西葫芦产量性状主基因-多基因混合遗传分析

Analysis of Yield Traits Using Mixed Major Gene and Polygene Inheritance Model in Summer Squash

选用蔓生和矮生的西葫芦自交系配制q-1×23-4G(组合1)和q-1×A-7(组合2)2个组合,构建P1、F1、P2、BC1、BC2和F2 6个家系世代群体,应用植物数量性状主基因-多基因混合遗传模型对该6个世代群体单株结果数和单果质量进行多世代联合分析。结果表明:2个组合的西葫芦的单株结果数遗传符合一对加性主基因+加性-显性多基因(D-2)模型,单果质量遗传为加性-显性-上位性两对主基因(B-1)遗传模型;组合1的单株结果数以基因的加性效应为主,而组合2除了加性效应之外,还有显性效应的影响;而西葫芦2个组合单果质量起主要作用的是显性效应与显性×显性互作效应。单株结果数的F2的基因遗传率较高,环境影响相对较小,表明对西葫芦单株结果数育种宜早代选择。2个组合单果质量的F2主基因遗传率较低,环境影响较大,表明对西葫芦单果质量的育种宜分离晚代进行。

Inheritance of the fruit number per plant and individual fruit mass of summer squash in P1,P2,F1,BC1,BC2 and F2 from two crosses q-1×23-4G（cross 1） and q-1×A-7（cross 2） was investigated by the mixed major gene and polygene inheritance model of quantitative traits.The results showed that the fruit number per plant was controlled by D-2 model and the individual fruit mass was controlled by B-1 model.Additive effect mainly played role on cross 1 of fruit number per plant,while additive effect and dominant effect both played role on cross 2;But genetic effect of the individual fruit mass of two crosses were mainly dominant effect of major gene and dominant×dominant epastasis.Heritability value of the genes of F2 was relatively high and environmental effect was relatively low;These results indicated that fruit number per plant breeding of summer squash should be selected in early generation selection.To the individual fruit mass of summer squash,heritability values of the genes of F2 was relatively low and environmental effect was relatively high;So high separated generations was effective on the individual fruit mass.