O presente trabalho refere-se ao levantamento das espécies do gênero Begonia L. (Begoniaceae) de Minas Gerais. A família inclui dois gêneros: Hillebrandia Oliv., monotípico, endêmico do Arquipélago do Havaí e Begonia L. com cerca de 1400 espécies de ervas e subarbustos, largamente distribuídas pelos trópicos e subtrópicos. A maioria das espécies de Begonia apresenta potencial ornamental com folhas vistosas, frequentemente variegadas e diversas espécies são cultivadas no Brasil com essa finalidade. As espécies nativas do Brasil (aproximadamente 240) concentram-se na Mata Atlântica, sendo raras as espécies Amazônicas. De acordo com o levantamento, são encontradas 31 espécies de Begoniaceae em Minas Gerais, crescendo preferencialmente em formações cujo índice higrométrico é bastante elevado, à margem de cursos dágua, nas grotas úmidas, sobre ou entre rochas. O estudo baseou-se no levantamento bibliográfico, consulta a herbários e observações de campo. Constam também descrições, ilustrações, mapas de distribuição geográfica e comentários. / The present work refers to the taxonomic survey of the genus Begonia L. (Begoniaceae) in Minas Gerais State. This family is comprised of two genera: Hillebrandia Oliv., with one species that is endemic to the Hawaiian Islands and the only member of the family native to those islands, and Begonia L. with approximately 1,400 species of herbs and subshrubs that are widely distributed in tropics and subtropics. Most species of the genus Begonia have ornamental potential with showy leaves, frequently variegated and many species are cultivated in Brazil for this purpose. The native Brazilian species (240 - estimated figure) is concentrated on the Atlantic Forest, being Amazonian species rare. According to the survey, there are 31 species of the Begoniaceae in Minas Gerais State, growing up preferably near water, on the moist places, above or among rocks. The study was based on bibliographic review, consults to herbaria, collections and fields observation. Descriptions, illustrations, geographical distribution maps and comments are also presented about each species.

O presente trabalho refere-se ao levantamento das espécies do gênero Begonia L. (Begoniaceae) de Minas Gerais. A família inclui dois gêneros: Hillebrandia Oliv., monotípico, endêmico do Arquipélago do Havaí e Begonia L. com cerca de 1400 espécies de ervas e subarbustos, largamente distribuídas pelos trópicos e subtrópicos. A maioria das espécies de Begonia apresenta potencial ornamental com folhas vistosas, frequentemente variegadas e diversas espécies são cultivadas no Brasil com essa finalidade. As espécies nativas do Brasil (aproximadamente 240) concentram-se na Mata Atlântica, sendo raras as espécies Amazônicas. De acordo com o levantamento, são encontradas 31 espécies de Begoniaceae em Minas Gerais, crescendo preferencialmente em formações cujo índice higrométrico é bastante elevado, à margem de cursos dágua, nas grotas úmidas, sobre ou entre rochas. O estudo baseou-se no levantamento bibliográfico, consulta a herbários e observações de campo. Constam também descrições, ilustrações, mapas de distribuição geográfica e comentários. / The present work refers to the taxonomic survey of the genus Begonia L. (Begoniaceae) in Minas Gerais State. This family is comprised of two genera: Hillebrandia Oliv., with one species that is endemic to the Hawaiian Islands and the only member of the family native to those islands, and Begonia L. with approximately 1,400 species of herbs and subshrubs that are widely distributed in tropics and subtropics. Most species of the genus Begonia have ornamental potential with showy leaves, frequently variegated and many species are cultivated in Brazil for this purpose. The native Brazilian species (240 - estimated figure) is concentrated on the Atlantic Forest, being Amazonian species rare. According to the survey, there are 31 species of the Begoniaceae in Minas Gerais State, growing up preferably near water, on the moist places, above or among rocks. The study was based on bibliographic review, consults to herbaria, collections and fields observation. Descriptions, illustrations, geographical distribution maps and comments are also presented about each species.

Call number: LD2668 .T4 1986 R35 / Master of Science / Horticulture, Forestry, and Recreation Resources

