Evaluation of some Tomato Genotypes for Nematode Resistance and Detection of the Mi-1.2 Resistance Gene

Response of fourteen tomato genotypesfrom different geographical regions to root-knot nematodes (RKN; Meloidogyne spp .) was evaluated for two seasons under greenhouse conditions. Two PCR-based markers (Mi-23 and REX-1) were used the detection RKN resistance gene (Mi-1.2) in tested genotypes. The results showed a wide variation among genotypes their responses RKNs. Highly significant differences observed gall index egg masses per root system. Based on nematode bioassay, genotype Strain B F1 highly resistant ranked top Floradade VF145-B resistant, Castlerock, Peto86 Qaha moderately Super strain B, E115, Marmande, M82 Edkawy susceptible, E37, E40 Giza-80 susceptible RKN. Molecular analysis with Mi23 REX-1 indicated heterozygous state (Mi/mi) Mi-1.2 F1; meanwhile, remaining displayed homozygous recessive (mi/mi). These finding suggested that could be develop new cultivars through breeding programs. In addition, identified present study as (mi/mi) considered or may possess other genes controlling resistance. However, further studies are still needed determine these control RKNs tomatoes.