种植密度对两种穗型冬小麦旗叶氮代谢酶活性及籽粒蛋白质含量的影响

在大田条件下，研究了种植密度对冬小麦多穗型（豫麦49-198）和大穗型（兰考矮早八）品种旗叶氮代谢关键酶活性和籽粒蛋白质含量的影响。结果表明，不同种植密度对旗叶氮代谢酶活性有显著影响。在花后前15 d，两品种旗叶谷氨酰胺合成酶(GS)活性、谷氨酰胺合酶（GOGAT）活性均随各自的种植密度增加而增加；硝酸还原酶（NR）活性则表现为中等密度的较低（兰考矮早八：375株 m^-2；豫麦49-198：150株 m^-2）；花后15 d之后，各酶活性随密度增加的变化趋势不尽相同。在一定范围内，两品种籽粒蛋白质含量随种植密度的增加而增加；表明氮代谢酶活性的提高在一定程度上有利于蛋白质含量的积累。

Effects of Planting Density on Activities of Nitrogen Metabolism Enzymes in Flag Leaves and Grain Protein Content in Winter Wheat with Two Spike Types

Two winter wheat(Triticum aestivum L.) cultivars,Yumai 49-198 with multi-spike and Lankao Aizao 8 with large spike were used to investigate effects of planting density on the activities of enzymes related to nitrogen metabolism and grain protein content.We found that the planting density significantly affected the activities of enzymes.In the first 15 days after anthesis,the activities of glutamine synthetase(GS) and glutamate synthase(GOGAT) in flag leaves of both cultivars were improved with the increase of planting density,and meanwhile nitrate reductase(NR) activity in flag leaves was the lowest in middle density treatment.In a certain range,the grain protein content was enhanced with the increase of planting density for both cultivars.The results indicate that the increase of the activities of enzymes related to nitrogen metabolism benefits the accumulation of grain protein.