东北春玉米区优良自交系配合力分析和遗传潜势

ANALYSIS OF COMBINING ABILITY AND GENETIC POTENTIAL ON QUANTITATIVE CHARACTERS OF CORN INBREDS IN NORTHEAST CHINA AREA

摘要:

以P₁×P₂不完面双列杂交设计, 分析了我国东北春玉米区优良自交系亚总体各数量性状的两种配合力及其变化和相互关系以及基本遗传参数。结果表明, 所有数量性状的一般配合力(g·c·a)和特殊配合力(s·c·a)存在着一定差异, 但大多数都不明显。s·c·a的高低与其双新的g·c·a平均值没有直接关系, 但具有高s·c·a的组合其中必有一亲的g·c·a高, 而另一亲也不能太低。优良自交系各性状变异系数都较小, 并且加性方差显著大于显性方差, 说明其遗传基础狭窄。为了选出更好的自交系间杂种, 迫切需要补充新的基因源。而现有的自交系可进行群体改良, 在选择下将能产生较快的育种进展。

Abstract:

Crosses were made between 10 lines and 6 lines randomly drawn from the sub-population consisting of excellent inbreds with P₁ × P₂ designs. The general combining ability (g·c·a) and special combining ability (s·c·a) as well as its relationships were analysised. The basic genetic parameters of quantitative characters were estimated for the population. The results showed that there were no apperant differances for g·c·a and s·c·a of the quantitative characters involved, there were no direct relationships between the s·c·a and the means of g·c·a for its parents, moreover, one parent of crosses with high s·c·a had high g·c·a and the g·c·a of another was not so lower. The additive component in genetic variance of most characters was principal, and genetic coeffi cients of variance was smaller. This indicated that the genetic base in the sub-population had been narrowed. In order to achieve the good succesive progress in corn breeding, it was imperative that new genetic variability must be supplemented. Some inbreds, on hand may yet be utilized to undertake the population improvement. The outstanding respnse to select may be expected owing to the abundant additive variation.