中国农业科学 ›› 2021, Vol. 54 ›› Issue (8): 1739-1750.doi: 10.3864/j.issn.0578-1752.2021.08.013

• 园艺 • 上一篇    下一篇

利用荧光SSR分子标记评估中国栗属植物遗传多样性

聂兴华1(),郑瑞杰2(),赵永廉3,曹庆芹1,4,秦岭1,4,邢宇1,4()   

  1. 1北京农学院植物科学技术学院,北京 102206
    2辽宁省经济林研究所,辽宁大连 116000
    3北京市怀柔区板栗技术试验与推广站,北京 102206
    4林木分子设计育种高精尖创新中心,北京 102206
  • 收稿日期:2020-07-02 接受日期:2020-09-15 出版日期:2021-04-16 发布日期:2021-04-25
  • 通讯作者: 郑瑞杰,邢宇
  • 作者简介:聂兴华,Tel:18813011218;E-mail: niexinghuabua@163.com
  • 基金资助:
    国家重点研发计划(2018YFD1000605);国家自然科学基金(31870671);北京市属高等学校创新团队建设与教师职业发展计划项目(IDHT20180509)

Genetic Diversity Evaluation of Castanea in China Based on Fluorescently Labeled SSR

NIE XingHua1(),ZHENG RuiJie2(),ZHAO YongLian3,CAO QingQin1,4,QIN Ling1,4,XING Yu1,4()   

  1. 1College of Plant Science and Technology, Beijing University of Agriculture, Beijing 102206
    2Liaoning Economic Forest Research Institute, Dalian 116000, Liaoning
    3Chestnut Technology Experiment and Extension Station of Huairou District, Beijing 102206
    4Advanced Innovation Center for Forest Molecular Design and Breeding, Beijing 102206
  • Received:2020-07-02 Accepted:2020-09-15 Online:2021-04-16 Published:2021-04-25
  • Contact: RuiJie ZHENG,Yu XING

摘要:

【目的】利用SSR分子标记研究中国栗属植物遗传多样性、亲缘关系和群体遗传结构的特点,为栗属植物的资源改良、种质创新与利用提供理论依据。【方法】利用不同产区的12个板栗品种对330个SSR分子标记进行筛选,获得高质量的12对SSR引物。随后在高分辨率的毛细管电泳上对栗属4个种的96份资源进行位点信息检测。用Power Marker 3.25、GenAlEx 6.51、FigTree v1.4.3和Structure 2.3.3对全部资源进行群体遗传多样性的相关分析。【结果】对96份资源进行检测,共获得129个等位变异,每个标记平均有10.750个位点变异。位点多样性(GD)变幅为0.656(CmSI0396)—0.877(CmSI0930),平均为0.800;观察杂合度(Ho)变幅为0.329(CmSI0742)—0.769(CmSI0702),平均为0.615;期望杂合度(He)变幅为0.489(CmSI0742)—0.789(CmSI0922),平均为0.672;多态信息含量(PIC)变幅为0.586(CmSI0396)—0.868(CmSI0930),平均为0.774。从不同栗属植物种群间的遗传多样性来看,茅栗种群的观察位点数(Na)、有效等位变异(Ne)和Shannon多样性指数最高,其次是板栗种群,最低是日本栗种群。从两两群体间的遗传分化指数(Fst)可知,栗属植物种间的遗传分化值在0.077—0.180,整体种群间存在中等以上程度的分化,板栗种群、锥栗种群与日本栗种群间的遗传分化值分别为0.165和0.180,表现出较大的遗传分化。同时,栗属植物种群的基因流(Nm)为1.580>1,也说明种群间存在较频繁的基因交流,由此降低了由基因遗传漂变所引起的各种群间遗传分化程度。分子方差分析(AMOVA)结果表明,变异主要发生在种群内,占总变异量的73%,种群间的变异占27%。UPGMA聚类分析、主坐标分析和群体遗传结构结果较一致,各资源的遗传背景存在明显的种间界限,部分资源在世代遗传中继承了不同祖先种的遗传信息。例如,资源65、71和82号为混合类型资源,包含有茅栗和日本栗的遗传背景,而现在的两种间存在地理隔离。在相同生态区域的栗属植物种间存在一定的基因交流,没有形成完全的生殖隔离。48号资源‘广东矮生’同时含有板栗和茅栗的遗传背景,在地理分布上该资源原生地正处于板栗和茅栗资源的重叠生态区。【结论】筛选的12对SSR引物能够准确地评估中国栗属植物的遗传多样性,综合聚类分析可确定栗属植物的类群划分与种间信息高度一致且种间存在一定的基因交换。

