ヒトエグサの配偶子放出における光の影響

Abstract

It has been determined that exposure to light following a period of darkness activates the immobile gametes in the cells of Monostroma. This report deals with a correlation between such activation and the light conditions concerned.1. After a sufficient period of darkness, exposure to light appears to act as a trigger agent.2. The length of darkness necessary to cause liberation becomes shorter as the “maturity” of the gametes advances, and finally activation can occur without exposure to darkness.3. The necessary duration of darkness is not additive.4. When the necessary dark period is interrupted by exposure to light, its effect is cancelled.5. Light periods following exposure to darkness: After a sufficient exposure to darkness, liberation was induced by 1 sec. irradiation, while insufficient dark periods required longer exposures to light. The condition of 1hr. exposure to darkness followed by 1 sec. light becomes sufficient to induce activation as the gametes become more “mature”. The quantity of gametes liberated after sufficient exposure to dark is proportional to the light intensity and length of light period within certain limits.6. Light of wave length shorter than 500mμ is necessary for liberation. Light of wave length that was ineffective for liberation had an effect similar to that of darkness. Light of short wave length was effective in nullifying the effect of a preceding dark period.From the above facts, it is suggested that in Monostroma the reaction which leads to activation of the gametes consists of two parts. The first reaction proceeds at a suitable temperature in the absence of blue light, and when this reaction is complete, the second reaction is induced by momentary exposure to blue light.