陆地棉主要产量相关性状的SSR标记关联分析

高产优质育种是我国棉花育种的主要目标。寻找与目标性状关联的分子标记,可克服常规育种的盲目性,提高分子标记辅助选择育种的准确性。本研究对118份陆地棉种质资源的衣分、单铃重、单株铃数及子指等4个产量相关性状进行2年2点的表型鉴定,并利用覆盖全基因组的、有多态性的214对SSR标记进行标记与性状的关联分析。结果表明:118份材料的4个产量相关性状表型变异丰富,平均变异系数的变幅在6.1%~19.1%之间,且在各环境中表现较为稳定;基因型分析表明,214对标记共检测到460个等位变异,基因多样性指数平均为0.5151,PIC值平均为0.4587,表明该批标记具有较多的等位变异数和较高的基因多样性;群体结构分析表明该批材料可分为4个亚群,且各类群中材料与地理来源无对应关系;关联分析结果显示,在显著条件下(-log10P1.3,P0.05),共有39个标记位点能够在2个及2个以上的环境中同时检测到,其中有4个标记位点同时与2个以上性状相关联,进一步比较发现,有7个位点与前人研究结果一致,其余32个位点为新发现的位点。研究结果可为陆地棉产量性状遗传改良的分子标记辅助选择提供理论依据。

Association Analysis of Yield-related Traits with SSR Markers in Upland Cotton ((Gossypium hirsutum L.)

s: Improving cotton yield and fiber quality is a major breeding goal for Chinese upland cotton. Discovery molecular markers associated with the target traits can overcome the blindness of conventional breeding and improve the accuracy of molecular marker assisted selection breeding. In this study, a diversity panel consisting of 118 upland cotton accessions was grown in four different environments, and the yield-related traits including lint percentage (LP), boll weight (BW), bolls per plant (BN) and seed index (SI) were measured, and 214 polymorphic SSR markers of covering the whole genome were performed in association mapping. The results were showed: 118 upland cotton accessions were rich in phenotypic variation, the mean coefficients of variance (CV) ranged from 6.1~19.1%, and were more stable in different environments; Genotyping was performed with genome-wide Simple Sequence Repeats (SSRs), a total of 201markers were polymorphic and generated 460 allele loci, the average genetic diversity index and polymorphism information content (PIC) were 0.5151 and 0.4587, respectively. The results indicated that the alleles and the genetic diversity were larger in upland cotton accessions; 118 cotton varieties were divided into 4 subgroups by analysis of population structure, there has no corresponding relation between each kind of group of accessions and the geographical regions. Association analysis results were showed that 39 marker loci were detected at least two of the four environments (-lg(p) >1.3, P<0.05 ), Of 39 associated markers, four marker loci were associated with more than two traits simultaneously, seven marker loci were coincident with previous studies, and 32 were identified as new association markers. The results could provide a theoretical basis for molecular assisted selection of upland cotton about yield traits.