Alleviation Harmful Impacts of Salinity Using Some Antioxidants Substances on Thompson Seedless Grapevines Seedlings

This work was conducted during two successive growing seasons of 2016 and 2017 in the shade house of the Viticulture Research Department, Horticulture Research Institute, Agricultural Research Center, Giza, Egypt, to evaluate the effect of foliar application of ascorbic acid at 400 ppm and salicylic acid at 200 ppm on vegetative growth, physiological characters and endogenous bio constituents, as well as anatomical structure of the leaf blade of the Thompson seedless grape rootings grown under three levels of salinity stress (1000, 2000 and 3000 ppm). The results indicated that, all parameters studied of vegetative growth of rootings significantly decreased by increasing salinity stress levels,in addition to significant decrease in photosynthetic pigments content comparison with untreated vines.In contrast, salinity stress significantlyincreasedproline, sodium, total phenols compoundand oxidative enzymes activity in leaves. Foliar spray with ascorbic acid (AA) gave the best results followed by salicylic acid (SA) to alleviate and overcome the harmful impacts of salinity stress on the aforementioned characters of both growing seasons compared to control vines. Moreover, irrigated plants with NaCl saline solution had considerable decrease in anatomical characters of Thompson seedless grape leaf. Treating rootings with ascorbic acid application at 400 ppm increased all anatomical features in comparison with control vines under salinity stress condition.