Vascular wilt of basil in Australia

Fusarium wilt of basil, caused by Fusarium oxysporum f. sp. basilici, occurs worldwide but has not been officially recorded in Australia. Fourteen isolates of F. oxysporum were collected from diseased basil from a number of locations in Australia. A PCR diagnostic test previously shown to react only with isolates of F. oxysporum f. sp. basilici was used to identify the isolates and Koch’s postulates were performed for a subset of isolates to confirm pathogenicity. Two techniques, vegetative compatibility grouping and DNA fingerprinting using enterobacterial repetitive intergenic consensus (ERIC) targeted primers, were used to analyse all isolates. Diagnostic PCR confirmed that 11 of the isolates were F. oxysporum f. sp. basilici and they were shown to belong to a single VCG and to have a single ERIC profile, indicating that the population is essentially clonal. This is the first report of this pathogen in Australia.