Africa, with seven and eight species respectively. These species have not previously been studied taxonomically nor phylogenetically, and the objective of this study was to provide a systematic and phylogenetic treatment of these groups for southern Africa. Plant material was collected from the diversity centres of Boerhavia and Commicarpus in southern Africa. Leaves, flowers and anthocarps stored in ethanol were measured and examined with a stereomicroscope and surface studies conducted with a scanning electron microscope (SEM). Material fixed in paraformaldehyde was embedded, sectioned, stained and examined with a light microscope. Pollen samples were acetolized before examination with a SEM. Sequencing analyses were done with a DNA Sequencer and neighbor-joining and maximum likelihood trees drawn. Distribution and habitat information were obtained from voucher specimens from various herbaria. The pollen grains are uniform in shape and sculpture and provide no diagnostic characters with which to distinguish between species. They do, however, provide broad characters to distinguish between the genera. Morphological, anatomical and molecular investigations, however, provided a series of characters to distinctly discern between Boerhavia and Commicarpus. Morphologically, Boerhavia and Commicarpus differ in growth form, inflorescence type, shape and indumentum of the upper and lower part of the flower, and shape and indumentum of the anthocarp. Anatomically, Boerhavia can be distinguished from Commicarpus by the Kranz anatomy around the minor veins of the leaves (which is absent in Commicarpus) and the sclerenchyma bundles which are present within the rib and inter-rib areas of the anthocarp (sclerenchyma bundles are only present in the rib area in Commicarpus). Molecular analyses group Boerhavia and Commicarpus as distinct clades with high bootstrap support. The differentiation is such in southern Africa, that Mirabilis and Acleisanthes, two non-African genera, are even placed intermediately between the two. The different species of Boerhavia and Commicarpus can be distinguished by the lower, coriaceous part of the flower and the anthocarp, as the arrangement of the glands, ribs and trichomes on these structures is species specific. The anatomy of the stems, leaves and anthocarps of the different species is uniform and uninformative and cannot be used to distinguish between the species. Molecular analyses support the distinction of the different species as defined by the morphology, and group the morphologically similar C. fruticosus and C. squarrosus in close relation. The aliens, Boerhavia cordobensis, B. diffusa var. diffusa and B. erecta, group together and the indigenous B. coccinea var. coccinea, B. deserticola, B. hereroensis and B. repens subsp. repens group together. The widely distributed C. plumbagineus and C. helenae var. helenae are closely related to each other, as are C. pentandrus and C. decipiens which are limited in theitr distribution to the African. This systematic study has shown that Boerhavia and Commicarpus are two distinct genera in southern Africa with well-defined species. This provides a workable classification system for southern Africa. This classification requires to be further refined by combining the morphology, anatomy, palynology and phylogenetics of the southern African Boerhavia and Commicarpus species into a single phylogeny. The phylogenetic investigations are, however, incomplete as the molecular analyses still need refinement and incorporation of more genes and taxa. / Thesis (Ph.D. (Environmental Science))--North-West University, Potchefstroom Campus, 2012
13

Aspectos taxonômicos e morfo-anatômicos das Bougainvillea Comm. ex Juss. (Nyctaginaceae) /

