羌活与宽叶羌活的群体遗传结构和种间分化研究

Species Differentiation and Population Genetic Structure of Notopterygium incisum and Notopterygium franchetii

为了合理利用羌活和宽叶羌活的药用植物资源,同时保护其物种多样性,该研究利用SSR分子标记技术对羌活与宽叶羌活邻域及异域分布的23个自然种群,共计227个个体进行多样性和种间分化研究。结果显示:(1)两个物种具有中等水平的遗传多样性;羌活的平均等位基因数(Na)、有效等位基因数(Ne)和期望杂合度(He)分别为2.603、1.777和0.313,均高于宽叶羌活(分别为2.200、1.641和0.308)。(2)分子方差分析表明,两个物种的遗传变异主要存在于群体内,羌活和宽叶羌活群体间分化系数分别为0.181和0.191。(3)Structure聚类分析和主坐标分析(PCoA)将所有取样个体分为两大遗传组分,分别对应于羌活和宽叶羌活两个物种,二者间存在着有限的基因交流。研究表明,羌活与宽叶羌活物种间存在较高程度的遗传分化,并且遗传变异主要源自群体内,应各自划分为不同的地理单元进行多样性保护。

In order to reasonable utilize the medicinal plant resources and protect species diversity of Notopterygium incisum and Notopterygium franchetii,this project collected 227 individuals from 23 allpatric and parapatric populations of two Notopterygium species to detect the genetic diversity and species differentiation based on the simple sequence repeats(SSR).The results showed that:(1)N.incisum and N.franchetii had moderate level of genetic diversity.The average number of alleles(Na),the number of effective alleles(Ne)and the expected heterozygosity(He)in N.incisum were 2.603,1.777,0.313,respectively.These diversity parameters were higher than that in N.franchetii,the values were 2.200,1.641,0.308,respectively.(2)AMOVA showed that the genetic variations were mainly occurred within populations for two Notopterygium species.The divergence index among populations Fst in N.incisum and N.franchetii,were 0.181 and 0.191,respectively.(3)Based on Bayesian's structure clustering analysis and principal coordinates analysis,it was concluded that the all sampled individuals have been divided into two genetic clusters,which corresponded to N.incisum and N.franchetii,respectively.The obvious genetic differentiation and few gene exchanges between the two species were identified.These findings suggested that there were higher genetic differentiation among species,and their genetic variations mainly occurred within populations,the two geographic units for N.incisum and N.franchetii should be constructed for further management and conservation.