Evaluation of storage and remobilization of stem dry matter of three wheat cultivars under different moisture regimes in before and after flowering stages

To investigate the storage capacity and remobilization of stem dry matter in three wheat cultivars under different moisture regimes, a factorial experiment was conducted in a randomized complete blocks design with three replications in the experiment field of the College of Agriculture and Natural Resources, University of Tehran, in 2014-2015. Treatments included three of wheat cultivars (Pishtaz, Sivand and Parsi), and 12 moisture regimes were combined (70, 90, 110 and 130 mm cumulative evaporation from class A evaporation pan in before flowering stage (30-60 Zadok’s stage) and  90, 110 and 130 mm levels of cumulative evaporation in after the flowering stage, 60-93 Zadok’s stage). The result showed that the highest amount of stem dry matter storage was related to Parsi cultivar (1046 mg/stem) and T79 moisture level, with 1070 mg /s average. However, wheat cultivars reacted differently under different moisture regimes in terms of remobilization traits and remobilization efficiency. Pishtaz cultivar under treatment of T1313 (130 mm at all stages of growth), had the highest remobilization and remobilization efficiency with mean of 476 (mg /stem) and 56% respectively, and the bottom internodes, had the highest rate of remobilization (195 mg /stem, under the moisture level T1313), than the other two internode. At the same time, under the same treatments (T1313), the Parsi cultivar, despite the highest dry matter storage in the stem, had the lowest remobilization and remobilization efficiency, with an average of 427(mg /stem) and 45%, respectively, than the two other cultivars. Combined with the higher power of the Pishtaz cultivar in the remobilization of dry matter, the highest grain yield (6850 kg/ha) was obtained in this cultivar, which can be very important in drought stress.