Institute of Biology/Geobotany and Botanical Garden, Martin Luther University of Halle-Wittenberg, Halle/Saale, Germany.
Plant Biol (Stuttg). 2010 May 1;12(3):526-36. doi: 10.1111/j.1438-8677.2009.00227.x.
Stipa capillata L. (Poaceae) is a rare grassland species in Central Europe that is thought to have once been widespread in post-glacial times. Such relict species are expected to show low genetic diversity within populations and high genetic differentiation between populations due to bottlenecks, long-term isolation and ongoing habitat fragmentation. These patterns should be particularly pronounced in selfing species. We analysed patterns of random amplified polymorphic DNA (RAPD) variation in the facultatively cleistogamous S. capillata to examine whether genetic diversity is associated with population size, and to draw initial conclusions on the migration history of this species in Central Europe. We analysed 31 S. capillata populations distributed in northeastern, central and western Germany, Switzerland and Slovakia. Estimates of genetic diversity at the population level were low and not related to population size. Among all populations, extraordinarily high levels of genetic differentiation (amova: phi(ST) = 0.86; Bayesian analysis: theta(B) = 0.758) and isolation-by-distance were detected. Hierarchical amova indicated that most of the variability was partitioned among geographic regions (59%), or among populations between regions when the genetically distinct Slovakian populations were excluded. These findings are supported by results of a multivariate ordination analysis. We also found two different groups in an UPGMA cluster analysis: one that contained the populations from Slovakia, and the other that combined the populations from Germany and Switzerland. Our findings imply that S. capillata is indeed a relict species that experienced strong bottlenecks in Central Europe, enhanced by isolation and selfing. Most likely, populations in Slovakia were not the main genetic source for the post-glacial colonization of Central Europe.
长芒野古草 L.（禾本科）是中欧一种罕见的草原物种，据认为曾在冰川后期广泛分布。由于瓶颈效应、长期隔离和持续的生境破碎化，这些残余物种预计在种群内表现出低遗传多样性，而在种群间表现出高遗传分化。这些模式在自交物种中应该更为明显。我们分析了兼性闭花授粉的长芒野古草的随机扩增多态性 DNA（RAPD）变异模式，以检验遗传多样性是否与种群大小有关，并初步得出该物种在中欧的迁移历史结论。我们分析了分布在德国东北部、中部和西部、瑞士和斯洛伐克的 31 个长芒野古草种群。种群水平的遗传多样性估计值较低，与种群大小无关。在所有种群中，都检测到极高水平的遗传分化（amova：phi(ST)=0.86；贝叶斯分析：theta(B)=0.758）和距离隔离。层次 amova 表明，大部分变异是在地理区域之间（59%）或在排除遗传上不同的斯洛伐克种群后，在区域之间的种群之间划分的。多元排序分析的结果支持了这些发现。我们还在 UPGMA 聚类分析中发现了两个不同的群体：一个群体包含了来自斯洛伐克的种群，另一个群体则将来自德国和瑞士的种群组合在一起。我们的研究结果表明，长芒野古草确实是一种残余物种，在中欧经历了强烈的瓶颈效应，加上隔离和自交的影响。很可能，斯洛伐克的种群不是中欧冰川后殖民化的主要遗传来源。
