Abstract:

Two rice varieties were used as experimental materials to study the effects of N application amount and application time on filling and respiratory rate of rice caryopsis.With N application,the rice caryopsis could maintain higher water content,respiratory rate and dehydrogenase activity in late filling phase,and the course for filling and maintaining higher respiratory rate and dehydrogenase activity of rice caryopsis were prolonged in comparison with no N fertilizer application.More N application at booting was more effective compared to more N application at tillering.

Key words: nitrogen fertilizer treatment, water content, filling time, respiratory rate, dehydrogenase activity, rice, caryopsis

摘要： 为了研究施氮量和施氮时期对水稻颖果生理活性的影响，以一籼一粳两个水稻品种为材料，施用分蘖肥和孕穗肥，并在施氮总量相同的条件下设置了前高后低和前低后高两个处理。研究结果表明：增施氮肥维持了水稻颖果灌浆后期较高的含水率，延长了颖果灌浆充实的时间；维持了水稻颖果灌浆充实期尤其是灌浆后期较高的呼吸速率，并且使颖果维持较高呼吸活性的时间延长；延长了颖果各组织维持脱氢酶活性的时间。其中孕穗肥较高的施氮处理比分蘖肥较高的施氮处理效果更为显著。

关键词: 施氮处理, 含水率, 灌浆时间, 呼吸速率, 脱氢酶活性, 水稻, 颖果