Variability ofXanthomonas oryzae: Specificity in Infection of Rice Differentials

Abstract

Rice [Oryza sativa] cultivars with specific resistance to bacteria blight showed distinct differential reactions to isolates of X. oryzae. Lesion length caused by 80 isolates collected from different regions in the Philippines was determined by the different genes for resistance of the cultivars. Specificity in infection of the different rices suggested 3 different virulence groups or strains. A major group included those that infected ''IR8'' or rice that carries no genes for resistance to bacterial blight. Specificity of the isolates in differential infection of the rice also was shown in infection of rice of different ages planted in the greenhouse or in the growth room under conditions most favorable for plant development.