Cidrão, Bruno Bravos January 2019 (has links)
Orientador: Rosana Marta Kolb / Resumo: O gênero Bougainvillea Comm. ex Juss., pertencente a família Nyctaginaceae, é nativo da América Latina e é atualmente cultivado em vários outros países de clima tropical ou temperado. Suas espécies possuem brácteas coloridas que envolvem as inflorescências, atraem os polinizadores e ainda auxiliam na dispersão do fruto depois de seco. Possuem um antocarpo estriado e em forma de haste, diferente do restante dos membros da família, que possui antocarpos maiores ou ausentes. Das espécies de Bougainvillea, B. spectabilis e B. glabra são as mais citadas na literatura. Boa parte dos trabalhos com Bougainvillea é relacionada à anatomia do crescimento secundário diferenciado do gênero ou a estudos fitoquímicos. A anatomia, como ferramenta para estudos taxonômicos, tem sido empregada há muito tempo e tem auxiliado na distinção de espécies morfologicamente semelhantes. Neste trabalho, foi realizado um estudo da anatomia foliar das Bougainvillea com o intuito de obter dados que auxiliem na identificação das mesmas, além dos já citados na literatura; associado a uma monografia do gênero que visou esclarecer as divergências taxonômicas existentes entre as espécies. O estudo anatômico mostrou que elas têm em comum cutícula delgada, epiderme unisseriada, idioblastos contendo cristais na forma de ráfides e prismas, e tricomas tectores unisseriados; mas diferem no formato das células da epiderme, localização dos estômatos, tipo de mesofilo e formato das células que compõem os tricomas. São su... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The genus Bougainvillea Comm. ex Juss., belonging to the family Nyctaginaceae, is native to Latin America and is currently cultivated in several other tropical or temperate countries. Their species have colored bracts that surround the inflorescences, attract the pollinators and even aid fruit dispersion after drying. They have a striated, rod-shaped antocarp, different from the other family members, which have larger or absent antocarps. Among the Bougainvillea species, B. spectabilis and B. glabra are the most cited in the literature. Much of the work with Bougainvillea is related to the anatomy of differentiated secondary growth of the genus or phytochemical studies. Anatomy, as a tool for taxonomic studies, has been used for a long time and has aided in the distinction of morphologically similar species. In this work, a study of the foliar anatomy of the Bougainvillea was carried out with the purpose of obtaining data that help in the identification of its species, besides those already mentioned in the literature; associated to a monograph of the genus that aimed to clarify the taxonomic divergences between species. The anatomical study showed that they have in common thin cuticle, uniseriate epidermis, idioblasts containing crystals in the form of raphides and prisms and uniseriate trichomes; but differ in the shape of the epidermis cells, localization of stomata, mesophyll type and shape of the trichome cells. New synonyms are suggested for species B. glabra, B. praeco... (Complete abstract click electronic access below) / Mestre
14

A systematic study of Boerhavia L. and Commicarpus Standl. (Nyctaginaceae) in Southern Africa / Madeleen Struwig

Struwig, Madeleen January 2011 (has links)
The Nyctaginaceae Juss. is a small flowering plant family of about 30 genera and 400 species mainly found in the tropical and subtropical regions of the New World. In Africa, six genera and 49 species occur, and in southern Africa, five genera and 19 species. Boerhavia L. and Commicarpus Standl. are the most species rich genera in southern Africa, with seven and eight species respectively. These species have not previously been studied taxonomically nor phylogenetically, and the objective of this study was to provide a systematic and phylogenetic treatment of these groups for southern Africa. Plant material was collected from the diversity centres of Boerhavia and Commicarpus in southern Africa. Leaves, flowers and anthocarps stored in ethanol were measured and examined with a stereomicroscope and surface studies conducted with a scanning electron microscope (SEM). Material fixed in paraformaldehyde was embedded, sectioned, stained and examined with a light microscope. Pollen samples were acetolized before examination with a SEM. Sequencing analyses were done with a DNA Sequencer and neighbor-joining and maximum likelihood trees drawn. Distribution and habitat information were obtained from voucher specimens from various herbaria. The pollen grains are uniform in shape and sculpture and provide no diagnostic characters with which to distinguish between species. They do, however, provide broad characters to distinguish between the genera. Morphological, anatomical and molecular investigations, however, provided a series of characters to distinctly discern between Boerhavia and Commicarpus. Morphologically, Boerhavia and Commicarpus differ in growth form, inflorescence type, shape and indumentum of the upper and lower part of the flower, and shape and indumentum of the anthocarp. Anatomically, Boerhavia can be distinguished from Commicarpus by the Kranz anatomy around the minor veins of the leaves (which is absent in Commicarpus) and the sclerenchyma bundles which are present within the rib and inter-rib areas of the anthocarp (sclerenchyma bundles are only present in the rib area in Commicarpus). Molecular analyses group Boerhavia and Commicarpus as distinct clades with high bootstrap support. The differentiation is such in southern Africa, that Mirabilis and Acleisanthes, two non-African genera, are even placed intermediately between the two. The different species of Boerhavia and Commicarpus can be distinguished by the lower, coriaceous part of the flower and the anthocarp, as the arrangement of the glands, ribs and trichomes on these structures is species specific. The anatomy of the stems, leaves and anthocarps of the different species is uniform and uninformative and cannot be used to distinguish between the species. Molecular analyses support the distinction of the different species as defined by the morphology, and group the morphologically similar C. fruticosus and C. squarrosus in close relation. The aliens, Boerhavia cordobensis, B. diffusa var. diffusa and B. erecta, group together and the indigenous B. coccinea var. coccinea, B. deserticola, B. hereroensis and B. repens subsp. repens group together. The widely distributed C. plumbagineus and C. helenae var. helenae are closely related to each other, as are C. pentandrus and C. decipiens which are limited in theitr distribution to the African. This systematic study has shown that Boerhavia and Commicarpus are two distinct genera in southern Africa with well-defined species. This provides a workable classification system for southern Africa. This classification requires to be further refined by combining the morphology, anatomy, palynology and phylogenetics of the southern African Boerhavia and Commicarpus species into a single phylogeny. The phylogenetic investigations are, however, incomplete as the molecular analyses still need refinement and incorporation of more genes and taxa. / Thesis (Ph.D. (Environmental Science))--North-West University, Potchefstroom Campus, 2012
15

