中国农业科学 ›› 2016, Vol. 49 ›› Issue (14): 2772-2791.doi: 10.3864/j.issn.0578-1752.2016.14.011

• 园艺 • 上一篇    下一篇

基于SSR标记的255个枣品种亲缘关系和群体遗传结构分析

刘秀云1,李慧1,2,刘志国1,赵锦 3,刘孟军1,4

 
  

  1. 1河北农业大学/中国枣研究中心,河北保定 071001
    2宁夏农林科学院种质资源研究所,宁夏银川 750002
    3河北农业大学生命科学学院, 河北保定 071000
    4北京林果业生态环境功能提升协同创新中心,北京 102206
  • 收稿日期:2016-01-18 出版日期:2016-07-16 发布日期:2016-07-16
  • 通讯作者: 刘孟军,E-mail:lmj1234567@aliyun.com。赵锦,E-mail:zhaojinbd@126.com
  • 作者简介:刘秀云,E-mail:jingxianyu705@126.com。李慧,E-mail:1063979927@qq.com。刘秀云和李慧为同等贡献作者。
  • 基金资助:
    “十二五”国家科技支撑计划(2013BAD14B03)、北京市2011协同创新中心项目(PXM2016_014207_000038)、河北农业大学青年学术带头人项目

Genetic Diversity and Structure of 255 Cultivars of Ziziphus jujuba Mill.

LIU Xiu-yun1, LI Hui1,2, LIU Zhi-guo1, ZHAO Jin3, LIU Meng-jun1,4   

  1. 1Reserch Center of Chinese Jujube, Agricultural University of Hebei, Baoding 071001, Hebei
    2Germplasm Resources Institute of Ningxia Academy of Agriculture and Forestry Sciences, Yinchuan 750002
    3College of Life Science, Agricultural University of Hebei, Baoding 071001, Hebei
    4Beijing Collaborative Innovation Center for Eco-enviromental Improvement with Forestry and Fruit Trees, Beijing 102206
  • Received:2016-01-18 Online:2016-07-16 Published:2016-07-16

摘要: 【目的】枣原产中国,种质资源丰富。对来自中国22个省区不同用途的255个枣品种进行SSR分析,揭示这些不同产地来源的枣种质资源之间的亲缘关系和群体遗传结构,为枣种质资源的科学管理和分子标记辅助育种提供参考。【方法】利用改良CTAB提取供试枣种质的基因组DNA,以前期枣基因组测序挖掘出的SSR引物为基础,进行高效率引物筛选,并利用SSR分子标记技术对255份枣种质资源的基因组DNA进行PCR扩增,然后利用8%聚丙烯酰胺凝胶电泳分离,银染后显色。根据条带有无统计数据,计算出多态性位点百分率(PIC),用NTSYS软件进行UPGMA聚类分析;利用Structure软件分析群体遗传结构,计算出最适群体数目,构建遗传结构图。【结果】从64对SSR引物中筛选出23对高效率SSR引物,在供试材料中共检测出117个多态性位点,各引物扩增的多态性位点数为2—10条,每对引物平均扩增多态位点数为5.09个,PIC值变幅为0.359—0.727,平均为0.548,这些多态性引物可应用到其他枣种质资源的研究中;建立了只需1—2个标记就可鉴别出来的部分枣品种的SSR指纹,可用于这些品种的快速分子鉴定;255个枣品种的聚类分析将所有枣品种分为15个亚类,包括4个大类和11个小类,不同品种间的相似系数范围0.71—1.00,其中北京花生枣单独聚为一类,与其他枣品种关系较远;‘奉节鸡蛋枣’和‘溆浦鸡蛋枣’、‘陕西奶枣’和‘天津大马牙枣’的相似系数均为1.00;结合聚类图、供试品种的用途和原产地分析,不同枣品种间的亲缘关系与品种原产地有一定相关性,但和品种用途没有显著相关性。群体结构分析中,通过绘制K与ΔK的关系图,K=15时,ΔK最大,据此将255个枣品种也同样划分为15个群体,与聚类分析结果基本一致;进一步分析表明,各群体中大部分品种血缘关系比较单一,较少品种含有其他类群的遗传成分。总体看,山西或陕西的枣品种出现在绝大部分居群中,说明这两个省的资源在不同群体间的基因交流中发挥了重要作用;南方栽培区域中来自湖南的枣品种形成了相对独立的居群,可能是其起源相对单一,且在长期栽培过程中和其他产地枣品种间基因交流较少所致。上述结果表明,供试枣品种中与来源区域相关性明显的品种由相同地域内枣品种演化而来,而另一部分与来源产地相关性不明显的品种则是由不同区域间品种经过频繁的基因交流和重组选育而来,融合了不同区域品种的特点,从而没有了明显的区域特征。【结论】不同地理环境在枣品种的群体进化中发挥了较重要的作用,影响了不同产地间枣种质资源的遗传结构组成。

