EVALUATION OF RHIZOBACTERIA FOR ANTAGONISTIC ACTIVITY AGAINST ROOT-KNOT NEMATODE, Meloidogyne javanica ON CUCUMBER, UNDER GREENHOUSE CONDITION

The effect of rhizosphere bacteria on root-knot nematode (Meloidogyne javanica) was investigated on cucumber under greenhouse conditions. The bacteria were isolated from infected cucumber, tomato and cedar from Garmsar, Marvdasht and Shiraz, as well as cedar, grass and wheat from Bajgah. After sampling, purification, rearing on root of tomato and identification of M. javanica species, the effect of 40 isolates were investigated on hatching (in 3 and 8 days after bacteria inoculation) and the activity of second stage juvenile of the nematode (24, 48 and 72 hours after adding bacteria) in vitro condition. Then 10 best isolates were used on cucumber (Super Amelia) in greenhouse. All isolates increased growth of the plants and decreased the indices of the nematode. Pseudomonas fluorescens CHAO was the most effective isolate and caused about 55.31% and 55.72% reduction in the gall number and also respectively 91.13% and 82.84% reduction in reproduction factor (RF) in the first and second experiments. The second one was an isolate of Pantoea sp. Additionally the effects of P. fluorescens, Bacillus subtilis and Pantoea sp. on the infected cucumber (Super Amelia) to M. javanica, as single application and in combination was tested. The results indicated that using combination of three bacteria are more effective than application of single and combination of two bacteria on increasing growth of plant and reducing indices of the nematode.