生物多样性 ›› 2019, Vol. 27 ›› Issue (4): 355-365.doi: 10.17520/biods.2019016

• 研究报告 •    下一篇

滇杨种群遗传多样性与遗传结构

张亚红1, 贾会霞1, 王志彬2, 孙佩1, 曹德美1, 胡建军1, *()   

  1. 1 林木遗传育种国家重点实验室, 国家林业和草原局林木培育重点实验室, 中国林业科学研究院林业研究所, 北京 100091
    2 张家口市金沙滩林场, 河北怀安 076150
  • 收稿日期:2019-01-21 接受日期:2019-04-18 出版日期:2019-04-20
  • 通讯作者: 胡建军 E-mail:hujj@caf.ac.cn
  • 基金项目:
    中央级公益性科研院所基本科研业务费专项资金(CAFYBB2017ZY008)

Genetic diversity and population structure of Populus yunnanensis

Zhang Yahong1, Jia Huixia1, Wang Zhibin2, Sun Pei1, Cao Demei1, Hu Jianjun1, *()   

  1. 1 State Key Laboratory of Tree Genetics and Breeding, Key Laboratory of Tree Breeding and Cultivation of State Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091
    2 Zhangjiakou Jinshatan Forest Farm, Huaian, Hebei 076150
  • Received:2019-01-21 Accepted:2019-04-18 Online:2019-04-20
  • Contact: Hu Jianjun E-mail:hujj@caf.ac.cn

滇杨(Populus yunnanensis)是我国西南地区的特有树种, 具有速生、易无性繁殖、适应性强等优良特性, 是典型的南方型杨属树种。研究滇杨遗传多样性及种群结构对其种质资源的收集、保存和利用具有重要的意义。本研究从我国滇杨主要分布区云南和四川共采集了6个种群, 包括云南的昭通(ZT)、会泽(HZ)、嵩明(SM)、洱源(EY)、拉市海(LS)以及四川的美姑(MG), 共64个个体, 利用34对SSR分子标记和3对cpDNA叶绿体标记开展遗传多样性与遗传结构研究。SSR引物共检测到154个等位基因, 平均等位基因数为4.529, 观测杂合度(Ho)与期望杂合度(He)分别为0.552和0.472, 遗传分化系数(Fst)平均值为0.238, 多态性信息含量指数(PIC)平均值为0.421, 基因流(Nm)为0.806。滇杨的遗传结构分析(DAPC)与遗传距离的主坐标分析(PCoA)、UPGMA聚类分析均将6个种群划分为3个亚类: 第?亚类包括昭通种群、会泽种群和嵩明种群的4个个体, 第??亚类包括嵩明种群的6个个体以及洱源种群和拉市海种群, 第III亚类为美姑种群; 嵩明种群包含第?和第??两个亚类的混合遗传成分。3个cpDNA联合序列中共检测到35个变异位点, 分为13个单倍型, 其中单倍型H5在种群中分布最为广泛, 其余的单倍型均为种群特有的单倍型。分子方差分析(AMOVA)表明种群内的遗传变异大于种群间变异。研究表明滇杨不同种群的遗传分化具有地域性, 可选择就地保护; 昭通种群遗传多样性最高, 且包含7种叶绿体单倍型, 单倍型类型最多, 应优先保护。

关键词: 滇杨, 遗传多样性, 遗传结构, 分子标记, SSR, cpDNA

Populus yunnanensis is an endemic tree species to Southwestern China. It is a typical southern Populus species that is fast-growing species with easy to clone propagules and is highly adaptable. It is important to research the genetic diversity and population structure of P. yunnanensis for the collection, preservation and utilization of the germplasm resources. In this study, 64 individuals were collected from six populations, spaning the main distribution areas of P. yunnanensis, including Zhaotong (ZT), Huize (HZ), Songming (SM), Eryuan (EY), Lashihai (LS) and Sichuan Meigu (MG). A total of 34 pairs of SSR primers and three pairs of cpDNA primers were used to determine out the genetic diversity and genetic structure. A total of 154 alleles were detected by SSR primers in P. yunnanensis. The average number of alleles was 4.529. The observed heterozygosity (Ho) and expected heterozygosity (He) were 0.552 and 0.472, respectively. And the average genetic differentiation coefficient (Fst) was 0.238. The average polymorphism information content (PIC) was 0.421 and the gene flow (Nm) was 0.806. The results of the DAPC, PCoA and UPGMA analyses showed that the six populations can be divided into three sub-categories: Group І included ZT, HZ and four individuals of SM. Group II included EY, LS and the six remaining individuals of SM; and group III included MG; SM population include mixed genetic components from І and ІІ. A total of 35 variable sites were detected in the three cpDNA combinations, forming 13 haplotypes. Among them, haplotype H5 was the most widely distributed in the population, while the remaining ones were of private haplotypes. Analysis of molecular variance (AMOVA) showed that genetic variation within the population was greater than between populations. The study clarifies that P. yunnanensis has geographical distribution characteristics and is suited to in situ conservation. As ZT population has the highest geneticdiversity and contains seven chloroplast haplotypes, it should be given protection priority.

