DNA fingerprint and pathotype diversity of Pyricularia grisea populations

VF CONSOLO, CA CORDO AND GL SALERNO

AUSTRALASIAN PLANT PATHOLOGY

CSIRO PUBLISHING

Año: 2008 p. 357 - 364

0815-3191

Abstract. The genetic diversity of the rice blast pathogen, Pyricularia oryzae, was analyzed in rice growing provinces of Argentina. A total of 161 isolates of the fungus was collected from 15 rice cultivars at 9 locations during 2000-2005 and characterized using Pot2-DNA fingerprinting. Based on DNA analysis (isolates with 70% band similarity), 42 haplotypes were identified and clustered into five lineages designated A, B, C, D and E. In each group were identified 11, 22, 4, 1, and 4 haplotypes, respectively. The predominant group B, representing 38% of the collected isolates, was recovered from four cultivars in five locations. In contrast to lineages A and B, which had not a most common haplotype, a single haplotype predominated in lineages C and E. Isolates representing all haplotypes were examined for virulence on a set of differential rice cultivars, near-isogenic lines and commercial cultivars commonly grown in Argentina, revealing 41 pathotypes and 24 international races. Overall, these data indicated that populations of P. grisea in Argentina are genetically simple and predominantly clonal yet have high pathotype diversity.