甘蓝型油菜茎秆强度性状的主基因+多基因遗传分析

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。

Genetics of stem strength in Brassica napus in mixed model of major gene and polygene

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, B2:2 and 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 polygene’ 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 impact on stem strength in rapeseed.