摘要： 探讨分子水平构建燕山板栗核心种质的适宜方法，以利于燕山种质的保存、保护和研究利用。基于SSR标记，采用非加权算数平均聚类（UPGMA）法对燕山地区10个市（县）的161份板栗种质进行多次聚类抽样分析，比较使用3种遗传相似系数（SM系数、Dice系数和Jaccard系数）和2种取样方法（随机取样法和位点优先取样法）相组合确定的不同样本群的有效等位基因数（Ne）、Nei's多样性指数（H）和Shannon's信息指数（I）的大小，确定构建燕山板栗核心种质的适宜方法；再分别对核心种质与原种质、核心种质与保留种质的遗传多样性指标进行t检验，以评价核心种质的代表性；通过绘制主坐标分布图观察核心种质和原种质的分布情况，并结合表型特征对构建的核心种质进行确认。结果表明：应用位点优先取样法取得的样本群比随机取样法具有更高的Ne、H和I，应用SM系数取得的样本群，其遗传多样性指标要优于Dice系数和Jaccard系数，综合利用位点优先取样法和SM系数筛选了46份燕山板栗核心种质，保留了原种质28.57%的样品，Ne、H和I分别为1.531 7，0.321 8和0.491 0。t检验表明，核心种质的遗传多样性指标显著大于原种质，经主坐标分析和表型特征确认，核心种质在原种质的主坐标图中分布均匀，能够较全面地代表整个板栗种质资源的遗传多样性。采用位点优先取样法和SM相似性系数进行多次聚类，是构建燕山板栗核心种质较适宜的方法，构建的容量为46份的板栗核心种质，能充分代表原种质的遗传多样性。

关键词: 燕山板栗, 核心种质, SSR, 遗传多样性

Abstract: The suitable means to construct core collection of Yanshan chestnut germplasm based on SSR makers was studied, which was beneficial for preservation, management and utilization of chestnut germplasm resources.Taking 161 Yanshan chestnut germplasm resources from 10 cities(counties)as original materials, an allele-preferred sampling method and random sampling strategy were compared using UPGMA cluster method according to 3 genetic similarity coefficients(SM, Dice and Jaccard coefficient)based on SSR molecular markers. The effective number of alleles(Ne), Nei's gene diversity(H)and Shannon's information index(I)of two groups were compared to determine the optimum method. t -tests of core collection, initial collection and reserve collection were conducted to evaluate the representativeness of core collection. The principle coordinate analysis method and phonotypic traits analysis were used to confirm on the core collection.Compared with the random sampling strategy, allele preferred sampling method was more representative with higher values of genetic diversity indexes. The results showed the method of stepwise clustering according to SM similarity coefficient was better than Dice coefficient and Jaccard coefficient. 46 core collection included 28.57% initial collection. The effective number of alleles, Nei's gene diversity, Shannon's information index were respectively 1.531 7, 0.321 8 and 0.491 0. t -test showed the genetic diversity index of core collection was significantly higher that of initial collection.The core collection was evenly distributed in the principle coordinate diagram of initial collection, which could represent genetic diversity of the whole chestnut germplasm comprehensively.The method of allele preferred sampling and stepwise clustering according to SM similarity coefficient was a suitable means to construct core collection of Yanshan chestnut germplasm based on SSR makers, and 46 core collection could represent genetic diversity of original germplasm resources.

Key words: Yanshan chestnut, Core collection, SSR, Genetic diversity

中图分类号: 

• S664.2