水氮耦合对苗期葡萄叶片氮素代谢酶活性的影响

Effect of Water and Nitrogen Coupling on Nitrogen Metabolism Enzyme Activities in Grapevine Seedling Leaves

为研究水氮耦合对苗期葡萄叶片氮代谢影响及最佳施氮量的制定,以一年生葡萄品种红提为研究试材,利用人工控制环境的方法,在温室内采用水、氮两因素各4水平的全面设计进行实验,水分处理分别为正常灌溉W1(田间最大持水量的70%~80%)、轻度胁迫W2(60%~70%)、中度胁迫W3(50%~60%)和重度胁迫W4(30%~40%)。4个氮素施用水平分别为1.5倍推荐施肥N1(施纯氮25.5g·m^-2)、正常推荐施肥N2(17g·m^-2)、0.5倍推荐施肥N3(8.5g·m^-2)、不施用氮肥N4(不施氮)。处理时间为10、20、30、40d。结果表明,在水分条件适宜时,葡萄叶片硝酸还原酶(NR)、谷氨酰胺合成酶(GS)、谷氨酸合成酶(GOGAT)活性、可溶性蛋白、游离氨基酸含量随施氮量增加而提高;在轻度干旱胁迫时,增施氮肥可缓解干旱胁迫;在重度干旱胁迫时,高氮处理使设施葡萄叶片中氮代谢酶活性、游离氨基酸和可溶性蛋白含量降低。葡萄叶片内氮含量始终随处理时间增加而降低,在轻度水分胁迫下氮的转运率较高,而水分胁迫严重时,高氮处理与无氮处理时氮转运率均偏低。最终得出:在水分条件适宜(W1)和轻度水分胁迫(W2)下,N1处理葡萄叶片的氮代谢能力最高;在中度水分胁迫(W3)和重度水分胁迫(W4)下,N3、N4处理氮代谢能力最高。研究结果可为实际生产中设施葡萄的干旱灾害防控提供理论依据,既能有效缓解水分胁迫带来的危害,又避免生产中肥料的浪费。

In order to study the effect of water and nitrogen coupling on nitrogen metabolism of grape leaves at seedling stage and the formulation of optimal nitrogen application, the annual "Hongti" grape was used as the research material. A comprehensive design of four levels of water and nitrogen in the greenhouse was used to carry out the experiment under the artificial environment control method. The water treatments were as follows: normal irrigation W1(70%-80% of maximum water capacity in the field), mild stress W2(60%-70%), moderate stress W3(50%-60%) and severe stress(30%-40%).The levels of nitrogen application were as follows:1.5 times recommended fertilization N1(pure nitrogen 25.5 g·m^-2), normal recommended fertilization N2(17 g·m^-2), 0.5 time recommended fertilization N3(8.5 g·m^-2), no nitrogen fertilizer N4(no nitrogen application).The treatment time was10, 20, 30, 40 days. The results showed that the content of nitrate reductase(NR), glutamine synthetase(GS),glutamine-oxoglutarate aminotransferase(GOGAT), soluble protein and free amino acid increased with the increase of nitrogen application when moisture conditions were appropriate. When drought stress was mild,increased application of nitrogen fertilizer can alleviate drought stress.When drought stress was severe, high nitrogen treatment reduced the activities of nitrogen metabolism enzymes, the content of free amino acids and soluble proteins in the leaves of the grape. The nitrogen content in the leaves of grape always decreased with the increase of treatment time. Under mild water stress, the nitrogen transport rate was higher. When the water stress was severe, the nitrogen transport rate of treatment under high nitrogen and no nitrogen were lower. Finally, under the suitable water conditions(W1) and mild water stress(W2), the nitrogen metabolism ability of grape leaves under N1(purified nitrogen 37.5 g·m^-2) was the highest. Under moderate water stress(W3) and severe water stress(W4), N3(pure nitrogen 12.5 g·m^-2) and N4(no nitrogen application) had the highest nitrogen metabolism capacity. The research results provide a theoretical basis for the prevention and control of drought disasters in the actual production of grapes, which can effectively alleviate the harm caused by water stress, and avoid the waste of fertilizer in production, so as to achieve less fertilizer efficiency.