The six populations (parents, F1, backcrosses and F2) of the two wheat crosses, Gemmeiza 9 · IL1 (C1) and Sids 1 · IL2 (C2) were grown under normal irrigation (N) and drought stress (D) at the farm of Faculty of Agriculture, Sohag University, Egypt to study the genetic background of drought stress tolerance. Genetic variation was found for No. |