Geographically Related Variation in Epicuticular Wax Traits of Pinus nigra Populations from Southern Carpathians and Central Balkans – Taxonomic Considerations

Abstract

The chemical composition of epicuticular waxes of nine populations from three Pinus nigra J. F. Arnold subspecies (namely subsp. nigra, subsp. banatica (Borbás) Novák, and subsp. pallasiana (Lamb.) Holmboe) from Southern Carpathians and central Balkan Peninsula were analyzed using GC/MS and GC/FID chromatography, and multivariate statistical techniques with respect to biogeography and taxonomy. In the needle waxes, four primary alcohols and 14 n-alkanes ranging from C21 to C33 were identified, and the most abundant compounds were the four odd-numbered n-alkanes C27 , C25 , C23 , and C29. Multivariate statistical analyses (CDA and CA) have shown existence of three P. nigra groups and suggested clinal differentiation as a mechanism of genetic variation across a geographic area: the first group consisted of the southernmost populations of subsp. pallasiana from Macedonia, the second consisted of the northernmost subsp. banatica populations from Romania, while all populations in Serbia described as three different subspecies (nigra, banatica, and pallasiana) formed the third group together with subsp. nigra population from Bosnia and Herzegovina. According to simple linear regression, geographic latitude and four bioclimatic parameters were moderately correlated with the contents of epicuticular wax compounds that are important in population discrimination, while stepwise multiple regression showed that latitude participated in most of the regression models for predicting the composition of the epicuticular waxes. These results agree with CDA and CA analysis, and confirmed the possibility of recognition of fine geographic differentiation of the analyzed P. nigra populations.

Terpenes as Useful Markers in Differentiation of Natural Populations of Relict Pines Pinus heldreichii, P. nigra, and P. peuce

“…nigra taxa, which are not reproductively isolated. Similar results were obtained by using epicuticular wax compounds as chemotaxonomic characters, as well as molecular data (plastid and mitochondrial) that failed to support circumscription of P . nigra taxa within the territory of Serbia .…”

Chemotaxonomic Considerations of the n‐Alkane Composition in Pinus heldreichii, P. nigra, and P. peuce

“…In the needle cuticular waxes of P. nigra range of n ‐alkanes was wider (C 16 – C 33 ) than in P. heldreichii and P. peuce (C 18 – C 33 , compiled after previous results respectively). The most abundant were n ‐alkanes C 25 and C 27 ( P. nigra ), C 23 ( P. heldreichii ), and C 29 ( P. peuce ).…”

“…n ‐Alkanes in cuticular waxes of P. heldreichii , P. nigra and P. peuce have already been investigated at population level on the central Balkans . Furthermore, recent investigation of taxonomic relations between Picea omorika , Pinus heldreichii and P. peuce populations in composition and abundance of n ‐alkanes gave interesting results …”

First Insights Into Micromorphology of Needle Epicuticular Waxes of South-Eastern European Pinus Nigra J. F. Arnold Populations

“…However, to the best of the authors' knowledge, the contents and variability of nonacosanol-10-ol in the needle waxes of P. nigra populations have not yet been studied. The composition of epicuticular waxes of this species has been addressed only regarding the contents of n-alkanes (Maffei et al 2004, Bojović et al 2012 or n-alkanes and primary alcohols (Mitić et al 2016).…”