Sensitivity among species of Solanaceae to AAL toxins produced by Alternaria alternata f.sp. lycopersici

The necrotrophic fungus Alternaria alternata f.sp. lycopersici produces AAL toxins that cause necrosis in tomato tissues with high specificity. Resistance or susceptibility of tomato to the fungus and insensitivity or sensitivity to AAL toxins are determined by a single locus, Asc. In order to investigate further the specificity of the host–fungus interaction, 200 species of Solanaceae were tested for their sensitivity to AAL toxins TA and TB. Twenty‐five species were found to be sensitive to AAL toxins at a concentration of (0·2 µm) used for distinguishing sensitive and insensitive tomato plants. Three species were as sensitive as the sensitive tomato line, indicating that AAL toxins effectively act on a broader range of plant species within the Solanaceae.