中国楸树(Catalpa bungei C.A.Mey)种质资源遗传多样性的ISSR分析

ISSR analysis of genetic diversity of Catalpa bungei C.A.Mey germplasm resources in China

采用简单序列重复区间标记法(ISSR)分子标记技术,对中国楸树(Catalpa bungeiC.A.Mey)10个类型156个单株进行了遗传多样性分析。从46个简单重复序列引物中筛选出的14个引物共扩增出190条稳定的谱带,其中多态性谱带186条,多态性条带百分率达97.89%。在物种水平上,Nei′s基因多样性指数(H)为0.290 9,Shannon信息指数(I)为0.446 3,基因多样度(Ht)为0.296 7,基因分化系数(Gst)为0.397 1,基因流(Nm)为0.759 2。分析结果表明,楸树各类型间变异占总变异的39.71%,类型内的变异占总变异的60.29%,约为类型间变异的1.5倍,说明中国楸树类型内的变异在其遗传变异中占主导地位。楸树类型间的遗传相似系数介于0.668 4和0.984 9之间,平均为0.863 7。基于遗传相似系数的UPGMA聚类分析,可将楸树10个类型分为4类。

The genetic diversity of 156 individuals from 10 types of Catalpa bungei was analyzed by inter-simple sequences repeats（ISSR） techniques.One hundred and ninety loci were generated with 14 simple sequence repeat primers screened from 46 primers,out of which 186 were polymorphic and the percentage of polymorphic bands was 97.89%.At the species level,Nei′s gene diversity（H） was 0.290 9,Shannon′s information index（I） was 0.446 3,the gene diversity（Ht） was 0.296 7,the coefficient of gene differentiation（Gst） was 0.397 1,and the gene flow（Nm） was 0.759 2.The genetic variation within types was 60.29%,which was about 1.5 times as large as that among types（39.71%）.The results revealed that variation within types was dominant.The genetic similarity（GS） of the 10 types of C.bungei C.A.Mey ranged from 0.668 4 to 0.984 9,and averaged 0.863 7.Based on the genetic similarity,cluster analysis by UPGMA method showed that 10 types of C.bungei C.A.Mey could be divided into 4 groups.