Differentiation of Physiologic Races of the Rice Blast Fungus, Pyricularia oryzae Cav. by PAGE‐electrophoresis

Abstract

AbstractEighty‐three isolates of the rice blast fungus (Pyricularia oryzae) were tested with respect to genetic diversity and the possibility of race differentiation by electrophoresis. The fungus was genetically very heterogeneous. The isolates were differentiated into 6 races by pathogenicity on race differential varieties. There was little correlation between pathogenicity and zymogram types of one particular enzyme such as esterase, phosphatase or catalase. The isolates were divided into 14 groups by the combination of the zymogram types of the three enzymes. The isolates in the same group showed similar pathogenicity. A new method is proposed which differentiates the blast fungus races by the combination of zymogram type of enzymes. The details, are discussed.