中国农业科学 ›› 2018, Vol. 51 ›› Issue (19): 3766-3777.doi: 10.3864/j.issn.0578-1752.2018.19.013

• 园艺 • 上一篇    下一篇

7个来源地区山荆子的遗传多样性与群体结构分析

高源,王昆,王大江,赵继荣,张彩霞,丛佩华,刘立军,李连文,朴继成   

  1. 中国农业科学院果树研究所/农业部园艺作物种质资源利用重点实验室,辽宁兴城 125100
  • 收稿日期:2018-04-25 出版日期:2018-10-01 发布日期:2018-10-01
  • 通讯作者: 丛佩华,E-mail:congph@163.com。王昆,E-mail:wangkun5488@163.com
  • 作者简介:高源,E-mail:gaoyuan02@caas.cn
  • 基金资助:
    中国农业科学院创新工程项目(CAAS-ASTIP-2016-RIP-02)、农业部现代农业产业技术体系建设专项资金(CARS-27)、农作物种质资源保护(NB2015-2130135-39)、国家公益性行业(农业)科研专项(201303093)

The Genetic Diversity and Population Structure Analysis on   Malus baccata (L.) Borkh from 7 Sources

GAO Yuan, WANG Kun, WANG DaJiang, ZHAO JiRong, ZHANG CaiXia, CONG PeiHua, LIU LiJun, LI LianWen, PIAO JiCheng   

  1. Research Institute of Pomology, Chinese Academy of Agricultural Sciences/Key Laboratory of Horticultural Crops Germplasm Resources Utilization, Ministry of Agriculture, Xingcheng 125100, Liaoning
  • Received:2018-04-25 Online:2018-10-01 Published:2018-10-01

摘要: 【目的】利用荧光SSR分子标记,对新收集的7个来源地区的山荆子种质资源进行遗传多样性和群体结构分析,明确群体内和群体间的遗传多样性和结构,为苹果属植物种质资源的收集保存和种的遗传进化研究提供依据。【方法】筛选19对多态性好的SSR引物检测7个来源地区山荆子的多态性,利用GenAlEx 6.501计算遗传多样性指标、分析群体间的分子变异(AMOVA),利用GenepopV4和Fstat293分析群体间的遗传分化,基于Nei遗传距离DA,利用POPULATION 1.2构建269份材料的Neighbour-Joining(NJ)进化树,使用STRUCTURE 2.3.4进行贝叶斯聚类并分析群体的遗传结构。【结果】19对SSR引物共检测出392个多态性等位基因,平均等位基因数20.6,平均有效等位基因数9.070,观察杂合度和期望杂合度的平均值分别为0.628和0.855,香农多样性指数为2.392。按照来源地区划分群体,以黑龙江群体的观测等位基因数最多为15.684,俄罗斯群体的遗传多样性最低,河北群体的遗传多样性最高。两两群体间遗传分化系数Fst为0.019—0.111,河北与多个地域的群体基因交流频繁,甘肃群体是7个群体中最为稳定的,群体间的遗传分化和基因交流与地理位置远近不完全相关。基于Nei遗传距离的聚类分析在遗传距离0.7444处将269份材料可以分成7个类群,多数类群与地理位置不相关。其中类群Ⅰ和Ⅱ与其他类群遗传距离较远,类群Ⅱ和Ⅲ的聚类比较混杂,类群Ⅵ的材料来源最为复杂,类群Ⅳ和Ⅴ相对比较单纯,类群Ⅶ中99%为黑龙江山荆子。群体结构分析将269份材料划分成了3个类群,具有3个可能的基因来源,不同来源地的材料在各群体中均有分布,与地理位置没有十分明确的相关性。只有黑龙江、山西和甘肃群体以及部分俄罗斯和河北材料的类群归属相对单一,与聚类有相似的结果。269份材料中Q≥0.6有232份,大部分山荆子的血缘相对单一。【结论】19对SSR引物具有高度的多态性,可以作为有效的标记用于山荆子群体遗传多样性和遗传结构评价。7个来源地区山荆子遗传多样性均较高,以河北地区的遗传多样性最高,遗传变异和分化主要发生在群体内和个体内部;群体间有基因交流,以河北与其他地区的交流最频繁;抵制基因漂变而导致的群体间的遗传分化,群体间的遗传分化程度和基因交流水平与地理位置远近不完全相关。

关键词: 山荆子, 荧光SSR, 遗传多样性, 遗传结构

Abstract:  【Objective】Genetic diversity and population structure of Malus baccata from 7 newly collected sources were analyzed using fluorescent SSR molecular markers. The identification of genetic diversity and structure within and among populations can provide references for germplasm collection and preservation of Malus and the study of the phylogenetic evolution of species. 【Method】19 pairs of polymorphic SSR primers were screened to detect the polymorphism of Malus baccata from 7 sources. GenAlEx 6.501 was used to calculate the index of genetic diversity and analyze the molecular variation (AMOVA) among populations. The genetic differentiation among populations were analyzed by GenepopV4 and Fstat293. Based on the Nei genetic distance DA, the Neighbour-Joining (NJ) evolutionary tree of 269 accessions was constructed using POPULATION 1.2. The Bayesian cluster was carried out using STRUCTURE 2.3.4 to analyze the genetic structure of populations.【Result】392 polymorphic alleles were detected by 19 pairs of SSR primers, with an average allele number of 20.6 and effective allele number of 9.070. The average values of heterozygosity and expected heterozygosity were 0.628 and 0.855 respectively, and the Shannon index was 2.392. Dividing populations according to their sources, the highest number of observed alleles in Heilongjiangpopulation was 15.684. The genetic diversity in Russian population was the lowest, and the highest genetic diversity was in Hebei population. The coefficient of genetic differentiation Fst between every two populations was from 0.019 to 0.111. The gene of Hebei population communicate frequently with other populations, andGansu population was the most stable among 7 populations. The genetic differentiation and gene exchange among populations were not completely related to the geographical location far or near. The cluster analysis based on Nei genetic distance could divided 269 accessions into 7 groups at 0.7444. Most of groups were not related to geographical location, among which group Ⅰ and Ⅱ were far away from other groups, and the cluster of groupⅡ and Ⅲ was mixed, the sources of group Ⅵ was the most complex, groupⅣ and Ⅴ were relatively pure, and finally 99% of all accessions in group Ⅶ were from Heilongjiang. The population structure analysis divided 269 accessions into 3 groups with 3 possible genetic sources. The accessions from different sources were distributed into every group, and there was no clear correlation with the geographical location. Only most part ofHeilongjiang, Shanxi and Gansu population, as well as some of accessions from Russia and Hebei belonged to a relatively simple group. This result was similar to the results of clustering. In 269 accessions, the Q value of 232 accessions were higher than 0.6, and most of them had relatively single genetic background. 【Conclusion】19 pairs of SSR primers were highly polymorphic and could be used for the evaluation of genetic diversity and population structure. The genetic diversity of Malus baccata from 7 regions was high with the highest genetic diversity of thosefrom Hebei, and genetic variation mainly occured within populations and individuals. There was genetic communication among populations with the most frequent communication between Hebei and other groups, but at the same time, it also resisted genetic differentiation among populations caused by gene drift. Genetic differentiation and gene exchange among populations were not completely related to geographical location.

Key words: Malus baccata, fluorescent SSR, genetic diversity, population structure