PHOTOMORPHOGENESIS IN PTERIS VITTATA III. PROTECTIVE ACTION OF ETHANOL ON BLUE-LIGHT-INDUCED INHIBITION OF SPORE GERMINATION

In the fern Pteris vittata, the low-energy blue-light-induced inhibition of phytochrome dependent spore germination was protected by 0.1 mol ethanol. This protective action was observed only with ethanol in a sampling of 9 alcohols. Ethanol does not induce dark germination of spores and may act directly on the inhibition induced by blue light. It takes about a 15 times more intense dose of blue light for the induction of 50% inhibition of spore germination in 0.1 mol ethanol containing media compared with control media. The protective action of ethanol was apparent within 2 days after treatment and reached a maximum level at the 4th day. The effect of ethanol continues for about 32 hours after withdrawal of the ethanol. This action of ethanol was also observed in the case of far-red light irradiation but the mode of action of ethanol may be different from the case of blue light irradiation.