香榧古树的遗传差异性

摘要

Leaves from 149 ancient Torreya grandis cv. Merrillii trees were collected in 5 counties (cities) such as Dongyang (DY), Pan’an (PA), Shengzhou (SZ), Zhuji (ZJ) and Shaoxing (SX), Zhejiang province. SRAP (sequence related amplified polymorphism) analysis on 149 samples resulted that a total of 260 loci was detected, among them 170 of polymorphic (Np), accounting for 65.38%of the total one. Number of alleles (Na) was 1.653 8, number of effective alleles (Ne) 1.271 3, Nei’s gene diversity index (H) 0.1696, Shannon Information index (I) 0.266 4, total gene diversity (Ht) 0.1694, genetic differentiation (Gst) 0.144 2, gene diversity within population (Hs) 0.145 0 and gene flow (Nm) 2.967 5. Cluster analysis indicated that the scions of the old trees may not be from the same source and there were gene exchanges among populations, which led to separation but relatively high identity.%对香榧主产地浙江省诸暨、绍兴、嵊州、东阳、磐安的5个香榧古树群体共149个样品进行了SRAP标记分析，共检测到260个位点，其中多态位点170个，多态位点占为65.38%（PPL%）；群体观察到的等位基因数（Na）为1.6538，有效等位基因数（Ne）为1.2713，基因多样性指数（H）为0.1696，Shannon信息指数（I）为0.2664；群体总的基因多样性指数（Ht）平均为0.1694，分化系数（Gst）为0.1442，群体内基因多样度（Hs）为0.1450，群体间基因流（Nm）为2.9675；利用加权平均数法（UPGMA）对香榧古树居群间进行了聚类分析，结果东阳、嵊州两个居群先聚在一起，再与磐安居群聚在一起，而绍兴和诸暨居群聚在一起，最后再与磐安、东阳、嵊州居群聚在一起。研究结果表明，香榧古树接穗来源非唯一，是一个栽培类型，同时群体间有基因交流，既有分离又保持相对较高的相似性。