Study the inheritance of water use efficiency in bread wheat (Triticum aestivum) under drought stress condition

Water use efficiency is positively correlated with grain yield، and being used for indirect selection of high wheat yield in drought prone environments. Yet little is known about genetic control of water use efficiency. In this research، a half diallel mating design was generated from crosses between 8 bread wheat to study the genetic of water use efficiency. Parents and F1 progenies were planted in drought stress condition in a randomized complete block design with four replications and water uptake، grain yield، water use efficiency، awn length، fertile tiller number، grains per spike، 1000-grain weight and harvest index were evaluated. Additive and dominant effects were significant for all traits. Non-additive variation was more important in genotypic disparity of water uptake، grain yield، water use efficiency، fertile tiller number، 1000-grain weight and harvest index. Accordingly، bulk، single seed descent and double-haploid methods are suggested in breeding program for these characters. Whereas، additive variation had imperative effect on genotypic variation of awn length and grains number per spike. Thus، despite of mentioned breeding methods، pedigree and backcross are recommended for these traits. Significant high correlation (r=0. 88**) between grain yield and water use efficiency demonstrated the importance of water use efficiency in drought stress condition. Therefore، selection for higher water use efficiency would improve grain yield in drought stress condition.