Karyotype analysis of interspecific fusants of basidiomycetes by pulsed-field gel electrophoresis

The purpose of this research was to analyze the karyotype of the interspeci fic fusants of two Pleurotus species. Auxotrophic mutants derived from the cultivated strain of P. ostreatus and P. cornucopiae were used. Protoplasts were fused electrically, and the fusants were selected under auxotrophic c omplementation. Esterase isozyme analysis showed that several fusants had i sozyme bands originating from both parental strains, and others had unilate ral isozyme bands. The fusant that had expressed isozyme bands of both pare ntal strains showed chromosomal DNA bands of both of the parental strains i n pulsed-field gel electrophoresis analysis. Despite the above results, the chromosomal composition of the fusants obtained by the pulsed-field gel el ectrophoresis did not exhibit all of the bands of both fusion parents.