Asian Journal of Microbiology, Biotechnology & Environmental Sciences Paper

A STRATEGIC APPROACH FOR ISOLATION AND IDENTIFICATION OF PLANT GROWTH PROMOTING RHIZOBIAL STRAINS FROM BHADRACHALAM FOREST AREA WITH RESPECT TO CHICKPEA (CICER ARIETINUM)

SADAM D.V. SATYANARAYANA, KRISHNA M.S.R. AND PAVAN KUMAR PINDI

Abstract

Soil has been one of the major habitats for microbial communities in the ecosystem. It is a well established scientific fact that Microorganisms are ubiquitous in nature, and not more than one percentage of the microbial population has been explored. The quest of microbial exploration in the name of biodiversity is being carried, as a result of which more and more novel microbial communities are getting added to the literature. One such attempt has been made with an indigenous strategy to reduce the input cost in exploration of compatible strains for chickpea avoiding serious constrain of biofertilizers i.e, shelf life in the name of acclimatization. Forest lands of Bhadrachalam receive heavy rain fall and are rich in microbial biomass. Soil samples are collected randomly from 40 different locations of Bhadrachalam forest and sown with chickpea seeds in triplets. Five out of 40 samples which supported the best plant growth were taken for further investigations. The NPK and micronutrient levels of all the soil samples were found to be comparatively similar. This may be because of the fact that all samples have been taken from same geographic region. Rhizobial strains from the root nodules of these five samples were isolated and maintained in pure cultures. Broths of each pure culture were inoculated on the seeds sown in sterile soil and controls were maintained. The results showed that the inoculated Rhizobia tremendously improved the plant growth when compared with control. Further phylogenetic analysis revealed that the contributing organisms are Mesorhizobium Ciceri, Rhizobium meliloti, Rhizobium fredii, Bradyrhizobium japonicum and Mesorhizobium loti sp. These Rhizobial species in the pure form exhibited high rate of plant growth at lab conditions followed by improved growth in low vegetative agriculture soils of the same geography. This infers that a simple strategic pot experiment could be applied for the preliminary screening of compatible, species specific strains for any leguminous plants making the process easy and less expensive.