High frequency gene conversion among benomyl resistant transformants in the entomopathogenic fungus Metarhizium anisopliae

Three different methods, (i) PEG, (ii) electroporation and (iii) biolistic, were employed to transform Metarhizium anisopliae using benomyl resistance as a selectable marker. Transformation frequencies and mitotic stability varied for each method, from 0.8 to 6.9 transformants mu g(-1) of DNA and 46%, respectively, by the PEG method; 1.3 to 1.8 transformants mu g(-1) of DNA and 67% by electroporation; and 32 to 201 transformants mu g(-1) of DNA and 90% by biolistic. We demonstrate by PCR that 60% of the transformants were generated by gene conversion.