水稻杂交后代灌浆成熟期籽粒淀粉合成关键酶和谷氨酰胺合成酶活性变化的初步研究

 以东农423和藤系180为试材，籽粒直链淀粉和蛋白质含量为选择指标，通过逐代的定向选择形成了遗传背景相近且直链淀粉和蛋白质含量有显著差异的杂种后代，并对水稻灌浆成熟过程中籽粒ADPG焦磷酸化酶、可溶性淀粉合酶、淀粉分支酶、谷氨酰胺合成酶活性变化进行了初步研究。高直链淀粉含量杂交后代的籽粒ADPG焦磷酸化酶、可溶性淀粉合酶、淀粉分支酶活性峰值显著或极显著高于低直链淀粉含量后代，而且在籽粒灌浆前期蛋白质含量高的后代籽粒谷氨酰胺合成酶活性显著或极显著高于蛋白质含量低的后代。因此，通过直链淀粉和蛋白质含量的连续定向选择可以显著提高或降低灌浆过程中的籽粒碳氮代谢关键酶活性。

Changes in Activities of Key Enzymes for Starch Synthesis and Glutamine Synthetase During Grain Filling of Rice Hybrid Progeny

The hybrid progenies differed in amylose and protein contents in grains derived from Dongnong 423×Toukei 180 were used to study the changes in the activities of ADP glucose pyrophosphorylase(AGPP), soluble starch synthase(SSS), starch branching enzyme(SBE), glutamine synthetase(GS) during grain filling. The activities of AGPP, SSS, SBE in the hybrid progenies with high and low amylose contents gradually increased and declined as a single peak curve during grain filling. The progeny with high amylose content peaked earlier in the AGPP, SSS and SBE activities and had higher GS activity at the early grain filling stage than those with low amylose content. The GS activity peaked earlier and was higher at the late stage of grain filling in the progeny with high protein content than in that with low protein content. It is suggested that the activities of key enzymes for starch synthesis and glutamin synthetase could be changed in oriented breeding for amylose and protein contents in grains.