Uso sustentável da biodiversidade brasileira: prospecção químico-farmacológica em plantas superiores : Guapira ssp

Severi, Juliana Aparecida [UNESP] 20 August 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:33:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-08-20Bitstream added on 2014-06-13T20:45:04Z : No. of bitstreams: 1 severi_ja_dr_arafcf.pdf: 986965 bytes, checksum: 59dd0bbc3cf54edc0cc3a73e327862ea (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Esse trabalho é parte do projeto temático BIOTA-FAPESP: “Uso Sustentável da Biodiversidade Brasileira: Prospecção Químico-Farmacológica de Plantas Superiores” e visa contribuir com a caracterização de espécies presentes no estado de São Paulo, investigando seu potencial químico-medicinal. Dentre as espécies com particular interesse, foram investigadas neste trabalho Guapira opposita, G. noxia e G. graciliflora, pertencentes à família Nyctaginaceae. O estudo químico do extrato clorofórmico das folhas foi conduzido por CG-FID e levou à identificação de esteróides e triterpenos. Os extratos metanólicos das três espécies foram fracionados por técnicas cromatográficas convencionais (permeação em gel, MPLC, HPLC) e as substâncias resultantes foram identificadas através de métodos espectroscópicos e espectrométricos (RMN, IV, UV e EM). Com este estudo, foram identificados em G. opposita onze flavonóides, dois monoacilgliceróis, um ureídeo e um ciclitol; em G. graciliflora cinco saponinas, duas delas inéditas, dois flavonóides e dois monoacilgliceróis; e de G. noxia dois compostos nitrogenados, um hemiterpeno e uma saponina inédita. As análises por HPLC-PDA-ELSD apontaram perfis químicos qualitativamente semelhantes entre as espécies. Dentre as atividades biológicas investigadas nas espécies, verificou-se que o extrato de metanólico de G. noxia possivelmente oferece efeito gastroprotetor na formação de úlceras, por elevar os níveis de glutationa, associado ao efeito antioxidante. Também foi verificada atividade antimicrobiana nos extratos de G.noxia e G. graciliflora, mutagênica em G. opposita e ausência de citotoxicidade em todos os extratos testados. Dessa maneira, este estudo contribui para aprofundar o conhecimento químico-farmacológico sobre espécies de Guapira, que ocorrem no estado de São Paulo / This work is part of the BIOTA-FAPESP thematic project “Sustaintable use of the Brazilian Biodiversity: Chemical and Pharmacological Prospection on Higher Plants”, and intents to contribute to improve the knowledge of plants present in the São Paulo State, by investigating their chemical and biological potential. Some of the species with particular interest are Guapira opposita, G. noxia and G. graciliflora, which belongs to the Nyctaginaceae family. The chemical study of the chloroformic extracts was performed by GC-FID and led to the identification of steroids and triterpenes. The methanolic extracts were fractionated by conventional chromatographic techniques (gel permeation, MPLC, HPLC) and the isolated compounds were identified by spectroscopic and spectrometric methods (NMR, IR, UV and MS). In this approach, have been identified from G. opposita eleven flavonoids, two monoacylglycerols, one ureide and one cyclitol; from G. graciliflora five saponins, two of them new, two flavonoids, and two monoacylglycerols; and from G. noxia two nitrogenated compounds, one hemiterpene and one new saponin. HPLC-PDA-ELSD analyses revealed similar qualitative chemical profile among the species. Concerning the investigated biological activities, it was observed that the methanolic extract of G. noxia has gastroprotector effects probably by incresing the levels of glutatione, associated to the antioxidant effect. Moreover, it was observed antimicrobial activity in G.noxia and G. graciliflora, mutagenic activity in G. opposita and absence of citotoxicy in all tested extracts. Thus, this work contributes to increase the chemical and pharmacological knowledge of plants from Guapira genus, presents in São Paulo State
16

Uso sustentável da biodiversidade brasileira : prospecção químico-farmacológica em plantas superiores : Guapira ssp./

