Variability in seed essential oil composition of the cultivated Satureja hortensis L. (Lamiaceae) populations in Iran

We examined seed essential oil profiles in 10 Iranian cultivated populations of Satureja hortensis L. (summer savory-Lamiaceae) plants. Seed essential oils were extracted using the hydro-distillation method by a Clevenger-type apparatus, and analyzed by a GC and GC/MS apparatus. Data were analyzed using PAST ver.4 and SPSS ver. 25 software. In most plant populations, the essential oil profiles are dominated by carvacrol, an oxygenated monoterpene, with p-cymene or γ-terpinene often following as the second major component. However, in some populations, p-cymene, a monoterpene hydrocarbon, can be the primary compound, followed by γ-terpinene or carvacrol. Other significant sub-main compounds include E-caryophyllene, anethole, and β-bisabolene. Several trace compounds are also present, some of which are widely distributed, while others have a more restricted presence. Significant correlations were detected between the main essential oil compounds with each other and some environmental factors of the population's habitats. The clustering analyses approved the existence of two chemotype groups (p-cymene and carvacrol) among the evaluated populations. However, each chemotype group was divided into some sub-groups with the unique biological properties, based on their main oil compounds. According to former investigations, the main compounds are often synthesized through shared biochemical pathways, with some acting as precursors for others. Environmental and genetic parameters can significantly change metabolic pathways, leading to variations in the types and quantities of metabolites synthesized by plants, resulting in the formation of various chemotypes. These differences can impact essential oils suitability and effectiveness across different industries. Therefore, careful analysis of essential oil compositions is crucial before their widespread utilize in various applications.