Variation in Essential Oil Yield and Composition of Dorema aucheri Boiss., an Endemic Medicinal Plant Collected from Wild Populations in Natural Habitats.

In the present research, variability in essential oil (EO) composition of five Dorema aucheri populations collected from natural habitats in different regions of Iran, were investigated. The EO content of populations varied from 0.28 to 0.68%. According to gas chromatography/mass spectrometry analysis, β-caryophyllene (7.17 - 35.73%), thymol (23.45 - 29.64%), β-gurjunene (2.58 - 5.89%), carvacrol (1.32 - 2.67%) and cuparene (1.97 - 2.98%) were the major components. Hierarchical cluster, principal component and canonical correspondence analyses classified the studied populations into three groups based on major EO components. The environmental parameters of the collected sites were also evaluated. According to the results, it might be suggested that sandy soils with high mean annual precipitation were major environmental factors influencing the amount of β-caryophyllene, while thymol, cuparene and caryophyllen oxide increased in silty and clay soils. Finally, the population collected in high altitudes and clay soils had higher amount of β-gurjunene.