Isolation and Characterization of Native Plant Growth Promoting Rhizobateria (PGPR) from Assam Phukan Amrita1, Sharma Pranamika2, Buragohain Preeti1, Baruah Rajen1 1Department of Soil Science, AAU, Jorhat-13, Assam 2Department of Plant Pathology, AAU, Jorhat-13, Assam Online published on 15 December, 2016. Abstract Plant growth promoting rhizobacteria (PGPR) has vital role in agriculture in order to promote the exchange of plant nutrients and reduce application of chemical fertilizers as much as possible in addition to its use as biocontrol agent. Moreover, the use of native PGPR is an added advantage as the microbes can easily adapt to the new environment. A total of 51 bacterial strains were isolated from the rhizospheric soils of rice, maize, toria and sugarcane. Altogether 10 out of 51isolates were selected as PGPR on the basis of their growth in different selective media. The 10 PGP cultures were characterized on the basis of cell morphology and some biochemical tests to assess variation within the cultures. All the isolates were screened for their plant growth promoting activities viz., Ammonia production, Proteolytic activity, IAA production, Phosphate solubilization, Siderophore production, HCN production, Seed germination test qualitatively. The results showed that not all the isolates possessed all the PGP activities. IAA production, Phosphate solubilization and Ammonia production was also determined quantitatively for all the isolates to screen the efficient cultures. The bacterial strains recorded a range from 0.240 to 3.86 per cent P-solubilization in Pikovskaya broth under incubation study from 0 to 15 days. The pH of the medium also varied from 6.733 to 3.483 during incubation. IAA production varied from 15.87 to 48.85 mg l−1 and ammonia production from 179.04 to 394.14 mg l−1 among the PGP organisms. Top Keywords PGPR, bacteria, siderophore, IAA, proteolytic activity. Top |