Variabilidade fisiológica de isolados de Cercospora coffeicola

• Ano de defesa: 2007
• Autor(a) principal: Souza, André Gomes Coelho de
• Orientador(a): Maffia, Luiz Antônio
• Banca de defesa: Vale, Francisco Xavier Ribeiro do , Teixeira, Hudson
• 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; Cercosporiose; Epidemiologia
• Palavras-chave em Inglês: Coffee; Brown eye spot; Epidemiology
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOSSANIDADE::FITOPATOLOGIA
• Link de acesso: http://locus.ufv.br/handle/123456789/4440

Despite the importance of brown eye spot, there are few studies aiming to define methodology to work with the pathogen, Cercospora coffeicola. Therefore, variability of 60 isolates, from three regions and two growing systems in Minas Gerais was evaluated with in vivo and in vitro tests. At the laboratory, area under mycelial growth curve (AUGC), cercosporin production at 18, 22, or 26ºC, and sporulation at 25ºC were evaluated. Six isolates were selected and inoculated in seedlings of Catuaí and Catucaí varieties, either fertilized or not with potassium chloride, and kept in growth chamber at 18, 22, or 26°C for 48 h after inoculation. Incubation period (IP), latent period (LP), disease severity, and leaf fall were evaluated under greenhouse conditions. High variability among C. coffeicola isolates was detected concerning all the variables assessed. The isolates were sorted in groups according to sporulation, AUGC, and cercosporin production. Out of the 60 isolates, 27 did not sporulate. Cercosporin production and mycelial growth tended to increase with temperature. Positive correlations were detected between: severity and leaf fall for Catuaí and Catucaí; severity and cercosporin production for Catucaí ; and potassium chloride and disease severity for both varieties. As IP and LP were also correlated, either one can be assessed in future studies. Variability of C. coffeicola was found to be affected by temperature, potassium fertilization, and plant genotype.