甘蓝型油菜茎秆强度性状的主基因+多基因遗传分析

摘要

为辅助抗倒伏育种,了解甘蓝型油菜茎秆强度的遗传调控,利用植物数量性状主基因+多基因混合遗传分离分析方法,对M417 × Brongoro(MB)组合和浙油18 × Brongoro(ZB)组合六个世代(P1、P2、F1、B1: 2、B2: 2和F2: 3)的茎秆强度性状进行遗传分析.结果显示:甘蓝型油菜茎秆强度性状的最佳遗传模型为MX2-ADI-ADI,即2对加性-显性-上位性主基因+加性-显性-上位性多基因模型,表明该性状受2对主基因和微效多基因共同控制,以主基因遗传为主,MB组合和ZB组合的平均主基因遗传率分别为19.46%和69.93%.2对主基因的加性效应和显性效应在MB组合中作用方向相反,而在ZB组合中作用方向相同,同时还存在多种上位性效应.两个组合中环境变异占表型变异的54.68%和13.23%,说明环境对茎秆强度性状具有较大影响.%To understand the genetic control of stem strength in Brassica napus,the'major gene and polygene mixed genetic model'was used to analyze the stem strength trait of 6 generations(P1,P2,F1,B1: 2,B2: 2and F2: 3) in both MB and ZB hybrid combinations. Results indicated that stem strength genetic was fitted in MX2-ADI-ADI model,i.e.,'2 pairs of additive-dominant-epistatic major gene plus additive-dominant-epistatic poly-gene'model. Stem strength was mainly controlled by 2 major genes and the average heritability of major gene were 19.46% and 69.93% in MB and ZB combinations respectively. The additive effects and dominant effects of the 2 major genes were in opposite direction in MB combination,but in same direction in ZB combination. Moreover, multiple epistatic effects influenced the 2 major genes. Proportion of environmental variance to phenotypic variance in these 2 combinations were 54.68% and 13.23% respectively,meaning that environment factors had strong im-pact on stem strength in rapeseed.