Ciências Biológicas e da Saúde
URI permanente desta comunidadehttps://locus.ufv.br/handle/123456789/3
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Resultados da Pesquisa
Item Systematic of foliicolous and phytopathogenic fungi associated with native plants of the Brazilian Cerrado stricto sensu(Universidade Federal de Viçosa, 2019-02-19) Abreu, Vanessa Pereira de; Pereira, Olinto Liparini; http://lattes.cnpq.br/1348590876266814Cerrado is a home of huge diversity of endemic species of plants and animals. Therefore, it is considered a global biodiversity hotspot, however it is the Brazilian biome that has lost most native vegetation cover in recent years. Recent studies emphasize that the Cerrado may suffer the greatest extinction of plant species and consequently, the fungi suffer the same effects, because they are associated with vegetation and soil. They may also be threatened, and few studies have been carried out to discover the fungal diversity associated with Cerrado plant species. Knowledge of Cerrado micodiversity began with the activities of European collectors in the late 19th century and descriptions of new species and genera were based only on fungi morphology. Even the most recent descriptions were based only on morphological data without molecular information, which would allow the comparison and phylogenetic analyzes with other species in the world. The objective of this work was to determine and describe the foliicolous and phytopathogenic mycobiota associated with Cerrado native plants, based on morphological and molecular analyzes, as well as to establish the phylogenetic positioning of the species found and to initiate a fungal culture collection of this biome. A total of 82 plant materials were collected and 92 fungi belonging to several genera were isolated, when possible, and of these, six genera were selected for the taxonomy and molecular phylogeny studies. This study reports 3 possible new genera (Paraopeba, Dictyosporina and Trochilispora); 5 possible new species (Mastigosporella pigmentata, Pseudocercospora styracina, Trochilispora schefflerae, Dictyosporina ferruginea and Paraopeba schefflerae) and a possible epitypification (Uleomyces sanguineus) will be proposed. These results corroborate the great diversity of fungal species found by other researchers in the Cerrado biome and represent a contribution to the knowledge of the diversity of follicolous and phytopathogenic fungi associated with different native plants of the Floresta Nacional de Paraopeba (FLONA - Paraopeba).Item Fungal Community profile of Zygopetalum maxillare and Zygopetalum mackayi (ORCHIDACEAE)(Universidade Federal de Viçosa, 2016-07-22) Veloso, Tomás Gomes Reis; Kasuya, Maria Catarina Megumi; http://lattes.cnpq.br/7872519897730290The orchids seeds are minute and easily dispersed by the wind. However, due to this reduced size there is no enough reserve tissue to allow seed germination, so that the nutrients uptake in the in the first steps of life cycle is done by the association to a mycorrhizal fungus. Once distinct orchids species associate can associate with distinct fungi is important to know for each orchid which are the fungi associate, because the conservation of threatened orchids requires the conservation of the fungi. Here, culture-depedent and independent on approaches were used for studying the fungal profile community of two orchid species, Zygopetalum maxillare, an epiphyte, and Zygopetalum mackayi, a terrestrial. The results of culture-independent methods showed fungi of Ascomycota as the majority present. Both Zygopetalum species associate with Sebacinaceae and Ceratobasidiaceae, however, while species of Ceratobasidiaceae are shared by both orchids, Sebacinaceae are not. These results were corroborated by the results of culture-dependent approaches, although no fungi of Ceratobasidiaceae could be isolated. The isolates obtained by this study are potential to be used in seed germination and seedling development of Z. maxillare and Z. mackayi and for future use in reintroduction program.Item Taxonomy and phylogeny of mycorrhizal fungi associated with Gomesa recurva (Orchidaceae) and characterization of endophytic bacteria of orchids(Universidade Federal de Viçosa, 2020-09-29) Cruz, Everaldo da Silva; Kasuya, Maria Catarina Megumi; http://lattes.cnpq.br/5276773620451113Orchids are dependent on an external source of carbon, due to the absence of reserve tissue in their seeds. Thus, in order to obtain carbon and other nutrients, they associate with mutualistic fungi in their root system, which are known as orchidoid mycorrhizal fungi. These fungi are characterized by forming pellets, a set of entwined hyphae inside the roots. In addition, they are able to colonize the embryo cells of the orchid seeds and can remain until the adult stage of the plant. Orchids can associate with other microorganisms such as endophytic bacteria, which can bring several benefits such as growth promotion, due to the production of phytohormones, biological nitrogen fixation, phosphate solubilization, production of siderophores, among others. The objective of this work was (1) to study the taxonomic diversity of mycorrhizal fungi associated with Gomesa recurva (2) to identify and characterize endophytic bacteria associated with Gomesa recurva R. Br. And Zygopetalum maxillare Lodd. By phylogenetic and morphological analyzes, all isolates of G. recurva belong to a new species of Ceratobasidium. Five bacterial isolates were obtained for each species of orchid. By sequencing the 16S rRNA region, it was found that they belonged to the genera Pseudomonas and Paraburkholderia, which, by in vitro tests, showed that they have the capacity to perform biological nitrogen fixation, to produce indole-3-acetic acid phytohormone (AIA) and solubilizing calcium phosphate. The isolates of fungi and bacteria obtained have the potential to be used for the production of orchid seedlings. Keywords: Phylogeny. Fungi. Bacteria. Phytohormones.