Genetic variation in six Oratosquilla oratoria populations revealed by random amplified polymorphic DNA (RAPD) markers

In this study, random amplified polymorphic DNA (RAPD) analysis was used to estimate the genetic diversity among six Oratosquilla oratoria populations: Dalian (DL), Wafangdian (WF), Zhuanghe (ZH), Donggang (DG), Suizhong (SZ) in Liaoning province and Qingdao (QD) in Shandong province. 18 random primers for RAPD analyzing generated 256 bands, out of which 209 were polymorphic loci. The number of bands of each primer ranged from 7 to 16, varying in size from 200 bp to 2500 bp. The average percentage, the average Shannon index and average Nei index of the polymorphism loci in all of the six populations were 81.84%, 0.5872 and 0.4015, respectively. Moreover the Nei index and the Shannon index among populations were higher than those indexes within population which indicates the resource of the six O. oratoria populations was in high genetic diversity. The result showed that the coefficient of interpopulational gene diversity (Gst) among the six population was 0.2658 indicating 26.58% gene differentiation come from the differentiation of different populations and most of them (73.42%) present within populations. Cluster analysis by unweighted pair group with arithmetic average (UPGMA) show six populations could be grouped into two clusters (the first cluster contained DL, ZH, WF, DG and SH; the second cluster contained QD alone). The genetic differentiation coefficient and genetic distance indicates the genetic differentiation closely was related to geographic location.