Molecular characterization of markers linked to Tomato spotted wilt virus and Tomato mosaic virus resistance loci in tomato

Abstract

The Tomato spotted wilt virus (TSWV) and Tomato mosaic virus (ToMV) are among the most common viral diseases that negatively affect the tomato crop. The use of tomato genotypes containing virus resistance genes is considered the best method for virus control. In this study, attempts were made to identify the Sw- 5 and Sw-5b as well as Tm-1 and Tm-2 and its allele Tm-2 2 loci known to influence resistance to the TSWV and ToMV, respectively, in 19 tomato genotypes using molecular markers. In this work, 18 tomato genotypes were found to be resistant to the TSWV. These lines have dominant alleles with homozygous or heterozygous Sw5 or Sw5b or both. Also, seven lines were resistant to the ToMV, which have dominant or recessive alleles for Tm-1 or Tm-2 or Tm-2 2 or tm-2 2 , separately or mixed. In general, phenotypic results were highly matched with genotypic data, but gene-based markers displayed clearer results than biological tests; e.g., the presence of dominant and recessive alleles of the resistance gene can be identified readily in tomato genotypes. Therefore, the originality of this work is the discovery of donor parents for developing tomato genotypes resistant to both the TSWV and ToMV in tomato breeding programs or the genetic improvement of Solanum lycopersicum L. lines with pyramided genes for pathogen resistance by marker-assisted selection.