四川部分玉米骨干自交系杂种优势群研究

Analysis of combining ability and research on the hterotic groups among elite maize inbred lines in Sichuan

以四川15个玉米骨干自交系及其按Giffing方法4组配的105个杂交组合为供试材料,通过配合力分析和单株产量特殊配合力、RAPD标记、SSR标记的聚类分析,研究供试自交系的配合力表现,杂优类群和杂优模式,并对不同研究方法划分杂优类群的可靠性进行比较。结果表明,单株平均产量及其构成性状GCA综合表现较好的自交系有18-599、7327、698-3、S37、48-2,单株产量SCA较高的组合中,自交系18-599和7327组配的杂交组合较多,其余自交系各自有其突出的优良特点,可根据育种要求加以利用;SSR分析可将供试的15个玉米骨干自交系较为合理地划分为4个类群和4个亚群,并发现杂优类群及其组配方式与单株产量的高低存在紧密的联系;三种聚类方法的分析结果,均能在一定程度上反映供试自交系的遗传特性,并且所划杂优类群具有程度不同的合理性,但无论从系谱关系还是从强优势组合方式来看,SSR分析结果更为准确和可靠。

In this article, the materials were 15 elite inbred lines in Sichuan and 105 crosses combined by them according to the 4th method of Griffing＇s. Combining ability （CA） performance among the inbred lines, heterotic groups and heterotic patterns were studied by combining ability analysis and the clusters based on special combining ability （SCA）, RAPT） markers and SSR markers to discuss the relations between heterotie groups and their combination patterns. The results are： inbred lines 18-599, 7327, 698-3, S37 and 48 2 had better comprehensive general combining ability （GCA） on kernel yield per plant （KYPP） and other traits contributing to KYPP.The crosses with higher KYPP SCA could probably be screened from those with the inbred line 18-599 or 7327 as parent. Other inbred lines had their own advantages and could be used to fulfil different breeding aims. Fifteen elite inbred lines were rationally classified into 4 groups and 6 subgroups based on the cluster of SSR analysis. It was found that there were close relations between heterotic groups and their combination patterns and KYPP. Three cluster methods could to some degree show the genetic characters among studied inbred lines and the group classifications were all rational to different degree, respectively. Judged by the pedigree or the combining types of the superior crosses, the classified heterotic groups by SSR cluster analysis were more rational and reliable than those by other 2 methods.