Screening and characterization of plant growth promoting traits of phosphate solubilizing bacteria isolated from wheat rhizosphere of Algerian saline soil

Abstract

Aims: The capacity of some soil microorganisms to solubilize in soil is an important activity exhibited by plant growth promoting rhizobacteria (PGPR) to increase plant performance. This study aimed at isolation and selection of phosphate solubilizing bacteria from saline soil and in vitro evaluation of their plant growth promoting traits. Methodology and results: Phosphate solubilizing bacteria isolated from wheat rhizosphere, of saline soil in western region of Algeria were tested for their plant growth promoting traits such us indole acetic acid (IAA), hydrogen cyanide (HCN), siderophore and ammonia production and their ability to fix nitrogen. Among 104 bacterial isolates, 41 were selected for their phosphate solubilizing activity using tricalcium phosphate (TCP) as a sole phosphorus source. IAA production was shown by almost all the bacterial isolates. Twelve isolates were recorded positive for HCN production, 32 produced siderophore and 31 were able to fix nitrogen. The most dominant phosphate solubilizing bacteria found were identified as Pseudomonas followed by Aeromomas hydrophila Bacillus sp. and Burkholderia cepacia. Conclusion: Phosphate solubilizing bacteria that were isolated from saline soil showed a high potential in to producing growth promoting traits and can be used as inoculants to increase the phosphorus uptake by plants.