Studies on the Production and Behavior of Carbohydrates in Rice Plant : III. Influence of environmental condifions on accumulation of carbohydrates

[摘要] Rice plants, the variety Norin No. 29, were grown in pots under various environmental conditions and several aspects concerning their carbohydrate accumulation were observed. The results may be summerized as follows: At higher levels of N nutrition, the amount of carbohydrates accumulated in the plant at its maturation period was found larger and the proportion of the amount of accumulation during the later period of growth to the total for the whole period was high, in comparison to that in the plant grown at lower levels of N. In the latter cases, the rate of carbohydrate accumulation was found to be accelarated by supplying N. in the ripening period, in contrast with the former cases where the plants had previously been grown at higher levels of N, the acceleration being less distinct. The plants grown at lower levels of P nutrition accumulated smaller amount of carbohydrate than that by the plants grown at higher P levels, but the rate of accumulation in the former plants was accelarated by application of P in its ripening period. The plants grown under low intensity of light (shaded by cloth) showed many characteristics similar to those in the plants grown with high levels of N nutrition, and the dry weight of the plant and the absolute amount of accumulated carbohydrates in it were found to be smaller than those in the plant grown under a natural light condition. At the period of maturation, it was found that about 90-95 % of accumulated carbohydrates were distributed in the panicles, while only a small part of them was distributed in the vegetative organs under the ordinary condition. Under the condition where the photosynthetic activitities of leaves were extremely vigorous, a large amnunt of surplus carbohydrates, being unable to move into the panicles because of exceeding the receiving capacity of the part for storage of the substance remained in the vegetative organs, particularly in the culms.

[学科分类] 农业科学（综合）