Response of bread two wheat cultivars to application of salicylic acid under variable Moisture conditions

To investigate the effect of Salicylic acid on yield and some physiological parameters of wheat under drought stress, an Split split plot experiment was conducted in a randomized complete block design with four replications at Agricultural Research Center of Ilam during 2014-2015 cropping season. Experimental factors included Moisture treatments in three levels (control (100), 70 and 40 % Field capacity) In the main plots, Salicylic acid in three levels (0, 50 and 100 µM) in the sub plot and two wheat cultivar (Bahar and Pishtaz) in sub sub plot. Studied traits in this study included yield and yield components, photosynthetic pigments, proteins, soluble sugars, malondialdehyde (MDA) and proline. The results showed that Triple interaction between drought stress, salicylic acid and Cultivars on all traits was significant. By increasing drought stress photosynthetic pigments, number of grains per spike, thousand seed weight and seed yield was significantly decreased while the use of salicylic acid in this situation improve these traits. Proline content, soluble proteins and soluble carbohydrates were ascending with increasing severity of drought stress, that this trend except in the case of proline, by use of salicylic acid continued and improved. Generally, it seems that application of salicylic acid under drought stress by improving the plant's physiological processes, while increasing plant resistance, lead to greater economic performance.