Abstract: The physiological traits of senescence and photosynthetic function of rice leaves were analyzed when two hybrid rice combinations were supplied with controlled release nitrogen fertilizer (CRNF), urea and no nitrogen fertilizer. CRNF showed obvious effects on delaying the senescence and prolonging the photosynthetic function duration of rice leaves. Compared with urea, CRNF could significantly increase the chlorophyll contents of the functional leaves at different stages in both early and late rices, and the difference between the treatments became larger with rice development. Photosynthetic rates of the functional leaves at different stages in CRNF treatment were significantly higher than those in urea treatment. Moreover, compared with urea, CRNF increased the activities of active oxygen scavenging enzymes, such as SOD and POD, and decreased the accumulation amount of MDA in the functional leaves during rice leaf aging. IAA and ABA contents in the functional leaves were also obviously regulated by CRNF. At the every stage, IAA content in CRNF treatment was higher and ABA content was lower than those in urea treatment. Being attributed to the effects of CRNF mentioned above, the rice yield was obviously increased after CRNF application.

Key words: controlled release nitrogen fertilizer, rice, photosynthetic function, senescence, physiological traits

摘要： 以杂交水稻组合八两优100和威优46为试验材料，探讨了控释氮肥对水稻光合功能衰退和叶片衰老的调控机制。结果表明，控释氮肥对延缓早、晚稻功能叶的衰老和延长叶片的光合功能期均具有明显的效应。与施用尿素的处理相比，施用控释氮肥后，早、晚稻生育中、后期功能叶中的叶绿素含量得到显著的提高，且与尿素间的差异随着水稻生育进程而增大。不同时期控释氮肥处理功能叶的净光合速率也均显著地高于尿素处理。此外，施用控释氮肥能显著地提高生育中、后期功能叶中的SOD、POD等活性氧清除酶的活性，降低功能叶中的丙二醛含量。施用控释氮肥对功能叶中的IAA、ABA含量具有明显的调控效果，早、晚稻各时期控释氮肥处理的IAA含量均显著地高于尿素处理，而ABA含量显著地低于尿素处理。由于控释氮肥对水稻的上述调控机理，因而，在水稻上施用控释氮肥可以明显提高水稻产量。

关键词: 控释氮肥, 水稻, 光合功能, 衰老, 生理特性