关键词: 枣, SSR分子标记, 产地, 亲缘关系, 遗传结构

Abstract: 【Objective】 There are abundant jujube germplasm resources in China. A total of 255 cultivars of Ziziphus jujuba Mill. from 22 provenances were used as materials to reveal their genetic diversity and phylogenetic relationship by SSR analysis, and the results of analysis would help us to manage jujube germplasm resources and offer references for molecular maker-assisted breeding.【Method】 Good genomic DNA was extracted from young leaves of jujube germplasm resources following the improved CTAB method, and then were amplified by simple sequence repeat molecular markers to analyze genetic diversity and genetic structure with the selected high-efficiency primer pairs which were excavated based on the genome sequencing. Separation of the amplified fragments was performed on 8% denaturing polyacrylamide gels and the gels were stained with AgNO3 for visualizing the SSR fragments. The data were counted by presence or absence of the band and the percentage of polymorphic loci (PIC) was calculated. UPGMA cluster analysis was carried by software NTSYS, the optimal number of groups and population genetic structure was analyzed by software Structure.【Result】Totally, 117 polymorphic alleles were revealed with 23 primer pairs which was selected from 64 primer pairs, each primer amplified polymorphic loci ranged from 2 to 10, with an average of 5.09 for each primer pairs. Polymorphism information content (PIC) values for the primer pairs ranged from 0.359 to 0.727, with an average of 0.548, these polymorphisms primers could be further applied to other study. The fingerprint for some jujube cultivars was established with 1-2 markers, providing a reference for the management of jujube germplasm. Meanwhile, based on the UPGMA cluster analysis, 255 cultivars were divided into fifteen subgroups, which included four big groups and eleven small groups. Similarity coefficients among the cultivars were between 0.71 to 1.00, ‘Beijinghuashengzao’ was clustered into one separate group, which has a distant relationship with other cultivars. The similarity coefficients of ‘Fengjiejidanzao’ and ‘Xupujidanzao’, ‘Shannxinaizao’ and ‘Tianjindamayazao’ were both 1.00. In some subgroups the genetic relationship between cultivars and their provenances has a significant positive correlation, but the cultivars and their uses has no significant correlation. Based on K and ΔK values, 255 jujube cultivars were also divided into fifteen populations by the population genetic structure analysis. The kinship among cultivars in the same population was relatively simple, and a few cultivars contained genetic component of other groups. The cultivars from Shanxi or Shannxi were distributed in most populations, indicating jujube cultivars of the two provinces played important roles in the gene exchange among populations. The jujube cultivars from Hunan of the South region formed a relatively alone population, indicating that the cultivars might be from the same source, or in the long-term cultivation few times of gene exchange were happened in Hunan cultivars with other populations. Different geographical environment played a key role in the evolution of jujube germplasm populations, some cultivars were selected from the same geographical environment and the others were selected by genetic recombination among those cultivars from the various geographical environment. Meanwhile, the consistency of the two different methods was further verifed the accuracy of the results, which provide useful clues and reference for the genetic diversity and structure of jujube germplasm.【Conclusion】Geographical environment play significant roles in the population evolution of jujube cultivars, affecting the genetic structure composition between different habitats.

Key words: Chinses jujube, SSR markers, provenances, genetic diversity, population structure