两个杂交水稻组合生育后期叶片中氮代谢的比较研究

Difference in Nitrogen Metabolism between Two Hybrid Rice Combinations during the Later Growth Stage

本试验以硝酸还原酶（NR）活性,谷丙转氨酶（GPT）活性等为指标,选用威优35（V35）和威优49（V49）为材料,研究了两个杂交水稻组合之间叶片中氮代谢的差异及赤霉酸（GA_3）的影响。结果表明,V35叶片中NR活性在乳熟中期以前高于V49,乳熟中期以后则相反;两组合的可溶性蛋白质含量也存在较大的差异,始穗后14天内的差异更大;两组合的GPT活性差异不大,但均为始穗后14天内高于14天后。GA_3使两组合叶片中的NR活性、GPT活性及可溶性蛋白质含量均有一定程度提高,NR活性及可溶性蛋白质含量增加更多。GA_3还使空秕率降低、产量提高。GA_3对杂交稻氮代谢的影响在不同组合及同一组合不同生育期存在一定的差异。

The difference of nitrogen metabolism in the flag leaves between Wei-you 35 (V35), a non-aging combination, and Wei-you 49 (V49) , an aging combination, and the regulation on nitrogen metabolism of the above hybrid rice combinations by gibberellic acid (GA3) during the later growth stage had been studied. The activities of nitrate reductase (NR) and glu-tamate pyruvate transaminase (GPT) were determined. The obvious differences in nitrogen metabolism of flag leaves during the later growth stage were abtained between two hybrid rice combinations, The NR activity of non-aging combination, V35, was higher than that of aging combination, V49, before the middle of milk-ripe stage, but it is contrary after the middle of milk-ripe stage. The soluble protein content of V35 is higher than that of V49. The difference of GPT activity between both combinations is not obvious. But their GPT activity is higher after the middle of milk-ripe stage than that before the middle of milk-ripe stage. NR activity, GPT activity, soluble protein content in the flag leaves of both combinations were all increased in some degrees after treatment of GA3. The increase of NR activity and soluble protein content was more marked than that of the others. In addition GA3 reduced the empty shell percentage and cousequently increased the yield of both combinations. Our results implied that there existed different influnce of GA3 on nitrogen metabotion in non-aging and aging combinations and in the same combination at different growth stage.