Severi, Juliana Aparecida. January 2010 (has links)
Orientador: Wagner Vilegas / Banca: Vera Lucia Garcia Rehder / Banca: Cid Aimbiré de Moraes Santos / Banca: Claudia Helena Pellizzon / Banca: Isabele Rodrigues Nascimento / Resumo: Esse trabalho é parte do projeto temático BIOTA-FAPESP: "Uso Sustentável da Biodiversidade Brasileira: Prospecção Químico-Farmacológica de Plantas Superiores" e visa contribuir com a caracterização de espécies presentes no estado de São Paulo, investigando seu potencial químico-medicinal. Dentre as espécies com particular interesse, foram investigadas neste trabalho Guapira opposita, G. noxia e G. graciliflora, pertencentes à família Nyctaginaceae. O estudo químico do extrato clorofórmico das folhas foi conduzido por CG-FID e levou à identificação de esteróides e triterpenos. Os extratos metanólicos das três espécies foram fracionados por técnicas cromatográficas convencionais (permeação em gel, MPLC, HPLC) e as substâncias resultantes foram identificadas através de métodos espectroscópicos e espectrométricos (RMN, IV, UV e EM). Com este estudo, foram identificados em G. opposita onze flavonóides, dois monoacilgliceróis, um ureídeo e um ciclitol; em G. graciliflora cinco saponinas, duas delas inéditas, dois flavonóides e dois monoacilgliceróis; e de G. noxia dois compostos nitrogenados, um hemiterpeno e uma saponina inédita. As análises por HPLC-PDA-ELSD apontaram perfis químicos qualitativamente semelhantes entre as espécies. Dentre as atividades biológicas investigadas nas espécies, verificou-se que o extrato de metanólico de G. noxia possivelmente oferece efeito gastroprotetor na formação de úlceras, por elevar os níveis de glutationa, associado ao efeito antioxidante. Também foi verificada atividade antimicrobiana nos extratos de G.noxia e G. graciliflora, mutagênica em G. opposita e ausência de citotoxicidade em todos os extratos testados. Dessa maneira, este estudo contribui para aprofundar o conhecimento químico-farmacológico sobre espécies de Guapira, que ocorrem no estado de São Paulo / Abstract: This work is part of the BIOTA-FAPESP thematic project "Sustaintable use of the Brazilian Biodiversity: Chemical and Pharmacological Prospection on Higher Plants", and intents to contribute to improve the knowledge of plants present in the São Paulo State, by investigating their chemical and biological potential. Some of the species with particular interest are Guapira opposita, G. noxia and G. graciliflora, which belongs to the Nyctaginaceae family. The chemical study of the chloroformic extracts was performed by GC-FID and led to the identification of steroids and triterpenes. The methanolic extracts were fractionated by conventional chromatographic techniques (gel permeation, MPLC, HPLC) and the isolated compounds were identified by spectroscopic and spectrometric methods (NMR, IR, UV and MS). In this approach, have been identified from G. opposita eleven flavonoids, two monoacylglycerols, one ureide and one cyclitol; from G. graciliflora five saponins, two of them new, two flavonoids, and two monoacylglycerols; and from G. noxia two nitrogenated compounds, one hemiterpene and one new saponin. HPLC-PDA-ELSD analyses revealed similar qualitative chemical profile among the species. Concerning the investigated biological activities, it was observed that the methanolic extract of G. noxia has gastroprotector effects probably by incresing the levels of glutatione, associated to the antioxidant effect. Moreover, it was observed antimicrobial activity in G.noxia and G. graciliflora, mutagenic activity in G. opposita and absence of citotoxicy in all tested extracts. Thus, this work contributes to increase the chemical and pharmacological knowledge of plants from Guapira genus, presents in São Paulo State / Doutor
17

Importância da investigação farmacológica de Mirabilis jalapa Linn validação de sua utilização

