Genetic Diversity Analysis of Red Clover (Trifolium pratense L.) in Iran Using Sequence Related Amplified Polymorphism (SRAP) Markers

Progress in plant breeding requires a broad genetic basis. Knowledge of genetic diversity in cultivated species and their wild relatives is of critical importance for breeding purposes. The red clover, T. pratense,grows wildly in Iran in a vast range of habitats, mainly along the Zagros and Alborz Mountains. Despite being economically important in many other countries, information regarding the genetic diversity of this species in Iran is significantly lacking. In this study, the genetic diversity of 56 genotypes of red clover collected from Iran and one genotype of T. diffusum, used as outgroup, was evaluated using nine SRAP markers. The nine SRAP primer combinations created a total of 294 bands from DNA of 57 genotypes, from which 291 (98.9%) were polymorphic. All the measured parameters showed significantly high genetic diversity in the Iranian genepool of T. pratense with no clear geographic partitioning of genotypes. However, genotypes collected from around Tehran, Isfahan, and Kermanshah-Hamedan were loosely clustered with their co-regional genotypes. Based on the results of the STRUCTURE analysis, genotypes were genetically divided into two clusters, but these were not correlated with the eco-geographical groups. There was no correlation between genetic distance and geographic distance of genotypes. The result of this study showed value in sampling the Iranian genepool of the red clover, with the Western and the Northwestern genepools in more depth, for conservation and breeding purposes.