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Palinotaxonomia de espécies brasileiras de Sinningia Nees (Gesneriaceae) - evolução da morfologia polínica e síndromes de polinização / Palinotaxonomy in brazilian species of Sinningia Nees (Gesneriaceae) - evolution of pollen morphology and pollination syndromesDutra, Fernanda Vitorete 24 September 2018 (has links)
Gesneriaceae é uma das famílias mais antigas da ordem Lamiales e possuí aproximadamente 150 gêneros, entre eles, Sinningia Nees, com um grande número de espécies endêmicas do Brasil. Foram estudados os grãos de pólen de 27 espécies brasileiras de Sinningia com o objetivo de caracterizar e identificar dados polínicos que possam auxiliar na taxonomia da família, ampliando os conhecimentos sobre a diversidade polínica do gênero, a fim de fornecer subsídios para o melhor entendimento das relações entre as espécies e da evolução dos caracteres polínicos, assim como relacionar os dados obtidos nesse trabalho com as síndromes de polinização descritas para o gênero. O material analisado foi obtido a partir de espécimes depositados nos herbários SP, MBM, MBML, ESA, UEC e INPA e de material de cultivo do Sítio Primavera em Mogi das Cruzes SP. Os grãos de pólen foram acetolisados, medidos, fotografados em microscopia óptica, microscopia eletrônica de varredura e transmissão e descritos qualitativamente. Os dados quantitativos foram analisados por meio de estatísticas descritiva e multivariada. Para as espécies brasileiras de Sinningia estudadas foram observadas variações entre os grãos de pólen, principalmente quanto ao tamanho, âmbito, forma, comprimento dos colpos e ornamentação. Foram encontrados grãos de pólen pequenos, pequenos à médios e médios; isopolares; âmbito circular, circular-lobados, subcircular e subtriangular; oblato-esferoidais, prolato-esferoidais, subprolatos e prolatos; área polar muito pequena, pequena ou grande; 3-colporados; colpos muito curtos, curtos, longos e muito longos e estreitos; colpos às vezes contritos na região mediana; endoabertura lolongadas; exina microrreticulada heterobrocada e homobrocada. Os dados obtidos confirmam o caráter estenopolínico do gênero, uma vez que as diferenças encontradas nos grãos de pólen são discretas e não permitem a identificação intragenérica. / Gesnericeae is one of the oldest families of the order Lamiales and has approximately 150 genera, among them, Sinningia Nees, that owns a great number of species endemic of Brazil. We studied the pollen grains of 27 Brazilian Sinningia with the objective of characterizing and identifying pollen data that could aid in family taxonomy, knowledge on pollen diversity of the genus,in order to provide support for a better understanding of the relationships between species and the evolution of pollinic characters, as well as to relate the data obtained in this work to the pollination syndromes described for the genus. The material analyzed was obtained from the specimens deposited in the herbaria SP, MBM, MBML, ESA, UEC and INPA and of cultive material of the Sítio Primavera in Mogi das Cruzes SP. 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. For the Brazilian Sinningia species studied, variations were observed between pollen grains, mainly in the size, amb, shape, length colpi and ornamentation. The pollen grains are small, small to medium and medium; isopolar; circular, circular-lobate, subcircular and subtriangular amb; oblate-spheroidal, prolate-spheroidal, subprolate and prolate; polar area is very small, small or large; 3-colporate; very short, short, long and very long colpi and narrows; sometimes contrite in the median region; lolongate endoaberture; heterobrocate and homobrocate microrreticulate ornamentation. The data obtained confirm the stenopalynous character of the genus, since the differences found in the pollen grains are discrete and do not allow intrageneric identification.
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Phylogenetic and population genetic studies in the genus Streptocarpus Lindl. (Gesneriaceae DC.)De Villiers, Margaret Jenifer 12 1900 (has links)
Thesis (PhD (Botany and Zoology))—-Stellenbosch University, 2008. / Streptocarpus Lindl. (Gesneriaceae DC.) is a genus of herbaceous plants containing
approximately 160 species, of which the majority occur in Africa and Madagascar. They are
largely restricted to shaded and moist habitats such as primary forest and rock outcrops. The
genus contains considerable morphological variation, with subgenus Streptocarpella containing
caulescent species and subgenus Streptocarpus mostly consisting of acaulescent growth forms,
mainly the unifoliates, plurifoliates and rosulates. Preliminary molecular analyses conducted
using nuclear ITS sequence data suggested that subgenus Streptocarpus evolved in tropical
central Africa, before radiating in several independent waves into southern Africa.
Streptocarpus has therefore only recently spread into South Africa. Amongst the South African
species, 11 morphologically similar species were identified as being closely related, together
forming the Cape primrose clade, based on the analysis of nuclear ITS sequence data. However,
these analyses only contained a few South African species, and the ITS data did not provide
enough resolution of relationships within this clade.
