Investigation of Halo-tolerant Phosphate Solubilizing Microbes on Wheat (Triticum aestivum L.) under Saline Conditions

Abstract

Phosphorus deficiency is the most common problem in the salinity affected areas as the water soluble phosphate rapidly converts into insoluble and plant un-utilizable form. Among different remediation strategies of this problem, use of plant beneficial phosphate solubilizing microbes (PSMs) is cost effect and eco-friendly measure. Two most potent halo-tolerant PSMs i.e. one phosphate solubilizing bacteria (PSB) and one phosphate solubilizing fungi (PSF) were screened on Pikovskaya’s agar amended with 5% NaCl. Bacterial isolate Bacillus subtilis PSB-S showed positive ACC deaminase activity, potash mobilization, IAA production, siderophore activity and Cladosporium herbarum PSF-S found positive for potash mobilization and antagonistic potential against plant pathogenic Fusarium oxysporum on the basis of different in vitro plant growth promoting traits. Field experimental data suggested that application PSB+PSF in combination, along with 100% recommended dose of chemical phosphatic fertilizer (RDP) in wheat under saline stress conditions showed increase in root length (28.30%), shoot length (41.16%), no. of tillers/plant (14.96%), no. of spikes/plant (6.86%), available phosphorus (27.54%) kg/ha, phosphorus uptake (29.03%), seed weight/plant (15.50%), seed (10.52%) and straw yield (6.40%) over full RDP un-inoculated control. Therefore, it is evident from field experimental data that application of these halo-tolerant PSMs under salinity conditions significantly improved phosphorus bioavailabilty and could save 50% of chemical phosphatic chemical fertilizers without compromising yield.