DIFFERENTIATION OF SPECIES AND STRAINS OF ENTOMOPATHOGENIC FUNGI BY RANDOM AMPLIFICATION OF POLYMORPHIC DNA (RAPD)

Polymerase chain reaction (PCR)-based technology, involving random amp lification of polymorphic DNA (RAPD), was used to assess the genomic v ariability between 24 isolates of deuteromycetous fungi (Metarhizium a nisopliae, Metarhizium flavoviride, unidentified strains of Metarhiziu m and Beauveria bassiana) which were found to infect grasshoppers or l ocusts. M. flavoviride showed little intraspecific variability in PCR- amplified fragments when compared to M. anisopliae. The high level of variability in PCR-amplified fragments contained within M. anisopliae was similar to the total variability between B. bassiana, M. anisoplia e and M. flavoviride, and suggests that M. anisopliae may include a nu mber of cryptic species. Four polymorphic RAPD fragments were used to probe the genomic DNA of the various species and strains. On the basis of these probes the fungi can be grouped into M. flavoviride, M. anis opliae, or B. bassiana. According to PCR-amplified fragments, previous ly-unidentified Metarhizium strains were characterized as M. flavoviri de. There was little evidence that these fungi, all isolated from, or virulent towards, grasshoppers or locusts, showed host-selection in PC R-amplified fragments. Nor was geographical origin a criterion for com monalty based on PCR-amplified fragments. PCR-fragment-pattern polymor phisms and the construction of probes from one or more of these fragme nts may provide a useful and rapid tool for identifying species and st rains of entomopathogenic fungi.