Essential Oil Variability in Natural Populations of Picea omorika, a Rare European Conifer

Abstract

This study is the first report on the composition and variability of essential oil in the relic, endemic, and vulnerable tree species Serbian spruce, Picea omorika, in its natural populations. In the needles of 108 trees of four natural populations, 49 components of essential oils were identified. The main compounds were bornyl acetate (29.2%), camphene (18.7%), and alpha-pinene (12.9%). Fourteen additional components had the contents of up to 0.5%: alpha-cadinol (6.1%), limonene (5.8%), santene (3.5%), (E)-hex-2-enal (2.9%), T-cadinol (2.9%), delta-cadinene (2.3%), tricyclene (2.1%), myrcene (1.6%), beta-pinene (1.2%), borneol (0.9%), germacrene D (0.9%), alpha-muurolene (0.6%), and two unidentified compounds. Population IV from Milesevka Canyon had a much higher content of bornyl acetate (42.9%). Populations I-III from Mt. Tara were more abundant in sesquiterpenes (up to 18.2%). The content of bornyl acetate, the multi-variation analyses according to seven selected components, especially the cluster analysis and genetic analysis of alpha-cadinol, which suggested the monogenic type of heredity, showed a clear differentiation of the two geographic areas, the similarity of populations I-III from the area of Mt. Tara, and the separation of the population IV from Milesevka Canyon.

Variability of n‐Alkanes and Nonacosan‐10‐ol in Natural Populations of Picea omorika

“…Two-year-old needles from trees of three Serbian populations, i.e., Vranjak (population I), Zmajevački potok (population II), and Mileševka Canyon (population III; for details concerning these populations, cf. [7]), were collected in late autumn from the lower third of the unshaded tree crown. The needles were stored in polyethylene bags labeled with the sample plot, date of collection, and age of the needles.…”

“…Most harvested needles were used for the terpene analysis [7], and the remaining needles were used for the determination of the nonacosan-10-ol content (78 trees in total, i.e., 30, 30, and 18 trees for populations I -III, resp.) and the n-alkane analyses (47 trees in total, i.e., 20, 15, and 12 for populations I -III, resp.)…”

“…5). Population III was also found to be the most distant with regard to some terpene compounds [7]. Table 3.…”

“…vukomanii [5] [6]. The population variability of the needle-essential-oil composition of P. omorika from Serbia has also been investigated [7].…”

Terpene Chemodiversity of Relict Conifers Picea omorika, Pinus heldreichii, and Pinus peuce, Endemic to Balkan

“…In our previous study [34], we found that population Mileševka Canyon was the most distant. High level of genetic divergence of Vranjak population was also detected [37], but it was not established in the most recent analysis (independent samplings) [38].…”