Abstract:

【Objective】 To analyze the genetic diversity and population structure of Xinjiang melon germplasm resources in the hope of providing a theoretical basis for future collection, genetic improvement, and efficient utilization of melon germplasm resources.【Methods】 182 melon germplasms were selected, and 19 pairs of primers with high polymorphism were selected from 152 pairs of SSR primers.The genetic diversity of 182 Xinjiang melon germplasms was analyzed using TP-M13-SSR molecular markers, and the cluster analysis was conducted according to Nei's genetic distance (D), and the population genetic structure was analyzed using the hybrid model cluster method of Structure software.【Results】 The results showed that a total of 160 alleles were detected using SSR markers, with a variation range of 3-16 allele numbers (Na), an average of 8.421,1 per primer pair, and a variation range of 1.092,0-6.087,9 effective allele numbers (Ne), an average of 3.077,0; The observed heterozygosity (Ho) ranges from 0.011,0 to 1.000,0, with an average of 0.309,7; The expected heterozygosity (He) is 0.084,5-0.838,0, with an average of 0.599,1; The Shannon’ S Diversity Index (I) from 0.190,6 to 2.061,3, with an average of 1.239,9; The polymorphism information content (PIC) of each site from 0.081,1 to 0.815,8, with an average of 0.555,8.Most sites exhibit high polymorphism.The cluster analysis results showed that 182 melon germplasm materials were divided into two major subgroups, with subgroup I consisting of 88 melon germplasm materials and subgroup II consisting of 94 melon materials.The analysis of population genetic structure showed that when K=2, ΔK showed a significant peak, indicating that 182 melon germplasm materials were more suitable to be divided into two subgroups and there was excessive homozygosity.【Conclusion】 The genetic diversity of Xinjiang melon germplasm resources is relatively rich, but the classification results are different from the four traditional varieties.It can be seen that Xinjiang melon germplasm resources can be divided into two major subgroups from the analysis of population structure.There are more homozygous individuals in the population, but there is some gene exchange between other heterozygous individuals, which may be due to variety improvement or germplasm innovation by breeders.

Key words: melon germplasm; genetic diversity; SSR; fluorescence markers; population structure analysis

摘要：

【目的】分析新疆甜瓜种质资源的遗传多样性与群体结构,为甜瓜种质资源收集、遗传改良和高效利用提供理论基础。【方法】选取甜瓜种质182份,利用152对SSR引物对其进行检测。筛选出19对多态性较高的引物,利用TP-M13-SSR分子标记分析182份新疆甜瓜种质材料的遗传多样性,并根据Nei's遗传距离(D)进行聚类分析,以Structure软件的混合模型聚类法分析其群体遗传结构。【结果】SSR标记共检测到160个等位基因,等位基因数(Na)的变化幅度为3~16个,平均每对引物8.421 1个,有效等位基因数(Ne)的变化幅度为1.092 0~6.087 9,平均为3.077 0;观测杂合度(Ho)为0.011 0~1.000 0,平均0.309 7;期望杂合度(He)为0.084 5~0.838 0,平均为0.599 1;香农信息指数(I)范围为0.190 6~2.061 3,平均为1.239 9;各位点的多态性信息含量(PIC)为0.081 1~0.815 8,平均为0.555 8,大多数位点表现为高度多态性。182份甜瓜种质材料被分为两大亚群,亚群Ⅰ为88份甜瓜种质材料,亚群Ⅱ为94份甜瓜材料。当K=2时,ΔK出现明显的峰值,182份甜瓜种质材料分为2个亚群较为合适,且存在过度的纯合性。【结论】新疆甜瓜种质资源遗传多样性较为丰富,但与传统4个变种的品种群分类结果不同。新疆甜瓜种质资源可分为两大亚群,群体中纯合个体较多,但其他杂合个体间存在一定的基因交流。

关键词: 甜瓜种质, 遗传多样性, SSR, 荧光标记, 群体结构