Genetic diversity in an endangered alpine plant, Eryngium alpinum L.. (Apiaceae), inferred from amplified fragment length polymorphism markers

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, w e investigated levels of genetic diversity within and among 14 populations from the French Alps. We used the amplified fragment length polymorphism (A FLP) 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. F-IS) could not be assessed. An alyses based either on the assumption of random-mating or on complete selfi ng lead to very similar results. Diversity levels within populations were r elatively high (mean Nei's expected heterozygosity = 0.198; mean Shannon in dex = 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, F-ST values and exact tests o f differentiation revealed high differentiation among populations (mean pai rwise F-ST = 0.40), which appeared to be independent of geographical distan ce (nonsignificant Mantel test). Founder events during postglacial coloniza tions and/or bottlenecks are proposed to explain this high but random genet ic differentiation. By contrast, we detected a pattern of isolation by dist ance within populations and valleys. Predominant local gene now by pollen o r seed is probably responsible for this pattern. Concerning the management of E. alpinum, the high genetic differentiation leads us to recommend the c onservation of a maximum number of populations. This study demonstrates tha t AFLP markers enable a quick and reliable assessment of intraspecific gene tic variability in conservation genetics.