云南48种木兰科野生植物资源遗传多样性研究

Study on Genetic Diversity of 48 Wild Species of Magnoliaceae

摘要:

云南省是木兰科植物的避难所和发源地,原始种和进化种相间分布,对研究木兰科植物系统进化与分类具有重要意义。本研究利用ISSR分子标记技术对云南省48种木兰科野生植物资源开展研究。结果表明,10条引物共扩增出条带151条,其中多态性条带为151条,多态性条带百分比为100%。总的观测等位基因数(Na)为2.0000,有效等位基因数(Ne)为1.5645,Nei"s基因多样性指数(H)为0.3379,Shannon"s信息指数(I)为0.5101。总的基因多样性指数(Ht)为0.3680,属间基因多样性(Dst)为0.2519,占68.4%,基因分化系数(Gst)为0.6840,基因流(Nm)为0.2310。UPGMA聚类结果将48种木兰科植物划分为7个类群,聚类结果并非按照属的划分方式聚在一起,而是不同属植物相间分布,长喙厚朴、素黄含笑和球花含笑可能为云南省木兰科植物中的原始种。云南省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,并且聚类结果与刘玉壶分类系统存在分歧,研究结果从分子水平上为木兰科植物间的起源、进化与分类提供了重要依据。

Abstract:

Yunnan province is the refuge and birthplace of magnolias, the primitive and evolutionary species of Magnoliaceae are distributed alternately in there. It is very important to study the phylogenetic evolution and classification of Magnoliaceae.In this study, ISSR molecular markers were used to study 48 species of Magnoliaceae wild plant resources in Yunnan province.The results showed that a total of 151 bands and 151 polymorphic bands were amplified from the 10 primers, and the percentage of polymorphic bands was 100%. The total number of observational alleles (Na), effective alleles (Ne), Nei"s genetic diversity index (H) and Shannon"s information index (I) of the 48 Magnoliaceae plants were 2.0000, 1.5645, 0.3379 and 0.5101, respectively. The total genetic diversity index (Ht) was 0.3680 and the intergeneric genetic diversity index (Dst) was 0.2519. The intergeneric genetic diversity accounted for 68.4% of the total genetic diversity index. The coefficient of gene differentiation (Gst) was 0.6840, and the gene flow (Nm) was 0.2310. 48 species of Magnoliaceae plants were divided into 7 groups by the UPGMA clustering, and the clustering results were not consistent with the classification of genera, but distributed in different genera.and Magnolia rostrata, Michelia flaviflora and Michelia sphaerantha may be the ancestors of Magnoliaceae in Yunnan province.The 48 species of Magnoliaceae wild plants in Yunnan province have high genetic diversity in general, but they have high inter-genus genetic variation and small gene flow, which may lead to the risk of genetic drift. Moreover, the clustering results are different from the classification system of Liu Yuhu.The results provide an important basis for the origin, evolution and classification of Magnoliaceae at the molecular level.