Light-Dependent Induction of Sekiguchi Lesion Formation by Bipolaris oryzae in Rice cv. Sekiguchi-asahi

The e}ect of light irradiation on Sekiguchi lesion for! mation induced by infection with Bipolaris oryzae on rice sl mutants was investigated[ Although the Sekiguchi lesions formed exclusively under daylight ~uorescent lamps\ brown spots and necrotic spot lesions formed in the dark[ The Sekiguchi lesions were larger than the brown spot lesions[ When leaf blades inoculated with B[ oryzae were irradiated through band!pass _lters of BPB! 34\ BPB!49\ BPB!44\ and BPB!59\ Sekiguchi lesions were formed regardless of the BPB _lters| wavelengths[ Under black!light lamps\ near!infrared ~uorescent lamps\ or in the dark\ however\ brown spot lesions were induced by B[ oryzae[ The e}ective wavelength region for light! dependent Sekiguchi lesion formation was 399 699 nm[ Furthermore\ there was a direct correlation between the length of the radiation wavelengths and the size of the Sekiguchi lesions[