Terpene chemodiversity of relict conifers Picea omorika, Pinus heldreichii, and Pinus peuce, endemic to Balkan.

Terpenes are often used as ecological and chemotaxonomic markers of plant species, as well as for estimation of geographic variability. Essential oils of relic and Balkan endemic/subendemic conifers, Picea omorika, Pinus heldreichii, and P. peuce, in central part of Balkan Peninsula (Serbia and Montenegro), on the level of terpene classes and common terpene compounds were investigated. In finding terpene combinations, which could show the best diversity between species and their natural populations, several statistical methods were applied. Apart from the content of different terpene classes (P. omorika has the most abundant O-containing monoterpenes and sesquiterpenes; P. heldreichii and P. peuce have the largest abundance of sesquiterpene and monoterpene hydrocarbons, resp.), the species are clearly separated according to terpene profile with 22 common compounds. But, divergences in their populations were established only in combination of several compounds (specific for each species), and they were found to be the results of geomorphologic, climatic, and genetic factors. We found similarities between investigated species and some taxa from literature with respect to terpene composition, possibly due to hybridization and phylogenetic relations. Obtained results are also important regarding to chemotaxonomy, biogeography, phylogeny, and evolution of these taxa.