Estrutura e relações genéticas de Curvularia eragrostidis no Nordeste do Brasil

• Ano de defesa: 2011
• Autor(a) principal: FRANÇA, Isadora Fernandes de
• Orientador(a): LIMA, Gaus Silvestre de Andrade
• Banca de defesa: LEAL JÚNIOR, Gildemberg Amorim, MONTEIRO, Jean Herllington Araújo, REIS, Ailton, LARANJEIRA, Delson
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal Rural de Pernambuco
• Programa de Pós-Graduação: Programa de Pós-Graduação em Fitopatologia
• Departamento: Departamento de Agronomia
• País: Brasil
• Palavras-chave em Português: Variabilidade genética; Dioscorea cayenensis; Filogenia; Cochliobolus; Inhame; Yam
• Palavras-chave em Inglês: Genetic variability; Phylogeny
• Área do conhecimento CNPq: FITOSSANIDADE::FITOPATOLOGIA
• Link de acesso: http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6600

The yam (Dioscorea spp.) has great social importance for the Northeast region of Brazil, due to the excellent nutritional quality and energy of their tubers and very useful for human alimentation. Leaf-spots on white yam, caused by the fungus Curvularia eragrostidis, is responsible for damage to yam in northeast Brazil, mainly in the states of Paraíba and Pernambuco. The aim of this study was to analyze the population structure of isolates of C. eragrostidis pathogenic to yam, D. cayennensis, in the states of Alagoas, Pernambuco and Paraiba, and to study the phylogenetic relationships of these with other species in the genus Cochliobolus. In the first study, 151 isolates were obtained from leaves of yam, which were analyzed the sequences of part of the ITS region and -tubulin gene and gpd and the profiles of DNA with ISSR. It was observed that the DNA sequences had no variation, and ISSR data showed the presence of six haplotypes. The pathogen population is characterized by low genotypic diversity, predominance of one or two genotypes evenly distributed, the predominance of asexual reproduction, and the presence of genotypic flow between the regions of cultivation. In the second study, it was conducted phylogenetic analysis sequences of 81 isolates of species of the family Pleosporaceae using the methods of maximum likelihood and Bayesian inference. The 16 isolates of C. eragrostidis from yam analyzed are related to the genus Cochliobolus species which has smaller conidia and they are phylogenetically closer to the species C. clavata, C. brachyspora, C. oryzae and C. intermedia.