ABSTRACT
This chapter discusses the consequences of using the methods of ‘protoplast fusion and culture in hybridization experiments with Penicillium. The viability and segregation properties of various hybrids have been investigated, together with some aspects of their biochemical activities. The ability to produce hybrids between fungal species originates from the development of the improved methods for protoplast fusion and culture. The viability of hybrids produced after protoplast fusion may be influenced by several factors arising from their genetic and biochemical compatibility. Species used in interspecies crosses showed differences in several biochemical features. Thus in any one pair of species used in a cross, frequently only one produced a particular metabolite and this was subsequently detected in the hybrid. Because penicillin is industrially a very important metabolite, it is of interest to know how the ability of a strain to produce the antibiotic is affected by hybridization.
