Effect of Water Deficit Stress on Physiological Characteristics in Wheat (Triticum aestivum L.)

Abstract Terminal drought stress is one of the most important environmental stresses affecting plant morphology and physiology and has major effects on agricultural production. The purpose of this experiment was to investigate the effect of water deficit stress on changes in physiological traits of wheat in a randomized complete block design with three replications in two cultivation years of 2013-2014 and 2014-2015 at Karaj Nuclear Research Institute Farm. Seven different generations of wheat, including two parents Gasspard and line DN11 along with generations F1, F2, F3, BC1 and BC2 were cultured and compared separately under normal and terminal drought stress conditions. The last irrigation was done under water deficit conditions after anthesis. The results showed that there was significant increase in performance index and significant decrease in single plant yield under stress conditions. For the chlorophyll index and stomatal conductance coefficient traits, the observed decrease in stress conditions were not significant. On the other hand, no significant increase in chlorophyll fluorescence parameters was observed under stress conditions.On the other hand, there was a significant difference between the generations studied for all measured physiological traits (except photosynthetic efficiency), indicating that there was variation among these generations for these traits. This diversity can be addressed in selection programs.