水稻杂种后代稻米直链淀粉含量的配合力分析

选用稻米直链淀粉含量比较相近的６个粳稻品种，采用Ｇｒｉｆｉｎｇ双列杂交方法四，再结合直链淀粉含量的单粒测定方法，对亲本在Ｆ１、Ｆ２代植株上结实的Ｆ２、Ｆ３稻米直链淀粉含量配合力作了分析。结果表明，稻米直链淀粉含量的ＧＣＡ和ＳＣＡ方差均极显著，表明在本试验中基因加性效应和非加性效应均起重要作用。但，由于二个世代的ｇｃａＭｓ／ｓｃａＭｓ值大于１或显著，且随着世代的推进这一比值又明显增加，因此，稻米直链淀粉含量在杂种后代的表现主要还是由基因加性效应决定。在Ｆ２的胚乳表现中基因非加性效应的作用很大，随着世代的增加，加性基因的作用越显重要。在总的遗传变异中，Ｆ２种子主要以非加性变异为主，Ｆ３种子主要以加性变异为主，但非加性变异仍然占很大比重。配合力效应两世代间相关不显著，亲本稻米直链淀含量的高低与一般配合力的高低并不一致。

ANALYSIS OF THE COMBINING ABILITY OF AMYLOSE CONTENT IN GRAINS OF RICE HYBRID

The combining abilities of amylose content were analysed in grains of F2 and F3 setting on the F1 and F2 plants from the crosses,made among 6 japonica rice cultivars which were different in amylose content by the means of the Griffing's diallel cross method 4. The results showed that there were very significant difference in all GCA and SCA variance of amylose contents in rice grains,indicating that the gene additive effect and non-additive effect all acted on it significantly in this experiment.However,the amylose content appearances of rice grains in offspring of hybrid were determinded by the gene additive effect,because the values of gca Ms/sca Ms in the two generatins were over/or significant and increased as the generation advanced.And the action of the gene non-additive effect on the amylose content appearance of F2 was more,but the gene additive effect became more important with the generation augmentation.The non-additive variation was chief in F2 and the additive one was chief in F3 thond its general combining ability.ugh the non-additive still accounted for a certain proportion .The relationship of the combining ability effect between the two generations was not significant and there was difference between the amylose content of rice grain of parents a