基于ISSR标记的96份兰属种质资源遗传多样性分析及指纹图谱构建

Analysis of Genetic Diversity and Fingerprint Construction of 96 Cymbidium Based on ISSR Markers

为加强我国兰属种质资源的保护利用,本研究通过ISSR分子标记对96份兰属种质进行多样性分析和指纹图谱构建。结果显示,共筛选出11条可扩增清晰条带的多样性引物,在96份材料共检测67条多态性条带,平均多态性条带比例为73.63%;等位基因数(Na)为1.925,有效等位基因数(Ne)为1.450,Nei′s遗传多样性指数(H)为0.277,Shannon多样性指数(I)为0.427,多态性位点百分比(PPL,percentage of polymorphic loci)为92.54%;种群内基因多样性(Hs)为0.1934,基因分化度(Gst)为0.3009,总遗传多样性指数(Ht)为0.2767,种群间的平均基因流(Nm)为1.1619,种群间的两两遗传分化固定指数值范围为0.002~0.527,平均值为0.325。系统聚类结果表明,兰属种群间遗传分化程度高,8个种群可分为3类,春兰和墨兰为一大类,寒兰、春剑、蕙兰、莲瓣兰、建兰为第二类,杂交种独为一类,与其他两类种群之间的遗传距离较大。主坐标分析表明,莲瓣兰和春兰表现出较远的亲缘关系。本研究筛选出6对引物构建了96个品种的指纹图谱二维码。本研究结果可为今后兰属新品种选育及品种鉴定提供重要依据。

In order to strengthen the protection and utilization of Cymbidium resources in China,ISSR markers were deployed to conduct the genetic diversity and fingerprint construction in this study.A total of 67 bands were detected with 11 primers in 96 samples,and the average of polymorphic bands rate is 73.63%,the number of alleles(Na)is 1.925,the number of effective alleles(Ne)is 1.450,the genetic diversity of Nei's is 0.277,and the Shannon index(I)is 0.427,the percentage of polymorphic loci(PPL)is 92.54%,the genetic diversity within populations(Hs)is 0.1934,the genetic differentiation coefficient(Gst)is 0.3009,the total genetic diversity(Ht)was 0.2767,and the average gene flow among populations(Nm)of Cymbidium is 1.1619,the fixation index of pairwise genetic differentiation among populations ranged from 0.002 to 0.527,with an average of 0.325.The systematic clustering results indicate that Cymbidium has high degree of genetic differentiation,which was divided into three groups by systematic clustering analysis,Cymbidium.goeringii and C.sinense were assigned to one category,while C.kanran,C.goeringii var.longibracteatum,C.faberi,C.tortisepalum and C.ensifolium were in the second category,the hybrids were in a unique category,which has a large genetic distance from the other two categories.Principal coordinate analysis indicated that C.tortisepalum and C.goeringii showed a distant genetic relationship.6 pairs of primers were selected to construct fingerprint QR codes for 96 species.Collectively,this study provided an important basis for the breeding and variety identification of Cymbidium in the future.