大别山山核桃种群遗传多样性研究

RAPD ANALYSIS ON GENETIC DIVERSITY OF CARYA DABIESHANENSIS POPULATIONS

为了更有效地保护和合理开发大别山山核桃(Caryadabieshanensis)资源,该文利用RAPD分子标记技术,对3个天然大别山山核桃种群的90个单株的遗传多样性、种群内和种群间的遗传变异进行了研究,结果表明:20对10bp随机引物共检测到238条谱带,其中多态带为162条,占68.1%。遗传多样性分析结果显示:Shannon多样性指数为0.4761,58.18%的变异分布于群体内,而种群间变异占了41.82%;Nei指数群体总基因多样度为0.3145,群体内平均基因多样度(HS)为0.1865,群体间的基因多样度(HST)为0.1280,群体Nei基因分化系数(GST)为0.4067,说明40.67%的变异存在于种群间,群体内的变异占了总变异的59.33%,与Shannon多样性指数相比基本一致,均表明种群内有较丰富的遗传变异,这为优良品种选育提供广阔前景;种群间的基因流(Nm)为0.7306,证明种群间遗传交换较小,这与环境适应性和高山阻隔有一定的关系。

The genetic diversity and genetic variation within and among three natural Carya dabieshanensis populations were studied using RAPD analysis. The result showed that 238 loci were detected by using 20 random primers （10 bp） of which 162 loci were polymorphic （68.1%）. Species genetic diversity indicated by Shannon＇ s index was 0.476 1, 58.18 % of which was due to within population genetic diversity and 41.82 % among population variation. Species gene diversity indicated by Nei＇s index was 0.314 5, gene diversity within populations （Hs） was 0. 186 5, gene diversity among populations （HST） was 0. 128 0 and the coefficient of gene differentiation （GST） among the populations was 0.406 7, 59.33% of which was within populations and 40.67 % was among populations. The gene diversity estimated by Nei＇ s index was consistent with that estimated by Shannon＇ s index. These results suggest that there is rich genetic within population variation, which offers excellent prospects for seeding selection. The estimate of gene flow from GsT（Nm） was 0.730 6, indicating that genetic recombination between populations is quite small, which probably is related to environmental adaptations of C. debieshanensis and population isolation in their high mountain habitat.