Abstract: Combining ability of dry weight and physiological N-use efficiency at different stages was analyzed by using 9×9 diallel crosses with nine different type rice varieties under N-fertilized and N-unfertilized conditions. The additive effects was principal in dry weight and physiological N-use efficiency at maximum tillering stage, dry weight and physiological N-use efficiency at booting stage under N-fertilized and N-unfertilized conditions, physiological N-use efficiency at harvesting stage under N-fertilized conditions, grain yield under N-unfertilized conditions while the non-additive effect was dominant in physiological N-use efficiency at harvesting stage under N-unfertilized conditions, and grain yield under N-fertilized conditions was controlled by additive and non-additive effects. The crosses with larger specific combining ability(SCA) effects did not exhibit high physiological N-use efficiency compared to their parents and were not correlated with crosses with good general combining ability(GCA) certainly. The performance and GCA effect for its parents could not be used to forecast the heterosis in hybrid rice.

Key words: rice, nitrogen, physiological nutrient-use efficiency, combining ability

摘要： 选用不同类型的9个水稻品种，利用不完全双列杂交方法，在施氮和未施氮水平下对干物质量和氮素利用效率的配合力进行了分析。结果表明，最高分蘖期和孕穗期的干物质量和氮素利用生理效率，在两种氮素水平下亲本的加性效应均对F1起主导作用，而收获期氮素利用生理效率在施氮条件下遗传变异主要来自基因的加性效应，而未施氮条件下主要来自于非加性效应；产量的遗传变异在施氮条件下来自基因加性和非加性效应，而未施氮条件下主要来自基因加性效应。特殊配合力优良的组合，其亲本自身表现不一定优良，与一般配合力也没有明显的相互关系，表明氮高效育种中利用亲本值和一般配合力很难正确预测杂种优势；另外，不同生育时期的氮素利用生理效率的遗传特性在不同氮素水平下变化较大。

关键词: 水稻, 氮素, 养分利用生理效率, 配合力