In vitro Potency Evaluation of Pseudomonas spp. Against Root-Knot Nematode, Meloidogyne incognita

Fifteen isolates of Pseudomonas spp. were isolated from egg masses of root-knot nematode infested condusive or suppressive soils of different crops (tomato, brinjal, okra and chilli) and localities in Karnataka. A total 19 isolates of Pseudomonas spp. including four identified soil rhizosphere isolates of NBAII collections were evaluated for their nematicidal potential on juvenile mortality under in vitro conditions. In this study, second stage juveniles of Meloidogyne incognita were exposed to different concentration of bacterial culture filtrate (25, 50, 75 and 100%) up to 48 h. Two isolates of 19 Pseudomonas isolates significantly killed juveniles of M. incognita in 100% concentration of bacterial culture filtrate. Death percentage of nematode juvenile ranged from 5.5 to 83.3%. The percent mortality increased with increase in concentration of culture filtrate. Two potent Pseudomonas isolates with higher nematicidal activity were selected and identified as Pseudomonas spp. (EM-5). The NBAII isolate of GRI-ARS1was identified as Pseudomonas putida (HM439967) was found effective against plant diseases caused by soil borne fungus. The culture filtrates of Pseudomonas spp. at 100% concentration was the most effective and induced highest larval mortality of M. incognita juveniles to 83.3% after 48 hours of exposure period in EM-5 isolate followed by GRI-ARS1 to 69.44% compare to un-treated control