辣椒果实性状主基因+多基因遗传分析

以西北农林科技大学蔬菜种质资源创新实验室提供的辣椒品系AA5与CK18为亲本构建F₂代群体，统计调查群体各性状的分离情况，经相关性分析以及主基因+多基因遗传分析的方法来获得辣椒6个果实性状的主基因模型以及遗传效应。结果表明：6个果实性状皆是受主基因调控的数量性状，而且其相关性密切。辣椒果形指数、果肉厚度和果宽等3个性状中存在两组等加性主基因，属于2MG-EA模型；果长和单果质量存在两组加-显性主基因，属于2MG-AD模型；果皮硬度性状的遗传属于1MG-AD模型，存在一组加-显 性主基因。辣椒的果形指数和单果质量第1对主基因的正加性更显著。果皮硬度和果长性状的主基因效应为负显性以及正加性。果宽和果肉厚度性状的两对主基因表现为正向等加性。主基因遗传率∶单果质量（53.69）>果宽（48.42）>果长（34.67）>果肉厚度（25.42）>果皮硬度（22.91）>果形指数（22.23）。因此辣椒的这6个果实性状不宜于低代开展选育。研究结果为本材料的后续分子标记以及更高效、更具针对性的辣椒分子选育工作提供理论参考。

Genetic Analysis of Major Genes and Polygenes of Fruit Traits in Capsicum annuum

In current study, the F₂ population of the Capsicum annuum lines AA5 and CK18 provided by the vegetable Germplasm Resources Innovation Laboratory of Northwest A&F University was constructed,and the segregation of each character of the population was investigated statistically. The correlation analysis and main gene + polygene genetic analysis were used to obtain the main gene models and genetic effects of 6 fruit traits in Capsicum annuum. The results showed that the six fruit traits were all quantitative traits regulated by major genes. There were significant correlations among six fruit characters. There were two groups of iso-additive major genes in Capsicum annuum fruit shape index, pulp thickness and fruit transverse diameter, which belonged to 2MG-EA model, fruit length and single fruit mass had two groups of additive-dominant major genes, which belonged to 2MG-AD model, and the inheritance of pericarp firmness traits belonged to 1MG-AD model, which had a group of additive-dominant major genes. The positive additive of the first pair of major genes in fruit shape index and single fruit mass of Capsicum annuum was more significant. The major genes affected the pericarp hardness and fruit length traits, which were negative dominance and positive additive. The two pairs of major genes of fruit transverse diameter and pulp thickness were positive and iso-additive. Major gene heritability was as follows:single fruit mass (53.69), fruit transverse diameter (48.42), fruit longitudinal diameter (34.67), pulp thickness (25.42), pericarp firmness (22.91), fruit shape index (22.23). Therefore, the six fruit characters of pepper are not suitable for breeding in lower generations. This study provides a theoretical reference for the follow-up molecular markers of this material and more efficient and targeted molecular breeding of Capsicum annuum.