摘要：

旨在评价陆地棉种质资源的遗传多样性和筛选代表性种质,为科学评价和高效利用陆地棉种质资源提供理论依据。基于367份陆地棉种质的SNP标记及其中353份种质的表型数据分别分析其遗传多样性、构建系统进化树及初级核心种质,并对初级核心种质的构建效果进行评价。结果显示,原始陆地棉群体SNP位点多态性信息含量为0.24,各表型性状的遗传多样性指数均接近或大于2.00,与前人研究结果相近。基于SNP标记可以将供试群体划分为3个类群,构建了73份基因型初级核心种质,初级核心种质的Nei's遗传多样性指数、多态性信息含量等指标数值大于原始种质。基于表型数据可将供试群体划分为3个类群,各性状均值呈第Ⅰ类群最小、第Ⅱ类群居中、第Ⅲ类群最大的趋势。构建了含70份材料的表型初级核心种质,各性状均值较原始种质的差异均不显著,极差、遗传多样性指数与原始种质相近,变异系数均高于原始种质。基于SNP标记构建的初级核心种质和基于表型数据构建的初级核心种质有15份重合,这些种质多为基因型第Ⅱ类群和表型第Ⅱ类群。以上结果表明,陆地棉种质资源基因型遗传多样性较低,但表型变异丰富、遗传多样性较高。本研究构建的基因型和表型初级核心种质遗传多样性代表性较好,可作为典型种质进行保存和利用。

关键词: 陆地棉, 遗传多样性性, 核心种质, SNP标记, 表型性状

Abstract:

The aim of this study was to evaluate the genetic diversity of upland cotton germplasm resources and screen representative germplasm,so as to provide theoretical basis for scientific evaluation and efficient utilization of upland cotton germplasm resources.Based on the SNP markers of 367 upland cotton resources and the phenotypic data of 353 resources,genetic diversities were analyzed,phylogenetic tree and primary core germplasm were constructed,and effects of primary core germplasm construction were evaluated.The results showed that the polymorphism information content(PIC)of the original upland cotton population was 0.24,and the genetic diversity index of each phenotypic trait was close to 2.00,which were similar to the results of previous studies.The upland cotton germplasm could be divided into three groups based on SNP markers,and 73 genotypic primary core resources were constructed.The Nei's genetic diversity index,PIC and other genetic diversity indexes of primary core germplasm were higher than those of original germplasm.Based on the phenotypic data,the upland cotton germplasm could be divided into three groups,and the mean value of each trait showed the trend that the group Ⅰ was the smallest,the group Ⅱ was in the middle,and the group Ⅲ was the largest.Seventy phenotypic primary core resources were constructed.Compared with the original germplasm,the mean values of all traits were not significantly different,the range and genetic diversity index were similar to that of the original germplasm,and the coefficient of variation was higher than that of the original germplasm.Fifteen primary core resources constructed based on SNP markers overlapped with those constructed based on phenotypic data.Most of these resources were genotypic group Ⅱ and phenotypic group Ⅱ.These results showed that the genotypic genetic diversity of upland cotton germplasm resources was low,but the phenotypic variation was rich and the phenotypic genetic diversity was high.The genotypic and phenotypic primary core germplasm constructed in this study had a good representation of genetic diversity and could be used as a typical germplasm for preservation and utilization.

Key words: Upland cotton, Genetic diversity, Core germplasm, SNP marker, Phenotypic traits