Distribution pattern and screening of phosphate solubilizing bacteria isolated from different food and forage crops

Abstract

The distribution pattern and population density of Phosphate Solubilizing Bacteria (PSB) was assessed in cultivated soils. PSB isolates were assessed for phosphate solubilizing capacity, production of growth regulators, phosphatase activity, pH changes and titrable acidity. The population levels of PSB were highest in the rhizosphere soil of Groundnut and lowest in the rhizosphere of Ragi, Sorghum and Maize. It could be observed from the data that the distribution pattern of PSB in the rhizosphere soils showed that the population levels decreased with the distance of soil sampling from the plants. A wide variation in the capacity to solubilize phosphorous by the PSB isolates was observed. Further, all the isolates were able to secrete phytohormones like gibberelic acid (GA3) and indole acetic acid (IAA) and acid phosphatase under in vitro condition. © 2006 Asian Network for Scientific Information.