Induced resistance of tomato plants to Clavibacter michiganensis subsp. michiganensis
In Germany experiments were carried out to induce resistance to Clavibacter michiganensis subsp. michiganensis (EPPO A2 organism) in tomato plants.
Young tomato plants were inoculated with a non-pathogenic strain of C. m. subsp. michiganensis which produces the wilting toxin. A subsequent inoculation with a pathogenic strain of the pathogen did not result in the expression of symptoms or in the expression of mild symptoms.
The time factor and the place of inoculation played an important role in the process. With an inoculation of the non-pathogenic strain into the root of the seedlings and the inoculation of the pathogenic into the shoot a time difference of 14 days between the first and the second inoculation were necessary to obtain a resistant plant. If both inoculations were carried out into the roots, the plant became resistant to the pathogenic strain within one day.
Sources
Griesbach, E.; Krämer, I. (1992) Induktion einer Resistenz gegen Clavibacter michiganensis subsp. michiganensis in Tomatenpflanzen durch Prämunisierung mit einem apathogenen Stamm des Erregers.
48. Deutsche Pflanzenschutztagung, Göttingen, 1992-10-05/08