关键词: SSR, 栗属, 聚类分析, 群体遗传结构, 群体遗传分化

Abstract:

【Objective】The characteristics of genetic diversity, relationships and population structure of Castanea plants in China were analyzed with SSR molecular markers, so as to provide a theoretical basis for variety improvement, germplasm innovation and utilization of Castanea plants. 【Method】Firstly, 330 SSR molecular markers were screened among 12 chestnut cultivars from different production areas, and 12 pairs of high-quality SSR primers were obtained from them. Secondly, 96 accessions of Castanea from 4 species were detected by high resolution capillary electrophoresis. Finally, Power Marker 3.25, GenAlEx 6.51, FigTree v1.4.3 and Structure 2.3.3 were used to analyze the population genetic diversity of all accessions. 【Result】A total of 129 alleles were acquired from 96 accessions, and the average variation of each marker was 10.750. The gene diversity (GD) ranged from 0.656 (CmSI0396) to 0.877 (CmSI0930) with an average of 0.800; the observed heterozygosity (Ho) ranged from 0.329 (CmSI0742) to 0.769 (CmSI0702) with an average of 0.615; the expected of heterozygosity (He) ranged from 0.489 (CmSI0742) to 0.789 (CmSI0922), with an average of 0.672; the polymorphic information content (PIC) ranged from 0.586 (CmSI0396) to 0.868 (CmSI0930), with an average of 0.774. Among different Castanea species, in terms of number of alleles (Na), number of effective alleles (Ne) and Shannon diversity index, Castanea seguinii had the highest genetic diversity, followed by Castanea mollissima, and Castanea crenata was the lowest. According to pairwise population Fst values, the genetic differentiation value of Castanea species was 0.077-0.180, showing moderate to high differentiation among the species. Compared with Castanea crenata, both Castanea mollissima and Castanea henryi exhibit relatively high genetic differentiation with Fst values of 0.165 and 0.180, respectively. At the same time, the gene flow (Nm) of the Castanea plants was 1.580>1, suggesting frequent gene exchange among Castanea plants, and which therefore reduced the degree of genetic differentiation among the species caused by genetic drift. The results of analysis of molecular variance (AMOVA) showed that the variation mainly occurred within populations, accounting for 73% of the total variation, and the variation among populations made up 27%. The results of UPGMA cluster analysis, principal coordinate analysis and population genetic structure were consistent, and the genetic background of each accessions had obvious inter-species boundaries. Some accessions inherited the genetic information of different ancestor species in generational inheritance. For example, accession 65, 71 and 82 are mixed types, which contain the genetic background of Castanea seguinii and Castanea crenata, but there is geographic isolation between the two species. Castanea plants in the same ecological region existed extensive gene exchange, and there were no complete reproductive isolation. Accession 48 (‘Guangdongaisheng’) had the genetic background of both Castanea mollissima and Castanea seguinii. In terms of geographical distribution, the native place of this accession was in the overlapping ecological area of Castanea mollissima and Castanea seguinii. 【Conclusion】The 12 pairs of SSR primers screened could accurately assess the genetic diversity of Castanea plants in China. Comprehensive cluster analysis could confirm that the classification of Castanea plants was highly consistent with the inter-species information and there was a certain amount of gene exchange between species.

Key words: SSR, Castanea, cluster analysis, population genetic structure, population genetic differentiation