Bacterial speck caused by Pseudomonas syringae pv. tomato (Okabe) Young et al. (P.s.t.) is of economic importance to many countries producing tomatoes. Our studies to date show only race O is spread in Bulgaria.
A collection of 39 Lycopersicon species have been tested for susceptibility to race O of Pseudomonas syringae pv. tomato. The plants without visible symptoms are defined as resistant. Three groups of accessions are differentiated according to their reaction to inoculation with race O of Pseudomonas syringae pv. tomato by the vacuum-infiltration method. The groups are:
1. Resistance species - these include: L. chilense LA 456, LA 460 and LA 164; L. peruvianum PI 128654 and PI 128659; L. peruvianum var. humifusum LA 2151; L. peruvianum var. glandulosum LA 2157; L. glandulosum LA 2158; L. hirsutum f. glabratum LA 407; L. pimpinellifolium PI 126444; L. esculentum sp. galenii. The plants are symptomless. The bacterium does not grow on them as an epiphyte. HR is observed 18 hr after injection.
2. Species of low susceptibility - these include L. chilense LA 130; L. peruvianum PI 128652; L. peruvianum var. humifusum PI 127828, PI 127829 and PI 129182; L. hirsutum LA 386; L. humboldtii; L. chemielevskii LA 1399; L. pimpinellifolium PI 126925; L. minutum LA 915. Individual plants are healthy and symptomless but the bacterium grows as an epiphyte on them. The remaining plants have 1 to 8 spots typical of bacterial speck. HR is low, manifested after 36 hr.
3. Highly susceptible - the disease is strongly manifested, the plants show symptoms typical of bacterial speck - necrosis on the neuration, leaf stems and stalks.