Skip to main content

Official Journal of the Japan Wood Research Society

Journal of Wood Science Cover Image

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


The purpose of this research was to analyze the karyotype of the interspecific fusants of twoPleurotus species. Auxotrophic mutants derived from the cultivated strain ofP. ostreatus andP. cornucopiae were used. Protoplasts were fused electrically, and the fusants were selected under auxotrophic complementation. Esterase isozyme analysis showed that several fusants had isozyme bands originating from both parental strains, and others had unilateral isozyme bands. The fusant that had expressed isozyme bands of both parental strains showed chromosomal DNA bands of both of the parental strains in pulsedfield gel electrophoresis analysis. Despite the above results, the chromosomal composition of the fusants obtained by the pulsed-field gel electrophoresis did not exhibit all of the bands of both fusion parents.


  1. 1.

    Gold MR, Cheng T, Alic M (1983) Formation, fusion, and regeneration of protoplasts from wild-type and auxotrophic strains of the white rot basidiomycetePhanerochaete chrysosporium. Appl Environ Microbiol 46:260–263

    CAS  PubMed  PubMed Central  Google Scholar 

  2. 2.

    Hashiba T, Yamada M (1984) Intraspecific protoplast fusion between auxotrophic mutants ofRhizoctonia solani. Phytopathology 74:398–401

    Article  Google Scholar 

  3. 3.

    Kiguchi T, Yanagi SO (1985) Intraspecific heterokaryon and fruit body formation inCoprinus macrorhizus by protoplast fusion of auxotrophic mutants. Appl Microbiol Biotechnol 22:121–127

    CAS  Article  Google Scholar 

  4. 4.

    Ohba K, Kawasumi T, Yanagi S0 (1988) Protoplast fusion between common-B mating-type monokaryons ofCoprinus cinereus. Trans Mycol Soc Jpn 29:271–280

    Google Scholar 

  5. 5.

    Toyomasu T, Arima S, Mori K (1988) Nuclear distribution of intraspecific protoplast fusants ofCoprinus cinereus. Trans Mycol Soc Jpn 29:431–436

    Google Scholar 

  6. 6.

    Sunagawa M, Ohmasa M, Yokota S, Yosizawa N, Idei T (1991) Intraspecific protoplast fusion between auxotrophic mutants ofAuricularia polytricha. Mokuzai Gakkaishi 37:1069–1074

    Google Scholar 

  7. 7.

    Ohmasa M (1986) Intraspecific protoplast fusion ofPleurotus ostreatus using auxotrophic mutants. Jpn J Breed 36:429–433

    Article  Google Scholar 

  8. 8.

    Toyomasu T, Mori K (1987) Intra- and interspecific protoplast fusion between somePleurotus species. Agric Biol Chem 51:935–937

    Google Scholar 

  9. 9.

    Sunagawa M, Miura K, Ohmasa M, Yokota S, Yoshizawa N, Idei T (1992) Intraspecific heterokaryon formation by protoplast fusion of auxotrophic mutants ofAuricularia politricha. Mokuzai Gakkaishi 38:386–392

    CAS  Google Scholar 

  10. 10.

    Toyomasu T, Matsumoto T, Mori K (1986) Interspecific protoplast fusion betweenPleurotus ostreatus andPleurotus salmoneostramineus. Agric Biol Chem 50:223–225

    CAS  Google Scholar 

  11. 11.

    Mizutani M (1987) Cell fusion of basidiomycetes and separation of fusant (in Japanese). Bull Technol Res Inst Miyazaki Pref 32:55–58

    Google Scholar 

  12. 12.

    Toyomasu T, Mori K (1987) Fruit body formation of the fusion products obtained on interspecific protoplast fusion betweenPleurotus species. Agric Biol Chem 51:2037–2040

    CAS  Google Scholar 

  13. 13.

    Senda M, Takeda J, Abe S, Nakamura T (1979) Induction of cell fusion of plant protoplasts by electrical stimulation. Plant Cell Physiol. 20:1441–1443

    CAS  Article  Google Scholar 

  14. 14.

    Zimmermann U (1982) Electric field-mediated fusion and related electrical phenomena. Biochim Biophys Acta 694:227–277

    CAS  Article  PubMed  Google Scholar 

  15. 15.

    Saito M (1990) Studies on breeding of excellent sake yeast and fermentation by protoplast fusion (in Japanese). Bull Res Center Nagasaki Pref 5:102–106

    Google Scholar 

  16. 16.

    Saito M (1991) Breeding of excellent sake yeast by protoplast fusion (in Japanese). Bull Res Center Nagasaki Pref 8:98–103

    Google Scholar 

  17. 17.

    Ogawa K, Fujii N, Sachi K, Ichinose E, Hirabayashi T, Katabuchi I (1991) Improvement of the shochu yeast (Saccharomyces cerevisiae MK 021) by electrofusion technique (in Japanese). J Brewer Soc Jpn 86:447–452

    CAS  Article  Google Scholar 

  18. 18.

    Ushijima S, Nakadai T, Uchida K (1992) Interspecific electrofusion of protoplasts betweenAspergillus oryzae andAspergillus sojae (in Japanese). Bull Soysaurce Res Center 18:19–24

    Google Scholar 

  19. 19.

    Wostemeyer A, Teepe H, Wostemeyer J (1990) Genetic interactions in somatic inter-mating type hybrids of the zygomyceteAbsidia glauca. Curr Genet 17:163–168

    Article  Google Scholar 

  20. 20.

    Tamai Y, Miura K, Kayama T (1990) Electrical fusion of protoplasts between twoPleurotus species. Mokuzai Gakkaishi 36:487–490

    CAS  Google Scholar 

  21. 21.

    Sunagawa M (1992) Interspecific heterokaryon formation betweenAuricularia auricula-judae andAuricularia polytricha by electrical protoplast fusion. Res Bull Hokkaido Univ For 49:219–259

    Google Scholar 

  22. 22.

    Yokono T, Ohmasa M, Miura K, Kayama T (1988) Auxotrophic mutants of edible mushroomsPholiota nameko andPleurotus cornucopiae var.citrinopileatus. Mokuzai Gakkaishi 34:765–768

    Google Scholar 

  23. 23.

    Kadomatsu M (1993) Studies of geographical variations of mizunara oak (Quercus mongolia FISCH. var.grosseserrata REHD. et WILS.). Res Bull Hokkaido Univ For 40:1–48

    Google Scholar 

  24. 24.

    Tamai Y, Yokono T, Sunagawa M, Kojima Y, Miura K (1995) Separation of large DNA molecules fromPleurotus cornucopiae by pulsed-field gel electrophoresis. Mokuzai Gakkaishi 41:952–955

    CAS  Google Scholar 

  25. 25.

    Brody N, Carbon J (1989) Electrophoretic karyotype ofAspergillus nidulans. Proc Natl Acad Sci USA 86:6260–6263

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  26. 26.

    Sagawa I, Nagata Y (1992) Analysis of chromosomal DNA of mushrooms in genusPleurotus by pulse-field gel electrophoresis. J Gen Appl Microbiol 38:47–52

    CAS  Article  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to Takeshi Yokono.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Yokono, T., Tamai, Y., Azuma, T. et al. Karyotype analysis of interspecific fusants of basidiomycetes by pulsed-field gel electrophoresis. J Wood Sci 46, 480–484 (2000).

Download citation

Key words

  • Pleurotus species
  • Protoplast fusion
  • Electrophoretic karyotype
  • Chromosome
  • Mushroom