Evaluation of antagonistic activity of Bacillus spp. in control of tomato root-knot disease

In this research, Bacillus strains efficiency were tested to control root knot nematode, Meloidogyne javanica .One hundred and fifty strains were isolated from tomato rhizosphere. Antagonistic activity of strains on M. javanica was checked in vitro assay. Nematicidal ability of bacterial suspension of 1 × 108 cfu/ml was investigated on nematode egg and larvae with three replication using Random Complete Design. Eight strains which were successful in egg hatch prohibition, larvae mortality and also were positive in enzymatic function were selected for greenhouse experiments. Based on morphological, physiological and biochemical methods, representative isolates are belonged to Bacillus cereus (Bag2.13, N2.2 Md1.8 and Chl.2), B. licheniformis (Ma1.3 and MA1.7) and Bacillus sp. (Bag2.13, MD1.8 and MD6.5). In greenhouse tests, the most effective strains were MD6.5 and Bag2.13 that can control the disease considerably. The results indicated acceptable correlation (-0.524) among bacterial suspension, egg hatch prohibition percentage in lab and gall index in greenhouse. This is the first report of application native Bacillus strains, on tomato root knot nematode control in greenhouse condition.