Chemophenetic investigation of epicuticular n-alkanes in Juniperus L. section Juniperus L. from the Balkans

Abstract

Junipers are one of the most diverse groups of gymnosperms today. They are adapted to arid areas of the world. In this study, we analysed the chemical composition of the leaf n-alkanes of 170 individuals belonging to Juniperus communis subsp. communis, J. communis var. saxatilis, J. deltoides and J. macrocarpa from the Balkans. Localities with at least two sympatric populations were chosen to study the chemical composition in order to limit the influence of environmental factors on the chemical composition. The leaf n-alkanes were extracted from the leaves with n-hexane and analysed using GC-MS. In all of the samples, n-C33 was the dominant alkane, with n-C29, n-C31 and n-C35 comprising over 80% of the n-alkane profile. The percentages of these dominant n-alkanes were taxon-specific, thus indicating their chemotaxonomic significance. In all the multivariate statistical analyses, samples belonging to different taxa were separated from each other. While the n-alkane profile can be used as a chemotaxonomic tool in the differentiation of these four taxa, it did not carry a phylogenetic signal. Instead, it reflected ecological adaptations, showing how different taxa have adapted to different arid environments within the study area.

Keywords

• cuticle
• n-alkanes
• junipers
• chemotaxonomy
• juniperus communis
• juniperus deltoides
• juniperus macrocarpa