ABSTRACT
Many filamentous fungi are endowed with natural ability to generate genetic variation via chromosomal crossing over and other sexual cycle events. In the laboratory, a large number of filamentous have been transformed using molecular genetic methods. The majority of such transformation procedures used with filamentous fungi are dependent on cell membrane permeability. Procedures utilizing both polyethylene glycol and electroporation need formation of protoplasts or osmotically sensitive cells of the recipient in order to achieve transformation. Methods based on Agrobacterium tumefaciens-rr\e6\a\e6 DNA transfer are also used with filamentous fungi. Several fungal species have been transformed using biolistic approaches, especially microprojectile bombardment techniques. The list includes a large number of saprophytes and pathogens (Bailey et al. 1993; Chaure et al. 2000; Fincham, 1989; Talbot et al. 2002). Some of the ECM fungi such as Lacearía bicolor, Paxillus involutus (Bills et al. 1995, 1998; Martin et al. 1994) and AM fungi such as Gigaspora rosea (Forbes et al. 1998; Harrier and Millam, 2001) have also been transformed using biolistic approaches.
