DETECTION OF MOLECULAR VARIATION IN THE INSECT PATHOGENIC FUNGUS METARHIZIUM USING RAPD-PCR

DNA polymorphism among isolates of the insect pathogenic fungus Metarh izium anisopliae and M. flavoviride was investigated by RAPD-PCR. DNA fragments of between 0.3 and 2.7 kb were obtained using eight 10-mer P CR primers of arbitrary nucleotide sequence, and each isolate differed in the size and number of RAPD products, indicating considerable poly morphism. Isolate-specific RAPD fingerprints were used to calculate re lative genetic similarity; this differentiated isolates into two major groups, separating nine of the ten isolates of M. anisopliae from the two of M. flavoviride. However, an Australian M. isolated from an Ort hopteran host exhibited a higher degree of genetic similarity to the M . flavoviride group. M. anisopliae isolates were further segregated in to three subgroups which were loosely related to their geographical or igins, although considerable polymorphism was observed within these gr oups. There was no apparent association between genotype and original insect host.