PATHOGENESIS OF MYCOGONE PERNICIOSA CAUSAL AGENT OF WET BUBBLE OF WHITE BUTTON MUSHROOM (AGARICUS BISPORUS) IN IRAN

Mycogone perniciosa, causes wet bubble disease of Agaricus bisporus, is very contagious and results in severe crop losses. The Pathogenesis of wet bubble disease (W.B.D) and structural change occuring during this mycotic infection of A. bisporus are presented from a morphologists point of view. By the use of light and scanning electron microscopy the mode of a parasitic fungus interactions with host tissue were studied. Result of these studies showed that the pathogen adheres to and penetrates the host during any stage of fruit body development. The host hyphae dediffrentiation process and an excessive, nodular, reactive or hyper plastic proliferation usually occur. Exudation of accumulated extracellular fluid results in a tear-drop phenomenon (hence wet bubble). When young primordia are infected, tumorus fungal masses are formed and no sings of cell differentiation and organogenesis can be found. The mycoparasite itself seemed not to be influenced by the change of the host tissue, and caused cytological differences of the host and finally occure lytic phenomenon.