Dehydration is the most important limiting factor in agricultural production in arid and semi-arid
regions, and water shortages (especially at the reproductive stages) due to lack of precipitation and
unequal distribution are inappropriate for limiting the yield. In this research, cross between the
Gasspard cultivar (dehydrated susceptible parent) and DN11 line (resistant parent) was performed. F1,
F2, F3, BC1 and BC2 generations along with parents, were planted in a randomized complete blocks
design with three replications in normal and water deficit conditions for two consecutive years.
Physiological traits were measured for single plant samples. Weighted analysis of variance showed
that water deficit stress caused significant decrease in flag leaf area and unsignificant decrease in
stomatal conductance. Generation mean analysis for Chlorophyll index was accompanied by different
results in terms of regression fitted models for each environment, but for stomatal conductance, the
results of the generation mean analysis were the same in both environments. In addition to additive
and dominant effects, epistatic interaction effects also played role in the inheritance of all studied
traits. Most of these effects were double-effects. In flag leaf area, additive, additive × dominant and
dominant × dominant effects were involved in inheritance. In water relative content, in addition to
these effects, dominant effect was also involved in inheritance. Generations variance analysis showed
that the gene action was additive for relative water content, dominant for flag leaf area and over
dominant (in both conditions) for stomatal conductance. The gene action for Chlorophyll index under
stress and normal conditions were over dominant and additive respectively.