In this study nuclear and chloroplast sequence data as well as nuclear microsatellite data were
therefore employed to unravel the complex relationships amongst the South African
Streptocarpus species. The analyses indicate that 16 rosulate, palynologically similar species
(S. primulifolius, S. rexii, S. johannis, S. baudertii, S. modestus, S. formosus, S. gardenii,
S. lilliputana, the S. cyaneus complex [S. cyaneus, S. parviflorus, S. fenestra-dei, S. kunhardtii
and S. roseo-albus], S. floribundus, S. aylae and S. kentaniensis), the core Cape primrose
species, are closely related, while five unifoliate/plurifoliate, palynologically more variable
species (S. denticulatus, S. dunnii, S. pusillus, S. rimicola and S. bolusii) consistently emerged
as more distantly related to the core Cape primrose species. However, the positions of a further
ten species (S. meyeri, S. montigena, S. fanniniae, S. caeruleus, S. longiflorus, S. polyanthus,
S. saundersii, S. porphyrostachys, S. grandis and S. vandeleurii) were more complex in the
analyses, indicating that hybridization has played a role in their evolution. Five of these species
(S. meyeri, S. montigena, S. fanniniae, S. caeruleus and S. longiflorus) are, however,
palynologically homogenous and rosulates, and therefore are probably more closely related to
the core Cape primrose species, while the other five (S. polyanthus, S. saundersii,
S. porphyrostachys, S. grandis and S. vandeleurii) are unifoliates/plurifoliates that are
palynologically more heterogenous, and are probably more distantly related to the core Cape
primrose species.
Amongst the core Cape primrose species, S. primulifolius emerged as being ancestral or having
hybridized with many of the other species, while the S. cyaneus complex forms a
geographically and genetically more isolated group. However, evolutionary relationships
amongst these species were to a certain extent obscured by incomplete lineage sorting caused
by limited interpopulation gene flow, frequent hybridization and rapid speciation. The analyses
confirmed that the Pondoland Centre forests constitute important Pleistocene refugia, and
revealed some of the historical migration routes along which the species had radiated.
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Systematics, biogeography and studies of floral evolution in GesneriaceaeLuna Castro, Javier Alejandro January 2017 (has links)
Understanding the processes that have affected the diversification of herbaceous plants is fundamental to understand how flowering plants evolve, how ecosystems form and to predict the effect of climate change and geological events in plant communities. Aiming to create a strong phylogenetic framework where biogeographic and morphological hypothesis can be tested a higher level dated phylogeny of Gesneriaceae was produced. Gesneriaceae is a good study group as it has variable floral morphology, a broad distribution throughout the tropics and subtropics - represented in all non-arid tropical and subtropical hotspots of biodiversity. There are evident differences between lineages in the numbers of species, and it is comparatively well studied compared with other asterid families. In this study a consolidated taxonomic hypothesis of Gesneriaceae is suggested based on a genus level phylogeny, the ages of the main lineages of the family are presented, the effect of geological events are explored, the geographic origin of lineages are suggested and an insight into the effect of floral morphology on the evolution of the family is given. Limiting the taxonomic scope and focusing on a single family should help us better understand how flowering plants diversify.
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Molecular species delimitation, taxonomy and biogeography of Sri Lankan GesneriaceaeRanasinghe, Subhani Wathsala January 2017 (has links)
The plant family Gesneriaceae is represented in Sri Lanka by six genera: Aeschynanthus, Epithema, Championia, Henckelia, Rhynchoglossum and Rhynchotechum, with 13 species (plus one subspecies/variety) of which ten are endemic including the monotypic genus Championia, according to the last revision in 1981. They are exclusively distributed in undisturbed habitats, and some have high ornamental value. The species are morphologically diverse, but face a problem of taxonomic delineation, which is further complicated by the presence of putative hybrids. Sri Lanka and Indian Peninsula, represent the Deccan plate of the ancient Gondwanan supercontinent. The presence of a relict flora may indicate the significance of the geological history of the Deccan plate for the evolution of angiosperms. The high degree of endemism here, along with their affinities to the global angiosperm flora paints a complex picture, but its biogeographic history is still unclear. The pantropical family Gesneriaceae distributed in Sri Lanka and South India is therefore an appropriate study group in this context. Besides, the family itself has a complex but largely unresolved biogeographical history especially concerning the origin and diversification of Old World Gesneriaceae. Modern approaches for the taxonomic studies were applied, integrating morphological and molecular data. Multiple samples were collected for each species across their geographical distribution. Nuclear ITS and chloroplast trnL-F sequences for the taxa from Sri Lanka were used to generate regional genus phylogenies of all six genera, using maximum parsimony. The rate of evolution of the nuclear ITS region versus chloroplast trnL-F was varied greatly across the six genera studied. Molecular delimitations were mostly congruent with the classical taxonomy. Over 65 taxonomic characters were studied in detail to recognize synapomorphies for clades and taxa. A complete taxonomic revision of Gesneriaceae in Sri Lanka, including lectotypification, was conducted based on both, the molecular and morphological data. This resulted in the recognition of 14 species in the six genera, including one newly described species H. wijesundarae Ranasinghe and Mich. Möller. Henckelia communis and H. angusta were not supported molecularly as two separate entities but are recognized as two species because of consistent morphological differences between them. Henckelia humboldtiana is proposed to represent a species complex due to its highly variable and inconsistent molecular and morphological diversity and overlap with H. incana and H. floccosa; more research is needed here. National conservation assessments were conducted, and all 14 species were recognized as threatened. Biogeographic affinities of Sri Lankan Gesneriaceae were elucidated, generating a dated phylogeny using an existing matrix of four plastid gene regions; trnL-F, matK, rps16 and ndhF, amended by sequences generated in this study. The final combined matrix included 175 taxa including newly generated sequences for the 13 Sri Lankan taxa. Phylogenetic trees were generated using parsimony, maximum likelihood and Bayesian inference. Molecular dating was carried out using BEAST and ancestral area reconstruction using BioGeoBears. These analyses indicated that the six genera of Gesneriaceae arrived in Sri Lanka separately and sometimes different time periods. One lineage dated back to the early diversification of the subfamily Didymocarpoideae (generally regarded as the Old World Gesneriaceae), which occurred around the KT boundary, before the Deccan plate was connected to Asia.
