inhibition of tea root lesion nematode, pratylenchus loosi, by rhizospher bacteria

root-lesion disease, which is caused by pratylenchus loosi , is one of the most important diseases currently impacting iran tea plantations. this disease causes great economic crop impacts. northern provinces, which supply much of iran’s tea production, have been especially hard impact by root-lesion disease.the purpose of this study was to biological control the nematodes as one of the main sections and sustainable agriculture in integrated management systems, allowing application of bacillus subtilis in the rhizosphere of tea plants infected with the root lesion nematode. in order to study this disease, more than fifty bacterial strains were collected from the rhizosphere area of the tea plants and screened for their antagonistic activities on the reduction of the density population of the adult and juvenile of pratylenchus loosi under in-vitro condition. four selected isolates with nematicidal activities were characterized and identified. all belonged to the species bacillus subtilis. death percentage of juveniles ranged from 62.88% to 86.01% for bacillus subtilis (rh-14) and (rh-18), respectively. all bacterial strains isolated in this study had the ability to produce protease. the information obtained was needed as the first step toward the search for control strategies of root-lesion disease in tea plantations in iran.