Plant Growth Promoting Activity, Induction of Systemic Resistance and Control of Collar Rot Disease in Arachis hypogaea L. by a Novel Pseudomonas species.

Abstract

Induction of systemic resistance in Arachis hypogaea L. by an agriculturally useful bacteria was studied. 25 bacteria were isolated from rhizospheric soil of groundnut plants grown in Junagadh region of Gujarat. The plant growth promoting and antagonistic activity (against A. niger) of all these bacteria were compared and a bacterium with high level of siderophore, GA3, IAA, ammonia and ACC deaminase producing and phosphate, zinc and potassium solubilizing ability was selected to study its effect on plants. This bacterium promotes the germination of seedlings from 65-88 % to 82-94 %. It could also recover the A. niger infected seedlings. The generation of ISR was evident as its treatment increased Phenyl alanine ammonia lyase, peroxidase, lipoxygenase, jasmonic acid, β-1,3-glucanase and chitinase activities in GG20 and GG2 varieties of A. hypogaea L. seedlings. The bacterized seeds sowed in field, reduced the disease incidence significantly in the plants challenged with A. niger. Field survivability was found to be 15 days. To identify this bacteria, 16s rRNA gene was isolated, sequenced and subjected to BLAST, which showed 99% analogy with P. plecoglossicida, P. monteilii, P. putida and P. mosselii. Results of biochemical and FAME analysis differed from P. plecoglossicida, P. monteilii, P. putida and P. mosselii, which showed that this is a novel bacteria. The bacterium was found to promote plant growth in field studies and could be useful.