花生籽仁蔗糖含量多世代联合群体主基因+多基因遗传模型分析

花生是重要的油料和经济作物，在世界范围内广泛种植。甜味是与花生口感及风味高度相关的遗传性状，花生的甜味主要来源于花生籽仁中的蔗糖，蔗糖含量达到6%以上时，其口感及风味较好。因此，提高花生籽仁的蔗糖含量是改善花生口感及风味的关键因素之一。但迄今为止，对花生籽仁蔗糖含量的遗传分析未见报道。本研究以2组高、低花生籽仁蔗糖含量正反交组合，4个世代（P1、P2、F1和F2）为材料，应用植物数量性状主基因+多基因混合遗传模型，对花生籽仁蔗糖含量进行遗传分析。结果显示，花生籽仁蔗糖含量受2对加性主基因+多基因控制，结合两组最优遗传模型均是E-0模型（MX2-ADI-AD）即2对加性-显性-上位性主基因+加性-显性-上位性多基因是最优遗传模型。该性状的主基因遗传率在以高花生籽仁蔗糖含量为母本的正交组合中表现较高（84.96%和83.00%），在以低花生籽仁蔗糖含量为母本的反交组合中主基因遗传率偏低（69.52%和60.32%）；相反，多基因遗传率在正交组合中表现较低（14.87%和16.75%），在反交组合中表现较高（30.23%和39.25%），说明该性状有明显的母体效应。通过对花生F2 群体籽仁蔗糖含量进行数量遗传分析，确定最适遗传模型并掌握其遗传规律，为高蔗糖含量花生品质改良提供参考信息，为进一步进行QTL定位奠定基础。

Genetic analysis of sugar content in peanut kernel via mixed major gene plus polygene inheritance model in multi-generation combined population

Peanut（Arachis hypogaea L.）is an important oil and cash crop, cultivated worldwide. Sweetness is a highly heritable aspect of peanut flavor, and it is positively correlated with overall roasted peanut quality. Sweetness of peanut mainly comes from the content of sugar in peanut kernel, especially when the content of sugar is more than 6%. Therefore, increasing the sugar content in peanut kernel is the key to improving peanut flavor. However,up to now, the genetic analysis of sugar content in peanut kernel has not been reported. To investigate the genetic inheritance of sugar content in peanut, a mixed major gene plus polygene in-heritance model was employed to analyze in four generations（P1, P2, F1 and F2）of two cross combinations with high and low sugar content. The results showed that the genetic model E-0（MX2-ADI-AD）, incorporating two additive – dominance – epitasis major genes plus an additive–dominance–epitasis polygene, was the best-fitting genetic model for sugar content in peanut kernel. The heritability of the major gene in the cross combinations with high sucrose content of peanut kernel as female parent was higher（84.96% and 83.00%）, while the heritability of major gene was lower（69.52% and 60.32%）in the reverse cross combination with low sucrose content in peanut kernel; on the contrary, the heritability of polygene was lower in the orthogonal combination（14.87% and 16.75%）and higher in the reverse cross combination（3 23% and 39. 25% respectively, indicating that this trait has obvious maternal effect. These results suggested that the sugar content of peanut kernel was mainly controlled by major gene and should be selected in early populations. Therefore, our findings may provide important information for flavor quality modification of peanut and may lay the foundation for further QTL mapping.