Effect of water stress on leaf level gas exchange capacity and water-use efficiency of wheat cultivars

Water stress constitutes one of the most important environmental constraints limiting wheat productivity worldwide. In an open pot experiments six spring wheat cultivars, viz., Barigom-23, Barigom-24, Barigom-25, Barigom-26, Barigom-27, and Barigom-28 were grown under control and water stress conditions to evaluate their genetic variations for gas exchange parameters and water-use efficiency. Results showed that genotypic variations for the gas exchange parameters and water-use efficiency were very prominent among wheat cultivars under control and water stress conditions. Water stress adversely affected net photosynthesis, stomatal conductance, internal CO2 concentration, transpiration rate, carboxylation efficiency, instantaneous and intrinsic water-use efficiencies compared to control condition. Wheat cultivars Barigom-23 showed best performances for most of the characters. Cultivars Barigom-26 and Barigom-27 showed medium performances, whereas Barigom-24 showed lowest performance for most of the characters under water stress condition. A clear significant positive linear relationship was observed between net photosynthesis and stomatal conductance which indicated that increase in stomatal conductance improves net photosynthesis. © 2016, Indian Society for Plant Physiology.