Genetic and morphological diversity of three Otostegia species in Iran

Taxonomic and genetic diversity of the genus Otostegia (Lamiaceae), despite its medicinal importance, is not properly known. In the present study, therefore, ۱۱ populations of three Otostegia species (O. aucheri, O. michauxii, and O. persica) collected from different localities across Iran. These localities are mostly situated in southern Iran, primarily in the Sistan and Baluchestan Province. Morphological divergence was assessed using ۲۹ characters, complemented by multivariate clustering and ordination techniques for both morphological and molecular datasets. Furthermore, genetic diversity parameters were determined in all populations. Principal components analysis (PCA) was performed to identify plant height, leaf succulence and leaf margin as the primary diagnostic features driving inter-specific variation. Phenetic reconstruction via Neighbor-Joining (NJ) trees corroborated the morphological findings, effectively segregating the species into well-defined clusters. Notably, while most populations showed morphological and genetic affinities, the populations near the Sarbaz area emerged as outliers, exhibiting peak levels of polymorphism, Shannon diversity, and Nei’s genetic index. While AMOVA confirmed significant molecular differentiation among species, Mantel test results indicated a lack of isolation-by-distance (IBD), as no significant correlation was observed between genetic divergence and geographical separation.

کلیدواژه ها:

Lamiaceae ، ordination ، population ، ranking ، Sistan and Baluchestan