Abstract:

By artificial inoculation detached leaves of 42 rice varieties, to ascertain the resistance spectrum and disease level of rice blast disease on Magnaporthe grisea of 21 strains. And the rice blast resistance of 42 rice varieties was studied. The cluster analysis on the pathogenicity of 21 isolates of Magnaporthe grisea and mulriple indexes on rice blast resistance of 42 rice varieties was made respectively. The rice blast was isolates into seven categories, and their virulence was significantly different. The pathogenic frequencies were significantly negative correlated with average virulence. The rice varieties were divided into seven categories, of which the third class, the best rice blast resistance was the first group, resistance spectrum in 85% to 100%, disease-level below 4.0. The result has a certain practical significance on breeding new varieties of resistance rice, distributing resistance rice rational in region and controlling rice blast outbreak.