Rhizosphere competent Pseudomonas aeruginosa in the management of Heterodera cajani on sesame

Screening, identification and application of soil bacteria with nematicidal activity against root-knot nematode (Meloidogyne incognita) on tomato

BACKGROUND

Root-knot nematodes (Meloidogyne spp.) are soilborne pathogens that can cause great damage to and economic loss of crops globally. Owing to the high toxicity of chemicals toward humans and the environment, the use of biocontrol bacteria, a promising method for controlling root-knot nematodes, has gained attention.

RESULTS

To screen novel bacterial strains for their ability to control root-knot nematodes, 106 bacterial strains were isolated from soil. Eight of the obtained isolates exhibited satisfactory nematicidal activity against Meloidogyne incognita at 2-fold dilutions (approximately 3 × 10¹²  CFU mL^-1 ) after 12 h of exposure. Based on their physiological, biochemical and molecular (16S rRNA and gyrB gene sequences) characteristics, the eight strains were identified as Bacillus halotolerans, B. kochii, B. oceanisediminis, B. pumilus, B. toyonensis, B. cereus, Pseudomonas aeruginosa and B. pseudomycoides. In greenhouse and field experiments, the eight isolates suppressed M. incognita up to 69.96% compared to the control. Additionally, the yield of tomato increased 1.4-26.1% over that of the control.

CONCLUSION

The strains of B. halotolerans DDWA, B. kochii DDWB, B. oceanisediminis DDWC and B. pseudomycoides JNC have potential to control M. incognita, which has not been previously reported. © 2020 Society of Chemical Industry.