Study on southern blight like disease of water chestnut (Trapa bispinosa Roxb.) 1. Corticium rolfsii Curzi isolated from water chestnut

Abstract

Southern blight like disease on cultivated water chestnut (Trapa bispionosa Roxb.) leaves occurred in paddy fields in August in 1989 in Saga Prefecture. Corticium rolfsii Curzi, causal fungus of southern blight, was isolated from lesions of infected leaves. Isolates of C. rolfsii from water chestnut were compared with isolates from many other plants in respect to their mycelial growth and pathogenicity: No differences in the mycelial growth were found between isolates from water chestnut and that from the other plants. The optimum temperature of both isolates on potato sucrose agar was about 30°C. Isolates from water chestnut were as severely pathogenic against the leaves of water chestnut, and seedlings of soy bean and burdock as isolates from other plants by artificial inoculation. From the experimental results, it was considered that isolates from water chestnut were identical with C. rolfsii isolated from other plants.