中国农业科学 ›› 2010, Vol. 43 ›› Issue (2): 240-251 .doi: 10.3864/j.issn.0578-1752.2010.02.003

• 作物遗传育种·种质资源·分子遗传学 • 上一篇    下一篇

世界栽培豌豆(Pisum sativum L.)资源群体结构与遗传多样性分析

宗绪晓,关建平,王海飞,马钰

  

  1. (中国农业科学院作物科学研究所/国家农作物基因资源与基因改良重大科学工程)
  • 收稿日期:2009-06-02 修回日期:2009-08-24 出版日期:2010-01-20 发布日期:2010-01-20

Population Structure and Genetic Diversity of Global Pea (Pisum sativum L.) Germplasm Resources

ZONG Xu-xiao, GUAN Jian-ping, WANG Hai-fei, MA Yu
  

  1. (中国农业科学院作物科学研究所/国家农作物基因资源与基因改良重大科学工程)
  • Received:2009-06-02 Revised:2009-08-24 Online:2010-01-20 Published:2010-01-20

摘要:

【目的】评价国家种质库长期保存的国内、外栽培豌豆(Pisum sativum L.)资源的遗传多样性水平,揭示其遗传多样性、等位基因和群体结构差异,据此评估其重要程度及价值,为中国豌豆资源研究策略和方向的正确选择、国内外资源的充分发掘利用和深入研究提供理论依据。【方法】利用21对豌豆多态性SSR引物,对来自国外五大洲66个国家和中国28个省(区、市)的1 984份栽培豌豆进行SSR标记遗传多样性和群体结构分析;采用Structure 2.2软件完成资源群体结构剖析、推断参试材料的合理组群数、确定每份参试材料的适当群体划入及其相关参数计算;利用NTSYSpc2.2d软件估算其遗传距离,进行主成分分析(PCA)并绘制三维空间聚类图;采用Popgene V1.32估算种质群的等位位点分布等参数,利用Fstat V2.9.3.2 进行种质群间遗传多样性差异显著性测验。【结果】通过对国、内外栽培豌豆资源群间SSR等位基因数(NA)、有效等位基因数(NE)、有效等位基因所占比重(NE/NA)、等位基因丰度(AR)、基因多样性指数(GD)、Shannon's信息指数(I)的比较,发现除等位基因数(NA)外,国内资源的其它5个遗传多样性指标全面高于国外资源。在21个SSR基因位点中,国内、外资源群在7个位点间存在等位基因种类的差异。群体结构分析将1 984份世界栽培豌豆资源划分成三大组群。组群A包含96.49%的国外栽培豌豆参试资源,可代表典型的国外栽培豌豆资源类型;组群B的资源88.18%来源于陕西和内蒙古,可代表中国典型的春播区栽培豌豆资源类型;组群C的资源52.05%源于中国秋播区,47.44%源于中国春播区,可代表中国秋播区和除陕西、内蒙古外的春播区栽培豌豆资源类型。组群间遗传多样性差异达到显著水平。PCA作图分析也明确显示世界栽培豌豆资源群体中存在3个边界明显的资源富集区(基因库I、II、III),且与三大组群的群体结构分析结果精确对应。【结论】国内资源的遗传多样性程度整体上超过国外资源,国外资源群体内个体间的差异程度平均高于国内资源。群体结构分析侦测到世界栽培豌豆资源中存在A、B、C共三大资源类群,类群间的遗传多样性差异达到了显著水平,且与PCA做图分析显示的3个边界明显的基因库间存在着精确对等关系:“类群A”几乎等同于“基因库I”,“类群B”几乎等同于“基因库II”,而“类群C”几乎等同于“基因库III”;基因库I由国外资源富集而成,基因库II由中国陕西和内蒙古资源富集而成,基因库III由中国秋播区资源和陕西、内蒙古以外的春播区资源富集而成,由此得出世界栽培豌豆由3个基因库构成的结论。国外栽培豌豆种质资源构成了“基因库I”,国内栽培豌豆种质资源构成了“基因库II”和“基因库III”,表明国内、外资源均很重要,但国内资源甚于国外。

