EN
The genetic diversity within and among twelve populations (379 individuals) of Pinus mugo from the Giant Mts., Carpathians and Alps was analyzed using ten chloroplast microsatellite markers. A stepwise mutation model (SMM) for microsatellite loci was used in order to estimate divergence between populations and provenances from three mountain ranges. High levels of genetic diversity and significant differentiation were found among the three population groups. The populations from Giant Mts., Carpathians and Alps were strongly differentiated between each other, while differences among populations within these massifs were much lower. The pattern of genetic structure observedin dwarf mountain pine can be characteristic in conifers with a disjunctive geographic distribution. The significant genetic structuring among isolated parts of the geographic range of the species may be a result of an ancient fragmentation andlong lasting geographic isolation between the Giant Mts., Alpine and Tatra populations of P. mugo.