Potential use of microbial inocula for improving wheat productivity in salty soils.

Wheat (Triticum aestivum-L.) is one of the main winter cereal crops in Egypt for grain production and straw. The combined use of mineral fertilizer and bio fertilizer is required so; wheat plants were inoculated with Azospirillum lipoferum strains and/or Anabaena oryza to evaluate plant growth parameters and productivity under salt affected soils. Salt-tolerant A. lipoferum isolates (A10 and A11) have been isolated and identified by 16S rRNA sequencing. Wheat grains were inoculated with A. lipoferum strains and/or A. oryza. Inoculation with A. lipoferum and/or A. oryza increased root length compared with un-inoculated grains. Wheat plants inoculated with bacterial species grown in pots and soil experiments which had different salinity levels that arranged from normal (2.4 dSm-1) to salty (6.9 and 11.4 dSm-1) soils. The activity of enzymes urease and phosphatase in the wheat rhizosphere were determined. A. lipoferum species had the variable microbial count at different salinity levels. In addition, salinity had deleterious effects on the dry weight of plants, the number and dry weight of branches, spikes and grains, total chlorophyll, nitrogen and potassium concentrations. Furthermore, Na% was increased in shoot and grains of wheat plants. Reashiry, inoculation with nitrogen fixed A. lipoferum strains and/or A. oryza enhanced these parameters. Thus, inoculation with the salt-tolerant A. lipoferum strains (A10 and/or A11) and/or A. oryza reduced the deleterious effect of salt stress on wheat plants and enhanced productivity as compared to un-inoculated plants which fertilized with full dose traditional mineral nitrogen.