effect of altitude and soil factors on morphological and phytochemical traits of mentha pulegium l. in different habitats of kerman province, iran

To investigate the effect of environmental and soil factors on morphological and qualitative characteristics of pennyroyal or m. pulegium, research was conducted in five habitats of the species in 2022 in kerman province of iran. plant samples were collected from random quadrats (1×1m2) during the flowering stage in natural habitats of kerman, kohbanan, raver, zarand, and chatrood. the collected data were subjected to one-way analysis of variance (anova) and means were compared among locations. the results indicated significant diversity among the sites. altitude significantly influenced essential oil yield and composition. the highest essential oil percentage (0.198%) was observed at kohbanan (highest altitude), which was 35% higher than chatrood (lowest altitude, 0.112%). however, ravar and kohbanan sites had the highest overall essential oil yields (2.77% and 2.133%, respectively). the greatest chlorophyll content (1.26) was recorded at kohbanan, which was 44% higher than at ravar. while soil properties like nutrient content and texture were important, altitude had a more pronounced effect on plant quality characteristics. this study demonstrates that altitude is a critical ecological factor influencing the growth and chemical composition of mentha pulegium. while soil characteristics contribute to plant development, environmental conditions at varying altitudes have a greater impact on essential oil content, chlorophyll levels, and anthocyanin production. these insights are valuable for optimizing pennyroyal cultivation for medicinal or industrial purposes.