基于ISSR标记的江西野生寒兰居群遗传多样性研究

Studies on Genetic Diversity of Cymbidium kanran Populations from the Main Mountains in Jiangxi Province Based on ISSR Marker

采用ISSR分子标记对江西省主要山脉12个野生寒兰居群共185个体进行遗传多样性和群体遗传结构研究。结果表明:12条ISSR引物共扩增出123个条带,其中多态性条带97个,多态性条带百分率(PPB)为78.9%。12个寒兰居群在物种水平上的遗传多样性较高,群体总观测等位基因数(N_a)为1.7967,有效等位基因数(N_e)为1.4461,N_ei’s基因多样性(H_e)为0.2649,Shannon’s信息多样性指数(I)为0.3995;在居群水平上遗传多样性较低,PPB平均值为43.97%,N_a平均值为1.4397,N_e平均值为1.2478,H_e平均值为0.1462,I平均值为0.2204;遗传分化系数(G_(ST))为0.4415,居群间基因流(N_m)为0.6325,表明居群内的遗传分化大于居群间的遗传分化;UPGMA聚类结果显示12个寒兰居群可聚为两支,第一支由资溪、武夷山大叶、武夷山小叶、崇义小叶、靖安、宜丰、井冈山、邵武大叶和邵武小叶9个居群组成;第二支由石城、安远和崇义大叶3个居群组成,聚类结果没有呈现出山脉分布的特点;Mantel检验结果表明遗传距离和地理距离之间无显著相关性(r=0.3791)。

This study used ISSR molecular marker to analyze the genetic diversity and genetic structure of 12 Cymbidium kanran populations from the main mountains in Jiangxi Province.The results showed that 123 bands were amplified from 185 individuals from 12 primers,of which 97 bands were polymorphic,the percentage of polymorphic bands was 78.9%.The genetic diversity of 12 populations at species level was higher（PPB = 78.9%,N_a = 1.7967,N_e = 1.4461,H_e = 0.2649,I = 0.3995）,while the genetic diversity at population level was lower（PPB = 43.97%,N_a = 1.4397,N_e = 1.2478,H_e = 0.1462,I = 0.2204）.The genetic differentiation coefficient（G_（ST））was 0.4415,gene flow（N＋m）was 0.6325,these indicated that the genetic differentiation in the populations was higher than the genetic differentiation among the populations.Based on cluster analysis by UPGMA,12 C.kanran populations were classified into two groups,the first group included nine populations of ZX,WYS,WYSX,CYX,JA,YF,JGS,SW and SWX,the second group included three populations of SC,AY and CY,the result of cluster analysis showed no obvious correlation with the distribution of C.kanran populations according to the mountains.Mantel test showed that there was no significant correlation between genetic distance and geographical distance（r = 0.3791）.