Determination of genetic diversity in some capsicum species using peroxidase gene markers

Capsicum is thought as one of the most diverse and significant genera due to its varied uses in different parts of the world. In Turkey, a broad and phenotypically diverse pepper germplasm collection has been traditionally used by local producers throughout the country. In this study, we worked with a total of 71 pepper genotypes from different locations of Turkey to investigate the level of their diversity by using the peroxidase gene polymorphism (POGP) markers to reveal their population structure. For this purpose, 14 peroxidase primer pairs were used. They produced 139 bands (mean=9.9 bands/primer), of which ~85.6% were polymorphic in the all germplasm collection. Polymorphism information content (PIC) ranged between 0.48 and 0.97 with an average of 0.75. Using three clustering methods (unweighted pair-group method with arithmetic means, principal coordinate analysis, and STRUCTURE) revealed a clear separation of all the C. annuum accessions from C. frutescens and C. chinense accessions in our study. Clusters did not establish an association between the accessions and their geographical origin. This is the first study exploring the population structure through the genetic diversity of Turkish peppers from different regions of the country based on the peroxidase gene markers. We believe that the results of this study will provide a basis for the development of new and improved pepper varieties in Turkey and the world.