不同生育期杂交谷子叶片氮代谢相关酶活性的杂种优势

以3个杂交谷子品种及其父母本为材料，通过对叶片生理生化指标的测定，研究不同生育期内叶片硝酸还原酶（NR）、谷氨酰胺合成酶（GS）、谷氨酸脱氢酶（GDH）活性及叶片氮含量变化，分析不同生育期内杂交谷子叶片氮代谢酶的杂种优势，以期对杂交谷子氮效率的遗传改良提供依据。结果表明,杂交谷子叶片GDH活性以及叶片氮含量在整个生育期内以表现中亲优势为主，NR活性在抽穗期表现正向超亲优势，GS活性在灌浆期和成熟期表现正向超亲优势。因此，NR和GS可作为杂交谷子氮效率改良的参考指标。

Heterosis of Enzymes Involved in Nitrogen Metabolism at Different Growth Stages in Hybrid Millet

Using hybrid millets and their parents as materials, activities of nitrate reductase (NR), glutamine sythetase(GS) and glutamate dehydrogensae(GDH) and nitrogen content in leaves were determined at different growth stages, and the heterosis of the enzymes involved in nitrogen metabolism were analyzed.The study may provide the basis of genetic improvement on nitrogen efficiency.The results showed that GDH activity and nitrogen content of hybrid millet mainly displayed the midparental heterosis at whole growth stage, but there were better parental heterosis of NR in the heading stage and better parental heterosis of GS at the grain filling and mature stages.Thus, NR and GS can be used as the reference indexes for improving nitrogen efficiency of hybrid millet.