Core-germplasm construction of apricot collections in South of Xinjiang by ISSR molecular markers

【Objective】The method for constructing core- germplasm of apricots in South of Xinjiangbased on molecular marker data was probed and the optimum core germplasm was established.【Methods】Taking 138 apricot collections as materials,an allele preferred sampling strategy was used to constructapricot core collection using UPGMA cluster method according to SM,Jaccard and Nei&Li genetic dis-tances by stepwise clustering and compared with the random sampling strategy. The number of lost alleleand t-test of gene diversity indexes were used to determine the optimal building methods. T-test of corecollection and initial collection,core collection and reserve collection were used to evaluate the represen-tative of core collections,and the genetic diversity compared of core collection,initial collection and re-serve collection was used,too. The principal coordinate analysis and phenotypic traits were used to con-firm of core collection.【Results】Compared with the random sampling strategy,allele preferred samplingstrategy could construct more representative core collections. According to Jaccard genetic distance toconstruct core collection of apricot collections was better than by SM and Nei&Li genetic distance. Theanalysis of principal coordinate analysis and phenotypic traits were showed that the core collection of apri-cot collections in the South of Xinjiang which was constructed by allele preferred sampling strategy andJaccard genetic distance can be more comprehensively representative for the genetic diversity of initial collection. The 31 core collection resources of apricot collections in South of Xinjiang have 22.46% germ-plasm samples of initial collection,the retention ratio of number of polymorphic loci,percentage of poly-morphic loci,observed number of alleles,effective number of alleles,Nei's genetic diversity and Shan-non information index were respectively for 92.37%,97.62%,98.82%,102.52%,107.17% and 106.36%.【Conclusion】The method of allele preferred sampling strategy and Jaccard genetic distance by stepwiseclustering was a suitable method for constructing core collection of apricot in South of Xinjiang. These re-sults demonstrated that the 31 core collections could stand for the genetic distance of initial collections ex-cellently.