甜槠种群遗传多样性的简单重复序列区间初步分析

Primary study on genetic variation and genetic diversity among Castanopsis eyrei populations based on inter-simple sequence repeat(ISSR) markers

应用简单重复序列区间（ISSR）分子标记方法对甜槠种群的遗传多样性和遗传分化进行了初步研究．从100个引物中筛选出12个用于正式扩增的ISSR引物，在9个种群179个个体中共检测到202个位点，其中198个是多态位点，多态位点百分率（P）为98．02％．各种群多态位点百分率在60．40％～70．30％，平均为65．29％．甜槠物种水平的Shannon信息指数（I）为0．5322、Nei指数（h）为0．3597．各种群J平均为0．3635、h平均为0．2468．AMOVA分子差异分析表明，65．96％的变异存在于种群内，34．04％的变异存在于种群间，种群间的基因分化系数（GST）为0．3138．甜槠种群间的基因流（Nm）为1．0933．9个种群的平均遗传距离为0．1849，遗传距离与地理距离呈显著正相关．利用UPGMA法对9个种群进行聚类，结果显示浙江省内的8个种群聚成一类，庐山种群单独成一类．

Using inter-simple sequence repeat （ISSR） makers, genetic diversity and genetic differentiation within and among Castanopsis eyrei populations were primarily analyzed. A total of 202 bands were detected from 9 populations with 179 individulas by 12 reliable primers. Among of them, 198 bands were polymorphic and the percentage of polymorphic loci was 98. 02%. The percentage of polymorphic loci of Castanopsis eyrei populations ranged ftom 60.40% to 70.30% with an average of 65.29%. Shannon information index （I） and Nei＇s gene index （h） at species level were 0. 532 2 and 0. 359 7, respectively, while those at population level averged 0. 363 5 and 0. 246 8, respec- tively. Analysis of molecular various showed that 65.96% of the total variation was distributed among populations, while only 34.04% was distributed among individuals within populations. The gene differentiation coefficient （GST） among populations was 0. 313 8 and the estimated gene flow was 1. 093 3. The average pairwise genetic distance of 9 populations was 0. 184 9. Significant correlation was found between Nei＇s genetic distance and geographical dis- tance. Using unweighted pair group method arithmatic average （UPGMA）, the nine populations could be clustered into three groups, while LS population occupied one group by itself.