Associação micorrízica e propagação simbiótica de espécies de Hadrolaelia e Hoffmannseggella (Orchidaceae)

• Ano de defesa: 2012
• Autor(a) principal: Cunha, Melissa Faust Bocayuva
• Orientador(a): Otoni, Wagner Campos
• Banca de defesa: Viccini, Lyderson Facio , Pereira, Marlon Corrêa
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Doutorado em Botânica
• Departamento: Botânica estrutural; Ecologia e Sistemática
• País: BR
• Palavras-chave em Português: Floresta Atlântica; Espécies ameaçadas; Conservação
• Palavras-chave em Inglês: Atlantic Forest; Endangered species; Conservation
• Área do conhecimento CNPq: CNPQ::CIENCIAS BIOLOGICAS::BOTANICA
• Link de acesso: http://locus.ufv.br/handle/123456789/371

Three species of endangered orchids, Hoffmannseggella caulescens, H. cinnabarina and Hadrolaelia jongheana were selected for this study because they are key species of the current situation one of the most important hotspot in the world, the Atlantic Forest. To start an integrated conservation model of for endangered orchids, the objectives proposed in this work are to characterize morphological and molecular Rhizoctonia-like isolates associated with these orchids, then protocols for propagation in vitro Epulorhiza spp. and acclimatization of inoculated plants in a green house, testing alternative substrates. Through molecular and morphological characterization, 30 Rizocthonia-like were identified as Epulorhiza spp. Isolates of rupicolous Hoffmannseggella species represent two clades very near Tulaneslla calospora. Isolates of H. jongheana are phylogenetically distants between them and to four species close to Tulasnella sp. Our results revealed that tropical orchids, epiphytes and rupicolous are probably generalists in their associations with mycorrhizal fungi of the genus Epulorhiza sp. The molecular tools have provided a more accurate identification than morphological characterization. Four Epulorhiza isolates promoted the germination of seeds, one (M65) promoted germination and growth rates significantly higher than the others. The seeds of all species also germinated in not inoculated treatments (B & G, Knudson and OMA), but for OMA treatment was observed only Stage 2. The GI of Hoffmannseggella species was significantly higher in the M65 treatment, but for H. jongheana in two treatments, HJ21B and Knudson, presented similar results. The epiphyte H. jongheana proved to be less dependent on mycorrhiza for germination and development of protocorms that rupicolous species. Finally, the proposed acclimatization methodology also demonstrates to be effective, obtaining the development of seedlings in all treatments with high percentages of survival for all species, as well as the root colonization still observed over 7 months of acclimatization of the three orchid studied .