Reaction to phytotoxins in a potato population derived from mesophyll protoplasts

Abstract

Alternaria solani, the causal agent of early blight disease in potato, produces 2 host-specific, lipidlike toxins in culture. Both compounds are required in the leaf bioassay for the elicitation of typical early blight symptoms, but the compounds are individually inactive. The procedures for the preparation of both compounds are outlined. These compounds can be used effectively to select for toxin-insensitive and sensitive clones of a ''Russet Burbank'' potato cultivar regenerated from single mesophyll protoplasts. Both sensitivity and insensitivity to the toxins in these clones are well correlated with susceptibility and resistance to A. solani. Potato clones produced by somatic cell regeneration techniques maintain their reaction type to these fungal toxins for at least 2 generations of vegetative propagation.