VII International Scientific Agriculture Symposium, Jahorina- Saraybosna, Bosnia And Herzegovina, 6 - 09 October 2016, vol.1, no.1, pp.12, (Summary Text)
Tomato is under attack by many bacteria, fungi and viruses. Tomato bacterial canker and wilting disease caused by bacterial Clavibacter michiganensis subsp. michiganensis (Cmm) pathogen is a serious infectious disease and resulting in devastating losses. Control of bacterial canker is difficult and relies on cultural practices and defense mechanisms. No effective resistant tomato cultivars are registered against the bacterial disease. This study aims to identify genetically resistant tomato cultivars using a chemical mutagen on susceptible tomato seeds and characterize resistance against the bacterial canker. M3-9 and M3-15 tomato mutants were obtained in pathogenicity tests against virulent Cmm2 isolate. The M3-9 and M3-15 have elevated chlorogenic acid and rutin hydrate levels compared to susceptible original plants. When the two mutants were crossed with a susceptible tomato variety, they produced F1 and F2 plants where 3 susceptible : 1 resistant plants were identified to the Cmm2 indicating that resistance inherited by recessive single gene. The resistant mutants were also crossed with each others, their F1 plants were also susceptible to the Cmm2 pathogen revealing M3-9 plant’s resistance is different from M3-15 mutant’s resistance. The M3-9 and M3-15 resistant plants further analyzed in real time PCR whether they produce pathogenesis related gene 1 (PR1) to Cmm2. PR1 gene transcript accumulated 4-6 times higher in M3-9 and M3-15 mutant plants than susceptible original parent in response to the virulent Cmm2 at 24 hours post inoculation. The PR1 transcript accumulation was rapidly and strongly increased from 0 to 72 hpi in response to Cmm2 in resistant mutant plants. These results are consistent with PR1 gene playing a role in plant disease resistance responses under resistant loci against the bacterial canker.
Keywords: Tomato, Bacterial canker, Resistance, Time course