مشخصات پژوهش

Geographic location, environmental conditions, and edaphic factors are interconnected, and collectively influence the total content of some plant-based compounds. Mountain tea (Stachys lavandulifolia Vahl) is a perennial plant in the Lamiaceae family, having prominent medicinal properties due to its unique chemical composition. The current research evaluated effective traits that shape the content of essential oil (EO) and phytochemical compounds in S. lavandulifolia populations (P). Samples were collected from 20 different habitats located in the west and northwest of Iran. The results indicated that the Heris (P3) and Sarab (P7) populations exhibited high levels of EOs and phytochemical properties. In the studied areas, principal component and cluster analyses considered environmental factors like climate and soil, thus revealing significant findings. Soil characteristics, including organic matter content, total nitrogen (N), potassium (K), and soil phosphorus (P) content, were identified as the most influential factors, with average annual rainfall following closely. The highest average annual temperatures largely contributed to distinguishing the areas, thus categorizing the habitats into three distinct groups. EO from 20 populations analyzed using GC/MS showed 41 compounds, the most important of which were α-pinene (1.21–33.29 %), α-bisabolol (0.71–53.05 %), and spathulenol (2.8–18.8 %), germacrene-D (1.13–12.18 %), β-phellandrene (0.09–16.72 %), myrcene (1.01–13.34 %), phytol (1.19–10.14 %), and viridiflorol (0.93–6.19 %). Grouping the S. lavandulifolia populations based on their main compounds in the EO divided them into two distinct habitats. The first habitat had eleven S. lavandulifolia populations, whereas the second had nine. Comparison of mean values among habitats showed that the first habitat was superior to the second, regarding sesquiterpene chemical compounds such as spathulenol, viridiflorol, α-muurolol, α-cadinol, and valeranone. The second habit