Evaluation of Pseudomonas chlororaphis subsp. aurantiaca SR1 for growth promotion of soybean and for control of Macrophomina phaseolina.

Pseudomonas chlororaphissubsp.aurantiacaSR1 was evaluated for control ofMacrophomina phaseolina in vitroand in soybean plants, for growth promotion of soybean plants and for production of antifungal compounds. Strain SR1 caused a significant inhibition ofM. phaseolina in vitroand reduced damping-off in thein vivoassays. In addition, strain SR1 significantly increased shoot and root length and shoot and root dry weight of soybean plants inM. phaseolinainfested soil, as compared to control plants in infested soil. Fragments for the phenazine-1-carboxylic acid, pyrrolnitrin and hydrogen cyanide encoding genes were amplified from the DNA of strain SR1 after polymerase chain reaction (PCR) assays with specific primers. Thus, this study establishes thatP. chlororaphissubsp.aurantiacaSR1 provides control ofM. phaseolina in vivoand suggests that strain SR1 might be applied as an effective biocontrol agent to protect soybean plants from this phytopathogen. [ABSTRACT FROM AUTHOR]