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Palinotaxonomia em espécies brasileiras de Beslerieae Bartl e Napeantheae Wiehler (Gesneriaceae) - caracteres evolutivos e influência fitogeográfica / Palynotaxonomy in brazilian species of Beslerieae Bartl and Napeantheae Wiehler (Gesneriaceae) - evolutionary and phytogeographical charactersTalita Kely Belonsi 30 October 2018 (has links)
Foram estudadas a morfologia polínica de 20 espécies de Beslerieae Bartl. (Anetanthus, Besleria e Tylopsacas) e quatro espécies de Napeantheae Wiehler (Napeanthus), nativas no território brasileiro e encontradas principalmente nos biomas da Amazônia e/ou Mata Atlântica. O objetivo deste trabalho é contribuir com a caracterização morfológica das espécies, identificando dados polínicos que possam auxiliar na taxonomia do grupo, ampliando desta forma os conhecimentos sobre a diversidade polínica nos gêneros estudados e fornecendo subsídios para o melhor entendimento das relações entre as tribos brasileiras de Gesneriaceae e da evolução dos caracteres polínicos nestes gêneros. Também foi discutida a relação entre a morfologia polínica de Besleria e sua distribuição fitogeográfica. O material analisado foi obtido a partir de espécimes depositados nos herbários INPA, SP e MBM. Os grãos de pólen foram acetolisados, medidos, fotografados em microscopia óptica, microscopia eletrônica de varredura e transmissão e descritos qualitativamente. Os dados quantitativos foram analisados por meio de estatísticas descritiva e multivariada. Os grãos de pólen são mônades; isopolares; de tamanho pequeno; com grande variação de forma, podendo ser, oblatos, suboblatos, oblatos-esferoidais, prolatos-esferoidais, subprolatos ou prolatos; âmbitos circulares, circulares-lobados, subcirculares a subtriangulares. As aberturas são 3-colpadas, 3- (4) colpadas ou 3-colporadas; colpos longos, curtos ou muito curtos; estreitos a largos; extremidades afiladas ou arredondadas, algumas vezes possuindo margem, colpo constrito ou membrana ornamentada; endoabertura predominantemente lolongada, as vezes circulares. Ornamentação da exina fossulada, microrreticulada, microrreticulada-rugulada, microrreticulada-fossulada, rugulada, rugulada-perfurada. Exina variando de muito fina, fina a espessa, sexina sempre mais espessa que a nexina. Variações no tipo de abertura e nos padrões da ornamentação da exina dos grãos de pólen contribuíram para a distinção das espécies estudadas e confirmam o caráter euripolínico de Beslerieae e Napeantheae. / The pollen morphology of 24 Brazilian species of Beslerieae Bartl. (Anetanthus, Besleria and Tylopsacas) and Napeantheae Wiehler (Napeanthus) was studied, these species are native to the Amazon and / or Atlantic Forest biomes. The objective of this study is to contribute to the morphological characterization of the species, identifying pollen data that may help in the taxonomy of the group, thus increasing the knowledge about the pollen diversity and evolution in the studied genera and providing subsidies for a better understanding of the relations between the Brazilian tribes of Gesneriaceae. Also we discussed the relationship between the pollen morphology of Besleria and its phytogeographic distribution. The material analyzed was obtained from specimens deposited in the INPA, SP and MBM herbaria. The pollen grains were acetolysed, measured, photographed under light microscopy, scanning and transmission electron microscopy and described qualitatively. Quantitative data were analyzed using descriptive and multivariate statistics. The pollen grains are monads; isopolar; small size; with variation in shape, oblate, suboblate, oblate-spheroidal, prolate-spheroidal, subprolate or prolate; circular, circular-lobed, subcircular to subtriangular amb. The apertures are 3-colpate, 3-(4) colpate or 3-colporate; long, short or very short colpi and narrow to wide; with or without margo, rounded or tapered at the polar ends, sometimes constricted or with ornate membrane; endoapertures lolongate or circular. Exine fossulate, microrreticulate, microreticulate-rugulate, microreticulate-fossulate, rugulate, rugulate-perforate. Very thin, thin to thick exine, sexine always thicker than nexin. Variations in the type of aperture and patterns of exine ornamentation of the pollen grains contributed to the distinction of the species studied and confirmed the eurypalynous character of Beslerieae and Napeantheae.
