生物多样性 ›› 2003, Vol. 11 ›› Issue (2): 100-108.doi: 10.17520/biods.2003014

• 论文 • 上一篇    下一篇

孑遗植物水杉的遗传多样性研究

李晓东, 黄宏文, 李建强*   

  1. (中国科学院武汉植物研究所武汉植物园,武汉 430074)
  • 收稿日期:2002-10-22 修回日期:2002-12-10 出版日期:2003-03-20
  • 通讯作者: 李建强

Genetic diversity of the relict plant Metasequoia glyptostroboides

LI Xiao-Dong, HUANG Hong-Wen, LI Jian-Qiang*   

  1. Wuhan Botanical Garden/Wuhan Institute of Botany,Chinese Academy of Sciences,Wuhan 430074
  • Received:2002-10-22 Revised:2002-12-10 Online:2003-03-20
  • Contact: LI Jian-Qiang

采用随机扩增多态DNA(RAPD)方法对孑遗植物水杉(Metasequoia glyptostroboides)的8个居群(包括6个孑遗居群和2个人工栽培居群)的48个个体进行了遗传多样性研究。用16个随机引物共扩增出清晰谱带57条。孑遗居群平均多态位点百分率为38.6%。各居群多态位点百分率差异显著(10.53%~33.33%):湖北利川的小河和桂花2个居群较高,分别是33.33%和31.58%;湖南龙山洛塔居群较低,为10.53%。人工栽培居群中,美国密西根州和湖北武汉2个居群的多态位点百分率也较低,仅分别为10.53%和8.77%。用POPGENE 1.31版软件进行数据处理后结果如下: 孑遗居群的平均Nei‘s基因多样性为0.1305,Shannon‘s遗传多样性信息指数为0.1921,水杉孑遗居群遗传距离与地理距离的相关系数r=0.23466(P=73.27%),基因分化系数Gst=0.1082,表明居群间有一定分化。用UPGMA方法聚类可知,2个人工居群与湖北利川居群优先聚类。鉴于目前水杉孑遗居群生境人为破坏严重、遗传多样性较低和原生母树分布分散,建议在湖北利川小河和桂花野生水杉最适生境建立水杉遗传多样性保护点,将现有的250多株原生母树分别采种育苗定植于保护点,以达到最大限度地保存现有水杉遗传多样性的目的。

Forty-eight individuals of eight populations of Metasequoia glyptostroboides (Dawn Redwood), including six relict populations and two cultivated, were analyzed by random amplified polymorphic DNA (RAPD) markers to determine the genetic variations among and within the populations. A total of 57 loci (including 22 polymorphic loci) were amplified using 16 random primers. The average percentage of polymorphic loci (PPL) was 38.6% in the relict populations. The difference of the percentage of polymorphic loci among all the populations was evident (10.53%~33.33%). Of the eight populations, Xiaohe and Guihua populations in Lichuan City, Hubei had high PPL(33.33% and 31.58%), while the population in Longshan Luota, Hunan had relatively low PPL (10.53%), and the two cultivated populations also had low PPL (10.53% and 8.77%). As analyzed by POPGENE version 1.31, the data from the relict populations has an average Nei's gene diversity of 0.1305, and Shannon's genetic diversity of 0.1921. Correlation coefficient between genetic distance and geographic distance was 0.23466 (P=73.27%). Among the relict populations,Gst was 0.1082, indicating that there was some differentiation among the populations. The two cultivated populations and the two Lichuan relict populations clustered together. In view of the damage and fragmentation of original habitats, the low genetic diversity and the dispersed distribution of wild Metasequoia glyptostroboides , we suggest establishing a conservation spot in the optimal habitat of Xiaohe and Guihua in Lichuan, where we can breed and plant seeds from the remaining 250 wild trees. By this means, the remaining genetic diversity resources of the species can be preserved to the greatest extent.

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