Analysis of cross-reactive antigens of Acrocylindrium oryzae and rice in relation to sheath rot disease

Immunodiffusion, immunoelectrophoretic and crossed immunoelectrophoretic analyses of rice antigens in relation to sheath rot disease revealed a serological relationship between susceptible rice cultivars and isolates of the causal organism of sheath rot, Acrocylindrium oryzae. One precipitin band was observed when the antigen preparation of A. oryzae was cross-reacted with its own antiserum or against the antisera of four susceptible rice cultivars. No precipitin band was detected between the antiserum of the resistant cv. Mahsuri and antigen preparations from three isolates of A. oryzae or between the antigens of the resistant cultivars Mahsuri and Rupsail and the antiserum of A. oryzae. Crossed-immunoelectrophoretic tests confirmed that there was a common antigen between Mahsuri and Jaya, and between Mahsuri and CR-126-42-1. The precipitin band between the antigen preparation of Jaya and A. oryzae was found to be similar.