甘蓝型油菜脂肪酸成分的基因作用形式和效应

Gene Actions and Effects of Fatty Acids in Brassica napus L.

对4种纯合芥酸基因型双列杂交所产生的9种芥酸基因型的6种主要脂肪酸的含量配适二基因模型,分析结果表明:芥酸含量的加性遗传方差占总遗传方差的99.5%以上,A 和 C 两染色体组中基因座位的加性效应基本上相等,F_1代和 F_2代的 d_a 分别为14.19和13.90,d_c 为13.81和13.38。廿碳烯酸以加×加互作为主,在 F_1和 F_2代中,该分量占总遗传方差的比例分别为66.6%和83.8%,显性效应占13—17%,加×显互作也占有一定的比例,特别是 F_1代。A 座位的加性效应和显性效应都大于 C 座位,显性效应大于加性效应,呈现超显性,非等位基因互作均为负效应。油酸其加性基因作用占90%,加×加互作和显性效应也占有一定的比例。两座位的加性效应和显性效应基本相等,显性方向为负,显性度为-0.35～-0.55,加×加互作为正,加×显互作为负。棕榈酸、亚油酸和亚麻酸受芥酸含量的影响甚微。

The full digenic interaction model was fitted to the data of contents of fatty acidsof 9 genotypes of erucic acid produced by diallel cross of 4 homozygous genotypes oferucic acid in Brassica napus.The results showed that the additive variance accountedfor more than 99.5% of the total genetical variance,the locus A and C had nearlyequal gene effects but the effect of A was slightly larger than that of C.The d_a's ofF_1 and F_2 were 14.19 and 13.90 respectively, and d_c's 13.81 and 13.38.The additive×additive component played very important role in the inheritance of eicosenoic acid,and accounted for 66.6% and 83.8% of the total genetic variance in F_1 and F_2respectively.Dominance effects(h's)accounted for 13—17% and the additive×dominance effect also had measurable effects,especially in F_1.The bothadditive and dominance effects of locus A were larger than those of locus C and thedominance effect was larger than the that of additive.All the non-allelic interactionswere negative.The additive effects of oleic acid accounted for ab.90%.Additive×additive played a certain role also.In general,the effects of additive anddominance of the two loci were nearly in same order.The direction of dominance wasnegative and the degree of dominance ranged from-0.35 to-0.55.Additive×additive was positive but additive×dominance was negative.The contentsof palmitic,linoleic and linolenic acids were hardly inflenced by the content of erucicacid.