Analysis of Developmental Factors Determining Yield and Yield Prediction in Lowland Rice : XLI. Studies on the Mechanism of Ripening (7) Relation of the diurnal change of the rate of carbon assimilation and the carbohydrate contents in different parts of rice plant to the diurnal change of the rate of translocation from leaves and culms to grains. (An aspect on the mechanism of translocation.)

Abstract

The diurnal change of the rate of carbon assimilation showed much the same as that reported in the previous papers (XII, XIII, XV, XXV), and the diurnal change of the sugar content in leaf-blades showed a marked change as seen in Table 1. The translocation from leaves and culms to grains were proved to be more rapid by day than by night, and the diurnal change of that translocation had also been investigated, the result being shown in Table 1. It had been made clear, furthermore, that the rate of translocation is likely most active at the time when the gradient in sugar concentration from leaves to grains tends to be greatest, as seen in Fig. 1, suggesting that the gradient in sugar concentration is one of the most influential factors in determining the rate of translocation.