THE USE OF AFLP FINGERPRINTING FOR THE DETECTION OF GENETIC-VARIATIONIN FUNGI

A new PCR-based technique for the detection of inter- and intraspecifi c genetic variation has been tested on isolates of the fungal phytopat hogens Cladosporium fulvum and Pyrenopeziza brassicae. The method is b ased on the selective PCR amplification of restriction fragments from digests of genomic DNA. We show that the technique is very efficient a t detecting polymorphisms, even in species where very little variation could previously be found by RFLP analysis. 21 primer combinations we re used on four isolates of P. brassicae, detecting a total of 162 pol ymorphisms (mean = 4 . 1 polymorphisms per primer combination per pair of isolates). Four primer combinations were used on eight isolates of C. fulvum, detecting a total of 32 polymorphisms (mean = 3 . 3 polymo rphisms per primer combination per pair of isolates). Primer combinati ons varied in their ability to detect variation, ranging from 0 to 24 polymorphisms between P. brassicae isolates and 0 to 10 polymorphisms between C. fulvum isolates. AFLP fingerprints were highly reproducible and have great potential as a tool for evaluating genetic diversity o f fungal pathogens.