黄瓜雄花性状的遗传分析

Genetic analysis of male floral traits in cucumber

关键词:  黄瓜  雄花性状  主基因+多基因  遗传分析

Key words:  cucumber  male flowers trait  major gene plus polygene  genetic analysis

摘要:

为了解黄瓜雄花花器的遗传特性,该研究以雄花器官较小的华南型黄瓜二早子为母本,花器较大的加工型黄瓜NC-76为父本,构建4世代遗传群体,并采用多世代联合分离分析方法,分析黄瓜雄花花器性状的遗传特性。结果表明:分离群体的雄花花梗和花冠长2个性状均表现为单峰分布,表明两性状为数量性状且有主基因控制; 花梗长性状符合2对完全显性主基因+加性-显性多基因(E-5)模型,花冠长性状符合2对加性-显性-上位性主基因+加性-显性-上位性多基因(E-1)模型; 控制花梗长性状的两对主基因的加性效应相等,为0.573,多基因的加性效应和显性效应值相差不大,且均为负向; 控制花冠长度性状的2对主基因的加性效应均为0,显性效应分别为-0.226和-0.472,在上位性作用中以加性×加性和显性×显性互作为主,多基因以显性效应为主,正向显性效应值为0.613,大于负向的加性效应值。花梗和花冠长度两个性状在F₂群体中主基因遗传率分别为61.04%和69.60%,多基因遗传率均为0。由此看出黄瓜雄花花器性状为数量遗传,遗传率相对较高。该研究结果显示在黄瓜杂交育种中对花器大小选择可以在较早世代选择。

Abstract:

To investigate the hereditary characters of male floral traits in cucumber,genetic analysis was carried out using erzaozi(small male flowers)and NC-76(large male flowers)as parents to build four generations by means of multigenerational joint segregation analysis. The results showed that two floral traits of segregation population were quantitatively genetic traits and controlled by major genes with unimodal skewness distribution. The inheritance of flower pedicel length was appropriate for the model of two complete dominance major genes+additive-dominance polygenes(E-5),flower corolla length was appropriate for the model of two additive-dominance-epitasis major genes+additive-dominance-epitasis polygenes(E-1). In addition,the additive effects of two major genes controlling flower pedicel length equal which were 0.573. The additive effect and dominant effect of polygenes were similar,and are all negative. The additive effects of two major genes controlling flower corolla lengths were zero,and the dominance effects of major genes were -0.226 and -0.472,respectively,the epistemic effects of additive×additive and dominant×dominant were the main factors. The dominat effect of polygenes was the major,and the value was 0.613 greater than the negative values of additive effect. The major genes heritabilities of F₂ population reached 61.04% and 69.60% in two floral traits,respectively,and the polygenes heritabilities were zero. Thus the male floral traits were quantitative inheritance,and the heritabilities were relatively high. In breeding practices,it could thus be seen that,gentic selection of floral charactors in cucumber should be performed at earlier separate generations.