Water Use Efficiency Variation and Its Components in Wheat Cultivars

Genetic variations of water use efficiency (WUE) in wheat cultivar were studied in different models. These models in addition accumulating WUE; evaluate the contribution of its components. In this study, seven bread wheat cultivars were sown at four separate randomized complete block design with four replications at different moisture regimes in two growing seasons. Combined analysis of variance showed significant differences for total dry matter, WUE, relative water loss (transpiration efficiency), and initial water of flag leaves (uptake efficiency). Sardary, Sabalan and Alamut cultivars had the lowest WUE and total dry matter, but Zarrin and Shahriar were the highest values. Sardary with low uptake efficiency and Zarrin with high grain yield had the minimum and maximum transpiration efficiency. The WUE and evapotranspiration efficiency had a positive significant correlation with total dry matter and grain yield respectively. Results of path analysis showed that WUE (0.6) and total dry matter (0.31) had the highest direct effect on grain yield. Contribution of evapotranspiration efficiency (0.82) on WUE was higher than harvest index (0.30).