| 359 strains of bacteria were isolated from the non-nematodes soil, the plantparasiticnematodes disease soil and nematodes deterioration soil. Their antaganistic abilities tothe second stage juvenile (J2) of Meloidogyne incognita (Kofoid and White, 1919)Chitwood, 1949 were tested. Among them, cell suspension of 9 strains caused more than80.00% mortality to the second stage juvenile of M. incognita in vitro test after 48 hourstreatment. Fermentation filtrate of these 9 strains also showed strong nematicidalactivity to the second stage juvenile of M. incognita, ferment filtrates of 8 strains hadmore than 80% revised mortality to J2 after 48 hours, and fermentation filtrate ofstrain 17, 119, 155, 333 showed stronger nematicidal activity than their cell suspension.Through the potted experiments of tomato in greenhouse, the better strains wereselected. The results of control test showed that these strains could reduce thepopulation of the root-knot nematode in soil and suppress the formation of the galls, thecontrol efficiency of strain 119, 333, 335 were 57.75%, 57.82%, 53.92% after 30 days,and 55.88%, 44.09% and 38.10% respectively after 60 days, the stain 119 was morestabile compared to other stains. These 9 strains could also promote the growth oftomato plant too, stain 333 showed best growth promoting, plant height and weight were43.00 cm and 11.17g respectively, and were increased by 37.25% and 76.46% comparedto those of CK. Followed by stain 119, plant height and weight were 42.00 cm and 11.00g, were increased by 34.06% and73.78% compared to those of CK. However, thesestrains applied in combination did not provide significant disease suppression comparedto applied individually, but could significantly promote the growth of tomato plant. 119and 333 were classified as Bacillus megaterium, based on analyzing their morphological,Physiological-biochemical testing and 16S rDNA sequences.
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