水稲収量の成立原理とその応用に関する作物学的研究 : 第91報 全光中散光成分の占める割合の多少と水稲個体群の光-同化曲線との関係

抄録

Noticing the fact that even under natural light of equal horizontal intensity, the rate of carbon assimilation of a rice plant population was not always equal. The authours examined the relation between the percentage of the amount of diffused light to the total amount of sunlight and the light curve of carbon assimilation under natural conditions. 1) When the light-curves of carbon assimilation on various days differing in the percentage of the amount of diffused light to the total amount of sunlight (hereinafter written as %-D.L.) were compared with one another, there were clear differences amnog the curves. 2) Even if a rice plant population has received the light of the same intensity on horizontal surface, the rate of carbon assimilation in the population was increased as %- D.L. was increased. In general, the light-curve of carbon assimilation in high %-D.L. was always drawn higher than that in low %-D, L, 3) As a result of the investigation reported in this paper, the authors round that the variation in light-reveiving degree of individual leaf in a rice plant population was much larger under the condition of low %-D.L. than that under the condition of high %-D.L. the change in the rate of carbon assimilation caused by the change in %-D.L. might be ascribed to the range of variation in light-receiving degree of each leaf-in the plant population. 4) The effect of diffused light on the rate of carbon assimilation differed with the plant type : the effect was much larger in the plant population with straight and errect leaves than in that with curved and drooped leaves. The light-curve of crabon assimilation of a plant population seemed to be changed with light conditions, particularly the %-D.L., and plant types.