Free-Living Diazotrophic Rhizobacteria with Plant Growth Promoting Traits Isolated from the Rhizosphere of Wheat Grown on Saline Soil in West Algeria

Abstract

Plant growth promoting rhizobacteria (PGPR) represent a very small portion of plant rhizobacteria that have the ability to promote plants growth. In this work we evaluated the potential of free-living diazotrophic bacteria isolated from saline soil in west Algeria for the presence of PGP traits. Selective media were used for the isolation and selection of these plant growth-promoting rhizobacteria. A total of 296 strains were isolated from rhizospheres of wheat in eleven different saline soil areas of the perimeter of Mina (Relizane province – west Algeria). All the strains were evaluated for Indole acetic acid (IAA) production, phosphate solubilization, siderophores production, Hydrogen cyanide (HCN) production and ammonia production. Amongst these 296 strains 35 with multiple PGPR traits were in addition tested for their ability to use ACC as a sole nitrogen source and for nitrogenase activity using the Acethylene Reduction Activity test. These thirty five strains selected for their high PGP traits performance were further characterized by 16S rRNA sequencing.