الفهرس 
Multifunctional diazotrophs are necessary to ameliorate cereal growth in salt affected environments
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Abstract
Among the corner stones for crop productivity in the semi-arid areas of the world, is the use soil and irrigation water with high contents of soluble salts. The growth and physiological responses of two maize (TWC 329 and TWC 353) and two wheat (Egypt 1 and Sakha 93) cultivars to salinity in presence of plant growth promoting (PGP) bacterial and cyanobacterial isolates were assessed in gnotobiotic and pot experiments. The phylogenetic analyses inferred from 16S rRNA gene sequence of 2 superior isolates of either bacteria or cyanobacteria demonstrated that these isolates are closely related to the species; bacillus megaterium, lysinibacillus sphaericus, dolichospermum circinale and dolichospermum spiroides. Salinity decreased cereal shoot and root lengths and dry weights as well as chlorophylls, carotenoids and nutrients (K⁺, Ca⁺⁺, Mg⁺⁺⁺) contents but increased phenol and proline levels, catalase and peroxidase activities as well as sodium accumulation. Microbiota inoculation greatly alleviated the detrimental effect of salinity. Irrigation with salted water (EC, 6.75 dSm⁻¹) adversly affected the development of maize cv. TWC 353 but to lower extent cv. TWC 329. Incorporation into soil of the organic material (humic acid) in presence of 50% of recommended N level was not that supportive for wheat growth. An striking point was the ability of the introduced inocula to modify the K⁺/Na⁺ ratios towards the proper values required for better establishment of plants in salt-affected environments