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Palinotaxonomia em espécies brasileiras de Beslerieae Bartl e Napeantheae Wiehler (Gesneriaceae) - caracteres evolutivos e influência fitogeográfica / Palynotaxonomy in brazilian species of Beslerieae Bartl and Napeantheae Wiehler (Gesneriaceae) - evolutionary and phytogeographical charactersBelonsi, Talita Kely 30 October 2018 (has links)
Foram estudadas a morfologia polínica de 20 espécies de Beslerieae Bartl. (Anetanthus, Besleria e Tylopsacas) e quatro espécies de Napeantheae Wiehler (Napeanthus), nativas no território brasileiro e encontradas principalmente nos biomas da Amazônia e/ou Mata Atlântica. O objetivo deste trabalho é contribuir com a caracterização morfológica das espécies, identificando dados polínicos que possam auxiliar na taxonomia do grupo, ampliando desta forma os conhecimentos sobre a diversidade polínica nos gêneros estudados e fornecendo subsídios para o melhor entendimento das relações entre as tribos brasileiras de Gesneriaceae e da evolução dos caracteres polínicos nestes gêneros. Também foi discutida a relação entre a morfologia polínica de Besleria e sua distribuição fitogeográfica. O material analisado foi obtido a partir de espécimes depositados nos herbários INPA, SP e MBM. Os grãos de pólen foram acetolisados, medidos, fotografados em microscopia óptica, microscopia eletrônica de varredura e transmissão e descritos qualitativamente. Os dados quantitativos foram analisados por meio de estatísticas descritiva e multivariada. Os grãos de pólen são mônades; isopolares; de tamanho pequeno; com grande variação de forma, podendo ser, oblatos, suboblatos, oblatos-esferoidais, prolatos-esferoidais, subprolatos ou prolatos; âmbitos circulares, circulares-lobados, subcirculares a subtriangulares. As aberturas são 3-colpadas, 3- (4) colpadas ou 3-colporadas; colpos longos, curtos ou muito curtos; estreitos a largos; extremidades afiladas ou arredondadas, algumas vezes possuindo margem, colpo constrito ou membrana ornamentada; endoabertura predominantemente lolongada, as vezes circulares. Ornamentação da exina fossulada, microrreticulada, microrreticulada-rugulada, microrreticulada-fossulada, rugulada, rugulada-perfurada. Exina variando de muito fina, fina a espessa, sexina sempre mais espessa que a nexina. Variações no tipo de abertura e nos padrões da ornamentação da exina dos grãos de pólen contribuíram para a distinção das espécies estudadas e confirmam o caráter euripolínico de Beslerieae e Napeantheae. / The pollen morphology of 24 Brazilian species of Beslerieae Bartl. (Anetanthus, Besleria and Tylopsacas) and Napeantheae Wiehler (Napeanthus) was studied, these species are native to the Amazon and / or Atlantic Forest biomes. The objective of this study is to contribute to the morphological characterization of the species, identifying pollen data that may help in the taxonomy of the group, thus increasing the knowledge about the pollen diversity and evolution in the studied genera and providing subsidies for a better understanding of the relations between the Brazilian tribes of Gesneriaceae. Also we discussed the relationship between the pollen morphology of Besleria and its phytogeographic distribution. The material analyzed was obtained from specimens deposited in the INPA, SP and MBM herbaria. The pollen grains were acetolysed, measured, photographed under light microscopy, scanning and transmission electron microscopy and described qualitatively. Quantitative data were analyzed using descriptive and multivariate statistics. The pollen grains are monads; isopolar; small size; with variation in shape, oblate, suboblate, oblate-spheroidal, prolate-spheroidal, subprolate or prolate; circular, circular-lobed, subcircular to subtriangular amb. The apertures are 3-colpate, 3-(4) colpate or 3-colporate; long, short or very short colpi and narrow to wide; with or without margo, rounded or tapered at the polar ends, sometimes constricted or with ornate membrane; endoapertures lolongate or circular. Exine fossulate, microrreticulate, microreticulate-rugulate, microreticulate-fossulate, rugulate, rugulate-perforate. Very thin, thin to thick exine, sexine always thicker than nexin. Variations in the type of aperture and patterns of exine ornamentation of the pollen grains contributed to the distinction of the species studied and confirmed the eurypalynous character of Beslerieae and Napeantheae.
