棉花耐涝相关种质资源遗传多样性分析

为了解棉花耐涝相关种质资源的遗传多样性，选用均匀分布于棉花全基因组的145对引物，从中筛选出44对SSR引物对48份涝相关种质资源进行遗传多样性分析。结果表明，44对SSR引物在48份材料中共检测出170个等位基因变异,平均每个位点有386个。其中耐涝材料的位点多态信息含量(PIC)、每个位点的有效等位基因数(Ne)、基因型多样性(H′)分别为0632、1710 4和0393 7,涝敏感材料的PIC、Ne、H′分别为0628、1721 6和0399 4。耐涝材料和涝敏感材料的Jaccard相似性系数分别在0462~0925和0398~0845之间,遗传相似性系数总体平均值接近,但耐涝材料的变化幅度更大。用类平均法(UPGMA)聚类将48份材料分成2个类群。其中，第Ⅰ类包含39个品种，第Ⅱ类包含9个品种。大多数材料之间的遗传相似性系数较高,表明陆地棉耐涝相关种质资源遗传基础狭窄。本结果可为棉花耐涝育种亲本选配和相关机理研究提供基础资料

GENETIC DIVERSITY ANALYSIS OF WATERLOGGING RELATED ACCESSIONS IN UPLAND COTTON

Waterlogging is one of the natural disasters frequently occur in Yangtze River Basin Cotton Area,which could cause abscission of cotton,blocked photosynthesis,reducing root absorption capacity,and result in production cuts. In order to elucidate the genetic variation of waterlogging tolerance related cotton germplasm,145 SSR markers spanning the whole genome were picked out.After screening,we chose 44 simple sequence repeat (SSR) makers which were explored to analyzed 48 upland cotton varieties.The results indicated that a total of 170 alleles,with an average of 3.86 alleles per locus were detected by the polymorphic 44 SSR primers.For the waterlogging tolerant accessions,mean polymorphism information content (PIC),the average effective numbers of alleles (Ne) and the average genotype diversity index (H′) were 0632,1710 4 and 0393 7 and 0628,respectively.For the waterlogging sensitive accessions,the PIC,Ne,and the H′ were 0628,1721 6 and 0399 4,respectively.The mean value of similarity coefficients were similar between waterlogging tolerance germplasms and waterlogging sensitive germplasms,varied from 0462 to 0925,and from 0462 to 0925,respectively.Relatively,the waterlogging tolerant germplasms exhibited relatively larger variation range.When the threshold value 058 was used in the UPGMA cluster analysis based on the Jaccard similarity coefficient,48 accessions were divided into two groups,in which the first category contained 39 varieties and the second category consisted of 9 accessions.NTSYS pc 22 and Excel software were applied to calculate the similarity coefficient between each two accessions,and the similarity coefficient was between 0355 and 0925,with an average value of 0629. The similarity coefficients of 23 waterlogging tolerant accessions were between 0580 and 0856,with an average value of 0665,The similarity coefficients of 25 waterlogging sensitive accessions were between 0580 and 0850,with an average value of 0663.The high genetic similarity coefficients we observed in most of the germplasms analyzed in the study indicated the waterlog related cotton accessions own narrow genetic base.The current study should be helpful for assessing cotton pedigrees in breeding elite varieties with high waterlogging tolerance,and studying the mechanism of waterlogging tolerance in upland cotton