Host–parasite interaction between cultivated mushroom,Agaricus bisporushybrid strain Sylvan A15, and the mycoparasiteVerticillium fungicola, a causal agent of dry bubble disease

Abstract

Verticillium fungicola is one of the most economically significant pathogens of the cultivated mushroom Agaricus bisporus throughout the world. A. bisporus basidiomes are reported to be more susceptible to infection by V. Fungicola than the vegetative mycelium. V. Fungicola spores were also reported to be dependent on A. bisporus mycelium. Transmission and scanning electron microscopy were used to investigate the host-pathogen interactions at the mycelial and sporophore stages of A. bisporus. The transmission electron micrographs showed that the V. Fungicola mycelium grows very close to the A. bisporus mycelium. There were no specialised penetration structures or any evidence of direct penetration of the pathogen in the host tissue. The scanning electron micrograph of the necrotic tissue of the diseased mushroom shows clusters of phialoconidia and hyphae of the pathogen in large numbers.