PIGMENT-LESS MUTANT INDUCED BY THE REGENE RATION OF PROTOPLASTS AND CELL-FUSION OF BASIDIOMYCETES

Pleurotus salmoneostramineus, which is now cultivated as an edible mus hroom in Japan, has pigment which makes the mycelia and fruiting bodie s pink in color. In our study however, a strain deficient in the pink pigment was induced in monokaryotic hypha regenerated from protoplasts . No relationship was noted between the induction frequency and the pr eparing conditions of the pigment-deficient strain, which is supposed to be a mutation expressing 1-3% of the protoplast regenerated strain. Protoplasts were prepared from monokaryotic hypha of pigment-keeping and deficient strains of P. salmoneostramineus, and of P. ostreatus an d Agrocybe cylindracea and cell fusion was carried out, using the indi vidual electrofusion method. As a result, inter-specific fusion strain s of P. salmoneostramineus and P. ostreatus were produced, but in the mycelia of a fusion strain between P. salmoneostramineus and P. ostrea tus the pinkish pigment was not observed.