Effect of habitat factors on aerial yield, morphological traits and essential oil content ‎of Nepeta binaludensis Jamzad ‎

Nepeta binaludensis Jamzad is an endemic and rare perennial plant that grows in a limited area in Binaloud Mountain in northeast of Iran. The aerial parts of 20 populations of N. binaludensis, were collected during their flowering stage and seven morphological traits and essential oil yield were evaluated. Results showed significant differences in all of traits between populations (p<0.01). The highest and lowest aerial fresh weight were obtained in Zoshk1 and Grineh populations with average values of 378.2 and 58.2 g/plant, respectivel. The highest and lowest essential oil yield were obtained in populations of Darood and Friezy1 with average values of 4.91 and 1.2%, respectively. The results of correlation analysis showed that plant height was positively correlated with stem diameter, aerial fresh and dry weights. Climatic factors such as rainfall, altitude and slope percentage were positively correlated with morphological traits and essential oil yield. Morphological traits and essential oil yield were positively correlated with climatic factors, such as rainfall, altitude and slope percentage and negatively correlated with temperature of the habitat, indicating that mean of mentioned traits were increased by increasing altitude and decreasing of temperature. Cluster analysis using Ward method, the studied populations were splited into two groups. The populations of cluster 1 (seven populations adapt to high altitude and cold) had higher mean values for morphological traits, i.e. plant height, aerial fresh and dry weights. Results indicate the presence of high diversity among populations of N. binaludensis that could be used for domestication and breeding improved varieties of this species.