Investigation of Genetic Polymorphism in Selected Thyme (Thymus vulgaris L.) Accessions Using SCoT Molecular Markers

Identifying plant species and evaluating their variation should not be based solely on morphological characteristics. Such studies should be expanded through biochemical and DNA analyses. In this context, the aim of our study is to reveal the genetic diversity of some thyme (Thymus) samples naturally growing in the flora of Divriği district of Sivas province, and to contribute to the sustainable conservation of natural resources as well as to determine their agricultural utilization potential. Additionally, this study aims to explore the use of SCoT (Start Codon Targeted) markers in evaluating the diversity among different thyme genotypes. The plants were collected from their natural habitats, and DNA was extracted from fresh leaves using the CTAB method. A total of 36 SCoT markers were screened in the samples and the 14 most polymorphic markers were selected for analysis. In this study, a total of 169 bands were obtained from the 14 SCoT primers used to determine the genetic relationships among the thyme samples. Among these, 141 bands were polymorphic, resulting in a polymorphism rate of 83.43%. The data obtained allowed for the construction of a dendrogram grouping the analyzed ecotypes according to their similarity indices. According to the UPGMA dendrogram and the correlation matrix generated from the SCoT molecular data, the lowest similarity (0.326) was observed between samples G12 and G17, while the highest similarity (0.854) was found between G8 and G10. As a result, it was demonstrated that evaluating variation in Thymus species and establishing similarity indices using SCoT markers is possible, providing a solid basis for advanced molecular genetic analyses.