Genotyping isolates of the entomopathogenic fungus beauveria bassiana by RAPD with fluorescent labels

Random amplified polymorphic DNA (RAPD) with incorporation of fluorescent deoxynucleotides was used to examine the genetic diversity among Beauveria bassiana isolates from Argentina and Brazil. High-resolution DNA fingerprints were generated on line, during polyacrylamide gel electrophoresis of amplification products, by automated laser fluorescence analysis. Each isolate displayed a distinct genotype. Cluster analysis showed a high level of variability among these genotypes. No correlation with geographical origin or host was detected. Nevertheless, a phenetic group of 80% similarity represented mainly the isolates exhibiting high virulence against the sugar cane borer, Diatraea saccharalis. Fluorescence-based RAPD fingerprints provide a useful tool for identifying entomopathogenic fungi, and this technique is specially applicable to screening many isolates in population studies. Copyright 1998 Academic Press.