Use of random amplified polymorphic DNA (RAPD) for detection of genetic variation and proof of the heterothallic mating system in Hypoxylon mediterraneum

The efficiency of RAPD analysis in the evaluation of genetic variability in Hypoxylon mediterraneum has been tested on 49 monoascospore isolates of th e fungus from different localities. A large genetic variability was detecte d within single stromata and among monoascospore isolates in a restricted a rea. The large variability in restricted populations can be explained by th e heterothallic mating system and the life cycle of the fungus and its ecol ogical adaptations. RAPD markers can discriminate monoascospore isolates bo th in the single stromata and among stromata. The application of RAPD marke rs for epidemiological studies is discussed.