巢式杂交群体的花生荚果性状遗传模型分析

Genetic model analysis of peanut pod traits in nested-crossing population

采用主基因+多基因遗传模型,对巢式群体的5个组合的F2家系的荚果性状进行了遗传模式解析,以期了解巢式杂交群体的荚果性状遗传变异特点。结果表明,巢式杂交群体具有丰富的荚果性状的变异类型,荚果长、宽和百果重在5个组合中的最小值至最大值变异幅度分别为(14.30~22.09)mm~(38.36~45.12)mm、(7.06~10.47)mm~(17.13~22.74)mm和(62.41~94.38)g~(266.75~364.00)g。荚果长与荚果宽、荚果表面积、荚果表面周长、百果重的相关性均极显著,与荚果长宽比的相关性较小;荚果宽与荚果表面积、荚果表面周长、百果重存在正相关,与荚果长宽比存在负相关。不同杂交组合的不同果型性状的遗传模式均有差异,最佳遗传模型为两对主基因加性-显性模型和两对主基因加性-显性-上位性模型;主基因遗传力22.79%~91.62%,不同群体中的基因效应值各不相同,表明多等位基因或非等位基因的不同遗传效应以及遗传背景差异对荚果性状的影响。本研究为利用NAM群体开展荚果性状QTL定位及分子标记开发、为专用型花生新品种选育提供了材料基础和理论依据。

The genetic pattern of pod traits were analysed using the major gene plus polygene model in five combinations of F2 families of a nested crossing population in peanut to dissect the genetic variation in nested crossing population.Results revealed rich variations in the five pod traits in the nested combination.The ranges of pod length,pod width,and hundred-pod weight were(14.30-22.09)mm-(38.36-45.12)mm,(7.06-10.47)mm-(17.13-22.74)mm,and(62.41-94.38)g-(266.75-364.00)g,respectively.There was a strong positive correlation between pod length and pod width,pod surface area,pod surface perimeter and hundred-pod weight,but little correlation with ratio of pod length to pod width;pod width was positively correlated with pod surface area,pod surface perimeter and hundred-pod weight,but negatively correlated with pod length to width ratio.The genetic models of different pod traits in different combinations were different,and the best genetic models were two major gene of additive-dominant model and two major gene of additive-dominant-epistatic model.The heritability of major genes was 22.79%-91.62%,and the genetic effects of the major genes in different families differed to each other,which implied the effects of multiple alleles or non-alleles as well as the genetic background on the pod traits.The results provide material and genetic basis for the further QTL mapping of pod traits and peanut breeding of specific pod shapes.