Phosphate solubilizing bacterial strains GRS3, GRP5, GPP3, GRZ3, GCP1, GCP2, GCP3 and GCN3 were isolated from the rhizosphere soils of different altitude and longitudes of Uttarakhand state of India. All eight strains demonstrated diverse levels of phosphate solubilization activity under in vitro conditions in the presence of tribasic calcium phosphate as a sole phosphorus source. At the same time, there is a reduction in pH of the medium and release of soluble phosphate. Acid production may have contributed to phosphate solubilization, but was not the only reason for phosphate release into the medium. Among the eight strains, GRS3, GRP5 and GCP1 were the most efficient in terms of phosphorus solubilization in NBRIP broth (pH 7.0) at 30 0C. The growth promotory abilities of potential candidate GRS3, GRP5 and GCP1 was documented under in situ condition green house experiment using different leguminous crops lentil, mungbean, gram, black gram and soybean respectively.
