冬小麦籽粒发育中蛋白质和氨基酸含量的变化及喷氮效应的研究

 本文探讨了冬小麦籽粒发育过程中蛋白质和氨基酸含量的变化趋势，并着重研究了不同时期叶面喷氮对籽粒蛋白质和氨基酸含量的影响。研究结果表明，供试的3个小麦品种在籽粒形成到成熟的过程中蛋白质含量的变化可用Y=ax#+2+bx+c的数学模式描述（其中Y代表蛋白质含量，x代表开花后的天数）。不同时期叶面喷氮均可相应提高各发育期籽粒蛋白质含量，但不能改变其在籽粒发育过程中的变化趋势。在各处理中，以半仁期、乳熟中期和乳熟末期喷氮提高籽粒蛋白质含量较多。因此可以认为，从半仁至乳熟末期是提高蛋白质含量的喷肥适期，其中以乳熟中期喷氮效果最佳。在籽粒发育过程中，氨基酸总量的变化趋势与蛋白质含量的变化相似。而必需氨基酸含量有随籽粒发育逐渐降低的趋势。适期适量叶面喷氮可以提高氨基酸总量及必需氨基酸含量与氨基酸总量的比率（EA/TA），从而提高蛋白质的营养价值。

STUDIES ON THE CHANGES IN PROTEIN AND AMINO ACID CONTENTS IN DEVELOPING GRAINAND THE EFFECTS OF FOLIAGE NITROGEN SPRAY ON WINTER WHEAT

The thesis discusses the tendency of changes in protein and amino acid contents in wheat grain during its development, patting emphasis on the effect of foliar application of nitrogen at different stages on the protein and amino acid in wheat grain.The main results of the studies are shown as follows:1. The change of protein content during the growth of the three experimented wheat varieties could be expressed in the equation y=ax~2 bx c , with y standing for protein content and x for days after blooming. The grain protein content could be increased relevantly with foliar application of nitrogen in various growth periods, but the variation tendency of protein content in grain development could not be changed. In different treatments, the protein content was raised considerably by spraying nitrogen on leaves at half kernel stage, middle milk stage and late milk stage. So, it could be considered that the appropriate period of nitrogen spraying is from half kernel stage to late milk stage so as to increase protein content, and the middle milk stage is the best of all.2. During the grain development, the changing tendency of total amount of amino acid is similar to that of protein content. The total essential amino acid decreases while the grain is developing. The total amount of amino acid and essential: total (EA/TA) amino acid rations could be increased by spraying nitrogen with appropriate quantity at appropriate stage, thereby, the nutrition value of protein is raised.