中国农业科学 ›› 2018, Vol. 51 ›› Issue (4): 626-634.doi: 10.3864/j.issn.0578-1752.2018.04.003

• 作物遗传育种·种质资源·分子遗传学 • 上一篇    下一篇

基于SNP芯片揭示中国玉米育种种质的遗传多样性与群体遗传结构

赵久然,李春辉,宋伟,王元东,张如养,王继东,王凤格,田红丽,王蕊   

  1. 北京市农林科学院玉米研究中心/玉米DNA指纹及分子育种北京市重点实验室,北京100097
  • 收稿日期:2017-10-17 出版日期:2018-02-16 发布日期:2018-02-16
  • 通讯作者: 宋伟,E-mail:songwei1007@126.com
  • 作者简介:赵久然,Tel:010-51503936;E-mail:maizezhao@126.com。李春辉,Tel:010-51502405;E-mail:lichunhui331@163.com。赵久然和李春辉同等贡献作者。
  • 基金资助:
    国家“十三五”科技支撑计划(2014BAD01B09)、北京市科技计划课题(D161100005716002)、北京市农林科学院院级科技创新团队建设项目(JNKYT201603)、现代农业产业技术体系专项(CARS-02-11)

Genetic Diversity and Population Structure of Important Chinese Maize Breeding Germplasm Revealed by SNP-Chips

ZHAO JiuRan, LI ChunHui, SONG Wei, WANG YuanDong, ZHANG RuYang, WANG JiDong, WANG FengGe, TIAN HongLi, WANG Rui   

  1. Maize Research Center, Beijing Academy of Agriculture and Forestry Sciences/Beijing Key Laboratory of Maize DNA Fingerprinting and Molecular Breeding, Beijing 100097
  • Received:2017-10-17 Online:2018-02-16 Published:2018-02-16

摘要: 【目的】选择具有重要育种价值的玉米自交系进行遗传多样性与群体遗传结构解析,为玉米育种实践提供指导和参考。【方法】选用344份具有广泛代表性和时效性的玉米自交系,其中包括美国主要杂种优势群、由国内地方种质发展来的杂种优势群、由美国商业化杂交种选系发展来的杂种优势群以及近年来在中国玉米育种中应用的新种质。利用北京市农林科学院玉米研究中心自主研发的包含3 072个SNP位点的MaizeSNP3072芯片对供试自交系进行全基因组扫描,揭示其遗传多样性与群体遗传结构。【结果】在344份自交系中,3 072个SNP标记所检测到的基因多样性为0.028—0.646,平均为0.442;多态信息含量(PIC)为0.028—0.570,平均PIC值为0.344。群体遗传结构分析表明,K=8时,△K值最大,即本研究所采用的自交系群体可以划分为8个类群,分别为旅大红骨群、黄改群(又称塘四平头群)、Iodent群、兰卡斯特群、P群、改良瑞德群、瑞德群和X群,其中前7个群已有报道且基本被育种家所公认,第8个群为近年来以X1132X等杂交种作为基础材料选育出的优新种质,命名为X群。比较8个类群,遗传分化系数(Fst)为0.319—0.512,遗传距离为0.229—0.514。AMOVA结果表明类群间存在显著的遗传变异,占总遗传变异的38.6%,类群内的遗传变异占58.1%。PCA(主成分分析)结果显示,X群与黄改群、兰卡斯特群遗传关系较远,与Iodent群遗传关系较近。各类群平均基因多样性分析结果表明,随着类群改良年代的增加,类群平均基因多样性降低,其中X群种质平均基因多样性最高;进一步分析表明,美国种质类群(兰卡斯特群、瑞德群和Iodent群)和国内地方种质改良系(旅大红骨群和黄改群)核心材料多样性下降幅度较大,P群和改良瑞德群核心材料下降幅度较小,X群核心材料则没有下降趋势,说明X群核心材料仍然保留了较高的遗传多样性,未来还有很大的育种潜力可挖掘。【结论】近年来,以X1132X等杂交种所构建的基础材料选育而成的京724等系列优良自交系,区别于其他已知的7大类群,可以单独成群,称之为X群。该群与黄改群之间存在较远的遗传距离,从分子水平验证了“X群×黄改群”这种强杂优模式具有良好的应用潜力。

关键词: 玉米, 自交系, X群, 遗传多样性, 群体结构

Abstract: 【Objective】 Understanding the genetic diversity and population structure of representative maize accessions are of importance in breeding practice for the guidance and reference. 【Method】A total of 344 maize inbred lines were selected, including American heterotic group, local germplasm, New germplasm used in maize breeding in China in recent years which were broadly representative. These lines were genotyped by 3 072 SNP markers which were developed by Maize Research Center, BAAFS to reveal the genetic diversity and population structure. 【Result】For 3 072 high-quality SNPs, the gene diversity averaged 0.442, ranging from 0.028 to 0.646, and the PIC averaged 0.344, ranging from 0.028 to 0.570. The result of population structure based on a model-based method indicated that these 344 lines could be divided into eight groups, including Lüda red cob, Huangzaosi improved lines, Iodent, Lancaster, P group, Improved Reid group, Reid and X group. The seven groups above were well-known, and the X group was selected from the populations constructed from X1132X. Among the eight groups, the Fst ranged from 0.319 to 0.512, and the genetic distance ranged from 0.229 to 0.514. AMOVA results indicated that 38.6% of the total genetic variation occurred among groups, 58.1% within groups and 3.3% within lines. PCA results showed that X group had higher genetic differentiation with Huangzaosi improved lines and Lancaster, but lower with Iodent. The genetic diversity of subpopulations indicated that with the increase of breeding years, the average of genetic diversity in each subpopulation was decreased, and among them, X group had the highest genetic diversity. Further analysis showed that the genetic diversity of core accessions in American heterotic group and local germplasm were higher decreased compared with that in P group and Improved Reid group. However, the genetic diversity of core accessions in X group was no decreased, which indicated that the core accessions of X group still maintained higher genetic diversity and had potential application in breeding.【Discussion】X group was different from the other seven known groups, which can be defined as an independent group. Furthermore, X group had further genetic relationship with Huangzaosi improved lines which indicated the strong heterosis pattern of "X group × Huangzaosi improved lines" had application potential.

Key words:  maize, inbred lines, X group, gene diversity, population structure