Alleviation of Salt Stress on Wheat (Triticum aestivum L.) by Plant Growth Promoting Bacteria strains Bacillus halotolerans MSR-H4 and Lelliottia amnigena MSR-M49

The plant growth-promoting rhizobacteria (PGPR) application could reduce the use of synthetic fertilizers and increase the sustainability of crop production. Halophilic bacteria that have PGPR characteristics can be used in different environmental stresses. Two different strains isolated, purified, characterized as a PGPRs and phylogenetic identification using 16sRNA which was revealed to be closest matched at 99% with Bacillus halotolerans and Lelliottia amnigena. The isolates possessed plant growth promoting properties as exopolysaccharides (EPS) and indole acetic acid (IAA) production, Bacillus halotolerans had the ability to fix elemental nitrogen and the two strains have the ability to P-solubilization. Furthermore, the strains were evaluated in alleviation of different levels of salt stress on wheat plant at two experiments (Pots and a Field). Strains under study conditions significantly increased the plant height, straw dry weight (DW g plant-1), spike number, 1000 grain DW recorded 31.550 g with Lelliottia amnigena MSR-M49 compared to un-inoculated and other strain in field, grain yield recorded 2.77 (ton fed-1) with Lelliottia amnigena as well as N% and protein content in grains recorded 1.213% and 6.916 respectively with inoculation with Lelliottia amnigena, also, spikes length, inoculated wheat show reduction in both proline accumulation in shoots and roots especially with Lelliottia amnigena recorded 2.79 (mg g-1DW), inoculation significantly increased K+ in root-shoot, K+/Na+ in root-shoot and reduced Na+ in root-shoot compared with control. This confirmed that this consortium could provide growers with a sustainable approach to reduce salt effect on wheat production.