Characterization of blast fungi isolated from wild gramineous plants in southern Tohoku region.

Abstract

Pathogenicity, morphological and genetic aspects of fungi isolated from seven gramineous plants with blast disease in the southern Tohoku region were studied. Spores had the typical form of Pyricularia. Most isolates did not form lesions on rice, but all were pathogenic to the host of origin. On the basis of toxin production and a phylogenetic tree based on the rDNA-ITS sequence of the isolates, the fungi isolated from plants in the grass genera Lolium, Erichloa, Panicum and Setaria were identified as Pyricularia oryzae, but are unlikely to serve as inoculum to cause rice blast disease.