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草业学报 ›› 2025, Vol. 34 ›› Issue (12): 170-182.DOI: 10.11686/cyxb2025012

• 研究论文 • 上一篇    

基于SSR标记的寡穗茅群体遗传多样性和群体遗传结构分析

富贵1,2,4(), 刘玉萍3,4,5, 苏旭3,4,5(), 曲荣举3, 才让扎西null3   

  1. 1.青海师范大学地理科学学院,青海 西宁810008
    2.青海民族大学生态环境与资源学院,青海 西宁810007
    3.青海师范大学生命科学学院,青海 西宁 810016
    4.青海师范大学,青海省青藏高原生物多样性形成机制与综合利用重点实验室,青海 西宁810008
    5.青海师范大学,高原科学与可持续发展研究院,青海 西宁810016
  • 收稿日期:2025-01-16 修回日期:2025-03-31 出版日期:2025-12-20 发布日期:2025-10-20
  • 通讯作者: 苏旭
  • 作者简介:E-mail: xusu8527972@126.com
    富贵(1987-),男,甘肃天水人,副教授,在读博士。E-mail: qhmdfg@163.com
  • 基金资助:
    青海省重大科技专项(2023-SF-A5);2023年中央林业草原生态保护恢复资金野生动植物保护项目(QHSY-2023-016);青海省省财政林业改革发展资金林草新技术推广项目(QSCZ-2023-001)

Population genetic diversity and genetic structure analysis of Littledalea przevalskyi based on SSR molecular marker

Gui FU1,2,4(), Yu-ping LIU3,4,5, Xu SU3,4,5(), Rong-ju QU3, Cairangzhaxi3   

  1. 1.School of Geosciences,Qinghai Normal University,Xining 810008,China
    2.College of Ecological Environmental and Resources,Qinghai Minzu University,Xining 810007,China
    3.School of Life Sciences,Qinghai Normal University,Xining 810016,China
    4.Key Laboratory of Biodiversity Formation Mechanism and Comprehensive Utilization of the Qinghai-Xizang Plateau in Qinghai Province,Qinghai Normal University,Xining 810008,China
    5.Academy of Plateau Science and Sustainability,Qinghai Normal University,Xining 810016,China
  • Received:2025-01-16 Revised:2025-03-31 Online:2025-12-20 Published:2025-10-20
  • Contact: Xu SU

摘要:

寡穗茅为分布于青藏高原的一种具有重要生态和经济价值的禾本科草本植物,为探明寡穗茅群体遗传多样性、遗传结构和物种分布格局,本研究基于15对简单重复序列(SSR)引物对21个不同地区的寡穗茅居群遗传多样性及遗传结构进行了研究。结果表明:15对SSR引物共扩增出等位基因数目(Na)为147个,平均每对引物扩增出9.8个等位基因,平均有效等位基因数(Ne)为5.418、Shannon’s 信息指数(I)平均值为1.808、期望杂合度(He)平均值为0.791、观测杂合度(Ho)平均值为0.882、Nei’s遗传多样性指数(H)为0.785,15对引物多态性信息含量为0.530~0.900,平均值为0.756;基于物种水平的遗传多样性结果显示,21个居群共扩增出15个多态性位点,平均多态性位点为13.57,Na、Ne、I、He、Ho和H平均值分别为3.299、2.806、1.028、0.717、0.841和0.598;居群遗传分化系数(Fst)和基因流(Nm)分析结果显示,寡穗茅居群间存在一定程度的遗传分化;分子方差分析(AMOVA)发现,居群间遗传变异为33%,居群内的遗传变异为67%;综合聚类分析、主成分分析及遗传结构分析发现,21个不同分布区样本基因型存在明显的差异,依据样本地理来源,21个居群样本大致可分为以玛多、玛沁、曲麻莱东南部、玉树和类乌齐为主的东南部种群(第I亚群),以格尔木、曲麻莱西北部和称多为主的西北部种群(第Ⅱ亚群);Mantel检验显示,不同居群遗传距离和地理距离之间显著相关(r=0.412;P<0.001),不同居群之间遗传分化可能和地理阻碍有关。该研究结果为探明扇穗茅属物种系统发育关系、物种界定、种质资源评价、野生资源保护及利用等提供了理论基础。

关键词: 寡穗茅, SSR分子标记, 遗传多样性, 遗传结构

Abstract:

Littledalea przevalskyi is a member of the grass family (Poaceae) with significant ecological and economic value and with a geographic distribution including Inner Mongolia and the Qinghai-Tibetan Plateau. This research investigated the genetic diversity, genetic structure, and species distribution patterns of L. przevalskyi. The L. przevalskyi populations studied originated from 21 different regions and the genomic investigation was based on 15 pairs of simple sequence repeats (SSR) primers. A total of 147 alleles (Na) were detected by the 15 primer pairs, the average number of alleles was 9.8, the average effective allele per SSR marker (Ne) was 5.418, the average Shannon’s information index (I) was 1.808, the average expected heterozygosity (He) was 0.791, the average observed heterozygosity (Ho) was 0.882, and Nei’s gene diversity index(H) was 0.785. The polymorphism information content (PIC) of the 15 primer pairs ranged from 0.530 to 0.900 with a mean value of 0.756. The results of species level genetic diversity showed that 15 polymorphic loci were detected in the 21 populations. The average polymorphic loci was 13.57, and the average values of Na, Ne, IHe, Ho, and H were 3.299, 2.806, 1.028, 0.717, 0.841, and 0.598, respectively. The results of coefficient of genetic differentiation and gene flow quantification showed a certain degree of genetic differentiation among the L. przevalskyi populations. Analysis of molecular variance (AMOVA) revealed that 33% of total genetic variation occurred among populations, while 67% resided within populations. Integrated analysis of cluster analysis, principal component analysis (PCA), and genetic structure analysis revealed that the genotype of samples derived from different distribution areas had significant differences. Based on the geographical origins of the samples, the 21 population samples can be roughly classified into two subgroups, the southeastern populations (subgroup I) primarily consisting of originating from Maduo, Maqin, southeastern Qumalai, Yushu, and Riwoqê, and the northwestern populations (subgroup Ⅱ) mainly including those originating from Geermu, northwestern Qumalai, and Chenduo. A Mantel test showed there was a significant correlation between genetic distance and geographical distance (r=0.412; P<0.001), implying the genetic differentiation among different populations may be related to geographical barriers. The results of this study provide a theoretical and quantitative basis for exploring and categorizing the phylogenetic relationships, species definition, germplasm resource evaluation, and conservation and utilization of wild resources of the genus Littledalea.

Key words: Littledalea przevalskyi, simple sequence repeats (SSR) molecular marker, genetic diversity, genetic structure