Investigation of the phenotypic variation in some populations of Mentha Mozaffarianii Jamzad

Mentha Mozaffarianii Jamzad. is an aromatic, medicinal and endemic plant that grown in the South of Iran. Overharvesting, drought stress, destruction of its natural habitats have increased the extinction risk of this unique species. To investigate the morphological variation, nine populations were collected from its natural habitats during the years 2019-2021 and 23 morphological traits were evaluated. The results of the analysis of variance indicated the existence of diversity among the studied populations. There were significant differences among populations (P<0.05) for all the traits except the leaf number, leaf length to width ratio and the number of flowering branches. The results showed significant correlation among most of the studied traits. Based on the principal component analysis (PCA), six main components explained 76.45% of the total variance among traits. The first, second and third components explained 23.24, 15.8 and 13.64% of the total variation, respectively, and they were considered as the effective components in plant height, inflorescence, and canopy cover. Based on cluster analysis using Ward method, the populations were divided into three main groups. The populations in cluster 3 had the highest plant height and crown area. Evaluation of phenotypic variation and collection of its genetic resources is necessary to facilitate the management and better investigation in breeding programs. Assessment the presence of phenotypic diversity can provide beneficial information in the management of collections and germplasm of Mentha Mozaffarianii. The data obtained from this research is useful and valuable in identifying appropriate populations for breeding purposes.