Filamentous and polyhedral virus-like particles in Boletus edulis

Abstract

In the north-east and east of the Netherlands a disease of Boletus edulis was noticed. Symptoms are described. The name 'little-cap disease' is proposed. In all cell-free preparations made from diseased, but also from healthy carpophores polyhedral virus-like particles about 33 nm and 42 nm in diameter were observed, the 33 nm particles prevailing. Occasionally a few polyheral particles of about 28 nm were isolated from healthy and diseased carpophores. Some healthy and diseased mushroom samples yielded filamentous virus-like particles about 500 nm long and 13 nm wide, with an axial canal. To our knowledge no other filamentous virus-like particles have been isolated from fungi so far. The role of the virus-like particles in B. edulis and the cause of 'little-cap disease' are still unknown. © 1975 Koninklijke Nederlandse Planteziektenkundige Vereniging.