珍稀濒危植物天目木兰（Magnolia amoena）遗传多样性的RAPD分析

运用随机扩增多态DNA(RAPD)技术，对天目木兰(Magnolia amoena)居群的遗传多样性进行了研究．从40个10-mer随机引物中筛选出14个能得到清晰、稳定扩增带的引物进行扩增，14个引物共检测了94个位点，其中多态性位点为23，占24．4％，计算了12个居群之间的遗传相似度和遗传距离，并运用UPGMA法进行了聚类分析，结果显示相同严地个体间(居群内)的遗传距离较小，遗传多样性水平很低；不同产地个体间(居群间)遗传距离较大，遗传多样性水平较前者高，即天目木兰个体间遗传多样性水平与它的地理分布有关，天目木兰总体较低的遗传多样性是导致它濒危的原因之一。

Genetic diversity of rare and endangered plant Magnolia amoena

The genetic variations within and between eleven natural populations and one cultured population of Magnolia amoena from different distribution regions were investigated at the DNA level by employing RAPD.Out of 40 random primers ,fourteen random primers were screened which could generate highly reproducible and clear RAPD fragments for further population analysis.With these primers,a total of 94 discernible DNA fragments were obtained and 23(24.4%) were polymorphic,which indicated that low levels of genetic variation existed in the investigated populations.In addition,UPGMA map were made according to the genetic similarity and distance of the twelve populations calculated in this article.The result showed that the genetic diversity between individuals within population was lower than that between populations.The individual genetic differentiation might be relation to their geographic distribution.The low total genetic diversity of Magnolia amoena was one reason for its endangerment.