ABSTRACT
Breeding of edible mushrooms using the technique of spore-crossing is only applicable to intraspecific hybridization in monokaryotic strains. Thus, an alternative approach to the breeding of basidiomycetes involving protoplast fusion is now being widely adopted in order to obtain interspecific and intergeneric hybrids which produce fruit bodies of desirable quality. One of the principal advantages of protoplast fusion is hybridization between incompatible basidiomycetes. Identification of fusants obtained by protoplast fusion has generally been accomplished by nutritional complementation using auxotrophic strains. However, hybridization of auxotrophic mutants by protoplast fusion may lead to genetic imperfections. Therefore, we attempted to obtain new hybrids by using practical protoplast fusion techniques. Interspecific and intergencric fusion products were obtained from protoplast fusion between basidiomycetes such as (1) Pleurotus ostreatus SM-1 [auxotrophic (cytidine-) and monokaryotic strain] and Pleurotus cornucopiae TN-6 (monokaryotic strain), (2) P. cornucopiae TN3–1 [auxotrophic 194(leucine -) and monokaryotic strain] and Lentinus edodes MYB-1 (monokaryotic strain), (3) P. ostreatus SM-A (monokaryotic strain) and L. edodes MYB-1, and (4) P. cornucopiae TN-6 and Lyophyllum decastes (Fr.) Sing..
