杂交水稻氮素代谢特性的研究(英文)

研究结果表明,在分蘖、孕穗和抽穗期,供试杂交稻组合的功能叶片中的氮浓度、可溶性蛋白质和叶绿素含量明显高于常规稻.在其氮素代谢过程中,NR,GS,Fd-GOGAT,GPT和GOT酶活力,在供试品种间的差异是:汕优64>汕优6号>浙丽1号>秀水48,氮素营养条件的变化对此差异无影响,在杂变稻与常规稻之间,Fd-GOGAT酶活力和NR酶活力差异最大(分别达到50～70％和40～70％),而GPT酶活的差异较小.结果还表明,在不同水稻品种的功能叶中,上述5种酶的活力,与叶中可溶性蛋白质含量及全氮量均呈积显著正相关,这说明在杂交稻叶片中,氮素同化和蛋白质合成的酶系统,其活力优于常规稻的该酶系统,它们是杂交稻吸收利用氮素能力强的重要生理基础之一.

Characteristics of Hybrid Rice in Nitrogen Metabolism

Field experiment was conducted to study the nitrogen synthetic metabolism of hybrid rice leaf under various N supply rates,as compared with that of the improved conventional rice varieties. The results obtained showed that in spite of external nitrogen level, the hybrid rice exhibited obviously do-minancy not only in N contents of both the top and the newly full-expanded leaves, but also in soluble protein contents of the leaves at all growth stages tested in comparision with the conventional varieties. The contents of total chlorophyll and chlorophyll a were found to be much higher in the leaves of the hybrid rice than that of the conventional varieties. It was also showed that the activities of several nitrogen metabolic enzymes of the leaves of the hybrid rice surpassed considerably those of the ordinary rice leaves, including nitrate reductase, glutaminc synthetase, glutamate synthase ( Fd-GOGAT ) , Glu-Pyr transaminas and Glu-OAA transaminase, implying there existed a more active nitrogen assimilation and amino acid synthetic enzymatic system in hybrid rice leaf. Statistic calculation demonstrated that the activities of the five enzymes mentioned above were positively correlated with both the soluble protein contents and the nitrogen concentrations as far as the four rice varieties tested were concerned.