濒危植物五小叶槭(Acer pentaphyllum Diels)天然种群遗传多样性的ISSR标记分析

Genetic diversity of the endangered Acer pentaphyllum Diels by ISSR analysis

摘要:

五小叶槭(Acer pentaphyllum Diels)是中国四川特有野生珍稀濒危植物,仅分布于雅砻江中上游干旱河谷地带;探索其遗传多样性特征可以为其遗传资源的保护和利用提供理论依据.本文采用ISSR技术对五小叶槭的5个野生种群的44份材料进行遗传多样性分析,8条引物总共检测到38个位点,其中多态性位点35个,多态位点百分率（PPL）平均为90.21%.应用分析软件Popgen32分析得出:在物种水平上,五小叶槭的香农多样性指数（I）为0.3924,Nei氏基因多样性指数（He）为0.2498;种群间基因分化系数（Gst）为0.3722,种群间的基因流（Nm）为0.8433,这表明五小叶槭的遗传变异主要存在于种群内.在种群水平上,香农多样性指数（I）为0.2125, Nei氏基因多样性指数（He）为0.1456.结果表明木里、九龙三垭宫和康定这3个种群的遗传多样性水平较高,而雅江和九龙洛莫种群遗传多样性较低.通过Mantel检测,种群间遗传距离和地理距离之间没有显著相关性.

Abstract:

Acer pentaphyllum is rare and endangered plant endemic to Sichuan Province, China. This species is only distributed in the arid valley area of the upper and middle reaches of Yalong River. Exploring its genetic diversity characteristics can provide a theoretical basis for the protection and utilization of its genetic resources. In the paper, genetic diversity and genetic structure of 5 Acer pentaphyllum Diels populations from Sichuan (total about 44 individuals) were analyzed by ISSR (inter simple sequence repeat) markers. Eight highly stable and repeatable ISSR primers were used to detect a total of 38 loci, of which 35 were polymorphic sites (90.21% of the total). At the species level, the Shannon index (I) was 0.3924, Neis gene diversity index (He) was 0.2498, the coefficient of gene differentiation (Gst) was 0.3722, and the gene flow (Nm) was 0.8433. The software Popgen 32 analysis of the results showed that the genetic variation mainly existed in the population. At the population Level, I and He were 0.2125 and 0.1456, respectively. All of these results showed that Muli, Sanyagong and Kangdiing population had higher levels of genetic diversity, while Yajiang and Luomo had lower genetic diversity. The mantel analysis showed no significant correlation between genetic distance and geographic distance.