Essential oil variation among different populations of Ziziphora tenuiorL. cultivated at semiarid climate

ABSTRACTIn this study, variation on the chemical compositions of the essential oil from eight populations of Ziziphora tenuior L. cultivated in semiarid climate, southwestern of Iran was performed. The essential oil analyzed by GC-FID and GC/MS. Significant variability in the main constituents of the essential oils was observed among the investigated populations of Z. tenuior. The major compounds were pulegone (18.46–46.28%), piperitenone (0–30.61%), p-mentha-3-en-8-ol (0.46–28.49%), caryophyllene oxide (0.13%–14.78%), and germacrene-D (0.11–14.23%). According to the multivariate analysis using principal component analysis (PCA) and hierarchical cluster analysis (HCA), three chemotypes were identified including chemotype-I: pulegone/germacrene-D/caryophyllene oxide; chemotype-II consisted of two subgroups (first subgroup: pulegone/p-mentha-3-en-8-ol, and the second subgroup: pulegone); and chemotype-III: piperitenone/pulegone. These chemotypes are the result of genetic differences and diversity between populations. The results of this investigation can help to improve the chemotaxonomic and phytochemical studies and the conservation and breeding programs of this herb.