Key words: Populus yunnanensis, genetic diversity, genetic structure, molecular marker, SSR, cpDNA

表1

滇杨各种群采样地地理信息及采样数"

种群 Population 代号 Code 样本量 Sample size 纬度 Latitude 经度 Longitude 海拔 Altitude (m)
昭通 Zhaotong ZT 12 27°33°52″-27°38°29″ N 103°45°05″-103°46°43″ E 1,802-1,914
会泽 Huize HZ 12 26°12°07″-26°23°42″ N 103°15°19″-103°24°09″ E 2,118-2,303
嵩明 Songming SM 10 25°12°07″-25°17°42″ N 103°02°42″-103°03°43″ E 1,900-1,930
洱源 Eryuan EY 12 26°05°56″-26°08°17″ N 99°58°13″-100°00°08″ E 2,056-2,060
拉市海 Lashihai LS 12 26°51°03″-27°00°28″ N 100°08°58″-100°15°24″ E 2,418-2,657
美姑 Meigu MG 6 28°19°40″-28°20°09″ N 103°08°22″-103°08°44″ E 1,944-2,027

表2

用于滇杨SSR扩增的引物序列及扩增结果"

表3

用于滇杨PCR扩增的3个cpDNA引物序列信息"

名称 Name 区域 Primer area 正向序列 Forward primer sequence (5’-3’) 反向序列 Reverse primer sequence (5’-3’)
CO2 trnK AGATGGAAAAAAGAGAGGATAGAGG CAAATAATATCCAAATACCAAACCC
CO5 rpoC1 CGAATGGAAGACATAGACAAGT AAGTGACCTTCGGGAGCTTCTC
CO9 atpF TTGAAGTCCAGACAGAGCAGGTTAC GGTCAAACAACTATTCAAAGTCCCT

表4

基于SSR和cpDNA所得的滇杨遗传多样性信息表。种群代号同表1。"

种群
Popula-tion
等位基因Number of alleles (Na) 有效等位
基因
Number of effective alleles (Ne)
观测杂合度Observed heterozygosity (Ho) 期望杂合度Expected heterozygosity (He) Shannon’s
信息指数Shannon’s information content (I)
近交系数Inbreeding coefficient (F) 单倍型多态性
Haplotype diversity (h)
核苷酸
多样性Nucleotide diversity (π)
单倍型组成(个体数)
Haplotype composition
(No. of individuals)
ZT 2.000 1.695 0.537 0.345 0.514 -0.439 0.864 0.00055 H1(3); H2(1); H3(1); H4(1);
H5(4); H6(1); H7(1)
HZ 2.000 1.759 0.522 0.345 0.528 -0.432 - - H5(12)
SM 2.265 1.806 0.532 0.368 0.585 -0.313 - - H5(10)
EY 2.559 1.904 0.520 0.385 0.639 -0.190 0.455 0.00013 H5(9); H10(1); H11(1); H12(1)
LS 2.441 1.862 0.559 0.390 0.627 -0.260 0.378 0.00025 H5(10); H8(1); H9(1)
MG 1.794 1.623 0.495 0.324 0.473 -0.454 0.333 0.00017 H5(5); H13(1)
平均Mean 2.177 1.775 0.528 0.360 0.561 -0.341 0.402 0.00020

图1

基于DAPC的滇杨个体分布图(K = 2, 3, 4, 5, 6)。种群代号同表1。"

图2

滇杨主坐标分析图及聚类图。(A)个体主坐标分析(PCoA); (B)依据SSR标记基于遗传距离的UPGMA聚类分析, 百分比表示1,000次bootstrap值的比例。种群代号同表1。"

表5

基于SSR和cpDNA对种群内和种群间分子变异的方差分析"

变异来源
Source of
variation
自由度
df
变异值
Estimated variance of components
变异来源占比
Percentage of variation (%)
遗传分化系数
Genetic differentiation coefficient (Fst)
基因流
Gene flow (Nm)
SSR cpDNA SSR cpDNA SSR cpDNA
种群间
Among population
5 1.966 9.663 18 15
种群内
Within populations
59 9.016 39.047 82 85
总计 Total 64 10.982 48.710 100 100 0.237 0.148 0.806

表6

种群间遗传分化系数(Fst, 对角线上方)和基因流(Nm, 对角线下方)。种群代号同表1。"

ZT HZ SM EY LS MG
ZT - 0.081 0.182 0.227 0.266 0.434
HZ 2.837 - 0.171 0.217 0.228 0.424
SM 1.124 1.214 - 0.174 0.124 0.409
EY 0.849 0.904 1.186 - 0.101 0.340
LS 0.689 0.844 1.763 2.216 - 0.372
MG 0.327 0.339 0.362 0.486 0.422 -

表7

滇杨叶绿体片段13个单倍型间的序列变异位点表"

单倍型 Hap-
lotype
变异位点 Mutation sites
CO2 CO5 CO9
1 1 1 1 1 1 2 2 2 2 2 2 2 3 3 3 3 3 3
6 7 8 8 8 8 8 8 8 9 9 9 9 9 9 9 0 0 1 3 4 5 5 6 6 6 6 6 6 1 3 3 3 4 7
6 9 4 6 6 7 8 8 9 0 0 0 0 1 4 9 0 2 9 3 3 7 8 6 6 6 7 8 8 2 0 3 8 2 7
3 3 2 4 6 1 3 7 7 1 2 3 8 0 3 5 2 7 8 4 2 0 5 0 1 3 4 4 9 3 1 5 1 3 2
H1 - - - G A - - - A A - C