利用ISSR分子标记构建南疆杏种质资源核心种质

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

【目的】探讨分子水平构建南疆杏核心种质的方法,建立最适核心种质。【方法】以138份南疆杏种质资源为材料,根据SM、Jaccard和Nei&Li遗传距离,采用UPGMA聚类法进行多次聚类,以随机取样策略为对照,利用位点优先取样策略研究核心种质构建的方法;采用丢失的等位基因数以及遗传多样性各指标进行t检验来确定最适构建方法;分别将核心种质与原种质和保留种质进行t检验和遗传多样性比较,以此来评价核心种质的代表性;并用主坐标轴分析法和表型性状对核心种质进行确认。【结果】位点优先取样策略优于随机取样策略;通过Jaccard遗传距离构建的核心种质要优于SM和Nei&Li遗传距离;采用主坐标轴分析法和表型数据分析显示,利用位点优先取样策略和Jaccard遗传距离构建的核心种质能够较全面的代表原种质的遗传多样性;31份核心种质资源,保留了原种质22.46%的样品,多态性位点数、多态性位点百分率、观测等位基因数、有效等位基因数、Nei’s遗传多样性指数和Shannon信息指数的保留率分别达到92.37%、97.62%、98.82%、102.52%、107.17%和106.36%。【结论】采用位点优先取样策略和Jaccard遗传距离进行多次聚类,是较适宜的构建南疆杏种质资源核心种质的方法,构建的31份核心种质能全面代表原种质的遗传多样性。

【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.