Eleven salt tolerant bacteria isolated from different sources (soil, plants) and their transformed strains were used to study their influence on Triticum aestivum var. Inqlab-91 growth under salt (100 mM NaCl) stress.Salt stress caused reduction in germination (19.4%), seedling growth (46%) and fresh weight (39%) in non-inoculated plants. In general, both wild and transformed strains stimulated germination, seedling growth and fresh weight in salt free and salt stressed conditions. At 100 mM NaCl, Staphylococcus xylosus ST-1 caused 25% increments in seedling length over respective control. Soluble protein content significantly enhanced (49%) under salt stress as compared to salt free control. At 100 mM NaCl parental strain PT-5 resulted about 32% enhancement in protein content over respective control treatment. Salt stress induced the promotion of auxin content in seedlings. Overall, Bacillus subtilis HAa2 and transformed E. coli-SP-7-T, caused 33% and 30% increases in auxin content, respectively, were recorded under salt stress in comparison to control.

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Salt tolerant bacteria were used to assess their potential for stimulating the growth of Triticum aestivum var. Inqlab 91. Certified seeds of Triticum aestivum var. Inqlab 91 were inoculated with monocultures (ST-1, ST-2, ST-3, ST-4, rhizosphere bacteria; HT-1, HT-2, HT-3, histoplane bacteria) and different combinations of mixed cultures of bacteria. Inoculated and non-inoculated seeds were germinated and grown under NaCl stress (0, 100 mM NaCl) for 10 days. After that growth measurements (length and weight parameters) were taken and Na + /K + contents, soluble protein content, auxin content and enzyme activities (peroxidase and acid phosphatase) were determined. Generally, with the application of NaCl, reduction in germination and growth parameters, whereas increase in Na + /K + contents, auxins content, soluble protein content as well as enzymes activities were observed. Bacterial inoculations stimulated germination and growth, over non-inoculated respective treatments, especially under saline conditions. Mixed culture inoculation with rhizosphere bacteria (some combinations) and histoplane bacteria was more effective in stimulating seedling growth than monoculture inoculations at 100 mM NaCl. Bacterial inoculations also enhanced fresh weight per seedling, auxin, soluble protein and K + contents of seedlings. Whereas decreases in dry weight accumulation, Na + content and activity of enzymes, at 100 mM NaCl with bacterial inoculations were recorded. From these results improved growth of seedlings could be related with increased auxin content but decreased dry weight increment, Na + content and enzyme activities.

In the present study mono and mixed culture bacterial combinations of Azotobacter were used to inculcate Vigna radiata seeds. In general, bacterial inoculations (mono and mixed cultures) promoted seed germination, early growth parameters, auxin content, soluble protein content, peroxidase and acid phosphatase activity relative to non-inoculated control seedlings. Increase of (23%) as well as decrease (6.8%) in the root length were observed with bacterial inoculations relative to non-inoculated seedlings. About 20.07% enhancements in fresh weight and 62% enhancement in dry weight was observed in case of bacterial inoculations. Among the monoculture Ab-4(A3) induced pronounced growth stimulator effects, mixed culture combinations B6, B7, and B10 showed pronounced synergistic effects relative to respective monocultures, while B2 exhibited negative in majority of the parameters being studied.