ROCHA, Laurimar Thomé da January 2006 (has links)
Made available in DSpace on 2014-06-12T16:32:32Z (GMT). No. of bitstreams: 2 arquivo6451_1.pdf: 1285930 bytes, checksum: a1dba4731acaffddfe2386346a59f111 (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2006 / Mirabilis jalapa Linné, família das Nictagináceas, é uma planta herbácea ereta, profundamente ramificada, de folhas simples ovais, caule tipo haste, com flores pequenas, cálices apicais e pétalas que podem ser brancas, vermelhas, róseas, rôxas ou com tons multicoloridos. Nativa da América Tropical, sendo amplamente cultivada com fins decorativos no Brasil, onde é conhecida como bonina ou maravilha e encontrada da Bahia ao Paraná. Seu uso é difundido na medicina tradicional de muitos países para o tratamento de infecções, inflamação, edemas, conjuntivite, sendo também empregada como diurética, purgativa, tônica, antiespasmódica, vermífuga e antifúngica. Em sua composição fitoquímica relata-se a presença de alcalóides, flavonóides, triterpenóides e esteróides. Devido à diversidade do seu uso popular, buscou-se validar essas informações etnobotânicas, procurando dar suporte científico ao verificado na medicina tradicional. O trabalho teve como objetivo avaliar a toxicidade aguda e farmacológica (antiinflamatória e anti-tumoral em roedores) do extrato das folhas de Mirabilis jalapa em sua fração hexânica. Os ensaios de toxicidade aguda foram realizados por via intraperitoneal, com observações das respectivas alterações comportamentais para cada dose administrada. As doses utilizadas foram 1,0 a 3,0 g/kg, onde foram observados efeitos estimulantes nos primeiros 20 minutos após a administração do extrato hexânico e, em seguida, observados efeitos depressores. Efeitos como aumento da diurese e excreção fecal, foram relatados durante todo ensaio. A DL50 encontrada foi de 2009,167 mg/kg enquanto que a Concentração Letal (CL50) foi de 788,987 ug/ml, avaliada através de ensaio com Artemia salina Leach, o que permite sua classificação quanto à toxicidade em moderadamente tóxico. Em sua avaliação histopatológica, foram encontradas alterações como: congestão com áreas de necrose focal em fígado, congestão renal tubular, congestão e enfisema pulmonar. Para a atividade antiinflamatória utilizou-se o modelo de edema de pata induzido por carragenina, com a administração do extrato hexânico por via oral (125; 225 e 250 mg/kg) e por via intraperitoneal (62,5; 125; 225 e 250 mg/ kg), em ratas fêmeas. Nos ensaios antiinflamatórios, por via oral, não houve diminuição considerável dos volumes do edema da pata dos ratos, enquanto por via intraperitoneal, ocorreram inibições significativas somente na fase final da inflamação. A avaliação antitumoral do extrato hexânico de Mirabilis jalapa Linn frente ao Sarcoma 180 e Carcinoma de Ehrlich por via intraperitoneal (100; 125; 225 e 250 mg/kg) apresentou significativa redução do peso médio dos tumores dos grupos tratados, com índices relevantes de inibição tumoral. Os estudos histopatológicos revelaram foram as seguintes alterações: congestão hepática, atrofia da polpa branca no baço, enfisema pulmonar e atrofia glomerular nos rins, além da presença de metástases principalmente, nos grupos controle e nas doses menos concentradas
18

Moth pollination, low seed set, and vestigialization of attractive floral traits in Abronia umbellata (Nyctaginaceae)

Doubleday, LAURA 05 September 2012 (has links)
Flowering plants display remarkable phenotypic diversity, especially in reproductive structures, much of which is thought to be associated with pollination by animals. Pollination syndromes are collections of floral traits (e.g. flower colour, shape, odour) that are associated with a plant attracting particular functional groups of animal pollinators. We explored the extent to which traits associated with the moth pollination syndrome translated into pollination by moths in the Pacific coast dune endemic Abronia umbellata and found mixed results: in one year of study, there was no difference in seed set by day- vs. night-pollinated inflorescences, but in another year of study, night-pollinated inflorescences set significantly more seed than those pollinated during the day. We integrate this work with tests of pollen and resource limitation of seed production and with seed set surveys of natural populations to address proximate and ultimate causes of low seed set, finding low rates of pollinator visitation, high pollen limitation of seed production in all populations studied, and no evidence of endogenous resource limitation of seed production. We propose that “excess” flowers may be functionally male, serving to increase outcross siring success. The transition from self-incompatibility and obligate outcrossing to self-compatibility and predominant selfing is the most common evolutionary transition among the flowering plants and traits associated with outcrossing may become reduced across such shifts, potentially through the action of natural selection, especially if pollinators are also herbivores, or if the signals that pollinators use to locate flowers are also used by herbivores. We examined the reduction of attractive visual and olfactory floral traits in A. umbellata across a shift from outcrossing to selfing and found a reduction of all floral traits considered. We found that floral volatile emissions were reduced more strongly than flower size or floral display (number of flowers per inflorescence), but there was no evidence of an ecological cost associated with conspicuousness: we did not find reduced leaf herbivory among selfers relative to outcrossers. / Thesis (Master, Biology) -- Queen's University, 2012-08-30 19:46:23.663

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