الفهرس 
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Abstract
A pot experiment was conducted to evaluate the beneficial effect of grain presoaking in kinetin (0.1 mM), spermine (0.3 mM) or their interaction on seawater-irrigated wheat plants (Triticum aestivum L.) variety Sakha 93. The obtained results showed that seawater at 25% decreased the growth vigor of root, shoot and flag leaf, as well as pigment content of wheat plants. Membrane stability and the content of total protein and nucleic acids in flag leaf were all decreased in response to salt stress. Exogenous application of kinetin, spermine or their interaction alleviated the adverse effects of salinity stress by improving growth vigor of root and shoot, retention of pigments content and increasing membrane stability as well as the content of total proteins and nucleic acids. Irrigation of wheat plants with seawater caused noticeable changes in anatomy of flag leaf and peduncle in addition to the ultrastructural features of mesophyll cells of wheat flag leaves. The exogenous application of kinetin and/or spermine induced some modifications in the anatomical features of the flag leaf and peduncle and enhanced the ultrastructural characteristics of mesophyll cells of wheat flag leaves which appeared to be an adaptive response to salinity caused by seawater. Seawater induced marked decrease in transpiration rate, relative water content and water use efficiency but significantly increased saturation water deficit in flag leaves of wheat plants. Grain priming with kinetin and/or spermine counteracted the stress induced by seawater salinity by recovering the turgidity in flag leaf of seawater-stressed wheat plants. Seawater also increased osmotic pressure, total soluble sugars, total soluble nitrogen, proline, organic acids, as well as ions in wheat flag leaf extract. The applied chemicals mitigated the effect of seawater by increasing the osmotic pressure and the osmolytes concentrations. Moreover, the effect was more pronounced with the interaction of kinetin and spermine treatment. Irrigation of wheat plants with seawater significantly decreased all yield components (shoot length, main spike length, plant height, main spike weight, number of tillers per plant, number of spikes per plant, number of spikelets per main spike and per plant, number of grains per main spike and per plant, grain yield per main spike and per plant, individual grain biomass, 100-kernel weight, biological, economic, straw and crop yields, mobilization, crop and harvest indices, as well as relative grain yield and evapotranspiration efficiency). The applied growth regulators appeared to alleviate the adverse impact of seawater stress on the yield components of wheat plants. Seawater induced marked reduction in biochemical aspects of the yielded grains especially carbohydrates content, nitrogenous constituents, total protein and nucleic acids contents as well as proline and organic acids contents. Conversely, seawater stress increased nitrite nitrogen, phosphorus and ions contents of the yielded wheat grains. Application of kinetin, spermine or their interaction appeared to alleviate the deleterious effects of seawater stress on biochemical aspects of yielded grains of wheat plants. Key Words: Wheat, Seawater, Kinetin, Spermine, Morphology, Anatomy, Ultrastructure, Water relations, Osmolytes, Yield.