ABSTRACT
Gene technological breeding, including the protoplast fusion technique, is rapidly progressing as new genetic breeding methods in place of anastomosis. The protoplast fusion technique has now become a very useful tool in the genetic breeding of true fungi, such as in the fields of brewing and fermentation technology. The process of breeding by protoplast fusion is as follows: incorporation of a genetic marker (into parental strains), protoplast formation, induction of protoplast fusion, regeneration of fusion products and heterokaryon formation, diploidization from the heterokaryon, recombinant formation from diploids, and genetic analysis. From a dipoid strain obtained from intraspecific hybridization of A. awamori var. kawachi by treatment with benomyl, we were able to obtain single and double auxotrophic and prototrophic strains. Interspecific hybridization between these fungi was brought about by protoplast fusion in the presence of 35% polyethylene glycol as a fusogen.
