Contribuições para o conhecimento dos fungos da ordem Meliolales e sua posição filogenética

• Ano de defesa: 2012
• Autor(a) principal: Pinho, Danilo Batista
• Orientador(a): Pereira, Olinto Liparini
• Banca de defesa: Soares, Dartanhã José , Evans, Harold Charles , Kasuya, Maria Catarina Megumi
• Tipo de documento: Tese
• Tipo de acesso: Acesso embargado
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Fitopatologia
• Departamento: Etiologia; Epidemiologia; Controle
• País: BR
• Palavras-chave em Português: Pyrenomycetes; Filogenia; Hevea brasiliensis
• Palavras-chave em Inglês: Pyrenomycetes; Phylogeny; Hevea brasiliensis
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOSSANIDADE::FITOPATOLOGIA
• Link de acesso: http://locus.ufv.br/handle/123456789/1072

The taxonomy of the order Meliolales is historically based on the combination of the supposed specificity in relation to the host species and morphology of fungal species. In the last decades, molecular techniques have been widely utilized for the characterization of fungal species, validation of morphological characters and verification of the supposed importance of specificity in relation to hosts at the delimitation of species. To test the hypothesis that the traditional bases of taxonomy in this order have support from molecular analysis, DNA extraction from specimens belonging to genera Amazonia, Appendiculella, Asteridiella, Irenopsis and Meliola was performed and sequences of the 18S and 28S regions of the rDNA and the second largest subunit of RNA polymerase 2 (RPB2) were obtained. Analyzing the 18S, 28S and RPB2 regions it was possible to distinguish the order Meliolales from the other orders of the class Sordariomycetes and prove that this order belongs to the subclass Sordariomycetidae. The analysis of the 18S and 28S regions of the rDNA indicate that the classification of the Meliolales based on morphological traits and comparison of species within each botanical family should be revise, for although the Amazonia, Appendiculella, Asteridiella, Irenopsis and Meliola species clustered in different clades, Asteridiella species clustered with species of the genus Meliola, probably indicating that the group is polyphyletic. We can also conclude that species identified in the same botanical family are not phylogenetically related. Irenopsis cornuta is not a basal species for most of the representatives of the genus, although this taxon is associated with a pteridophyte (Lygodium volubile). When populations of the model species were collected at different habitats we could observe a clear plasticity within the species, because specimens collected at a) a commercial cultivation of rubber trees (Espirito Santo State); b) a seedling nursery of rubber trees (Para State); and c) rubber trees native of the Amazon forest (Para State) showed great morphological variation. An index of the species of black mildews reported in Brazil was elaborated to subsidize the expansion of knowledge of the diversity of this fungal group in the Brazil.