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作 者 ：戴廷波,邹铁祥,荆奇,姜东,曹卫星*

期 刊 ：生态学报 2009年 29卷 9期 页码：4976~4982

关键词：冬小麦；蛋白质；关键酶活性；氮/钾比；

Keywords:winter wheat, protein, key enzyme activity, N/K ratio,

摘 要 ：在大田栽培条件下，以蛋白质含量差异的两个冬小麦（Triticum aestivum L.）品种宁麦9号（低蛋白）和扬麦10号（中蛋白）为材料，研究了不同氮、钾施肥水平对小麦旗叶与籽粒中游离氨基酸含量、蛋白质合成关键酶活性和籽粒蛋白质含量的影响及其与开花期旗叶氮、钾营养的关系。结果表明，氮、钾施肥显著提高了小麦花后旗叶与籽粒中游离氨基酸和籽粒蛋白质含量、旗叶谷氨酰胺合成酶（GS）及籽粒GS和谷丙转氨酶（GPT）活性，其中氮肥的作用大于钾肥、氮钾肥配合达到最大，对扬麦10号的效应大于宁麦9号。开花期旗叶氮/钾比随施氮水平的增加呈二次曲线变化，随施钾水平的增加呈下降趋势。旗叶GS活性和成熟期籽粒蛋白质含量与氮/钾比均呈显著或极显著的二次曲线关系。因此，旗叶和籽粒中蛋白质合成关键酶活性受开花期旗叶氮/钾比的显著影响，是氮、钾素影响小麦籽粒蛋白质形成的重要生理原因。

Abstract:Field experiment was conducted in 2004-2005 using two winter wheat cultivars differing in grain protein content, Ningmai 9′ (low protein) and Yangmai 10′ (medium protein) in order to investigate the effects of N and K rates on key enzyme activities for protein formation in flag leaves and grains, grain protein contents, and their relationships with leaf N and K nutrition status at anthesis. The results showed that free amino acid contents and GS activities in flag leaves and grains, and GPT activity in grains all increased with nitrogen and potassium supply. Compared with potassium fertilization, the effects of N on free amino acid contents and relative enzyme activities for grain protein formation were greater than those of K, with largest effects from N K treatment, and greater with Yangmai 10′ than with Ningmai 9′. The N/K ratio in flag leaves at anthesis showed quadratic curve with nitrogen supply, while decreased with potassium supply. Correlation analysis showed that the GS activity and grain protein content both had significant quadratic correlations with leaf N/K ratio at anthesis. The results suggested that the leaf N/K ratio at anthesis was the vital factor for affecting grain protein formation under different nitrogen and potassium supply.

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