甜高粱茎秆含糖量相关性状的遗传分析

Genetic analysis of stalk sugar content related traits in sweet sorghum (Sorghum bicolor)

关键词:  甜高粱  茎秆含糖量  出汁率  茎秆鲜重  遗传分析

Key words:  sweet sorghum  stalk sugar content  juice ratio  stalk fresh weight  genetic analysis

摘要:

为探讨甜高粱茎秆含糖量相关数量性状的遗传基础,以粒用高粱品系LR625(P₁)和甜高粱品系Rio(P₂)为亲本杂交构建的一组包含4个世代的遗传群体(P₁、P₂、F₁、F_2:3),采用数量性状主基因+多基因混合遗传模型,对茎秆含糖量(混合锤度)、出汁率和茎秆鲜重性状进行了遗传分析。结果表明:茎秆含糖量符合E-1模型,性状是由两对主基因+多基因遗传模型控制的,主基因作用方式包括加性、显性和上位性3种效应。其中多基因效应高于主基因效应,遗传率分别为48.89%和39.52%。环境效应较小,占总表型方差的11.59%;出汁率性状符合B-5模型,即性状表现受2对主基因遗传控制,基因作用方式为完全显性作用。遗传力决定了出汁率表型变异的75.3%,环境因素影响24.7%,该性状的表现受遗传因素和环境因素共同影响;茎秆鲜重符合E-2模型即两对加性-显性主基因+加性-显性多基因遗传模型,无上位性效应,性状的主基因效应大于多基因效应,主基因遗传率为58.85%,多基因遗传率为17.63%,环境因素影响占23.52%。

Abstract:

A genetic segregation analysis of stalk sugar content related traits was made with the parents of LR625,a grain sorghum variety (P₁),Rio,a sweet sorghum variety (P₂) and their F₁ and F_2:3 populations by using the mixed major gene plus poly-gene inheritance model.The results suggested that the genetic control of the stalk sugar content (brix) is consistent with E-1 model,the trait is controlled by two major genes with additive-dominant-epistatic effects and poly-genes.The poly-genes effects were higher than major gene effects,and the heritability of major genes and poly-genes were 48.98% and 39.52%,respectively.Environmental effects accounted for 11.59% of total phenotypic variance.Juice ratio was consistent with B-5 model,the trait is controlled by two major genes with dominant effects.Heritability account for 75.3% of phenotypic variation,and environmental factors accounted for 24.7%.Stalk fresh weight was consistent with E-2 model,the trait was controlled by two major genes with additive-dominant effects and poly-genes with additive-dominant effects.Heritability of major genes was 58.85%,and heritability of poly-genes was 17.63%,environmental factor effects accounted for 23.52%.