摘要
本试验在3N 性状加性-显性模型的基础上,提出了3N 胚乳性状的三重测验杂交的分析方法,并对两套 O_2玉米软硬自交系所组配产生的 F_2群体的三个胚乳品质性状硬质度、赖氨酸含量及粗蛋白含量进行了遗传规律的分析研究。结果表明:3个胚乳品质性状不仅存在显著的加性或显性效应,还存在显著的基因上位性效应,说明8个供试性状的遗传符合加性-显性-上位性模型;3个性状的实际上位性方差σ_d^2占总遗传方差σ_g^2的比率均小于15%,表明了上位性效应对性状遗传的贡献作用不大,8个胚乳性状的遗传主要由加性或显性效应控制。本文还对3N 和2N 模型在三重测交条件下的异同进行了讨论。
The analysis method of triple test cross for 3N endosperm traits was established based on the 3N additive-dominance model and two sets of Opaque-2 inbred lines with hard and soft endosperm structure on a homogenous cytoplasm base were selected to make completely triple test cross.The inheritance of three endosperm traits of vitreousity lysine and protein con- tent were studied and the results indicated that(1)there were significant epistatic effects on 3 endosperm traits in addition to additive and dominance effects and this meant that the inhertiance of these three quality characters followed the additive-dominance-epistatic model.(2)the ratio of estimated epistatic variance σ~2_((?)d)to estimated gross genetic variance σ~2g for each of the 3 endosperm trarts was Less then 15% which indicated that the additive or dominanse effects play- ed an important role on the genetic expression of 3 enodsperm traits rather than epistatic effects did.The differences between 3N model and 2N model for triple test cross were also discussed.
关键词
玉米
遗传规律
胚乳
三重测验杂交
modifiers for Opaque-2 gene
epistatic effects
3N endosperm genetic model
triple test cross
