Phylogenetic relationships and genetic diversity of landrace populations of thyme (Thymus spp.) of Iran using AFLP markers and GC-MS

In this study, the genetic diversity of Thymus collected from Gilan province in Northern Iran was evaluated using AFLP markers and chemical compositions of the essential oil derived from GC/MS. Polymorphic information content varied from 0.26 to 0.37 with an average of 0.31. Estimating Nei's gene diversity (H) and Shannon's information index (I) showed that the highest and lowest genetic variation was related to markers E32-M93 (H = 0.32 and I = 0.47) and E33-M39 (H = 0.19 and I = 0.32), respectively. Cluster analysis classified the studied populations in four major groups. Furthermore, essential oil of the studied populations was extracted by hydro-distillation and the chemical compositions of essential oil were identified by capillary GC and GC/MS. In total, 37 compounds were identified in the essential oil of all populations which ranged from 42.786 to 93.337%. Also, the populations of each species had similar chemical compositions. Results of cluster analysis of the chemical compositions grouped the studied populations into four groups. Generally, the observed variation in AFLP markers was associated with the geographical variation.