الفهرس 
SalinityOnly 14 pages are availabe for public view
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Abstract
Wheat is one of the major crops cultivated in the black clay soil, the salinized soil reduces the productivity due to the improper nutrition of plants as well as osmotic and drought stress. The current study used salt tolerated Azotobacter chroococcum and Azotobacter vinelandii, isolated from salt-affected soils in Kafr El-Sheikh governorate. The two bacterial strains were exposed to different increasingly salt concentrations in the growth media to detect their level of salt tolerance, their production ability of auxins and nitrogenase proteins under salt stress. Both two strains were inoculated to wheat plant during dseedling stage to tolerate salt and facilitate plant growth in salinized soils in pots then field expermints. Results showed that inoculated wheat crops with salt tolerated bacterial strains under ingoing study gave significantly better results than uninoculated one in growth criteria as stem high (cm), 1m2 weight (g), grains weight (g/m2), straw weight(g/m2), and 100 grains weight (g). The improvement ability of bacteria was correlated to the production of plant growth regulators as auxins Indole-3Acetic Acid (IAA), which facilitate and improve crop productivity under drought and salinity stress, and led to increase in nitrogenase activity which improve nitrogen fixation via plants, indicated that applying of salt-tolerant Azotobacter spp. was beneficial and effective in improving the productivity of wheat under salinity stress conditions and suggested the ability of using of salt tolerated Azotobacter spp. as salt-tolerant plant growth promoting rhizobacteria (ST-PGPR) that help better growing of wheat in salinized soils.