陆地棉SSR核心引物筛选及95份骨干种质的遗传多样性分析

Screening of the SSR Core Primers of Upland Cotton and Analysis of Genetic Diversity for 95 Core Germplasms with SSR Markers

从391对棉花SSR引物中筛选出均匀分布于棉花26条染色体的52对核心引物,对92份陆地棉和3份亚洲棉骨干种质进行多样性分析,结果表明,52对引物的等位基因数范围为2～13,平均5.7692个,多态信息含量(Polymorphism Information Contents,PIC)在0.3457～0.8800间,均值为0.7100,显示在这些位点上,供试材料的遗传变异比较丰富;聚类分析显示,在相似系数为0.73处,3份亚洲棉种质单独聚为一类,92份陆地棉种质被分为4大类群,与系谱分析结果较为吻合;在陆地棉种内,92份种质资源的相似系数在0.71～0.97之间,平均为0.84,表明陆地棉种内的遗传相似性较高,遗传基础狭窄;而广泛的亲本选配与频繁的引种,以及选育过程中未知血缘的渗入,又致使陆地棉遗传背景丰富。

Fifty-two pairs of core primers distributing evenly on 26 chromosomes of cotton were screened out from 391 pairs of cotton SSR primers for the diversity analysis of 92 accessions of G. hirsutum and three accessions of G. arboretum germplasm resources. The results show that these primers have 2-13 alleles, with the mean of 5.7692; polymorphic information content （PIC） about 0.3457-0.8800,with the mean of 0.7100;primers＇ discrimination power （DP） about 0.2859-0.8780, with the mean of 0.6896; effective number of alleles （Ne） about 1.5283-8.3327,with the mean of 4.1771; diversity （H＇） about 0.5297-2.2248, with the mean of 1.4366. This suggests that there are abundant genetic variations at these loci detected. Cluster analysis indicated that at the similarity coefficient of 0.73, 3 accessions of G. arborettun resources fell into a sub-branch and 92 accessions of G. hirsutum resources into four other sub-branches, basically according with pedigree analysis results. The similarity coefficients of 92 accessions of G. hirsutum resources were between 0.71-0.97, with the mean of 0.84, indicating that G. hirsutum resources possess high genetic similarity and accordingly narrow genetic basis. Broad selection of parents, frequent introduction and intermingle of unknown consanguinity during breeding process, causes abundant genetic background of G. hirsutum resources. Thus, polymorphism analysis of founder parents and understanding of the genetic variation of breeding materials, can provide technical support for breeding novel varieties.