92份棉花资源遗传多样性的SSR分析

Genetic Diversity of 92 Cotton Accessions Evaluated with SSR Markers

选用均匀分布于棉花全基因组的132个SSR标记,对精选的92个棉花品种（系）进行分析,结果表明,共扩增出494个多态性条带,每个引物平均3.69个.等位基因变异的多态性信息含量（PIC）在0.010 0～0.871 4之间,平均为0.546 6.采用NTSYS-pc软件计算品种对间的相似系数,92个品种之间的成对相似系数平均为0.729 2±0.135 0,变幅在0.411 8～0.957 5之间,其中陆地棉种内48.94%的品种对相似系数≤0.800 0,海岛棉种内50.91%的品种对相似系数≤0.800 0,表明此自然群体的遗传基础较为宽泛.根据Jac-card s相似系数所得的UPGMA聚类图和系谱追溯的结果显示,此群体中品种的选育过程复杂,血统来源多样,存在较高程度的遗传多样性.

A set of 132 SSR markers,spanning the whole genome with an average of 5 SSRs per chromosome,were selected to genotype the natural population consisting of 92 accessions.Four hundred and ninety-four polymorphic bands were obtained with the average of 3.69 polymorphic bands per SSR marker.The polymorphism information content（PIC） for a marker locus is 0.010 0～0.871 4 with the average of 0.546 6.Jaccard＇s genetic similarity coefficients were calculated using the software of NTSYS-pc version 1.80.Mean pairwise genetic similarity coefficients of 92 cultivars（lines） was 0.729 2±0.135 0,with the range of 0.411 8 to 0.957 5.The percentage of pairwise similarity coefficient less than 0.800,is 48.94% and 50.91% for the upland accessions and sea-island accessions,respectively.This indicated that the genetic basis of natural population was broad to a certain extent.The UPGMA dendrogram based on Jaccard＇s similarity coefficients and the information of genealogy of accessions indicated that：these accessions were developed through a complex breeding process and the ancestry was multi-descent origins,which resulted that a high genetic diversity in some extent was preserved in the natural population.