Drought Stress in Wheat during Flowering and Grain-filling Periods

Drought is a major environmental stress threatening wheat productivity worldwide. Global climate models predict changed precipitation patterns with frequent episodes of drought. Although drought impedes wheat performance at all growth stages, it is more critical during the flowering and grain-filling phases (terminal drought) and results in substantial yield losses. The severity and duration of the stress determine the extent of the yield loss. The principal reasons for these losses are reduced rates of net photosynthesis owing to metabolic limitations—oxidative damage to chloroplasts and stomatal closure—and poor grain set and development. A comprehensive understanding of the impact of terminal drought is…