花生种子脂肪含量的直接和母体遗传效应分析

种子脂肪含量是花生的重要经济性状。本研究旨在通过分析花生脂肪含量遗传的直接效应和母体效应，为高脂肪含量新品种选育、分子标记开发及基因组选择策略的确定提供依据。选用不同脂肪含量的中间型花生品种豫花9326及潍花6号，龙生型农家品种永城小麻壳，珍珠豆型品种湛油62及泉花6号，配置完全双列杂交组合，索氏残渣法分析5个亲本、20个杂交组合的F1和F2等3个世代种子的脂肪含量，利用广义遗传模型分析脂肪含量遗传的种子胚基因直接效应、母体效应及其遗传力。研究结果表明，双亲之一具有较高脂肪含量，另一亲本具有中等以上脂肪含量，则F1的脂肪含量较高；双亲脂肪含量中等，或者亲本之一脂肪含量较低，则后代脂肪含量较低。种子直接加性效应方差最大，其次为母体加性效应，母体显性效应的方差较小，种子脂肪含量无细胞质效应。种子直接效应的遗传力大于母体效应。高脂肪含量亲本的直接加性效应正值较大，低脂肪含量亲本的直接加性效应的负值较大，中间脂肪含量亲本的直接加性效应数值基本居中，方向有正有负。本研究表明脂肪含量的遗传主要受种子自身基因型的加性效应控制，其次是母体加性效应，无细胞质效应。高脂肪含量花生品种豫花9326和永城小麻壳是优良的高脂肪含量供体亲本。挖掘种子脂肪含量关键调控基因应该兼顾荚果皮中表达基因对种子脂肪含量的调控作用。杂交后代选择及分子标记开发应注重基因的累加效应和优良单倍型的选择。

Genetic analysis of direct and maternal effects of fat content in peanut seed

Fat content is an important economic trait of peanut seed (Arachis hypogaea L.). The purpose of this study is to analyze the direct and maternal effects of fat content inheritance in peanut, so as to provide the strategy for the design of breeding program and developing related molecular markers in high fat content peanut breeding.Five peanut varieties of different plant types with different fat content, including Yuhua 9326, Yongcheng Xiaomake, Weihua 6, Zhanyou 62 and Quanhua 6, were selected as the parents for complete diallel cross. The fat content of seeds from the parents, F1 and F2 of 20 combinations were analyzed by Soxhlet residue method. The direct effect of embryo gene, maternal effect and their heritability were estimated using general genetic model. The results showed that when one of the parents had higher fat content and the other parent had more than medium fat content, the fat content of F1 would be higher. When the fat content of both parents was medium, or the fat content of one of the parents was lower, then the fat content of offspring was lower. The variance of direct additive effect was the largest, followed by maternal additive effect in the variation analysis. The variance of maternal dominant effect was small while no cytoplasmic effect was detected. Meanwhile, the heritability of seed direct effect was greater than that of maternal effect. The direct additive effect of parents with high fat content was positive, while that of parents with low fat content was negative. It is indicated that the inheritance of fat content was mainly controlled by the additive effect of seed embryo genes, followed by maternal additive effect and without cytoplasmic effect. Yuhua 9326 and Yongcheng Xiaomake with high fat content are superior donor parents for high fat content peanut breeding. It is essential to pay more attention to the genes expressed in pods when exploring the regulation genes for seed fat content.The accumulation effect of genes and the selection of promising haplotypes should be emphasized in the selection of hybrid progenies and the development of molecular markers.