Molecular And Phenotypic Screening Of Tomato Genotypes For Resistance To Fusarium Wilt
Fusarium wilt, caused by Fusarium oxysporum fsp. lycopersici (Fol), affects tomatoes worldwide. It constitutes close to 40% yield loss of tomato in Nigeria. A feasible option is to recommend to farmers those genotypes with resistant genes to the pathogen. In this study, fifty tomato genotypes were molecularly screened with a cleaved amplified polymorphic sequence (CAPS) to identOltomato genotypes possessing the 1-2 gene, which confers resistance to Fol. The marker TAO!, previously associated with this resistance gave PCR amplification in 21 genotypes. Four homozygous resistant and 13 susceptible genotypes were identified. Four other genotypes, with unfamiliar restriction enzyme bands at around 925 and 800bp, were also observed. Phenotypic resistance test confirmed the results of molecular analysis obtained for homozygous and susceptible genotypes. The four homozygous resistant genotypes — UTC18, K-Small, Derica Opa and Oxheart - are recommended to farmers in areas endemic with vascular wilt, and also recommended as parent lines while breeding for resistance to Fusarium vascular wilt.