Journal of Pure and Applied MicrobiologyVol. 9 No. 1

Assessment of Bacterial Diversity and PGP Activity of Rhizobacteria in Rhizosphere of Vigna mungo

Shikha Devi1, Ashish Tiwari1, Shivesh Sharma1*, Vivek Kumar2 and Sandeep Bisht3

1Department of Biotechnology, Motilal Nehru National Institute of Technology Allahabad Allahabad - 211004, India. 2Amity Institute of Microbial Technology, Amity University, Noida, India. 3Department of Microbiology, UUHF, College of Horticulture, Bharsar, Pauri, India.

Received on 08 June 2014 and accepted on 10 November 2014

 

ABSTRACT

Little information is known about the composition of bacterial diversity associated with roots of Vigna mungo plant. With this background, the present study was carried out to investigate the diversity of bacterial isolates and PGP activity of rhizobacteria from the soils of Vigna mungo, grown in different regions of Indo Gangetic plains. Investigations of the rhizobacterial population associated with collected soils done by the means of colony forming units using serial dilution agar plate technique. In this context, total bacterial count, occurrence percentage, rhizospheric to soil (R: S) ratios were examined. Total bacterial count of all soil samples were found to be in the range of 12x105 to 98x105 with occurrence percentage of 1.07% to 92.85%. The values of R: S ratio lies in between 0.85 to 3.25 which is above 1 clearly indicates presence of positive rhizospheric effect in soil samples of Indo Gangetic plains. From the rhizosphere of selected plant, a total of seventeen bacteria were isolated and checked for Indole-3 acetic acid production colorimetrically using Salkowski reagent. Among all the isolates, IAA production was positively exhibited by majority of bacterial isolates and were found to produce IAA in the range of 34.97 and 90.64 ?g/ml. In our findings, two isolates IGV6 and IGV7 showed best positive result for indole-3-acetic acid production. Therefore, these promising isolates can be considered for as possible phytostimulator and bio-inoculant in rhizosphere of Vigna mungo plant. In addition to this, bacterial communities associated with rhizosphere of Vigna mungo plant acting as a reservoir of species which can be further explored for their bioprospecting potential and its application in agriculture and industry.

Keywords : IAA, phytostimulator, rhizosphere and rhizobacterial population.