基于SNP标记的西瓜种质资源遗传多样性分析

Genetic diversity analysis of 64 watermelon germplasms by SNP markers

种质资源遗传背景狭窄是当前西瓜育种面临的一大瓶颈。利用449个SNP标记对64份西瓜材料进行遗传多样性分析,结果表明,平均多态性信息含量(PIC)为0.229,平均Nei’s多样性指数(H)为0.28,平均Shannon多样性指数(I)为0.43,平均期望杂合度(He)为0.282;64份材料的最优群体结构数为4,各亚群材料的地理来源与遗传关系没有显著相关性;材料之间的平均遗传距离为0.175。农艺性状统计分析表明,4个亚群在首雌花节位、坐果节位和果皮厚度3个性状之间存在显著差异。本研究将为西瓜种质资源创制、杂交育种的亲本选择和培育优异、适应性强的西瓜新品种提供理论依据。

Watermelon is an important fruit in China,the narrow genetic background of germplasm resources is a bottleneck problem in watermelon breeding,449 SNP markers were used to analyze the genetic diversity of 64 watermelon germplasms in this research.The results showed that,the average polymorphism information content(PIC)was 0.229,the average Nei's diversity index(H)was 0.28,the average Shannon's information index(I)was 0.43,and the average expected heterozygosity(He)was 0.282.The optimal subgroup number was 4,however,no significant correlation was found between the subpopulation and geographic origin.The average genetic distance between the 64 watermelon accessions was 0.175.According to the agronomic traits statistical analysis,the traits of the first female flower node,fruiting node and rind thickness were observed significant differences among the four subgroups.The results of this study will provide theoretical guidance for the creation of watermelon germplasm resources,the selection of parents in cross breeding and the breeding of new watermelon varieties with excellent and strong adaptability.