Abstract
<title>Abstract</title> <p> Soil salinity severely limits global crop productivity. Native plant growth-promoting rhizobacteria (PGPR) from saline ecosystems offer a sustainable strategy to alleviate salt stress, yet their efficacy often depends on host and niche. This study evaluated the biostimulant potential of three rhizobacterial isolates— <italic>Staphylococcus xylosus</italic> SF6 (PQ123789), <italic>Pseudomonas</italic> sp. TA3 (PX957002), and <italic>Bacillus simplex</italic> SA1 (PX957145)—recovered from the rhizosphere of halophytes in an Algerian sebkha. Their individual and combined (tri-strain consortium) effects were assessed on tomato under in vitro NaCl gradients (0–150 mM) and on wheat cultivated in naturally saline soil. Data were analyzed via two-way ANOVA and Principal Component Analysis. Salt stress significantly impaired all growth parameters in non-inoculated controls. PGPR inoculation markedly mitigated these effects, though responses were strongly modulated by host species and treatment formulation. In tomato, the tri-strain consortium performed best, maintaining 100% germination at 0 mM NaCl and 60% under 100 mM stress, with a 186% increase in fresh biomass. PCA (90.27% total variance) revealed robust, salinity-independent growth promotion by the consortium. Conversely, in wheat, <italic>Pseudomonas</italic> sp. TA3 was most effective, increasing germination by 75%, root length by 100%, and Seedling Vigor Index by 240%. Notably, <italic>S. xylosus</italic> and <italic>B. simplex</italic> performed poorly on wheat, falling below non-inoculated controls, highlighting host-specific incompatibility. These findings demonstrate that PGPR-mediated salt tolerance is not interchangeable; optimal bioinoculant design requires precise matching of strain ecophysiology to target host and substrate. The tri-strain consortium shows promise for tomato, whereas <italic>Pseudomonas</italic> sp. TA3 emerges as a specialized candidate for wheat biofertilization in saline fields, supporting ecotype-adapted microbial consortia for sustainable agriculture in saline-affected regions. </p>