Genetic affinities of Fusarim spp. and their correlation with origin and pathogenicity

Random amplified polymorphic DNA (RAPD) analyses was used in combination with pathogenicity assays to study the taxonomic kinships among five Fusarium species. A total of 46 isolates of Fusarium spp. obtained from diseased cotton seedlings showing typical root rot and dampping-off symptoms were characterized. Of 10 primers tested, four primers produced polymorphic amplification patterns with taxon-specific bands, in addition to individual-specific bands. Genetic analysis indicated into 2 main clusters, with the minor cluster included all F. moniliforme and F. solani at the genetic similarity of GS=57.82%. The major cluster consisted of all F. oxysporum, F. avenaceum and F. chlamydosporum clustered at 71% similarity. There was no clear-cut relationship between clustering in the RAPD dendrogram, pathogenicity test and geographic origin of tested isolates. The results suggest that RAPD-PCR is a useful method for analysing genetic variation within and between Fusarium spp. (African Journal of Biotechnology: 2003 2(5): 109-113)