The double-resistance-breaking Tomato mosaic virus strain ToMV1-2 contains two independent single resistance-breaking domains

Tomato mosaic virus (ToMV) causes a serious loss of yield and fruit quality in tomato crops. To control ToMV, three resistance genes, Tm-1, Tm-2, and Tm-22 from wild tomato species were introduced into commercial tomato cultivars. Soon after, however, single and, rarely, double-resistance-breaking virus strains for Tm-1 and Tm-2 emerged. Sequence analysis of a Tm-1/Tm-2 double-resistance-breaking virus, designated ToMV1-2, revealed 30 nucleotide...