Development of the HybProb molecular marker for the L4 allele for marker-assisted selection of sweet pepper Capsicum spp. on the Real-Time PCR platform

Relevance. One of the conditions for creating a modern high-tech hybrid of sweet pepper is the presence of resistance to the Pepper mild mottle virus (PMMoV). This virus belongs to the genus Tobamovirus. This virus can spread through seeds, causing enormous damage to the sweet pepper crop. The main method of controlling of virus is the cultivation of Fi hybrids of pepper with genetic resistance. To date, the L4 gene is able to confer resistance to all known strains of this virus. However, there is still no reliable marker system that could be integrated into the MAS. Methods. Based on data from the NCBI, we generated a molecular diagnostic system based on hybridization probes. Validation was performed on seven pepper accessions from the world's germplasm banks. After validation, the new marker was successfully tested on 2540 plants of F2 and F3 generation. Results. Using the experimental marker system Fret4, we tested 7 reference samples of pepper germplasm with full correspondence of the melt peaks to the declared alleles of the L gene (L0/L1/L3/L4). Then, using a marker system, MAS was carried out on 10 populations of an number of 10 thousand plants to identify the L4 allele. As a result, we were able to create a highly accurate and cost-effective marker system for the most important pepper resistance gene. This marker system based on hybridization probes is easily integrated into the MAS, allowing fast and reliable determination of the L4 allele state in sweet pepper breeding to Tobamovirus.