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Drought stress during grain filling period in wheat causes yield losses.
There are limited information about the efficiency of non-structural
carbohydrates stored in wheat (T. aestivum L.) internodes and their
remobilization to the grains under water deficit. An experiment was conducted to study the role of these kinds of carbohydrates on relative yield stability
under water stress. Two regimes, full irrigation and drought stress during
anthesis and grain filling, and three isogenic lines ot a spring wheat variety, Maringa, for plant stature, rht rht (tall), Rht2 Rht2 (semidwarf), and Rht3 Rht3
(dwarf) were experienced. The experiment was factroial with randomized
complete blocks and four replications. The results indicated that the first and
the second internodes of stem, near the spike, acting as a sink for non
structural carbohydrates especially fructans until 14 days after anthesis
transferred these carbohydrates to the spike till physiological maturity completed. The amount remobilized was higher for the dwarf line and water
stress condition than semidwarf and tall isolines. This line was also superior with respect to grain yield in main spike and acquired a lower ratio of chaff
weight to total spike weight. Two other lines were similar in these respects. It
seems that dwarf varieties were observed to loose smaller amount of yield and
were more efficient than semidwarf and tall varieties in remobilization of non
structural carbohydrates from two upper internodes under water stress
conditions.