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Estudo fitoquímico da Paliavana tenuiflora Mansf. (GESNERIACEAE)Silva, Evandro Ferreira da 07 March 2014 (has links)
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Previous issue date: 2014-03-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The genus Paliavana. belongs to Gesneriaceae family and is composed of about 140
species distributed in all South and Central America (except Caribbean and Mexico).
In Brazil are found in the Southeast region of Espírito Santo, Minas Gerais and Rio
de Janeiro and Northeast region Bahia, Paraíba, Pernambuco . Occurs on rocky
outcrops of high altitude grasslands, called "rock fields", these are represented by
herbs and shrubs. Paliavana tenuiflora is found in rain forests on rocky outcrops in
Paraíba, Pernambuco, Bahia and Minas Gerais, there are no reports of
phytochemical study of this species. Thus, this study aimed to contribute to the
phytochemical study of Paliavana tenuiflora Mansf . Plant material was material was
collected in Pedra de Santo Antônio of Paraíba- Galante and deposited in the
Herbarium Prof. Lauro Pires Xavier (JPB) under code M.F. Agra, 6090. For the
phytochemical study, aerial parts of plant were subjected to extraction processes,
partition and chromatography for chemical constituents isolation. Chemicals
structures of the compounds has been assessed by spectroscopic methods such as
IR, mass and nuclear magnetic resonance 1H and 13C two-dimensional and
comparisons with literature data. From ethyl acetate phase was obtained a mixture of
glycosylated steroids (sitosterol -3-O-D- glucopyranoside and stigmasterol-3-O-Dglucopyranoside)
and tree phenolic compounds, hexacosanoic acid 2-(phydroxyphenyl)-
ethyl ester, hexacosanoic acid 2-(3, 4-dihydroxyphenyl) - ethyl ester
beyond acid 3-(3,4-dihydroxyphenyl) prop-2-enoic (caffeic acid), being this two
esters reported for the first time in the genus thus contributing to the chemical study
of the genus Paliavana. / O gênero Paliavana pertence a família Gesneriaceae e é composto por cerca de
140 gêneros que se distribuem em toda América do Sul e Central, (exceto Caribe e
México). No Brasil são encontradas na região Sudeste no Espírito Santo, Minas
gerais e Rio de Janeiro e Nordeste na Bahia, Paraíba e Pernambuco. Ocorre em
afloramentos rochosos dos campos de altitude, chamados de ―campos rupestres‖,
estes são representados pelas ervas e arbustos. Paliavana tenuiflora é encontrada
em florestas úmidas em afloramentos rochosos na Paraíba, Pernambuco, Bahia e
Minas Gerais e não há relatos de estudo fitoquimico dessa espécie. Desta forma,
esse trabalho objetivou contribuir com o estudo fitoquímico da Paliavana tenuiflora
Mansf. O material vegetal foi coletado na Pedra de Santo Antônio, município de
Galante- Paraíba e depositado no Herbário Prof. Lauro Pires Xavier (JPB) com o
código M.F. Agra, 6090. Para o estudo fitoquímico, partes aéreas do vegetal foram
submetidas a processos de extração, partição e cromatografia para isolamento dos
constituintes químicos. As estruturas químicas dos compostos foram determinadas
por métodos espectroscópicos, tais como: infravermelho, massas e ressonância
magnética nuclear de 1H, 13C bidimensionais e comparações com modelos da
literatura. Da fase acetato de etila obteve-se uma mistura de esteroides glicosilados
(sitosterol-3-O-D-glicopiranosídeo e estigmasterol-3-O-D-glicopiranosídeo) além de
três compostos fenólicos, hexacosanoato 2-(p-hidroxifenil)-de etila, hexacosanoato
2-(3, 4-dihidroxifenil)- de etila além do ácido 3-(3,4-dihidroxifenil) prop-2-enoico(ácido
cafeico), sendo esses dois ésteres relatados pela primeira vez no gênero,
contribuindo, portanto para o estudo químico do gênero Paliavana.
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Adaptation florale aux pollinisateurs : étude des Gesneriaceae antillaises et de l’Impatiente du CapFaure, Julie 10 1900 (has links)
L’environnement a un effet considérable sur les végétaux par différents facteurs abiotiques (climat,
sol, urbanisation) ou biotiques (pollinisateurs, herbivores). Les fortes pressions de sélection
exercées par ces facteurs sur certains traits phénotypiques aboutissent souvent à des adaptations
chez les plantes. Les pollinisateurs exercent une pression de sélection sur les traits floraux qui
résultent en des adaptations convergentes que l’on appelle syndromes de pollinisation. L’étude de
ses syndromes, mais aussi de la performance de pollinisation de chaque visiteur, permet de mieux
comprendre l’intensité de cette pression de sélection ainsi que l’évolution florale.
