||The project is oriented towards experimental verification of hybridological relationship between Scots pine (Pinus sylvestris L.) and mountain dwarf pine (P. mugo Turra). Within putative hybrid swarms of these species in northern Slovakia, the extent of introgressive hybridization with the parental species mentiontd above will be determined. Except for the classical approaches of artificial hybridization, the chloroplast DNA (cpDNA) is expected to be used in verification of both the interspecific and intraspecific hybrids of these pines. The degree of genetic divergence between hybrid swarms and natural populations of both parental species will be determined using cpDNA and mitochondrial DNA (mtDNA) markers. The project aims in validation of the hybrid nature of the putative hybrid swarms on the localities in Zuberec – Medzi Bormi, Suchá Hora and Terchová – Sokolie all of which are taken for rare endemites on our territory.