水分胁迫对桃树叶片氮代谢相关指标的影响

［目的］为桃树优质、高产栽培提供理论依据。［方法］以2年生盆栽桃树为试材，对其进行不同程度的水分胁迫处理（CK：浇水500 ml/d；处理Ⅰ：浇水2 000 ml/d；处理Ⅱ：浇水200 ml/d），研究不同处理对桃树叶片氮代谢相关指标的影响。［结果］水分胁迫处理20 d后，处理Ⅰ、Ⅱ桃树叶片可溶性蛋白含量分别较CK下降了10.6%和14.3%，游离脯氨酸含量分别较CK增加了40.3%和20.5%，硝酸还原酶（NR）活性分别较CK下降了34.2%和62.2%，谷氨酰胺合成酶（GS）活性分别较CK下降了29.7%和60.7%；谷氨酸合成酶（GOGAT）活性与GS活性的变化趋势相同，谷氨酸脱氢酶（GDH）活性先升高后降低。［结论］水分胁迫处理后，桃树叶片可溶性蛋白含量降低，游离脯氨酸含量增加，NR、GOGAT、GS活性降低。

Effect of Water Stress on Nitrogen Metabolism Indexes of Peach Leaves

Objective] The study was to provide the theoretical basis for high quality and yield cultivation of peach. Method] With 2-year-old pot peaches as the materials, they were treated by water stress in different degree (CK: watering 500 ml/d; treatmentⅠ: watering 2 000 ml/d; treatmentⅡ: watering 200 ml/d). And the effects of different treatments on nitrogen metabolism indexes of peach leaves were studied. Result] After 20 d of water stress, the contents of soluble protein in peach leaves of treatment ⅠandⅡ were decreased by 10.6% and 14.3% than that of CK resp., the contents of free proline were increased by 40.3% and 20.5% than that of CK resp., the activities of NR were decreased by 34.2% and 62.2% than that of CK resp. and the activities of GS were decreased by 29.7% and 60.7% than that of CK resp. The changing trend of activity of GOGAT was similar with that of GS. The activity of GDH was increased at first and then decreased. Conclusion] After water stress, the content of soluble protein in peach leaves was decreased, the content of free proline was increased and the activities of NR, GOGAT and GS were decreased.