南京林业大学学报(自然科学版) ›› 2020, Vol. 44 ›› Issue (4): 18-25.doi: 10.3969/j.issn.1000-2006.202003075

所属专题: 木本花卉专题

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基于SNP标记的紫薇遗传多样性分析

乔东亚(), 王鹏, 王淑安, 李林芳, 高露璐, 杨如同, 汪庆(), 李亚()   

  1. 江苏省中国科学院植物研究所,江苏 南京 210014
  • 收稿日期:2020-03-25 修回日期:2020-04-02 出版日期:2020-07-22 发布日期:2020-08-13
  • 通讯作者: 汪庆,李亚
  • 作者简介:乔东亚(qdylol@outlook.com)。
  • 基金资助:
    江苏省科技计划重点项目(BE2017375);国家自然科学基金面上项目(31770745);江苏省林业科技创新与推广项目(LYKJ[2019]40)

Genetic diversity analysis of Lagerstroemia germplasm resourcesbased on SNP markers

QIAO Dongya(), WANG Peng, WANG Shu’an, LI Linfang, GAO Lulu, YANG Rutong, WANG Qing(), LI Ya()   

  1. Institute of Botany,Jiangsu Province and Chinese Academy of Sciences,Nanjing 210014,China
  • Received:2020-03-25 Revised:2020-04-02 Online:2020-07-22 Published:2020-08-13
  • Contact: WANG Qing,LI Ya

摘要: 目的

利用SNP标记对85份紫薇种质资源进行聚类分析,探究其遗传多样性,为紫薇品种选育和品种鉴定提供理论支持。

方法

以源于国内外的85份紫薇种质为材料进行简化基因组测序,采用Massarray技术筛选高质量的SNP标记,获得SNP分型数据。通过PowerMarker V3.25对SNP分型数据进行遗传多样性分析,计算多态性信息含量(polymorphism content,PIC) 、期望杂合度( expected heterozygosity )、基因多样性(gene diversity)、遗传相似系数(genetic similarity,GS)等;基于Nei’s 1972算法计算种质间遗传距离,通过MEGA 6.0构建NJ聚类图;同时根据堇、红、银、复色等4种花色对85份紫薇种质进行分群。利用GenAIEx 6.5对聚类群和花色群进行遗传多样性分析和AMOVA分析,分别计算聚类群和花色群的遗传分化参数。

结果

根据测序结果筛选出21个高质量的SNP标记,这些标记在85份紫薇种质中的多态性信息含量为0.04~0.37,平均含量为0.33;期望杂合度变化范围为0.05~0.49,平均期望杂合度为0.25;遗传相似系数为0.24~0.95。通过聚类分析,将85份紫薇种质划分为7大类群。类群Ⅵ的等位基因数最高,为2.00个;类群Ⅶ的等位基因数最低,为1.33个;类群Ⅰ的期望杂合度和观望杂合度值最高,类群Ⅱ最低。根据花色分为4个群组,分别为堇薇群、红薇群、银薇群和复色群。堇薇群的等位基因数最高(2.00个),复色群最低(1.33个);银薇群期望杂合度和观测杂合度最高,复色群最低。

结论

85份紫薇种质资源遗传多样性丰富,不同类群间存在较高的基因流;SNP标记适用于紫薇遗传多样性分析及亲缘关系研究,可为紫薇种质资源利用提供参考。

关键词: 紫薇属, SNP标记, 遗传多样性, 亲缘关系, 聚类分析, 遗传分化

Abstract: Objective

Lagerstroemia is an economically important ornamental shrub that is distributed from tropical to northern temperate zones. It commonly blooms from summer until fall, and it has a significant value in city landscaping and environmental protection. However, classification of Lagerstroemia plants at the species level is currently challenging. To provide a theoretical support for crape myrtle breeding and identification, 85 Lagerstroemia germplasms were collected and the genetic diversity of Lagerstroemia germplasm resources was studied using single nucleotide polymorphisms (SNP) markers.

Method

85 Lagerstroemia germplasms at home and abroad were used to study genetic diversity. The high-quality SNP markers were selected depending on the mini-sequencing result. The polymorphism information content (PIC), expected heterozygosity (He), gene diversity, and genetic similarity (GS) were calculated using PowerMarker V3.25 software. The genetic distance between the 85 germplasms was calculated based on Nei’s 1972 method. A dendrogram of 85 Lagerstroemia germplasms was constructed using MEGA 6.0 software according to the genetic similarity based on neighbor-joining method. Additionally, 85 samples were classified based on four different flower colors (46 purple-flowered, 26 red-flowered, 5 white-flowered, and 5 compound-flowered individuals). Next, the genetic differentiation parameters with the cluster and color groups were computed using GenAIEx 6.5 software, and the genetic diversity and genetic relationship were analyzed among the cluster and color groups.

Result

The 21 high quality SNP markers were selected from MassARRAY sequencing results. The polymorphic information content of Lagerstroemia germplasm resources ranged from 0.04 to 0.37 and the mean was 0.33. The expected heterozygosity ranged from 0.12 to 0.49 and the mean value was 0.33. The genetic similarity ranged from 0.24 to 0.95. The 85 Lagerstroemia germplasms were divided into seven major groups using the unweighted pair group method with the arithmetic mean (UPGMA) method cluster analysis. The cluster group Ⅵ had the highest number of alleles with the 2.00, and the cluster group Ⅶ had the lowest number of alleles with 1.33. In contrast to the expected heterozygosity and observed heterozygosity, cluster group Ⅰ had the highest value and cluster group Ⅱ had the lowest. Meanwhile, the 85 Lagerstroemia germplasms were classified into four major groups based on four different flower colors, including the purple-flowered, red-flowered, white-flowered, and compound-flowered group. The purple-flowered group had the highest number of alleles at 2.00, while the compound-flowered group was the lowest at 1.33.

Conclusion

Lagerstroemia possessed abundant genetic diversity and high levels of gene flow between groups. The purple-flowered and white-flowered groups had the highest genetic diversities. In addition, the SNP markers were useful for analyzing the genetic diversity of Lagerstroemia.

Key words: Lagerstroemia, SNP marker, genetic diversity, genetic relationship, cluster analysis, genetic differentiation

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