Evaluation of genetic diversity among and within some endemic populations of Thymus migricus Klokov & Desj.-Shost using RAPD molecular markers

In the present study, the genetic variation within and among some populations of Thymus migricus Klokov & Desj.-Shost was investigated using the RAPD markers. Twenty-one decamer RAPD primers produced 310 unique bands. RAPD analysis showed 14 monomorphic and 296 polymorphic bands in different genotypes. The number of polymorphic bands per primer varied from 5 to 20 with a mean of 14.09. Genetic distance was measured by Nei’s coefficient and cluster analysis was carried out. A dendrogram was drawn based on genetic distance data, applying the UPGMA clustering method. Analysis of molecular variance (AMOVA) was performed. According to the dendrogram, among T. migricus populations, Band and Jolfa populations had maximum differences with a distance of 0.130. Evaluation of genetic diversity within populations with an average of Nei’s gene diversity analysis and Shannon’s information index, showed that diversity within population of Jolfa (h = 0.196 & I = 0.294) was more than other populations while genetic diversity within population of Ghushchi (h = 0.139 & I = 0.209) was less than other populations. Mean of Fst and Nm indexes which show gene flow among populations, were 0.30 and 1.14, indicating a greater gene flow among five populations of T. migricus. The results of the present study showed that there was a greater level of genetic variation in the Iranian natural populations of T. migricus which could be applied for future breeding programs.