Asian Journal of Microbiology and Biotechnology

Drought and salinity are major environmental constraints affecting wheat growth and yield. Therefore, there is a need for sustainable approaches to improve crop performance under adverse conditions. In this study, indigenous bacteria associated with the wheat rhizosphere were isolated from the Malwa and Nimar regions of Madhya Pradesh, India, to identify strains capable of tolerating drought- and salt-related stress. A total of 150 bacterial isolates were obtained from rhizospheric soil samples collected from Indore, Khargone, and Maheshwar. Of these, 20 representative isolates were selected and evaluated for their morphological, biochemical, physiological, and plant growth-promoting characteristics. The isolates were assessed for tolerance to different concentrations of NaCl, polyethylene glycol (PEG)-induced osmotic stress, temperature variations, and pH conditions. Among the isolates, WR4, WR5, and WR9 retained growth at NaCl concentrations of up to 12%, while WR4 and WR9 demonstrated comparatively greater tolerance to PEG-induced osmotic stress. The isolates also exhibited several plant growth-promoting traits, including nitrogen fixation, ammonia production, phosphate and potassium solubilisation, hydrogen cyanide (HCN) production, and indole-3-acetic acid (IAA) synthesis. Phosphate-solubilising activity ranged from 31.3–39.2 mg/mL, whereas IAA production ranged from approximately 11–21 µg/mL, with WR4 showing the highest IAA production. Overall, the findings indicate that wheat rhizosphere-associated bacteria from the studied regions possess both abiotic stress tolerance and plant growth-promoting properties. These indigenous isolates may therefore represent promising candidates for microbial inoculant development for drought- and salinity-prone environments. Molecular characterisation and subsequent greenhouse and field experiments will be required to confirm their taxonomic identity, functional stability, and effectiveness under agricultural conditions.