DEVELOPMENT OF SCAR MARKERS AND PCR ASSAY FOR FUSARIUM OXYSPORUM f sp MELONIS RACE 2SPECIFIC DETECTION
L. Luongo, S. Vitale, A. Haegi, A. Belisario
Fusarium oxysporum f. sp. melonis (FOM) is the cause of vascular wilting of melon, the most severe infectious disease of this cucurbit. Four races (0, 1, 2, and 1,2) of FOM have been identified all of which occur in Italy. A PCR assay based on race-specific SCAR markers for FOM race 2 identification was developed which proved specific, sensitive, and reliable, regardless of the origin of isolates. SCAR primers developed from RAPD markers were able to identify unambiguously FOM race 2, that causes symptoms similar to those elicited by the other FOM races. These are morphologically indistinguishable from one another and from the other formae speciales of the same fungus. The specificity of these primers, which did not amplify the most common melon pathogens, makes them a reliable tool for diagnosis. This finding may have additional practical applications in the epidemiology and management of Fusarium wilt of melon caused by this race in areas where the disease is widespread.