陕北黄芥芥酸含量的主基因+多基因遗传分析

Inheritance of Erucic Acid Content of Brassica juncea in Northern Shaanxi with Mixed Model of Major Gene Plus Polygene

以吴旗黄芥×长安芥菜组合的6个世代P1、P2、F1、B1、B2和F2群体为材料,利用植物数量性状主基因＋多基因模型的多世代联合分析方法研究了该组合芥酸含量的遗传特征.结果表明：吴旗黄芥×长安芥菜组合芥酸含量受2对加性-显性-上位性主基因＋加性-显性-上位性多基因（E模型）控制.主基因效应中,加性效应大于显性效应,第一对主基因加性效应（da）和显性效应（ha）分别为-4.718 0和4.419 5;第二对主基因的加性效应（db）和显性效应（hb）分别-4.005 8和2.023 7;2对主基因对芥酸含量的贡献差异较大,第二对主基因加性和显性效应之和占第一对主基因加性和显性效应之和的65.98%;2对主基因间存在一定的互作效应（绝对值在0.338 7~3.694 1）,其中第一对主基因显性×第二对主基因加性效应（jba）较大,为3.694 1.B1、B2和F2群体芥酸含量主基因遗传率分别为68.83%、44.76%和87.99%;多基因遗传率分别为20.29%、41.21%和0,F2代表现出较高的遗传力,可在早期世代对芥酸含量进行选择.

Yellow mustard（Brassica juncea） in northern Shaanxi is an important germplasm for rapeseed quality improvement,which is different from other types of Brassica juncea with a lot of good traits.In this paper,the inheritance of erucic acid content in the cross of Wuqi yellow mutard×Changan mutard（Brassica juncea） was analyzed by applying the major gene plus poly-gene model of quantitative traits to a joint analysis of multi-generations（P1,P2,F1,B1,B2 and F2）.The results showed that the erucic content in the cross of Wuqi yellow mutard×Changan mutard was dominated by two pairs of major genes with additive-dominant-epistatic effects plus polygene with additive-dominant-epistatic effects（E model）.Additive effect was higher than dominant effect in the two major genes.Additive and dominant effects（da and ha）of the first major gene were-4.718 0 and 4.419 5,respectively.Additive and dominant effects（db and hb） of the second major gene were-4.005 8 and 2.023 7,respectively.Additive plus dominant effect（db＋hb） of the second major gene was only 65.98% compared to that of the first major（da＋ha）,which indicated that the contributions to erucic acidcontent of the two major genes was not equal in the cross.There was a certain interacted effect between the two major genes（the absolute value was 0.338 7～3.694 1）,in which the first major gene dominant effect and the second major gene additive effect（jba） was 3.694 1,largerthan the others.Heritability values of major gene（h2mg） of B1,B2 and F2 population were estimated as 68.83%,44.76% and 87.99%,respectively,while those of polygene were 20.29%,41.21% and 0,respectively.Heritability of major gene was the highest in F2 population,which suggested that selection in early generations will be an effective way for erucic acid content in breeding.