Propagation of avirulent race of rice blast fungus on rice and ragi (finger miller) leaves previously infected with virulent blast fungus

Abstract

Leaves of rice variety Aichiasahi were previously inoculated with virulent race 003 or 303 of rice blast fungus and those of Kanto 51 were inoculated with virulent race 031. Leaves of Ragi (finger millet) were previously inoculated with virulent ragi blast fungus. After development of lesions, the infected leaves of Aichiasahi, Kanto 51 and Ragi were reinoculated with avirulent race 031, 003 and 001 of rice blast fungus respectively. A few conidia of avirulent challenge races 031, 003 or 001 were produced on lesions of Aichiasahi, Kanto 51 and Ragi leaves 7 or 10 days after reinoculation.