INTERSPECIFIC PROTOPLAST FUSION BETWEEN S OME PLEUROTUS SPECIES USINGAUXOTROPHIC MUTANTS

Interspecific protoplast fusions using auxotrophic mutants were perfor med between three Pleurotus species, that is Pleurotus ostreatus (jacq .: Fr.) Kummer, Pleurotus pulmonarius (Fr.) Quel., and Pleurotus cornu copiae (Paul.) Rolla. var. citrinopileatus (Sing.) Ohira. These auxotr ophic mutants used in this experiment were induced from monokaryotic s trains which were isolated from the monospores of each parents. They a re strains requiring methionine, leucine, and inositol respectively, f or growth on minimal medium. A clamp connection was not detected in th e hyphae of the strains obtained by protoplasts fusion in every combin ation, and whose growth rates were considerably later than those of th eir parents. However, both strains obtained by combinations between P. ostreatus and P. pulmonarius, and between P. pulmonarius and P. cornu copiae formed fruiting bodies on sawdust-wheat bran medium. These were very similar to those of P. pulmonarius in morphology. On the other h and, the strain obtained by protoplast fusion between P. ostreatus and P. cornucopiae did not form even a primordium on the sawdust-wheat br an medium.