Biological Control of Meloidogyne arenaria by Pasteuria penetrans

An obligate parasitic bacterium of nematode, Pasteuria penetrans 98–35 (PP), isolated from oriental melon greenhouse soil in Korea, was evaluated against root-knot nematode, Meloidogyne arenaria (MA), in tomato (Lycopersicon esculentum Mill. var. Youngkwang) and oriental melon (Cucumis melo L. var. Eunchun). Pot experiments were conducted by planting the tomato seedlings in a medium inoculated with 5,000 MA juveniles/pot (J2), J2+100,000 PP endospores/1 g medium, and J2+200,000 PP endospores/1 g medium. After 10 weeks from planting, root gall percentage in J2+100,000 and J2+200,000 PP endospores/1 g medium were significantly lower with 37.5% and 6.7%, respectively, compared with the J2 of 85%. In the second planting of tomatoes in the same pots, root gall numbers were significantly lower in PP treated pots representing 68.8 and 31.4/root in J2+100,000 and J2+200,000 PP endospores/1 g medium, respectively, compared with the J2 of 460.6/plant. In oriental melon experiment, numbers of root galls after 10 weeks from planting were significantly lower in J2+100,000 endospores/1 g medium with 32.5 compared with 64.1 and 87.5 in J2+100,000 endospores/1 g medium and the J2, respectively. However, there were no significant differences in plant growth characteristics among the treatments in the both crops.