Regulation of antioxidant system in wheat cultivars by using chitosan or salicylic acid to improve growth and yield under salinity stress

Background and Objective: Chitosan (CHT) is a natural molecule that stimulates many biological responses in plants. Salicylic acid (SA) is endogenous growth bioregulator in plants. Applications of chitosan and salicylic acid have defensive effects on plants in improving salinity stress. This study designed to evaluate the response of wheat cultivars for CHT or SA in alleviating salinity stress. Materials and Methods: Field experiment was carried out at the experimental station, Wadi El-Natrun district El-Behera Governorate, Egypt, during the two winter seasons of 2017/2018 and 2018/2019. To study the effect of spraying CHT and SA on wheat (Triticum aestivum L.) cultivars (Sakha 94 and Gemmieza 9) grown in saline soil. Results: Grains priming with different treatments of CHT and SA increased all studied morphological parameters as compared with the corresponding controls. Both spraying treatment materials increased photosynthetic pigments, osmoprotectant substances in both wheat cultivars. Treated plants with both materials increased in antioxidant enzymes, antioxidant compounds and decreased lipid peroxidation in both wheat cultivars. Applications of CHT or SA increased all studied yield parameters as well as the content of carbohydrates and protein of the yielded grains in both cultivars. Conclusion: Foliar spraying with CHT and SA improved the yield parameters of wheat cultivars grown in saline soil. High level of SA on both cultivars proved to be the most effective and Gemmieza 9 cultivar surpassed Sakha 94 in grain yield.