关键词: 豌豆(Pisum sativum L.), 种质资源, SSR, 遗传多样性, 群体结构, 基因库

Abstract:

【Objective】 Assessing the genetic diversity between Chinese and alien accessions of cultivated pea (Pisum sativum L.) sampled from National Gene Bank, analyzing their differentiation on allelic loci and population structure, the study try to evaluate the importance and value of these conserved genetic resources, to provide essential information for guidance on strategy and direction choices for future studies of pea genetic resources in China, and for the effective exploration and utilization of global pea genetic resources. 【Method】 1 984 cultivated pea accessions from 66 countries of five continents and 28 provinces of China were employed for SSR analysis using 21 polymorphic primer pairs to detect genetic diversity and population structure. The Structure 2.2 software was used for population structure detection, definition of real population number, genotype allocation to its real population, and calculation of related parameters. Calculation of genetic distance, PCA analyses, 3-dimensional PCA graph, was conducted and drawn by NTSYSpc 2.2d statistical package. Allelic statistics were carried out by Popgene V1.32. The significance test between groups of genotypes was carried out by Fstat 2.9.3.2 statistical package. 【Result】 Based on SSR markers, the observed number of alleles (NA), the effective number of alleles (NE), the ratio of NE/NA, the allelic richness (AR), the gene diversity (GD) and the Shannon's information index (I) of pea germplasm resources from China and foreign countries were thoroughly compared. Except the observed number of alleles (NA), the values of other parameters on genetic diversity detected from Chinese landraces were all higher than that from foreign germplasm resources. Among the 21 tested SSR loci, the difference between Chinese and foreign germplasm collections appeared in 7 SSR loci. The population structure analysis divided all the 1 984 tested genotypes into 3 populations (Pop A, Pop B and Pop C). Pop A consisted of almost all alien accessions (96.49% genotypes of all alien accessions), referred to foreign germplasm population. Pop B consisted of most accessions from Shaanxi and Inner Mongolia (88.18% genotypes of this population), standing for typical Chinese spring sowing germplasm population. Pop C consisted of majority (52.05% genotypes of this population) from Chinese winter sowing areas, and minority (47.44% genotypes of this population) from Chinese spring sowing areas, standing for Chinese winter sowing and spring sowing (except Inner Mongolia and Shaanxi) germplasm population. There were significant differences among the three populations. 3-dimension PCA graph showed 3 concentrated domains with clear boundaries in between, each of the domain (gene pools I, II and II) approximated to Pop A, Pop B and Pop C. 【Conclusion】 The genetic diversity level of domestic Chinese accessions as a group was generally higher than that of alien group, while the level of difference among genotypes within alien group on each parameter was higher than that within Chinese accession group. Three independent populations named Pop A, Pop B and Pop C were detected by population structure analysis, with significant difference in genetic diversity among them. 3-dimension PCA graph showed 3 concentrated domains (gene pools I, II and II) with obvious boundaries in between. Gene pool I concentrated alien genotypes, Gene pool II concentrated Shaanxi and Inner Mongolian genotypes, and Gene pool III concentrated genotypes from Chinese winter sowing areas and spring sowing areas except Shaanxi and Inner Mongolia. By pairs, the three gene pools detected by PCA almost equal to the three populations identified by Structure 2.2 in genotype composition. Pop A approximated to Gene pool I, Pop B approximated to Gene pool II,and Pop C approximated to Gene pool III. Results from PCA fully supported the findings from population structure analysis, within global cultivated pea genetic resources the three gene pools can be defined. Alien genotypes constructed Gene pool I, Chinese genotypes constructed Gene pool II and Gene pool III, which revealed the importance of Chinese and alien collections and Chinese collection was superior.

Key words: pea (Pisum sativum L.), germplasm resources, SSR, genetic diversity, population structure, gene pool