黄山花楸种群遗传多样性研究

利用RAPD技术，对黄山花楸(Sorbus amabilis)自然分布区的13个自然种群的遗传多样性进行了研究，从40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105个位点，其中多态性位点30个，占28．6％，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，也是其濒危的主要原因。

Genetic diversity of rare and endangered plant Sorbus amabilis

The genetic diversity of 13 natural populations of Sorbus amabilis Cheng ex Ya from diferent distribution regions was investigated using RAP D ．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 d~drograms were established for the 13 natural populations，based on UPGMA and Neighbo r-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 po pulations were prim arily related tO their geographic distribution．
Its special evolutionary himory，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．