关键词: 杂交水稻, 灌水方式, 衰老, 氨基酸, 生理特征

Abstract: The effect of irrigation modes on the senescence of hybrid rice and some physiological activity was studied in the experiment. The results showed that irrigation modes affected obviously the senescence of hybrid rice. By cutting off the water supply at different stages after flowering, plant was subjected to water stress, and the decrease rate of the physiological activity speeded up, then the rate for the accumulation of dry weight in grain slowed down and seed setting percentage reduced, as a result, the output reduced. The earlier stare the water supply was cut off at, the more serious the yield reduced. However, intermittent irrigation, because of delaying the senescence of root, increasing photosynthetic rate, prolonging the duration of the accumulation of dry weight in grain, enhancing seed setting, and raising efficiency of increase production, consequently, the yield respectively increased by 7.4% and 17.7-28.3% compared with long term irrigation and cutting off the water supply earlier than expected. It is possible that irrigation modes control the senescence of the aerial parts by means of promoting the synthesis of some amino acids and restraining the synthesis of other amino acids in roots.

Key words: Hybrid rice, Irrigation mode, Senescence, Amino acid