Análise da estrutura genética da população de Hemileia vastatrix com base no marcador AFLP

• Ano de defesa: 2009
• Autor(a) principal: Maia, Thiago Andrade
• Orientador(a): Zambolim, Laércio
• Banca de defesa: Zambolim, Eunize Maciel , Sakiyama, Ney Sussumu
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Fitopatologia
• Departamento: Etiologia; Epidemiologia; Controle
• País: BR
• Palavras-chave em Português: Café; Doenças; Hemileia vastatrix; Ferrugem; Marcadores moleculares; Genética
• Palavras-chave em Inglês: Coffee; Disease; Hemileia vastatrix; Rust; Molecular markers; Genetic
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOSSANIDADE::FITOPATOLOGIA
• Link de acesso: http://locus.ufv.br/handle/123456789/4373

Obtaining coffee plants with durable resistance to coffee rust has been hindered by the lack of information about the evolutionary potential of Hemileia vastatrix. Seeking to give subsidies to the breeding program, the population structure of H. vastatrix was analyzed based on AFLP markers. To do this, 91 pathogen isolates were collected in genotypes from Coffea arabica, C. canephora, Híbrido de Timor and Icatu derivatives cultivated in the main production regions in Brazil. After the selective amplification using four primer combinations (EcoRI/MseI), 100 polymorphic fragments were analyzed. Each isolate presented a unique pattern of AFLP alleles, accounting for a high genotype diversity. The genetic similarity between the H. vastatrix isolates ranged from 0.08 to 0.70 and no cluster formations were observed in the dendrogram. There was no correlation between genetic and geographical distance between the isolates (r = 0.307, P = 0.234). H. vastatrix isolates were separated based on the host in three populations (Coffea arabica, C. canephora and Híbrido de Timor/Icatu derivates) and low genetic differentiation (GST = 0.026) was observed among them. After analyzing the populations, subdivided based on their geographical area, the genetic diversity (HT, HS and GST) showed no significant difference among the populations and based on AMOVA it was verified that a genetic variance (99.56%) exists within the pathogen populations. The analysis of the number of migrants (Nm) revealed a high gene flow rate among the populations originating from different hosts. The association index showed that the hypothesis of random mating was not rejected among H. vastatrix isolates from the C. canephora population (IA = 0.15, P = 0.18). The presented results show that H. vastatrix populations are not consistent with clonal reproduction indicating a high evolutionary potential, which would have direct implications in handling this pathosystem, mainly in the variety with durable resistance obtained.