Dans cette thèse, nous nous sommes appuyés sur l’utilisation de deux modèles d’études végétaux :
la famille des Gesneriaceae des Antilles et l’Impatiente du Cap. Ces deux modèles, de par leurs
stratégies de pollinisation et leurs variations florales, sont appropriés pour étudier l’adaptation
florale aux pollinisateurs. Nous avons ainsi pu tester 1) si la forme florale est expliquée par la forme
du bec des colibris pollinisateurs chez les Gesneriaceae antillaises ; 2) si l’espèce Rhytidophyllum
bicolor Urb. est généraliste en pollinisation et si ses différents types fonctionnels de pollinisateurs
ont une performance de pollinisation similaire ; 3) si l’urbanisation affecte la forme florale de
l’espèce Impatiens capensis Meerb., à travers des changements dans les communautés de
pollinisateurs.
Pour tester ces hypothèses, des approches de morphométries géométriques ont été utilisées
(hypothèses 1 et 3), ainsi que des observations de pollinisation in situ et la mesure du taux de visite
(hypothèses 2 et 3). La mesure de performance de pollinisation a été réalisé via le comptage des
grains de pollen déposés sur le stigmate après chaque visite, et à la mesure du taux de visite. Enfin,
des tests statistiques (ANOVA, régressions linéaires) et analyses multivariées (analyses de
redondance, analyse en composantes principales) ont été réalisées sur les données obtenues pour
chaque étude.
Les résultats de la première étude montrent une corrélation positive entre la longueur de la corolle
de fleurs spécialistes aux colibris et la longueur du bec des pollinisateurs. Bien que moins
significatifs, les résultats des comparaisons de formes globales, obtenues par application de
morphométrie géométrique, indiquent que cette approche est prometteuse pour ce genre d’analyse.
Nous avons démontré que la forme florale des fleurs généralistes est impactée par les colibris
pollinisateurs, bien que d’une manière différente des spécialistes.
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Pour l’hypothèse 2, la prédiction de stratégie de pollinisation de l’espèce Rhytidophyllum bicolor a
été validée, puisque cette plante est pollinisée par des colibris, chauves-souris et abeilles.
Cependant, face au déclin des populations de colibris après le passage de l’ouragan Matthew sur
Haïti, seules les performances de pollinisation des abeilles et des chauves-souris ont pu être
mesurées. Les résultats montrent que les chauves-souris sont des pollinisateurs efficaces et
conséquents, bien que la performance des abeilles ne soit pas négligeable. Il a ainsi pu être mis de
l’avant que la stratégie de pollinisation généraliste semble être un avantage pour les plantes
présentes dans les zones sujettes aux fluctuations de populations de pollinisateurs, comme cela peut
souvent être le cas sur les îles à la suite du passage d’un ouragan.
La troisième étude montre que l’urbanisation n’a pas d’effet direct sur la forme florale de
l’Impatiente du Cap, mais qu’elle a des effets indirects significatifs via les changements causés sur
les communautés de pollinisateurs. Sur les six sites échantillonnées les pollinisateurs principaux,
Bombus sp. Latreille et Apis mellifera Linnaeus, sont les mêmes. Cependant les taux de diversité
obtenus montrent une variation entre les sites, due à la présence de certaines espèces de
pollinisateurs occasionnels dans certains sites et pas dans d’autres. Ces taux ne sont pas plus faibles
dans les sites les plus urbains. Les résultats indiquent que certaines formes florales sont associées
à des espèces de pollinisateurs particulières. Les différentes espèces de pollinisateurs ayant une
pression de sélection différente sur les traits floraux, l’urbanisation a ainsi un impact indirect sur la
forme florale chez l’espèce étudiée.
À travers trois études différentes, cette thèse a mis en avant l’impact que l’environnement peut
avoir sur les traits floraux, de manière indirecte, via les pollinisateurs. Alors que la deuxième et
troisième étude ont montré la pression exercée par les pollinisateurs sur les traits floraux dans
différents cas de perturbations de l’habitat, la première étude a permis de mieux comprendre
l’adaptation remarquable des fleurs à leurs pollinisateurs, même pour des espèces généralistes en
pollinisation. / The environment has a considerable effect on plants through various abiotic (climate, soil,
urbanization) or biotic (pollinators, herbivores) factors. The strong selection pressures exerted by
these factors on phenotypic traits often results in adaptations. Pollinators exert selection pressure
on floral traits that result in converging adaptations called pollination syndromes. The study of
syndromes, as well as the pollination performance of each floral visitor, allows us to better
understand the intensity of a/biotic selection pressure and floral evolution.
