节水栽培水稻某些氮代谢生理特性研究

田间试验研究了节水栽培对水稻某些氮代谢生理特性的影响。结果表明，覆膜旱作水稻产量比常规水作显著降低，与裸地旱作相比则显著提高；3种栽培模式水稻叶片中氨基酸态氮和硝态氮含量、硝酸还原酶、谷氨酰胺合酶、谷草转氨酶和谷丙转氨酶活性均表现为生育前期较高、生育后期较低的动态特征。与常规水作相比，生育前期覆膜旱作水稻叶片中氨基酸态氮和硝态氮含量、硝酸还原酶和谷丙酰胺合酶活性均有所增加；整个生育期间谷草转氨酶活性有所提高而谷丙转氨酶活性则降低。与裸地旱作相比，覆膜旱作对水稻叶片中氨基酸态氮和硝态氮含量、硝酸还原酶、谷氨酰胺合酶、谷草转氨酶和谷丙转氨酶活性都有提高。水分胁迫对氮代谢生理特性及产量具有一定的负效应，而覆膜旱作能不同程度缓解这种效应，甚至有所促进；适量增加氮肥用量可以提高覆膜旱作氮代谢生理活性（尤其生育早期）及产量。

Some physiological characteristics of nitrogen metabolism under water-saving cultivation condition in rice

Field experiments were conducted to evaluate the effects of water-saving cultivation on some nitrogen nutritional physiology traits of rice taking traditional flooding cultivation (TF) as check. The results showed that the rice grain yield of non-flooded film mulching cultivation (PM) was significantly declined below TF, and markedly increased over non-flooding unmuching cultivation (UM). The patterns of the free amino acid (AA-N) and nitrate concentrations (NO₃^--N), nitrate reductase (NR), glutamine synthetase (GS), glutamic oxalacetic transferase (GOT) and glutamic pyruvic transferase (GPT) activities were analogously characterized by higher concentrations/activities at early growth stages than later stages especially the four enzymes. Compared with TF, PM had some positive influence on AA-N, NO₃^--N, NR and GS in rice leaves at early growth stages, and decreased GOT but increased GPT in leaves during the growing season. Compared with UM, PM increased AA-N, NO₃^--N, NR, GS, GOT and GPT activities in leaves. Soil water-stress had a negative effect on nitrogen metabolisms in rice leaves and subsequent straw and grain yields, however, PM system tend to alleviate the negative effect even promote them. Nitrogen can improved the traits of PM treatments especially at early growth stages.