云南48种木兰科野生植物资源遗传多样性研究

为了解云南省木兰科（Magnoliaceae）野生植物资源的遗传多样性，利用ISSR分子标记技术对48种木兰科野生植物资源进行研究。结果表明，10对引物共扩增出151条带，均为多态性条带，多态性条带百分率为100%。总的观测等位基因数（N_a）为2.000 0，有效等位基因数（N_e）为1.564 5，Nei’s基因多样性指数（H）0.337 9，Shannon’s信息指数（I）为0.510 1。总的基因多样性指数（H_t）为0.368 0，属间基因多样性指数（D_st）为0.251 9，占68.4%，基因分化系数（G_st）为0.684 0，基因流（N_m）为0.231 0。UPGMA聚类分析将48种木兰科植物划分为7个类群，各类群并非按照属聚在一起，而是不同属植物相间分布，长喙厚朴（Magnolia rostrata）、素黄含笑（Michelia flaviflora）和球花含笑（M.sphaerantha）可能为云南省木兰科植物中的原始种。48种木兰科野生植物总体具有较高的遗传多样性，但属间遗传变异较高，基因流较小，存在遗传漂变的风险，聚类结果与刘玉壶的分类系统存在分歧，这从分子水平为木兰科植物间的起源、进化与分类提供了重要依据。

Study on Genetic Diversity of 48 Wild Species of Magnoliaceae

The genetic diversity of 48 wild species of Magnoliaceae in Yunnan Province were studied by using ISSR molecular markers. The results showed that a total of 151 polymorphic bands were amplified by 10 pairs of primers with percentage of polymorphic bands for 100%. The total observed number of alleles (N_a), effective number of alleles (N_e), Nei''s genetic diversity index (H) and Shannon''s information index (I) of 48 Magnoliaceae species were 2.000 0, 1.564 5, 0.337 9 and 0.510 1, respectively. The total genetic diversity index (H_t) was 0.368 0, and the intergeneric genetic diversity index (D_st) was 0.251 9, accounting for 68.4% of total genetic diversity index. The coefficient of gene differentiation (G_st) was 0.684 0 with gene flow (N_m) of 0.231 0. Forty-eight Magnoliaceae species could be divided into 7 groups by UPGMA clustering, which were not consistent with the classification of genera, each cluster was included species of different genera. Magnolia rostrata, Michelia flaviflora and M. sphaerantha might be the ancestors of Magnoliaceae in Yunnan. The 48 Magnoliaceae species in Yunnan province had high genetic diversity in general, but they had high inter-genus genetic variation and small gene flow, which may lead to the risk of genetic drift. Moreover, the clustering results were different from the classification system of Liu Yuhu. So, it would provide an important basis for the origin, evolution and classification of Magnoliaceae at molecular level.