Genetic relationship of Gardenia jasminoides among plantations revealed by ISSR

Objective To evaluate the genetic differences and mutual relationship of Gardenia jasminoides at DNA level among Zhangshu,Fengcheng,and Xingan GAP plantations in Jiangxi Province,so as to provide reference for G.jasminoides breeding.Methods Genetic variations were revealed by inter-simple sequence repeats(ISSR)markers.Results Ten ISSR primers generated 58 loci of which 32 loci were polymorphic.The average percentage of polymorphic bands(PPB)is 55.17%.The range of Nei's genetic diversity is 0.005—0.167,and the range of Shannon information index(Ⅰ)is 0.008—0.254.The variations within populations account for 75.12% and among them for 24.88% of the total.The NJ dendrogram showed two basic clusters.One consists of the samples from Zhangshu,and the other mainly consists of the samples from Xingan and Fengcheng with very few samples from Zhangshu.Conclusion Zhangshu population has the highest genetic diversity,while Fengcheng has the lowest genetic diversity,possibly because of very few samples assayed.The samples from the same population are more similar than those from different populations,indicating that ISSR makers have the power to trace the origin of samples.The geographical distance between Fengcheng and Xingan is farther but the genetic distance between them is shorter.This is quite possibly because of inter-introduction between them,and some exceptions of a few samples from Zhangshu clustered with samples from Fengcheng might be because of parallel mutations which are common below specific level.