Molecular Markers for Tm-2 Alleles of Tomato Mosaic Virus Resistance in Tomato

Tomato mosaic virus (ToMV) is one of the most infectious virus diseases in tomato (Solanum lycopersicum L). The practical and effective method of controlling this disease is through genetic control by using major resistance genes. So far, three genes Tm-1, Tm-2 and Tm-22 conferring resistance to ToMV have been reported and utilized in tomato culti-var development. Marker assisted selection (MAS) has become very important and useful tool in selection of ToMV re-sistant tomato lines or hybrids. The objective of this research was to identify allele-specific PCR-based, cleaved ampli-fied polymorphic sequence (CAPS), and allele-derived single nucleotide polymorphism (SNP) markers for Tm-2 loci. Four allele-specific PCR-based markers were identified: one for Tm-2, one for Tm-22, and two for the susceptible allele tm-2. Three allele-derived CAPS markers were identified, which can identify and distinguish three alleles, tm-2, Tm-2 and Tm-22 in tomato germplasm. Three SNP markers were developed specific for Tm-2 locus. These markers will pro-vide breeders with a tool in selection of Tm-2 and Tm-22 resistance genes in tomato breeding program.