Identification and molecular analysis of races of Fusarium oxysporum f. sp. lycopersici isolated from tomato in Baja California, Mexico

In Baja California, Fusarium oxysporum f. sp. lycopersici ( Fol ) is the causal agent of vascular wilt of tomato; however, the races present in the state remain unknown. The objective of this work was to isolate and identify Fusarium spp. and to validate a multiplex-PCR system to identify strains Fol and at the race level. Sixty symptomatic plants were collected, of which 45 isolates were obtained. When analyzed microscopically, it was confirmed that 44 corresponded to Fusarium spp. The use of the sp13 and sp23 oligonucleotide pairs that amplified the pgx4 and pg1 polygalacturonase genes, respectively, indicated the presence of Fol races 1 and 3 in the area. Sequence analysis of the elongation factor of the 1? translation (TEF1- ? ) of representative strains served to confirm its identity and the presence of Fol and F. solani in tomato plants with symptoms of vascular wilt. Finally, a RAPD analysis showed that the oligonucleotide OPA-11, generates a specific banding pattern in Fol race 1, so it could be used as a quick way to identify them.