A method is described for identifying strains of Metarhizium
suitable for use in field experiments. It involves the restriction
endonuclease digestion of a PCR product derived from the Pr1 protease gene
and the analysis of the fragments by electrophoresis.
Using this technique, 40 Metarhizium strains produced 15 different
profile
types and were clustered into four groups. Correlation
between the profile of restriction fragments and geographic origin was
observed for certain groups of strains. This PCR strategy
allowed the identification of fungal strains, using as samples spores
scraped from the surface of single insects killed by the fungus or
single whole dead insects with external mycelium. The sequence of the
Pr1 PCR product from two strains revealed that Pr1 gene
has at least three introns.