Development and validation of a user-friendly KASP marker for the Sw-5 locus in tomato

Tomato spotted wilt virus (TSWV) is a serious pathogen of tomato. The most efficient strategy for control of TSWV is the breeding of varieties resistant to the virus. In tomatoes, the Sw-5 locus controls resistance to TSWV. Molecular markers based on single nucleotide polymorphisms (SNPs) are widely used for screening in plant breeding. In the present study, we developed primers specific to the Sw-5 locus for use in Kompetitive Allele-Specific PCR (KASP) which is a novel method based on SNPs. These primers were validated in a number of tomato genotypes with different genetic backgrounds, showing that this KASP assay can be used successfully for the selection of TSWV-resistant plants in tomato breeding.