2022年7月7日 星期四
基于EST-SSR标记的青榨槭天然种群遗传多样性分析
Analysis on genetic diversity of natural populations of Acer davidii based on EST-SSR marker
2022年 第31卷 第2期 页码[57-63]    下载全文[1.3MB]  
摘要

采用28对EST-SSR引物对北京、河南、陕西、广东和浙江的青榨槭(Acer davidii Franch.)8个天然种群231株样株的基因组DNA进行扩增,在此基础上对供试种群的遗传多样性和遗传结构进行分析。结果表明:8个天然种群的观测等位基因数和有效等位基因数较为接近,均值分别为3.2和1.6;Shannon’s多样性指数、观测杂合度、期望杂合度、Nei’s基因多样性指数和多态性信息含量均值分别为0.512 7、0.237 9、0.276 9、0.271 9和0.243 6。总体来看,8个天然种群中,广东南岭国家森林公园(P7)种群的遗传多样性最高,河南嵩山地质公园(P5)种群的遗传多样性最低,且8个天然种群的观测杂合度小于期望杂合度。8个天然种群间的遗传分化系数为0.334 5,基因流为0.508 8,种群内和种群间的遗传变异贡献率分别为66.55%和33.45%。供试种群中,P7种群和浙江西天目山森林公园(P8)种群与其余6个种群间的遗传相似系数相对较小,而遗传距离却相对较大。Mantel检验结果显示:青榨槭种群间的遗传距离和地理距离存在极显著正相关(R2=0.568 6,P=0.002)。UPGMA聚类分析和STRUCTURE分析结果均表明:供试青榨槭8个天然种群被分成2个集群,其中,P7种群和P8种群为一个集群,其余6个种群为另一个集群。综合上述研究结果:青榨槭天然种群的遗传多样性水平较高,其遗传分化主要存在于种群内,种群间的基因交流较少。供试种群内均存在一定程度的自交或近交现象,种群容易衰退,故应加强对青榨槭天然种群的保护力度。

Abstract

 The genomic DNA of 231 samples from eight natural populations of Acer davidii Franch. in Beijing, Henan, Shaanxi, Guangdong, and Zhejiang were amplified with 28 pairs of EST-SSR primers, and the genetic diversity and genetic structure of the test populations were analyzed on the basis. The results show that the numbers of observed alleles and effective alleles of eight natural populations are relatively close, and their means are 3.2 and 1.6, respectively; the means of Shannon’s diversity index, observed heterozygosity, expected heterozygosity, Nei’s gene diversity index, and polymorphism information content are 0.512 7, 0.237 9, 0.276 9, 0.271 9, and 0.243 6, respectively. Overall, among eight natural populations, the genetic diversity of Nanling National Forest Park of Guangdong (P7) population is the highest, while that of Songshan Mountain Geopark of Henan (P5) population is the lowest, and the observed heterozygosity of eight natural populations are smaller than their expected heterozygosity. The genetic differentiation coefficient among eight natural populations is 0.334 5, the gene flow is 0.508 8, and the contribution rates of genetic variation within and among populations are 66.55% and 33.45%, respectively. Among the test populations, the genetic similarity coefficients of P7 population and West Tianmu Mountain Forest Park of Zhejiang (P8) population with the other six populations are relatively small, but the genetic distances are relatively large. The Mantel test result shows that there is an extremely significantly positive correlation between genetic distance and geographical distance among A. davidii populations (R2=0.568 6, P=0.002). The UPGMA cluster analysis and STRUCTURE analysis results both show that the test eight populations of A. davidii are divided into two clusters, in which, P7 population and P8 population are one cluster, and the other six populations are the other cluster. It is suggested that the genetic diversity level of natural populations of A. davidii is relatively high, its genetic differentiation mainly exists within populations, and there is less gene exchange among populations. There are some selfing or inbreeding phenomenon in the test populations, and the populations are easy to decline, therefore protection of natural populations of A. davidii should be strengthened.

关键词青榨槭; EST-SSR标记; 遗传多样性; 遗传结构; 聚类分析
Key wordsAcer davidii Franch.; EST-SSR marker; genetic diversity; genetic structure; cluster analysis
作者穆莹, 张梦璐, 白云海, 张睿鹂, 郑健, 窦德泉
所在单位北京农学院园林学院 城乡生态环境北京实验室, 北京 102206
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基金项目北京市教育委员会科技计划面上项目(KM202010020005)