植物生态学报 ›› 2007, Vol. 31 ›› Issue (6): 1190-1198.DOI: 10.17521/cjpe.2007.0148

• 论文 • 上一篇    下一篇

不同地理分布区紫椴种群的遗传多样性变化

穆立蔷1(), 刘赢男2   

  1. 1 东北林业大学林学院,哈尔滨 150040
    2 黑龙江省科学院自然资源研究所,哈尔滨 150040
  • 收稿日期:2006-12-08 接受日期:2007-05-17 出版日期:2007-12-08 发布日期:2007-11-30
  • 作者简介:E-mail: mlq0417@163.com

GENETIC DIVERSITY OF TILIA AMURENSIS POPULATIONS IN DIFFERENT GEOGRAPHICAL DISTRIBUTION REGIONS

MU Li-Qiang1(), LIU Ying-Nan2   

  1. 1Forestry College, Northeast Forestry University, Harbin 150040, China
    2Institute of Natural Resource, Heilongjiang Academy of Sciences, Harbin 150040, China
  • Received:2006-12-08 Accepted:2007-05-17 Online:2007-12-08 Published:2007-11-30

摘要:

该文运用ISSR分子标记技术,研究不同纬度、不同海拔紫椴(Tilia amurensis)天然种群的遗传多样性变化规律,探讨紫椴种群的濒危机制,为紫椴遗传资源的有效保护和合理利用提供理论依据。14个ISSR引物扩增结果显示:紫椴种群多态位点百分率(P)为93.85%,基因多样性指数(H)和Shannon多样性指数(I)分别为0.243 3和0.380 3。不同纬度紫椴种群的遗传多样性由高到低依次为:CBS种群>BL种群>NA种群>LS种群>FHS种群>DYS种群;不同海拔紫椴种群的遗传多样性由高到低依次为:H1种群>H2种群>H3种群>H4种群>H6种群>H5种群。紫椴种群的遗传多样性没有随纬度的升高而呈现规律性的变化,但随海拔的升高呈现遗传多样性逐渐降低的趋势。用AMOVA进行分子方差分析表明,紫椴种群间遗传分化较大,遗传变异主要来自种群内部。紫椴种群间遗传距离与地理距离没有相关性,但随着海拔的逐渐增高种群间遗传距离增大。该研究结果揭示,紫椴种群具有较高的遗传多样性,遗传多样性不是导致其种群濒危的主要原因,导致其濒危的主要原因可能与人为采伐、生境破坏和生境退化及其自身生物学特性所导致的自然更新不良有密切关系。因此,应加强对紫椴生境的保护,防止人为因素对紫椴天然种群的进一步破坏。

关键词: 紫椴种群, ISSR, 遗传多样性, 保护策略

Abstract:

Aims Tilia amurensis is one of the II-grade Chinese protected plants with an important economic value and ecological significance. The population of T. amurensis has gradually declined due to overdrafting. Our objectives were to 1) study the genetic diversity of six natural populations varying in longitude and latitude and six varying in altitude and 2) discuss strategies to conserve germplasm resources.

Methods The newly developed inter-simple sequence repeats (ISSR) marker was used to examine genetic diversity.

Important findings The results of 14 ISSR primers showed that polymeric percentage of the six populations was 93.85%, the gene diversity (H) was 0.243 3 and Shannon Index of diversity (I) was 0.380 3. The genetic diversities of T. amurensis decreased with increasing altitude, had a single-peak curve with increasing latitude, and were higher in the central region than in the edges. Analysis of molecular variance (AMOVA) revealed that the majority of genetic variation occurred within populations. Genetic distance and geographic distance were uncorrelated. We concluded that the genetic diversity of T. amurensis was high and mainly within populations. Also, the major factors threatening the development of T. amurensis included direct damage to natural populations due to destruction of habitat and poor regeneration ability caused by innate biological and ecological characteristics. Habitat should be protected, as individuals, especially in core areas.

Key words: Tilia amurensis population, ISSR, genetic diversity, protect strategy