Different phages parasiting Pseudomonas syringae pv. phaseolicola were isolated from infected bean leaves growing in four localities using enrichment technique. The isolated phages produced plaques with 3 to 5 mm, diameter and a distinct translucent spreading halo. Presumptive phage particles associated with P. syringae pv. phaseolicola were observed by Transmission Electron Microscope (TEM). Bioagent and garlic extract were inhibited P. syringae pv. phaseolicola in vitro. Halo blight disease severity was determined under greenhouse condition using the effective phage isolates. The effect of phage isolates (namely Ph1, Ph2 and ph1+2) were reduced disease severity by 58.57-61.14 and 70.8%, respectively compared with P. fluorescence treatment (35.82%); P. putidae treatment (22.17%) and Garlic extract (30.54). These phages may be useful as a tool to efficient detection and control of halo blight pathogen. Mixed phages (1+2) was more effective than single phage treatments on all disease characteristics. Although all phages that used as single or mixed were more effective to reduce disease incidence when compared with control. These results indicated that these phages may offer a new possibility for the identification and diagnosis of P. syringae pv. Phaseolicola strains from bean plant. |
