TRANSFORMATION OF THE ENTOMOPATHOGENIC FUNGUS, METARHIZIUM FLAVOVIRIDE STRAIN CG423 TO BENOMYL RESISTANCE

Metarhizium flavoviride strain CG423 is being developed as a mycoinsec ticide against grasshoppers. This strain has been transformed to resis tance to the fungicide benomyl by a polyethylene glycol (PEG)-mediated procedure using a mutant tubulin from Neurospora crassa. Transformati on frequencies of up to 84 transformants per microgram of transforming DNA were achieved. Benomyl-resistant transformants were obtained that could tolerate greater than 30 mu g ml(-1) benomyl. Southern blot ana lysis of genomic DNA. reveals that the mechanism of genetic transforma tion of all transformants was by homologous gene replacement of the be ta-tubulin allele.