Evaluation of Indigenous Pseudomonas Fluorescens Isolates for Plant Growth Promotion and Biocontrol Efficacy.

The efficacy of eight indigenous isolates of Pseudomonas fluorescens obtained from the rhizosphere was evaluated for biocontrol and plant growth promotion activity. Among the isolates, P. fluorescens 4 provided good biocontrol activity on a wide spectrum of plant pathogens. Isolates were tested for inducing systemic resistance against hot pepper in the Fusarium solani system. P. fluorescens 4 was the best in induction of defense related enzymes, peroxidase, poly phenol oxidase, phenyl alanine ammonia lyase, total phenol and ß 1,3 glucanase. High vigor index including germination, and root and shoot lengths were observed in hot pepper treated with P. fluorescens 4, challenged with F. solani. Six of the P. fluorescens isolates produced hydrogen cyanide, an antimicrobial metabolite. P. fluorescens 3, 4, and 8 were considered as high hydrogen cyanide producers whereas P. fluorescens 2, 5 and 6 were moderate hydrogen cyanide producers. Four of the P. fluorescens isolates produced salicylic acid with P. fluorescens 4 recording the highest amount. P. fluorescens 4 was considered as the isolate with the most potential for biocontrol and as a plant growth regulator rhizobacteria.