Oil composition variability among populations in relationship with their ecological areas in TunisianRosmarinus officinalis L.

The essential oil of Rosmarinus officinalis L. (Lamiaceae) from 14 wild Tunisian populations, sampled in three ecological areas (sub-humid, semi-arid superior and arid superior bioclimatic stages), was analysed by GC and GC–MS. According to populations, 25 constituents, representing 93.68–98.77% of the total components, were identified. 1,8-cineole (20.34–45.79%), camphor (8.5–30.17%), α-pinene (6.53–13.1%) and borneol (3.73–25%) represent the major compounds. However, the mean percentages of compounds varied significantly among populations; α-pinene, 1,8-cineole were the main constituents which differentiated the populations. In addition, the proportion and nature of the constituents varied according to population bioclimatic stage, showing large differences between the ecological groups considered. Populations from arid superior bioclimate, represented by Rosmarinus officinalis var. troglodytorum, were characterized by high proportions of α-pinene, camphor and a relatively low content of 1,8-cineole.