This fruit body was 20 mm in cap size when infected with spore suspension of Mycogone perniciosa . Wet and erosive surfaces of the fungi are the source of aleuriospores. Megaselia halterata . Polymorphic hyphal cells, which are gigantic in size, occur during the development of WBD of A. bisporus. Many hyphal segments are transformed into giant, atypical cells.
All cell organelles are hypertrophic.
When infection occurs before organogenesis, no organs such as pileus, stipe, lamellae can develop. The resulting large, irregular, fungal lump may only be designated as a tumorous growth. Focal cell wall thickening may be a defence mechanism of the host. Mitochondria proliferate and form long chains and rings. Experiments were also repeated with a diluted spore suspension containing less than 100 aleuriospores in one drop.