Grape softwood cuttings of Khoshnaw cultivar were cultured using tissue-culture methods to consider the effect of iron nanoparticles and potassium silicate under salinity conditions during the 2015-2016 growing season. The treatments consisted of salinity stress (0, 50, and 100 mM NaCl), nanoparticles of iron (0, 0.08, and 0.8 ppm), and potassium silicate (0, 1, 2 mM). The results also showed that the application of iron nanoparticles and potassium silicate significantly increased the content of free proline and total protein as well as enzymatic antioxidant activity, thus lowering the content of hydrogen peroxide. Iron and potassium silicate were shown to lower the sodium content and increase the potassium content under salinity-stress conditions. These results indicate that the application of micronutrients in stressful conditions is a suitable method to compensate for the negative effects of salinity stress. Tissue culture in this study was shown to be an economically efficient and applicable technique for producing grape softwood cuttings to be used in experiments.
