沿海岛屿与内陆藓类植物遗传多样性和分化的比较研究——以真藓(Bryum argenteum Hedw.)为例

Genetic diversity and differentiation between coastal and inland populations of mosses:a case study of Bryum argenteum Hedw.

基于11个内陆居群和32个岛屿居群的252份标本,采用ISSR分子标记技术对真藓( Bryum argenteum Hedw.)的遗传多样性进行了研究。结果显示:岛屿与内陆居群间的遗传多样性差异显著,岛屿居群间的分化程度( G st = 0. 453)大于内陆居群( G st = 0. 387),岛屿居群的遗传分化与地理来源间存在极显著相关性( r = 0. 478, n = 175, P < 0. 001)。地理隔离效应是导致岛屿居群间遗传分化的重要因素。岛内居群间的遗传分化水平较低,仅有29. 4%~ 29. 7%的遗传多样性存在于居群间。聚类分析表明,43个居群可划分为10大类群,真藓遗传关系受地理因素和生境异质性的影响,水域隔离影响了真藓繁殖体在岛屿间的传播。

The genetic diversity of Bryum argenteum Hedw. was studied based on 252 samples from 11 inland and 32 island populations using Inter-Simple Sequence Repeat (ISSR) markers. Significant genetic differentiation between island and inland populations was detected, with a higher degree of differentiation found in the island populations ( G st = 0. 453) compared with the continental populations ( G st = 0. 387). There was a significant correlation between genetic differentiation of the tested samples and their geographical origin ( r = 0. 478, n = 175, P < 0. 001), indicating a significant effect of geographical isolation on genetic differentiation among the populations of mosses. Genetic variation among the island populations of B. argenteum was low, varying from 29. 4% to 29. 7% among populations. 43 populations were divided into 10 groups based on the ISSR results using cluster analysis. Both geographic origin and environmental heterogeneity exerted marked effects on the genetic diversity of B. argenteum . The spread of propagules was likely impacted by watershed isolation to a certain degree.