生物多样性 ›› 2008, Vol. 16 ›› Issue (6): 562-569.doi: 10.3724/SP.J.1003.2008.08201

• 论文 • 上一篇    下一篇

花楸树天然群体的遗传多样性研究

郑健1, 2, 郑勇奇1*, 张川红1, 宗亦臣1, 李伯菁1, 吴超3   

  1. 1 (中国林业科学研究院林业研究所, 北京 100091)
    2 (中国林业科学研究院热带林业研究所, 广州 510520)
    3 (天津市河东区绿化管理二所, 天津 300176)
  • 出版日期:2008-11-20

Genetic diversity in natural populations of Sorbus pohuashanensis

Jian Zheng1, 2, Yongqi Zheng1*, Chuanhong Zhang1, Yichen Zong1, Bojing Li1, Chao Wu3   

  1. 1 Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091
    2 Research Institute of Tropic Forestry, Chinese Academy of Forestry, Guangzhou 510520
    3 Afforestation Management Office of Hedong District, Tianjin 300176
  • Online:2008-11-20

花楸树(Sorbus pohuashanensis)是我国北方一种观赏兼经济用途的树种。本研究采用水平淀粉凝胶同工酶电泳技术, 对采自山东、山西、河北、辽宁4个省的8个花楸树天然群体的种子样本进行了分析, 旨在了解花楸树天然群体的遗传多样性和遗传结构, 为该树种的保护与利用提供科学依据。4个酶系统10个位点的检测结果表明, 花楸树群体水平上的遗传多样性较高, 每位点平均等位基因数(Na)为2.2000, 多态位点百分率(P)为100%, 期望杂合度(He)为0.4240。花楸树8个群体间的有效等位基因数(Ne)、He和Shannon信息指数差异较小,3个指标从高到低依次为: 河北驼梁山>河北雾灵山>山西庞泉沟>河北白石山>山东崂山>河北塞罕坝>山东泰山>辽宁老秃顶子。群体间遗传分化系数(Fst)为0.0758, 群体间总的基因流较高(Nm = 3.0472), 群体间遗传一致度较高(I为0.8585– 0.9872), 表明群体间遗传分化程度小。在单个群体中, 通过χ2检验, 花楸树群体有73.62%的位点组合显著偏离Hardy-Weinberg平衡(P<0.05), 总群体水平近交系数(Fit)和单个群体水平近交系数(Fis)分别为–0.3105和–0.4180, 表明无论在总体水平还是群体内个体间, 花楸树群体表现为杂合体过量的现象。UPGMA聚类结果显示, 8个群体的遗传距离与地理距离相关性不显著。

Sorbus pohuashanensis is a tree species native to northern China with high potential for ornamental use. The genetic structure and diversity of eight natural populations of Sorbus pohuashanensis were studied at ten loci encoding four isozymes using horizontal starch gel electrophoresis. Genetic diversity was high at the species level with the mean number of alleles per locus Na = 2.2000, the percentage of polymorphic loci P = 100%, and the mean expected heterozygosity He = 0.4240. Values of the three parameters of He, Ne, and Shannon′s information index indicated a random pattern of genetic diversity among the eight populations. A low level of genetic differentiation among populations (Fst = 0.0758) and a high estimate of gene flow (Nm = 3.0472) were detected together with a high level of genetic identity (I) among the populations (from 0.8585 to 0.9872). Wright’s F-statistics analysis indicated an excess of heterozygotes both at the individual population level (Fis = –0.4180) and at the total population level (Fit = –0.3105). χ2-tests (P<0.05) indicated that 73.62% of the assayed loci departed from the Hardy-Weinberg equilibrium. The UPGMA cluster analysis suggested that the genetic distances among populations were weakly correlated with their geographic distances.

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