2018 ASHS Annual Conference

Viral diseases severely limit the production of vegetable crops, and Cucumber mosaic virus (CMV) is one of the most recurrent viruses in chili pepper (Capsicum annuum L.) worldwide. An extensive host range and diverse pathogen strains make CMV control difficult in the field hence CMV-resistant pepper variety is required. In this study, we developed SNP markers linked to the QTLs for CMV_P1 resistance through genotype-by-sequencing (GBS) and high-resolution melting (HRM) analyses. The single seed descent (SSD) F₃ segregating population obtained from a cross between a resistant line ‘A1’ and a susceptible line ‘2602’ was assessed for CMV_P1 resistance. The individuals were inoculated with CMV_P1 strain, and 30 days after inoculation the phenotype was confirmed by RT-PCR. A total of 96 individuals including 48 resistant and 48 susceptible plants were selected for GBS analysis. QTL analysis with composite interval mapping (CIM) exhibited two QTLs, cmvP1-5.1 and cmvP1-10.1, resistant to CMV_P1, detected on chromosome 5 and 10, respectively. SNP markers linked to these two QTLs were developed by performing HRM analysis. For validity test of the HRM markers, an SSD F₅ population of the same cross was used and evaluated. In chromosome 5, a total of 20 markers were developed and mapped, and QTL analysis revealed a marker SNP07838 with LOD value 7.0 strongly linked to CMV_P1 resistance. In addition, a total of 15 markers on chromosome 10 were developed, and a marker SNP13607 with LOD value 3.2 was detected by QTL analysis. These two SNP markers are expected to be useful for pepper breeding with CMV_P1 resistance.