RAPD characterization of Fusarium oxysporum isolates pathogenic on Argyranthemum frutescens L.

The random amplified polymorphic DNA (RAPD) technique was used to analyse total genomic DNA of 10 isolates of a new Fusarium oxysporum pathogenic on Argyranthemum frutescens (Paris daisy), by comparing them with representatives of the formae speciales basilici , chrysanthemi , cyclaminis , dianthi , gladioli , lilii , lycopersici , melonis , pisi , radicis-lycopersici , tracheiphilum , and a non-pathogenic isolate of F. oxysporum . A close genetic relatedness was observed among most of the new isolates from A. frutescens . These isolates also shared RAPD markers with the tested representatives of the forma specialis chrysanthemi . A single isolate among those tested from diseased A. frutescens was placed in a different cluster, which included representative isolates of forma specialis tracheiphilum . All the new isolates from A. frutescens , with the exception of the single divergent one, could be identified by their characteristic amplification profile, using selected random primers. A rapid protocol for DNA extraction directly from fungal colonies grown on Fusarium selective medium allowed the complete analysis in less than 4 h.