Volume 16 Part 1 Article 66: Agaricus Susceptibility to Verticillium fungicola

Volume 16 Part 1 Article 66
Year 2004
Title: Agaricus Susceptibility to Verticillium fungicola
Authors: M.L. Largeteau, A. Rodier, T. Rousseau, S. Juarez del Carmen, R. VĂ©die and J.M. Savoie


Dry bubble caused by Verticillium fungicola remains a major threat on mushroom (Agaricus bisporus) farms. The use of chemicals to control the disease is restricted, and resistance to available fungicides has been reported. Breeding A. bisporus for resistance to dry bubble disease is in progress. Herein, we examined several parameters affecting the assessment of mushroom strains for susceptibility to dry bubble disease. Strain susceptibility was evaluated using conventional strains of A. bisporus and a calibrated inoculum of V. fungicola. Experiments carried out at two different facilities with two commercial mushroom strains and three isolates of V. fungicola resulted in variation in disease severity that correlated to the facility (compost, environmental conditions), but not the mushroom strain or pathogen isolate. No generalized resistance to V. fungicola, Trichoderma aggressivum and Pseudomonas tolaasii was observed within a collection of wild, commercial and hybrid mushroom strains. Introduction of V. fungicola at various times after casing revealed a correlation between the fruiting stage at the time of infection and the intensity of the disease. High variation in susceptibility was observed for strains derived from two factorial crosses and a progeny. Results showed that susceptibility was under genetic control.

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