enotypic Variation of the Trait Stem Reserves in Bread Wheat (Triticum aestivum L.) Genotypes under Post Anthesis Drought Stress Condition

Wheat crop grown under post anthesis drought stress condition may need a high level of stem reserve for grain filling. For an understanding of the genotypic variation of the traits stem reserves in wheat under drought stress conditions, 20 winter wheat genotypes were evaluated under both post-anthesis drought stress and normal conditions in Ardabil Agricultural Research Station in two successive growing seasons 2000-2002 using a Randomized Complete Block Design with three replications. The results showed that there were significant differences among the genotypes for stem reserve under either normal or post anthesis drought stress conditions. Post-anthesis drought stress did not affect kernel number per spike. The rate of dry matter accumulation in kernels considerably decreased by water deficit. Dry weight of vegetative organs decreased during grain filling period under either of the stress and normal conditions. But, the rate of translocated dry matter was much higher in genotypes 14, 15, 16, 18, 19 and 20 under drought stress conditions. On thousand GW and weight of kernels per spike were more severely reduced as due to water deficit. The significantly positive correlation of grain yield with remobilization of dry matter, harvest index as well as with stress tolerance index (STI) along with significantly negative correlation of grain yield with drought susceptibility index (SSI) revealed the fact that selection must be exercised for high harvest index, remobilization of dry matter and STI in a more effectively meeting of stress conditions.