Mutations Found in the Gene That Confer Susceptibility to the AAL-Toxin in Ancestral Tomatoes from Peru and Mexico.

Tomato susceptibility/resistance to stem canker disease caused by f. sp. and its pathogenic factor AAL-toxin is determined by the presence of the gene. Several cultivars of commercial tomato ( var. , ) are reported to have a mutation in , resulting in their susceptibility to AAL-toxin. We evaluated 119 ancestral tomato accessions including (), var. () and var. "jitomate criollo" () for AAL-toxin susceptibility. Three accessions, PER018805, PER018894, and M5-3, were susceptible to AAL-toxin. PER018894 and M5-3 had a two-nucleotide deletion (nt 854_855del) in identical to that found in cv. Aichi-first. Another mutation (nt 931_932insT) that may confer AAL-toxin susceptibility was identified in PER018805. In the phylogenetic tree based on the 18 COSII sequences, a clade (S3) is composed of , including the AAL-toxin susceptible PER018805, and . AAL-toxin susceptible PER018894 and M5-3 were in Clade S2 with cultivars. As is thought to be the ancestor of , and is an intermediate tomato between and , s with/without the mutation seem to have been inherited throughout the history of tomato domestication and breeding.