Improvement the activities of plant growth-promoting rhizobacteria in root-knot nematode Meloidogyne javanica and tomato plant growth in Wasit Province

Abstract

This study had been conducted to detect the existence and dispersal of bacteria in the agricultural area in Wasit province and the role of them in controlling root knote nematode .Two genera of bacteria Azotobacter and Pseudomonas were isolated from six locations in Wasit province which were Alsiwarah , Alnuamania , Alahrar , Alhay , Alkut and Algardhia with five isolates of Azotobacter and eight isolates of Pseudomonas . The infectivity study of five Azotobacter isolates revealed that there is a significant differences between the isolates comparing with the control in reduction eggs hatching and the more effective isolates was Azotobacter sp1 ( Az1) with inhibition percentage 95.05% followed by the isolate Azotobacter sp2 (Az2 ) 84.32%. while the study of eight Pseudomonas isolates revealed that the more effective isolates was Ps eudomonas fluorescens2 ( Ps2) ) with inhibition percentage 90.16% and the lowest percentage recorded in the case of the isolate P. fluorescens6 ( Ps6) which was 55.76% . The infectivity study of four selective bacterial isolates (Az1, Az2, Ps1 , Ps2 ) with the fungus Glomus against nematode revealed the highest percentage of reduction in root galling recorded when the tomato plants inoculated with the fungus and the two bacterial isolates( Az1) , ( Ps2) and the number of galls were 3 galls/gm roots comparing with the control 10.6 galls/gm roots and the percentage of reduction 71.69 follwed by the treatment with the fungus and the two bacterial isolates( Az1) , ( Ps1) 68.86 %. The result also revealed that the combination between Glomus and bacterial isolates induced plant growth and increased the criteria of growth parameters. The result also revealed G lomus alone achieved percentage of reduction in root galling recorded when47.16% and the number of galls were 5.6 galls/gm roots comparing with the control 10.6 galls/gm roots.