Studies on Phosphate Solubilizing Rhizobacteria Associated with Apple

Although, many studies have been conducted to identify the specific traits by which plant growth promoting rhizobacteria (PGPR) promote plant growth, usually they are limited to studying only one or two of these traits. But, in the present investigation the strains isolated from apple seedlings were tested for four traits viz., phosphate solubilization, siderophore production, growth on nitrogen free media and antagonism against Dematophora necatrix, the causative agent of white root of apple. The strain solubilized a substantial amount of TCP (957.3 mg/l) in PVK broth and also exhibited the production of IAA (15.13 g/ml), siderophore (49.49%) and per cent growth inhibition against D. necatrix (46.57%). Concurrent production of IAA, siderophore, antifungal antibiotic activity along with phosphorus solubilization revealed its plant growth promoting potential. Thus the ability of performing multifarious activities in tandem suggest B. circulans MTCC 8983 a novel isolate for plant growth promotion and has significance to develop cost effective ecofriendly sustainable system in the management of environmental and agricultural problems.