Investigation of Altitude on Morphological Traits and Essential Oil Composition of Nepeta pogonosperma Jamzad and Assadi from Alamut Region

Nepeta is one of the biggest geniuses of Lamiaceae family which N. pungens, N. binaludensis, N. isphanica, N. pogonosperma and N. bracteata has been used traditionally in Iran. Nepeta pogonesperma is one of the endemic Nepeta species in Alamut region (Qazvin Province ). So in this research the aerial parts of Nepeta pogonesperma in full flowering stage were collected from Kheshchal altitudes of Alamut (2400, 2600 and 2800 m). Some main morphological characters of plant were measured. Essential oil were obtained by hydro distillation (Clevenger apparatus) and were analyzed by GC/MS. Results were showed that in high altitude (2800m) the yield and quantity of the essential oil components of plant were increased and the 1,8-cineole had the highest content (80.7%). 19 compounds were identified in the essential oil of this plant, Such as α-Pinene, Sabinene, β-Pinene, Myrcene, δ-3-Carene, ρ-Cymene, Limonene, 1,8-Cineole, Cis-Sabinene hydrate, Terpinolene, Linalool, Cis-p-Menth-2-en-1-ol, Pinocarvone, Borneol, Terpinen-4-ol, α-Terpineol, 4aα-7α-7aβ-Nepetalactone, α-Humulene and Viridiflorol. Variance analysis revealed that there was a significant difference between altitudes in the weight of leaf, stem and flower and total plant weight and oil percentage (α≤0.01).  According to the means comparison of the highest leaf and flower weight were belonged to 2400 and 2600 m with 63.7 and 35.7g, respectively. The maximum amount of oil percentage and 1,8-Cineole were observed in 2400 m with 0.55 and 80.7%, respectively. In this research, there were many changes in altitudes in essential oil combinations, which can be increased the production and performance of Nepetalactone, by applying nature-generated modeling factors.