Volatile and molecular analysis of Juniperus brevifolia (Seub.) Antoine, an Azorean endemic species

Chemical and molecular analyses were performed for the characterization of Juniperus brevifolia (Seub.) Antoine (Cupressaceae), an Azorean endemic species. Forty-two individual twig samples were collected at seven Azorean islands (S. Miguel, Terceira, S. Jorge, Pico, Faial, Flores and Corvo). Volatile compounds were isolated by distillation–extraction and analyzed by GC and GC-MS. The volatile oils consisted mainly of monoterpene hydrocarbons (84–96%), limonene (33–87%), α-pinene (1–48%) and β-myrcene (1–5%) being the main components, and cluster analysis showed a high correlation among all samples (Scorr = 0.84). DNA fingerprinting was performed using thirty-seven RAPD and eleven ISSR primers, generating 881 polymorphic bands. Cluster analysis showed a moderate correlation among accessions (SDice = 0.43), which grouped according to their geographical origin. Chemical and molecular data did not show superimposable clustering profiles. Although the molecular approaches tested were useful in assessing genetic diversity, no straight correlation could be drawn between chemical and molecular data sets.

Research highlights
► Limonene and α-pinene dominance in Azorean Juniperus brevifolia volatiles.
► Volatiles data cluster analysis revealed a high correlation among all samples.
► Molecular data cluster analysis showed moderate correlation between accessions.
► No straight correlation could be found between volatile and molecular data sets.