Isolation and Characterization of Plant Growth Promoting Bacteria from Root Nodules of Cicer arientinum L.

Aims: The aim of the present study is to isolate and characterize root nodulating bacteria from Cicer arientinum L cv. GNG 1958 and assess its plant growth promoting properties. The study is based on previous reports that native symbiotic bacteria may be replaced by better performing strains by corss-inoculation to increase productivity and tolarance to Biotic and abiotic stresses.

Study Design: Isolation of symbiotic bacteria, its biochemical and molecular characterization and assessment of plant growth promoting property through ammonia production, phosphate solubilization and HCN production.

Place and Duration of Study: Department of Bioscience and Biotechnology, Banasthali Vidyapith, Rajasthan, during 2019-2022.

Methodology: Root nodulating bacterial strain was isolated from C. arientinum L. cv. GNG 1958 grown at the agricultural fields' located at the Krishi Vigyan Kendra, Banasthali Vidypapith, Rajasthan. Morphological characteristics of the isolates were noted following Bergey’s Manual of Systemic Bacteriology and biochemical tests performed as per standard methods. Molecular characterization of the potential symbiont was performed by PCR of 16s rRNA genes and the PCR product was sequenced. Plant growth promoting property was determined through ammonia production, phosphate solubilization and HCN production.

Results: Root nodulating bacterial strain was isolated from C. arientinum L.cv. GNG 1958. Out of eighteen isolates, BVCA-58 grew fast and changed the color of BTB dye in media from green to yellow and deep yellow within 2 days of incubation. White colonies were observed when BVCA-58 was inoculated on YEMA media supplemented with Congo red. BVCA-58 has the ability to produce hydrogen cyanide, ammonia and solubilize phosphate. Molecular study of BVCA-58 using 16f-16r and 63f-1244r primers showed 99.89% and 99.62% of similarity with Mesorhizobium jarvisii ATCC-33669 and Mesorhizobium erdmanii USDA-3471 respectively on performing NCBI Blast. BVCA-58 was submitted to NCBI portal as Mesorhizobium sp. strain BVCA-58 with accession nos. OP646813 and OP646810.

Conclusion: The present study revealed that isolated strain from Cicer arientinum GNG 1958 variety was Mesorhizobium sp. which has potent plant growth promoting traits.