Caracterização da virulência de Magnaporthe grisea em cultivares diferenciadoras japonesas e linhas quase-isogênicas das cultivares IAC-25 e de CO-39 de arroz

Abstract

The virulence of the population of Magnaporthe grisea collected from eight upland rice farms of cultivars 'BRS Bonança' and 'Primavera', located in five municipalities in the State of Goiás was studied. A total of 681 isolates, 321 collected from BRS 'Bonança' and 360 from 'Primavera' were utilized for the analysis. The genotypes included for characterizing virulence were nine Japanese race differentials, six near-isogenic lines of 'IAC-25', five nearisogenic lines of 'CO-39' and the rice cultivars 'Primavera', 'BRS Bonança', 'IAC-25' and 'CO-39'. The isolates of M. grisea from 'BRS Bonança' were more virulent than those of 'Primavera' on NIL's of 'IAC-25'. The majority of isolates from leaf and panicle of both cultivars were avirulent to the near-isogenic line 'CNA 8212'. The virulence was present in low frequency in the pathogen subpopulations of 'BRS Bonança' and 'Primavera' to the genes Pi-z RESUMO