Influence of DNA treatments on Southern blot hybridization analysis of Fusarium oxysporum F. sp lycopersici and F. sp <i>radicis-lycopersici</i> genomic DNAs

Abstract

DNA samples obtained by a non-phenol/chloroform isolation method, from three races of Fusarium oxysporum f. sp. lycopersici and f. sp. radicis-lycopersici were treated in different ways with a view to evaluating the effect of three pre-electrophoresis DNA treatments on the outcome of Southern blot hybridization analysis using a Digoxigenin (DIG)-IGS fragment probe. Results showed that where DNA material is scarce, the use of undigested (native) fungal DNA not only saved time but it also gave better hybridization signal than predigestion treatments with EcoRV restriction enzyme. Hot water digestion of DNA prior electrophoresis and hybridization gave the least satisfactory result.