Development of KASP molecular markers related to the fertility restoration of cytoplasmic male sterility in pepper

Cytoplasmic male sterility (CMS) and Restorer-of-fertility (Rf) breeding systems can save the cost of the production of F1 hybrid seed in crops. However, the breeding of the restorer lines is not easy and the current molecular markers related to Rf gene is not very versatile because of diverse genes regulating the restoration. In this study, 11 SNPs in the previous Rf gene mapping region near the 3' end of chromosome 6 of pepper were used to develop the competitive allele-specific PCR (KASP) molecular markers. The results showed that KS23 was proposed to relate to the Rf genes with the restoring genotype A/A and the maintaining genotype G/G. There were 91.6% in consistency for KS23 between the genotyping results in F2 individuals. In addition, the accuracy of KS23 achieved 100% among six restorer lines and 67.8% among 44 inbred lines in universalities, respectively. These results provided an efficient and labor saving KASP marker related to Rf, which will be beneficial for the breeding of restorer lines and accelerate the utility of CMS/Rf system in the production of F1 hybrid seed in pepper.