In this thesis, we relied on two plant models: the Gesneriaceae family in the Antilles, and the
common Jewelweed, Impatiens capensis Meerb. Due to their pollination strategies and their floral
variation, both of these models are suitable for studying floral adaptation to biotic factors,
specifically, their pollinators. We were thus able to test the following hypotheses: 1) whether the
floral form is explained by the beak shape of pollinating hummingbirds in West Indies Gesnericeae;
2) whether the Gesnericeae Rhytidophyllum bicolor Urb. has a generalist strategy for pollination
and whether their different functional types of pollinators have similar pollination performances;
3) whether urbanization affects the floral form of the common Jewelweed, through changes in
pollinator communities.
To test these hypotheses, geometric morphometric approaches were used (hypotheses 1 and 3), as
well as in situ pollination observations, and estimation of the visitation rate (hypotheses 2 and 3).
Pollination performance was measured by counting pollen grains deposited on the stigma after each
visit, and by measuring the visitation rate. Finally, statistical tests (ANOVA, linear regressions)
and multivariate analyses (redundancy analysis, principal component analysis) were carried out on
the data obtained to test each hypothesis.
The first results show a positive correlation between the length of the corolla of flowers specialized
for hummingbirds and the beak length of pollinators. Although less significant, our results of the
comparisons of global shapes, obtained by applying geometric morphometry, indicate that this
approach is promising for this kind of analysis. We show that the floral form of generalist flowers
is impacted by pollinating hummingbirds, albeit in a different way from specialists.
For the second hypothesis, our prediction that R. bicolor has a generalist pollination strategy was
validated, since this plant is pollinated by hummingbirds, bats and bees. However, faced with the
decline in hummingbird populations after Hurricane Matthew hit Haiti in 2016, only the pollination
performance of bees and bats could be measured. Our results show that bats are efficient and
consistent pollinators of R. bicolor, although the performance of bees is not negligible. Thus, it has
been possible to put forward that the generalist pollination strategy seems to be an advantage for
plants present in areas subject to fluctuations in their pollinator populations, as can often be the
case on hurricane-prone islands.
The third study shows that urbanization does not have a direct effect on the flower form of common
Jewelweed, but that urbanization does have significant indirect effects through changes caused on
pollinator communities. At the six sites sampled, the main pollinators, Bombus sp. Latreille and
Apis mellifera Linnaeus, are the same. However, diversity rates show variation between sites, due
to the presence of certain species of occasional pollinators in some sites and not in others. These
rates are not lower in the most urban sites. Our results indicate that certain floral forms are
associated with particular pollinator species. Since different pollinator species have different
selection pressures on floral traits, urbanization has an indirect impact on the floral form in the
species studied.
Through three different studies, this thesis highlighted the impact that the environment can have on
floral traits, indirectly, via pollinators. While the second and third studies showed the pressure
exerted by pollinators on floral traits in different cases of habitat disturbance, the first study helped
to better highlight the remarkable adaptation of flowers to their pollinators, even for generalist
species in pollination.
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Identification de gènes impliqués dans la variation morphologique des fleurs entre deux espèces du genre RhytidophyllumPoulin, Valérie 08 1900 (has links)
Les adaptations florales à des pollinisateurs comme les changements de forme de la corolle
entraînent souvent un isolement reproducteur et donc la spéciation. Malgré leur importance
écologique, les mécanismes génétiques à l'origine de cette diversité de caractères sont encore mal
compris, surtout en dehors des espèces modèles. L’objectif de mon projet de maîtrise était donc
d'identifier les gènes impliqués dans la variation de la forme de la corolle entre deux espèces du
genre Rhytidophyllum (famille des Gesneriaceae), qui ont des modes de pollinisation différents.
La première, R. rupincola, a des fleurs tubulaires et est strictement pollinisée par les colibris, tandis
que la seconde, R. auriculatum, a des fleurs plus ouvertes et est pollinisée par les colibris et les
chauves-souris. Dans cette étude, nous avons fait une revue de littérature et utilisé une approche
de transcriptomique comparative pour identifier des gènes candidats qui pourraient expliquer la
variation de la forme florale entre R. auriculatum et R. rupincola. Nous avons ensuite testé leur
association avec la variation de la forme de la corolle en utilisant la cartographie de loci de traits
quantitatifs (QTLs) pour une population hybride F2. Les résultats ont montré que 7 des 29 gènes
candidats étaient associés à 8 QTLs différents. La répartition et la fonction supposée de ces gènes
suggèrent que la forme de la corolle est un trait complexe. Ce type d'étude est rarement entrepris
chez des espèces non-modèles, mais il est important afin d'intégrer la génétique du développement
floral dans une perspective évolutive. / Floral adaptations to specific pollinators like corolla shape changes often result in reproductive
isolation and thus speciation. But despite their ecological importance, the genetic mechanisms
behind this diversity of traits are still poorly understood, especially outside model species. Hence,
our goal is to identify genes involved in corolla shape variation between two species of the
Rhytidophyllum genus (Gesneriaceae family) from the West Indies, which is characterized by
shifts in pollination modes during its evolution. The first one, R. rupincola, has a tubular corolla
and is strictly pollinated by hummingbirds. The second one, R. auriculatum, has more open flowers
and is pollinated by both hummingbirds and bats. We know from previous work that the variation
in morphological floral traits between these species is explained by a few quantitative trait loci
(QTLs) of moderate to small effect (Alexandre et al., 2015), but we still do not know which genes
underly these loci. In this study, we surveyed the literature and used a comparative transcriptomic
approach to identify candidate genes that could explain floral variation between R. auriculatum
and R. rupincola. We then tested their association with corolla shape variation using QTL mapping
for a F2 hybrid population. Results showed that 7 out of 29 candidate genes were included within
8 different QTL. The number, repartition and putative function of these genes suggest that corolla
shape is a complex trait. This sort of investigation is rarely undertaken in non-model species, but
is important to integrate developmental genetics with an evolutionary perspective.
