利用ISSR分子标记构建濒危植物水青树核心种质

基于全国26个居群的174份水青树Tetracentron sinense种质，利用14条ISSR引物，采用UPGMA聚类法进行多次逐步聚类，利用三种取样策略(随机取样策略、位点优先取样策略和偏离度取样策略)构建初始核心种质，并将各遗传多样性指标进行比较分析，从而确定构建水青树核心种质的最佳方法。利用14条ISSR引物扩增出180个条带，其观测等位基因数(Na)、有效等位基因数(Ne)、Nei’s基因多样性指数(H)与Shannon信息指数(I)分别为1.6944、1.3912、0.2321和0.3509，说明水青树具有较低的遗传多样性。采用位点优先取样策略构建的核心种质各遗传多样性指数均大于随机取样策略和偏离度取样策略。利用位点优先取样策略构建了78 份核心种质资源，保留了44.83%原种质样品，遗传多样性指数Na、Ne、H和I的保留率分别为98.69%、100.01%、99.27%和98.67%，比较完好地保留了原种质的遗传多样性和遗传变异。因此，位点优先取样策略是构建水青树核心种质的最佳取样策略。

Core Collection Construction of Endangered Plant Tetracentron sinense Based on ISSR Molecular Markers

Taking 174 individuals of Tetracentron sinense 26 populations as materials, 3 sampling strategies (random sampling strategy, allele preferred sampling strategy and deviation sampling strategy) were used to construct its core collection based on ISSR markers. Genetic diversity indexes were used to determine the most suiconstruction method. 180 bands were amplified14 ISSR primers, and the observed number of alleles(Na), effective number of alleles(Ne), Nei’s genetic diversity(H) and Shannon information index(I) of original germplasm were 1.6944, 1.3912, 0.2321, 0.3509 respectively, indicating the abundant genetic diversity of T. sinense was low. Genetic diversity indexes of the core collection constructedallele preferred sampling strategy were higher than those of other two strategies. 78 core collection resources of T. sinenseallele preferred sampling strategy accounted for 44.83% initial collection, and the retention rate of genetic diversity indexes(Na, Ne, H and I) were respectively 98.69%, 100.01%, 99.27%, 98.67%, which indicated that the genetic diversity and variation were well preserved. The result demonstrated that the allele preferred sampling strategy was the most appropriate method for core collection construction of T. sinense.