黄山花楸种群遗传多样性研究

Genetic diversity of rare and endangered plant Sorbus amabilis

利用RAPD技术 ,对黄山花楸 (Sorbusamabilis)自然分布区的 13个自然种群的遗传多样性进行了研究 .从 4 0个 10碱基随机引物中筛选出能产生稳定多态性标记的引物 14个 ,共扩增出 10 5个位点 ,其中多态性位点 30个 ,占 2 8.6 % .应用UPGMA法和Neighbor Joining法对遗传距离进行聚类分析构建树系图 ,结果表明 ,黄山花楸自然种群具有较低的遗传多样性 ,对环境变化的适应能力较差 ;其种群间的遗传差异与其地理分布有关 ;黄山花楸自身的特殊进化历史和人为砍伐以及自然灾害 (火灾、病虫害等 )和小种群的遗传漂变作用是黄山花楸遗传多样性水平低的主要原因 。

The genetic diversity of 13 natural populations of Sorbus amabilis Cheng ex Yü from different distribution regions was investigated using RAPD.Fourteen primers were screened from 40 ten bp arbitrary primers,and a total of 105 DNA fragments were amplified,among which,30(28.6%) were polymorphic. DNA molecular dendrograms were established for the 13 natural populations,based on UPGMA and Neighbor Joining.The result showed that S.amabilis had a low genetic diversity,and its adaptability to environmental change was weak.The genetic diversity of S.amabilis among the 13 natural populations were primarily related to their geographic distribution.Its special evolutionary history,man made destruction,natural disaster (fire,plant diseases and insect pests etc.) and genetic drift caused by small population were the main reasons for the low level genetic diversity of S.amabilis and its endangered position.