Induced systemic resistance of selected endophytic bacteria against Meloidogyne incognita on tomato.

In previous work, the four endophytic bacteria Pantoea agglomerans MK-29, Cedeca davisae MK-30, Enterobacter spp. MK-42 and Pseudomonas putida MT-19 were shown to reduce Meloidogyne incognita on tomato when applied as a seed treatment and/or soil drench. The objective of this work was to study these bacteria for their potential to induce systemic resistance against root knot nematodes on tomato. To guarantee spatial separation between inducing agent and pathogen a split-root system was chosen and inoculated with the bacteria as a drench application on one side of the root system and 6 days later with 2000 juveniles of Meloidogyne incognita on the other side of the split-root system. The experiment was maintained in the greenhouse and repeated once. The penetration rate of juveniles as well as the total number of root-knot galls and egg masses was recorded. Treatment with all four bacteria significantly reduced juvenile penetration and the number of root-knot galls when compared with the non-treated control. Induced systemic resistance is considered a possible control mechanism of endophytic bacteria against root-knot nematodes.