Pseudomonas tolaasiiand tolaasin: comparison of symptom induction on a wide range ofAgaricus bisporusstrains

A wide range of Agaricus bisporus, including commercial, wild and hybrid strains, were tested for resistance to brown blotch disease caused by Pseudomonas tolaasii. Effects of toxin and living bacteria were compared. Wild and hybrid A. bisporus ranged in the same order from very poorly to highly susceptible whatever the inoculum type used, tolaasin or bacteria. Symptom aspects induced by both inocula were visually identical, but some differences occurred in response intensity. The data suggest that toxin is probably not the only factor involved in symptom development.