STUDIES ON ECOLOGY AND DIVERSITY OF PLANT GROWTH PROMOTING RHIZOBACTERIA IN MARATHWADA REGION

Abstract

Plant growth promoting rhizobacteria (PGPR) are a collection of bacteria that strongly colonize plant roots and enhance plant growth and yield The mechanisms by which PGPR promote plant growth are not completely understood, but are considered to consist of the ability to produce phytohormones against phytopathogenic microorganisms through the production of siderophores and the synthesis of antibiotics, enzymes and/ or fungicidal compounds (Ahmad et al., 2006). Considerable increase in growth and yield of agronomical important crops in response to inoculation with PGPR has been reported Pseudomonas strains could affect seed germination and seedling growth Strains of Pseudomonas putida and Pseudomonas fluorescens were reported to increase root and shoot elongation in canola Therefore, it has been shown that Pseudomonas has the potential for agriculture utilization and could be used as biofertilizers Fluorescent Pseudomonas, capable of multiple mechanisms for biocontrol of phytopathogens and plant growth promotion, are being used widely as they produce a wide variety of antibiotics, chitinolytic enzymes, growth promoting hormones, siderophores, HCN and catalase. The use of PGPR has become a common practice in many regions of the world. Larger use of PGPR is possible in agriculture for biocontrol of plant pathogens and biofertilization. The bacterial strains isolated from Lolium perenne rhizosphere are capable of acting as plant growth promoting bacteria and show various plant growth promoting activities (Shoebitz et al., 2007) Pseudomonads are Gram-negative bacteria comprising chemoheterotrophs predominantly inhabiting the soil and having versatile functions. They are potential colonizers of rhizosphere of many crops like cereals, pulses, oilseeds and vegetables. Both fluorescent and non-fluorescent species constitute the genus Pseudomonas. The fluorescent species produce diffusible yellow-green pigment and fluoresce under low-wavelength UV radiation. newlineThe Marathwada region is well known for its hot summer and genera