玉米改良单交种选育的研究——Ⅰ 玉米姊妹系间杂种优势与配合力

Study on the Heterosis and Combining Ability in Corn Sister Lines

用6个玉米姊妹系及以之组配的15个杂种F_1进行了杂种优势和配合力的研究。结果表明,姊妹种各性状普遍存在着平均优势、对照优势和超亲优势;不同组合间和不同性状间杂种优势存在着显著差异;姊妹系绝大多数性状的遗传主要受加性基因效应的作用,广义遗传力和狭义遗传力高达70%～90%;杂种优势表现属于部分显性基因作用模式。配合力分析表明,不同姊妹系间配合力有明显差异,因而,有充分地选择余地,选择一般配合力高的亲本组配成姊妹单交种,其配合力仍可保持原自交系的水平。

A set of 6×6 dialle crosses of 6 corn sister lines was designed to study the heterosis and combining ability in order to select the sister crosses and modified single hybrids. The results showed that 10 characters investigated in 15 F_1 hybrids were remarkably manifested in heterosis, and there were significant differences in the heterosis and combining ability between different F_1 combinations and between different characters, and that the inheritance of most characters in sister lines was mainly affected by additive gene effects, the broad and narrow heritabilities reached as high as 70% ～90%; the performance of heterosis belonged to the model of partial dominance. Therefore, it was possible that the combining ability of sister single cross crossed with the high gca sister lines selected from sister lines could remain the same as that of the original line for single cross hybrid.