Diversity of headspace volatiles in native population of Abies x borisii-regis from the central Rhodopes

The present study investigates diversity of headspace needle volatiles in native population of Abies x borisii-regis (King Boris fir) from the central Rhodopes (southern Bulgaria) as well as the relationships among this and seventeen previously studied fir populations from the presumed zones of natural hybridization in the Balkan Peninsula. According to multivariate statistical analyses, all four populations identified as A . x borisii - regis from southern Bulgaria, northern and central Greece included volatile profiles of both supposed parent species ( A. alba and A. cephalonica ), where profile frequencies changed clinally along the latitudinal gradient. Considering that one of the indicators of the presence of a hybrid zone is the clinical variation of all or a larger number of characters located in the same area, the observed geographic distribution of volatile entities supports the hypothesis that studied A . x borisii - regis populations are of secondary origin due to hybridization between A. alba and A. cephalonica .