Grain Filling in Rice Subjected to Drought at Three Stages

Japanese Journal of Crop Science

Makoto TSUDA¹ 

关键词: Drought;    イネ;    Grain filling;    旱ばつ;    Imperfect rice kernel;    精籾;    Rice;    登熟;    Water stress;    不完全米;    Winnowed paddy.;    水ストレス.;   

DOI  :  10.1626/jcs.62.199

学科分类：农业科学（综合）

来源: Nihon Sakumotsu Gakkai / Crop Science Society of Japan

【 摘 要 】

The effects of water stress on the grain growth of rice appear to depend on the stages of plant development. The plants which were subjected to water stress during the grain-filling period produced more imperfect rice kernels than those subjected to water stress before heading. Since the grain growth of rice is affected by dry matter supply to the grain, one can expect that the production of imperfect rice kernels changes with dry matter production during the grain-filling period in rice subjected to water stress. To prove this hypothesis, an experiment was conducted in which the relationship between the production of imperfect rice kernels and the dry matter production during the grain-filling period was examined. A rice cultivar, Koshihikari, was grown in 4liter pots containing sandy loam soil. Plants were subjected to water treatment in which daily evapotranspiration was replaced by 60% for a week. The treatment was started either at fifteen days before heading, or two or twelve days after heading. Control plants were kept continuously submerged. The dry matter increase during grain-filling period was not affected by water stress before heading, whereas it was decreased by water stress after heading. Water stress before heading reduced the number of spikelets per plant and the size of single spikelet, resulting in the decrease of panicle weight per plant. After heading, the decrease of panicle weight per plant by water stress was associated with dry matter production during the grain-filling period. Also found was the increase of the number of spikelets wherein specific gravity ranged from 0.84 to 1.06. These spikelets enclose imperfect rice kernels. The rcsults suggest that winnowed paddy yield is coupled with the number and size of spikelets under water stress before heading. After heading, the effect of starch deposition is predominant.

【 授权许可】

Unknown