Chemotaxonomic implications of the n-alkane composition and the nonacosan-10-ol content in Picea omorika, Pinus heldreichii, and Pinus peuce.

The n-alkane composition and the nonacosan-10-ol content in the needle cuticular waxes of Serbian spruce (Picea omorika), Bosnian pine (Pinus heldreichii), and Macedonian pine (Pinus peuce) were compared. The amount of nonacosan-10-ol in the needle waxes of P. omorika was higher than those in P. heldreichii and P. peuce. The range of n-alkanes was also wider in P. omorika (C18 -C35 ) than in P. heldreichii and P. peuce (C18 -C33 ). The dominant n-alkanes were C29 in the needle waxes of P. omorika, C23 , C27 , and C25 in those of P. heldreichii, and C29 , C25 , C27 , and C23 in those of P. peuce. The waxes of P. omorika contained higher amounts of n-alkanes C29 , C31 , and C33 , while those of P. heldreichii and P. peuce had higher contents of n-alkanes C21 , C22 , C23 , C24 , and C26 . The principal component analysis of the contents of nine n-alkanes showed a clear separation of the Serbian spruce populations from those of the two investigated pine species, which partially overlapped. The separation of the species was due to high contents of the n-alkanes C29 and C31 (P. omorika), C19 , C20 , C21 , C22 , C23 , and C24 (P. heldreichii), and C28 (P. peuce). Cluster analysis also showed a clear separation between the P. omorika populations on one side and the P. heldreichii and P. peuce populations on the other side. The n-alkane and terpene compositions are discussed in the light of their usefulness in chemotaxonomy as well as with regard to the biogeography and phylogeny of these rare and endemic conifers.