Novel primers developed from mitochondrial intergenic spacers are useful for multi-locus sequence typing of Fusarium oxysporum strains

The Fusarium oxysporum species complex causes serious vascular diseases of a wide range of crops. In an effort to locate new highly variable regions for multi-locus sequence typing (MLST) of Fusarium oxysporum populations, mitochondrial intergenic regions were targeted. Five regions were amplified and sequenced from five randomly selected isolates. For these isolates, all regions contained at least as many variable sites as the mitochondrial ribosomal RNA small subunit region commonly used in MLST. Most regions contained short indels; however, 80–120 base indels were present in the nad5-arg2 intergenic region. Only the nad5-arg2 region was found to be more variable than the single copy nuclear translation elongation factor (1α) gene introns. The nad5-arg2 region is likely to be a useful inclusion in MLST of Fusarium oxysporum populations.