Gaudeul M, Taberlet P, Till-Bottraud I
Laboratoire de Biologie des Populations d'Altitude, UMR CNRS 5553, Université J. Fourier, BP 53, F-38041 Grenoble Cedex 09, France.
Mol Ecol. 2000 Oct;9(10):1625-37. doi: 10.1046/j.1365-294x.2000.01063.x.
Eryngium alpinum L. is an endangered species found across the European Alps. In order to obtain base-line data for the conservation of this species, we investigated levels of genetic diversity within and among 14 populations from the French Alps. We used the amplified fragment length polymorphism (AFLP) technique with three primer pairs and scored a total of 62 unambiguous, polymorphic markers in 327 individuals. Because AFLP markers are dominant, within-population genetic structure (e.g. FIS) could not be assessed. Analyses based either on the assumption of random-mating or on complete selfing lead to very similar results. Diversity levels within populations were relatively high (mean Nei's expected heterozygosity = 0.198; mean Shannon index = 0.283), and a positive correlation was detected between both genetic diversity measurements and population size (Spearman rank correlation: P = 0. 005 and P = 0.002, respectively). Moreover, FST values and exact tests of differentiation revealed high differentiation among populations (mean pairwise FST = 0.40), which appeared to be independent of geographical distance (nonsignificant Mantel test). Founder events during postglacial colonizations and/or bottlenecks are proposed to explain this high but random genetic differentiation. By contrast, we detected a pattern of isolation by distance within populations and valleys. Predominant local gene flow by pollen or seed is probably responsible for this pattern. Concerning the management of E. alpinum, the high genetic differentiation leads us to recommend the conservation of a maximum number of populations. This study demonstrates that AFLP markers enable a quick and reliable assessment of intraspecific genetic variability in conservation genetics.
高山刺芹是一种分布于欧洲阿尔卑斯山地区的濒危物种。为获取该物种保护的基线数据，我们调查了法国阿尔卑斯山14个种群内部及种群间的遗传多样性水平。我们使用扩增片段长度多态性（AFLP）技术，采用三对引物，在327个个体中共检测到62个明确的多态性标记。由于AFLP标记是显性的，因此无法评估种群内的遗传结构（如FIS）。基于随机交配或完全自交假设的分析得出了非常相似的结果。种群内的多样性水平相对较高（平均Nei氏期望杂合度 = 0.198；平均香农指数 = 0.283），并且在这两种遗传多样性测量与种群大小之间均检测到正相关（斯皮尔曼等级相关：P分别为0.005和0.002）。此外，FST值和分化的精确检验显示种群间存在高度分化（平均成对FST = 0.40），这似乎与地理距离无关（曼特尔检验不显著）。我们推测冰期后殖民化过程中的奠基者事件和/或瓶颈效应可解释这种高度但随机的遗传分化。相比之下，我们在种群和山谷内部检测到了距离隔离模式。花粉或种子的主要本地基因流可能是造成这种模式的原因。关于高山刺芹的管理，高度的遗传分化使我们建议尽可能多地保护种群。本研究表明，AFLP标记能够快速可靠地评估保护遗传学中的种内遗传变异性。
