The study evaluated the resistance of 11 tomato lines and cultivare to bacterial canker caused by Clavibacter michiganensis subsp. michiganensis (Cmm). Plants were inoculated with Cmm strain 1203 by injection of a bacterial suspension. Symptoms were assessed after 4 weeks using a 4-point scale with calculation of the Disease Index (DI), and a threshold of DI < 2,5 points was used to distinguish samples with partial resistance. All genotypes exhibited symptoms; however, symptom severity varied substantially. The lowest DI values were recorded for lines Cm VF 232 (1,6 points) and IRAT L3 (1,9 points), and moderate resistance was observed for line Heinz 2990 (2,3 points). The control cultivar Belyi Naliv 241 was highly susceptible (3,6 points). The obtained data confirm genetic variability in resistance and identify promising donors for breeding tomato resistance to bacterial canker.
Nguyen et al. (Thu,) studied this question.