小黑麦穗部性状的主基因+多基因混合遗传模型分析

Geneticanalysis on the mixed model of major gene pluspolygenes for the panicle related traits in triticale

摘要:

以小黑麦品种石大1号为母本(P1)和小黑麦品系C18为父本(P2)构建的重组自交系群体为材料,采用数量性状的主基因+多基因遗传模型分析方法对小黑麦的芒长、穗长、小穗数、穗密度、穗粒数等性状进行遗传模型分析。结果表明:芒长的最优遗传模型是4MG-AI,受4对加性上位性主基因控制,其主基因遗传率为85.06%;穗长和小穗数的最优遗传模型相同,均为MX2-CE-A,受2对互补作用连锁主基因+加性多基因混合遗传控制,穗长、小穗数的主基因遗传率分别为20.35%、31.77%,多基因遗传率分别为62.93%、32.48%;穗密度和穗粒数的最佳遗传模型相同,均为PG-AI,由加性-上位性多基因控制,穗密度和穗粒数的多基因遗传率分别是35.34%、86.96%。芒长存在主基因遗传特性,主基因遗传率高(85.06%),受环境影响较小,育种时可在早期世代进行选择,实现单株定向选择,提高育种效率。

Abstract:

Panicle traits are important for seed yield,therefore the improvement of panicle traits is the key to increase seed yield of triticale.Analyzing panicle traits of triticale has important significance to improve the breeding efficiency and seed yield of triticale.The recombinant inbred lines(RILs)constructed by Shida No.1(P1)and triticale strain C18(P2)were used as the material,and the major gene plus polygene mixed inheritance model were used to perform genetic analysis of panicle related traits.The results found 4MG-AI as the best genetic model for awn length,which showed that the inheritance was controlled by incorporating four major genes additive-epistasis genetic model.The heritability of the main gene was 85.06%.The optimal genetic model for panicle length and spikelet number were MX2-CE-A,which was consistent with two pairs of complementary main genes + additive polygene genetic model.The heritability of main genes controlling panicle length and spikelet number were 20.35% and 31.77% respectively,and the heritability of polygenes was 62.93% and 32.48%,respectively.The optimal genetic model for spike density and grains per spike were PG-AI,which was the additive-superordinate multi-gene genetic model,and the polygenes heritability was 35.34% and 86.96%,respectively.The awn length has the genetic characteristics of the main gene.The main gene had high heritability(86.96%)and was affected by the environment.The awn length could be selected in early selections in breeding,achieving single plant directional selection and improving breeding efficiency.