Seed Priming of Bread Wheat Varieties with Growth Regulators and Nutrients Improves Salt Stress Tolerance Particularly for the Local Genotype

Salt stress is a main factor limiting the production and productivity of wheat in arid and semi-arid zones. The objectives of this study were to compare the salt tolerance of a selected bread wheat (Triticum aestivum L.) genotype, ‘Bohoot 210’ and Libyan local variety ‘Krassie’ and to evaluate the effect of plant growth regulators and nutritional elements on emergence and seedling growth at the germination stage under salt stress conditions. Sterilized seeds were soaked in the priming solutions for 12 h at room temperature, air-dried, and placed in Petri dishes for germination with four levels of seawater salinity (0% = 0 mS/cm (S1), and seawater salinity at 0.75% = 13.053 mS/cm (S2), 1.5% = 24.695 mS/cm (S3), and 3% = 46.253 mS/cm (S4)). Six moderators (Control, Kinetin: 80 ppm, Gibberellic acid GA3: 50 ppm, Auxin: 7 ppm, Iron: 50 µmol/L Fe-EDTA, and Potassium Nitrate: 150 mg/L) were used to test the behavior of two bread wheat varieties submitted to salt stress. Germination rate, coleoptile and radicle weight, the number of radicles, and coleoptile and radicle length were measured at the germination stage. The results revealed that salt stress significantly reduced plant growth at an early stage in both varieties. Moreover, the application of three plant growth regulators and two nutrients improved all parameters and the effect differed significantly with the applied moderator, variety, and salinity level. Iron treatment was the best priming treatment and improved the germination rate, the roots weight, length and number, and coleoptiles length under salt stress. The autochthonous bread wheat variety, Krassie, was more tolerant to salt stress than the selected variety Bohoot 210.