土壤水分对豫麦34花后GS同工酶及籽粒产量与蛋白质含量的影响

采用盆栽方法，连续两年研究了豫麦34在田间最大持水量40%(40%FC)、60%(60%FC)和80%(80%FC)条件下花后旗叶与籽粒中谷氨酰胺合成酶(GS)及其同工酶活性和可溶性蛋白含量及籽粒产量等的变化特征。结果表明，旗叶中GS活性较同期籽粒中GS活性高10倍以上，并均在波动中下降；旗叶中有GS1、GSx和GS2三种同工酶，其中GS2活性最高，GSx活性最低；籽粒仅有GS1。小麦花后旗叶和籽粒中GS和GS同工酶活性表现为60%FC>80%FC>40%FC，尤以旗叶GS2活性受影响最大。籽粒灌浆高峰前期，旗叶中可溶性蛋白含量表现为60%FC>80%FC>40%FC，随后表现为80%FC>60%FC>40%FC。籽粒中可溶性蛋白含量均表现为80%FC>60%FC>40%FC；60%FC处理的旗叶GS和GS2活性与可溶性蛋白含量呈显著正相关。籽粒产量和蛋白质含量均以60%FC处理最高，说明豫麦34生长中后期适宜的水分管理指标为田间最大持水量60%。

Effects of Soil Water Holding Capacity after Anthesis on Isozymes of Gluta-mine Synthetase, Grain Yield, and Protein Content in Winter Wheat Yumai 34

In a two-year experiment, the strong-gluten wheat cultivar, Yumai 34, were planted with three treatments, i.e., 40% (40%FC), 60% (60%FC), and 80% (80%FC) of field water holding capacity. The activities of GS and GS isozymes and the soluble protein contents in flag leaf and grain were measured after anthesis. The results showed that GS activity in flag leaf was more than higher than that in grain, and decreased gradually after anthesis. Isozymes GS1, GS2, and GSx were identified in flag leaf, of which GS2 had the highest activity. Only GS1 was observed in grain. The effects of water treatment on activities of GS and GS isozymes both ranked as 60%FC>80%FC>40%FC, and was largest for GS2 in flag leaf. The content of soluble protein in flag leaf ranked as 60%FC>80%FC>40%FC at early stage of grain filling and as 80%FC>60%FC>40%FC afterwards. The content of soluble protein in grain ranked as 80%FC>60%FC>40%FC. In the 60%FC treatment, the content of soluble protein in flag leaf was positively correlated with the activities of GS and GS2 in flag leaf. The highest grain yield and protein content were observed in the 60%FC treatment, indicating that 60% of field water holding capacity was the optimal soil moisture for Yumai 34 growth after anthesis.