Variabilidade de isolados de Curvularia eragrostidis (Henn) meyer causando queima das folhas do inhame (Discorea cayennensis Lam.) no estado de Pernambuco

Detalhes bibliográficos
Ano de defesa: 2000
Autor(a) principal: PAULA, Helenilza de
Orientador(a): MICHEREFF, Sami Jorge
Banca de defesa: MARIANO, Rosa de Lima Ramos, PEDROSA, Elvira Maria Régis, CAVALCANTE, Uided Maaze Tiburcio
Tipo de documento: Dissertação
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:
Área do conhecimento CNPq:
Link de acesso: http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6564
Resumo: Leaf blight, caused by Curvularia eragrostidis, is one of the main diseases of the yam in Brazilian Northeast, however studies on the pathogen variability are inexistent. In order to characterize the variability of C. eragrostidis, 42 strains obtained from yam fields in the Pernambuco State were evaluated in relation to epidemiological components, physiologic characteristics and sensibility to iprodione. In the epidemiological components study, yam plants, cv. Da Costa, were inoculated with strains of C. eragrostidis (1x104 conidia/ml) and evaluated daily for occurrence and severity of disease symptoms, to record incubation period (IP) and area under disease progress curve (AUDPC). Strains were evaluated “in vitro” for micelial growth rate (MGR), sporulation (SP) and germination of conidia (GER), as well as for sensitivity to iprodione, evaluated by the lethal dose which inhibited 50% of micelial growth (DL50) and percentage of inhibition of conidium germination (ICG). There were significant differences (P=0.05) among the strains of C. eragrostidis in relation to all variables, resulting in different similarity groups of strains according to the Scott-Knott test. There were no significant correlation (P=0.05) between the variables associated with disease (IP and AUDPC) and the other variables studied (MGR, SP, GER, DL50 and ICG). When all variables were analyzed by the Euclidean distance (single linkage), the 42 strains were gathered into seven similarity groups. Therefore, there is variability among the strains of C. eragrostidis, which causes leaf blight of yam in different planting areas in Pernambuc