Orientador: Marlies Sazima / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-15T04:48:07Z (GMT). No. of bitstreams: 1 Wyatt_GrahamEdward_M.pdf: 9293107 bytes, checksum: b33c1975f0e55d35f2d12ecf77d49b40 (MD5) Previous issue date: 2009 / Resumo: Neste estudo, são apresentadas informações sobre a biologia floral, polinização e reprodução de 13 espécies monóicas de Begônia (Begoniaceae) ocorrentes no Parque Estadual da Serra do Mar, São Paulo. A fenologia da reprodução destas espécies é anual e as flores apresentam tépalas brancas com algumas variações, odor leve e agradável, não há néctar sendo pólen o único recurso, os elementos reprodutivos são de cor amarela, sendo os estigmas amplos e os estames numerosos. A antese é diurna e a duração das flores é longa (seis a 15 dias). A presença de numerosas semelhanças morfológicas entre flores estaminadas e pistiladas das espécies apóia a hipótese de mimetizmo intersexual. Não ocorre apomixia, as autopolinizações em B. integerrima e B. itatinensis não desenvolveram frutos e sementes, mas a formação de frutos em condições naturais é alta para várias espécies (77 - 88%). Não houve o desenvolvimento de tubos polínicos em flores autopolinizadas de B. integerrima, indicando a possível ocorrência de autoincompatibilidade esporofitica. A presença de grande quantidade de tubos polínicos atingindo os óvulos em flores de condições naturais indica que as flores receberam altas cargas de pólen. Os polinizadores principais foram abelhas de pequeno porte pertencentes a diversas tribos de duas famílias. Dez espécies de abelhas foram registradas em oito espécies de Begônia e o modo de obtenção de recursos é por vibração, com exceção de Trigona spinipes. As visitas às flores estaminadas foram mais freqüentes que às para flores pistiladas, cujas visitas são por engano, uma vez que não oferecem recurso. Assim também, a duração das visitas às flores pistiladas foi significativamente mais curta do que a duração em flores estaminadas (P < 0.001). Concluímos que visitas às flores pistiladas, embora sejam relativamente menos freqüentes do que as para flores estaminadas, ocorrem por engano e com freqüência suficiente para o sucesso reprodutivo destas espécies / Abstract: The reproductive biology of 13 monoecious species of Begonia (Begoniaceae) that occur in the Serra do Mar State Park, São Paulo, Brazil, was investigated. The reproductive phenology of these species is annual and present flowers with white tepals with some variations, light and agreeable odor, present pollen as a reward, lack nectar, yellow reproductive elements, ample style/stigma and numerous stamens. Anthesis is diurnal and floral duration is long (6 - 15 days). The presence of numerous morphological similarities between staminate and pistillate flowers of these species supports the intersexual mimicry hypothesis. Of 11 species tested, none proved to be apomictic, despite high levels of fruit-set (77 - 88%) under natural conditions. Self-pollinations of B. integerrima and B. itatinensis produced no fruits or seeds, and the complete absence of pollen tubes in self-pollinated flowers of B. integerrima suggests that the species is genetically self-incompatible. Flowers pollinated under natural conditions showed many pollen tubes that reached ovules, suggesting that adequate numbers of compatible pollen grains were transported by pollinators. The principal pollinators were small bees of the Apidae and Halictidae. Ten species of bees were observed to visit eight species of Begonia, and pollen collection occurred by means of vibration, except for Trigona spinipes. Visits to rewarding staminate flowers were significantly more frequent than visits to unrewarding pistillate flowers. Duration of visits to pistillate flowers also were significantly shorter than the duration of visits to staminate flowers. We conclude that mistake visits to pistillate flowers, though relatively less frequent than visits to staminate flowers, occur by mistake but with sufficient frequency to allow for successful reproduction in natural populations of these species / Mestrado / Mestre em Biologia Vegetal

The island of Sri Lanka’s exceptional biodiversity and enigmatic biogeography begs investigation, as the island is key in understanding the evolution of the Asian tropical flora. Since the Jurassic, Sri Lanka has been subjected to remarkable tectonic changes, thus its flora could have been influenced by that of a number of nearby landmasses, as well giving Sri Lanka the potential to have played a wider role in the assemblage of floras elsewhere. Firstly, as Sri Lanka originated as a fragment of the supercontinent Gondwana, part of its flora may contain Gondwanan relict lineages. There is also the potential for immigration from Laurasia after the Deccan Plate collided with it 45-50 Mya. Further, Sri Lanka may harbour floristic elements from nearby land masses such as Africa and Southeast Asia as a result of long distance dispersals, and in situ speciation has the potential to have played an important role in enhancing the endemic Sri Lankan flora. I tested the relative contributions of the above hypotheses for the possible origins of the Sri Lankan flora using three representative families, Begoniaceae, Sapotaceae and Zingiberaceae. These families represent both herbaceous and woody elements, and have high diversity across the tropics. Dated molecular phylogenies were constructed for each family. I used recent analytical developments in geographic range evolution modelling and ancestral area reconstruction, incorporating a parameter J to test for founder event speciation. A fine scale area coding was used in order to obtain a better picture of the biogeography of continental Asia. Amongst all the models compared, a dispersal-extinction cladogenesis model incorporating founder event speciation proved to be the best fit for the data for all three families. The dates of origin for Sri Lankan lineages considerably post-date the Gondwanan break up, instead suggesting a geologically more recent entry followed by diversification of endemics within the island. The majority of Sri Lankan lineages have an origin in the Sunda Shelf (53%). Persistence of warm temperate and perhumid climate conditions in southwestern Sri Lanka resembling those of Peninsular Malaysia and Sumatra could have facilitated suitable habitats for these massive dispersals from the Sunda Shelf region. Some trans-oceanic long distance dispersals from Africa (11%) are also evidenced, again these are too young to accept a hypothesis of dispersal during the Deccan Plate’s migration close to the African coast during the late Cretaceous, but occurred later during the Miocene. Further, some lineages of Laurasian origin (20%) are evidenced in the Zingiberaceae with ancestral areas of China and Indochina, which is congruent with a post collision invasion. Among the families tested, dispersals have occurred stochastically, one during the Eocene, six during the Oligocene, seven during the Miocene, two during the Pliocene and one during the Pleistocene. The highest number of dispersals occurred during the Miocene when a warm climate was prevailing during the Miocene thermal maximum. My results confirm that in situ speciation is an important contributor to the Sri Lankan flora. More rapid radiation of endemics has occurred during Pliocene-Pleistocene; two endemics in Begoniaceae, ten endemics in Sapotaceae and ten endemics in Zingiberaceae have evolved in situ during this period. Sri Lanka will have been subjected to expansion and contraction of climatic and vegetation zones within the island during glacial and interglacial periods, potentially resulting in allopatric speciation. As a conclusion, long distance dispersals have played a prominent role in the evolution of the Sri Lankan flora. The young ages challenge the vicariant paradigm for the origin and current disjunct distributions of the world’s tropical lineages and provide strong evidence for a youthful tropics at the species level. The thesis contains six chapters; first two are introductory chapters, then there are three analytical chapters, one for each family, and finally a summary chapter is provided. Each analytical chapter is written as a stand-alone scientific publication, thus there is some repetition of relevant content in each.