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Comparative analysis of corolla shape transitions in the sister genera Gesneria and Rhytidophyllum (Gesneriaceae)Vergolino Martini, Carolina 12 1900 (has links)
La convergence, soit l'acquisition indépendante de phénotypes similaires, est un aspect intéressant
de la diversité qui peut fournir des informations importantes sur la nature du changement évolutif.
Dans les systèmes végétaux, les syndromes de pollinisation – combinaisons de traits floraux
adaptés à leurs pollinisateurs – constituent de bons exemples de convergence se produisant sur les
fleurs. Nous avons utilisé une approche globale incluant la morphologie cellulaire et la
transcriptomique pour analyser la convergence de formes florales de deux syndromes de
pollinisation trouvés dans les genres frères non Gesneria et Rhytidophyllum (Gesneriaceae), un
groupe antillais qui contient environ 81 espèces avec différentes morphologies et stratégies de
pollinisation variables dans leur degré de spécialisation écologique. Il a déjà été démontré que la
forme des fleurs joue un rôle important dans l’évolution de ce groupe, qui présente de nombreuses
transitions entre les stratégies de pollinisation. Nous avons testé la présence de convergence dans
les forms de cellules de la corolle et dans l’expression des gènes de la corolle en utilisant (1) une
analyse pour mesurer la forme des cellules de pétales matures à l’aide d’un modèle phylogénétique
mixte et (2) une approche transcriptomique comparative combinant l'expression différentielle des
gènes (DESEq2) et l'analyse de co-expression (WGCNA) de gènes exprimés dans certaines
regions précises des pétales. Toutes les analyses ont pris en compte les relations phylogénétiques
entre les espèces. Nous avons trouvé une anisotropie cellulaire convergente se produisant dans les
régions distales des pétales au sein des espèces du même syndrome (forme). Nous avons également
constaté une plus grande similarité dans les modèles d'expression génique entre les espèces d’un
même syndrome qu'entre les espèces apparentées et avons produit une liste de 203 gènes
potentiellement associés aux formes de fleurs convergentes. La convergence morphologique
florale observée dans les syndromes de pollinisation des espèces étudiées se retrouve tant au niveau
cellulaire qu'au niveau de l'expression. Les résultats présentés ici amplifient les informations de
base sur la famille des Gesneriaceae pour les études futures sur la convergence et la forme florale
dans le groupe. / Convergence, the independent acquisition of similar phenotypes, is an important aspect of
diversity that can provide valuable insights about the nature of evolutionary change. In plants,
pollination syndromes - combinations of floral traits adapted to their pollinators - make good
examples of convergence occurring on flowers. We used a comprehensive approach that includes
cell morphology and transcriptomics to analyze the floral shape convergence of two pollination
syndromes found in the sister genera Gesneria and Rhytidophyllum (Gesneriaceae), an Antillean
group that contains approximately 81 species with different morphologies and pollination
strategies varying in their degree of ecological specialization. Flower shape has already been found
to play an important role in the evolution of this group, which shows many transitions between
pollination strategies. We tested convergence in the corolla cell shapes and in gene expression for
the pollination syndromes using (1) cell measurement statistical analysis (Phylogenetic Mixed
Model) of mature petals and (2) a comparative transcriptomic approach that combined differential
gene expression (DESEq2) and co-expression analysis (WGCNA) in genes expressed in specific
regions of the petals. All analyses took the phylogenetic relationships of the species into account.
We found convergent cellular anisotropy occurring in the distal regions of the petals within species
of the same syndrome (form). We also found greater similarity in gene expression patterns
occurring among species of the same syndromes than between more closely related species and
produced a list of 203 genes potentially associated with convergent flower forms. The floral
morphological convergence observed in the pollination syndromes of the investigated species is
paralleled both at the cellular and expression levels. The results shown here amplify the
background information of the Gesneriaceae family for future studies of convergence and floral
form in the group.
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