半矮生基因sd-1有抗倒伏和改善株型的效果,广泛存在于世界各地的水稻丰产品种中。最近发现该基因具有减少穗长和千粒重的副作用。为澄清此副作用,能否通过遗传背景的改良得以克服,进而培育成粳稻型的半矮生大穗品种。本研究用高秆品种农林29号及其半矮生纯合系SC-TN1和大穗品种Akenohoshi的杂种进行了分析。用F_4代系统的实验结果表明,半矮生系统的穗长较高秆系统的为小。但是,由于半矮生系统的枝梗数,枝梗长度和各枝梗着粒数的增加,穗粒数较SC-TN1有明显的提高。而且,F_4和F_5代的穗粒数间有高度的相关关系。表明该性状的遗传力较高。进而指出,在粳稻品种中,由sd-1基因所控制的半矮生性和大穗性状的结合是可能的。 The semidwarf gene sd-1 has the effects of lodging resistance and plant type improvement and is widely present in abundant rice varieties around the world. The gene was recently found to have the side effects of reducing spike length and 1000-grain weight. In order to clarify this side effect, whether can be overcome by the improvement of genetic background, and then cultivate into japonica rice semi-dwarf big ears varieties. In this study, the high-stalk variety Nonglin 29 and its semi-dwarf homozygous line SC-TN1 and the big-ear variety Akenohoshi were analyzed. Experimental results using F_4 generation system showed that the spike length of semi-dwarf system was smaller than that of high-stalk system. However, the number of grains per spike was significantly higher than that of SC-TN1 due to the increase of the number of branches, the length of branches and the number of stems per stem. Moreover, there was a high degree of correlation between grain number of F_4 and F_5 generations. The trait of this trait is higher. Furthermore, it is indicated that the combination of semi-dwarf and big-spike traits controlled by the sd-1 gene is possible in japonica rice varieties.