ABSTRACT
Since the development of DNA-mediated transformation of Aspergillus nidulans (Ballance et al., 1983) and Neurospora crassa (Case et al., 1979), molecular methods have been successfully applied to the analysis and exploitation of many filamentous fungal species. Transformation was the critical step, since without the ability to introduce DNA into genomes little could be achieved, either academically or commercially, by the routine cloning and manipulation of individual genes. The diversification into many filamentous fungal species is because of their fundamental importance in the agricultural, chemical, and pharmaceutical industries. Plant pathogens are a considerable source of annual revenue loss and have unique experimental problems concerning the requirement for an interaction with a host. Many species do not grow in culture and molecular methods offer a way to investigate their biology (e.g., Upshall, 1986a; Rambosek and Leach, 1987; Upshall and McKnight, 1987). Recombinant DNA methods as applied to plant pathogens will be discussed in Chapter 9 of this volume.
