Drought Stress in Wheat during Flowering and Grain-filling Periods

• Published in: Critical reviews in plant sciences Vol. 33; no. 4; pp. 331 - 349
• Main Authors: Farooq, Muhammad, Hussain, Mubshar, Siddique, Kadambot H. M.
• Format: Journal Article
• Language: English
• Published: Philadelphia, PA Taylor & Francis 04.07.2014; Taylor & Francis Ltd
• Subjects: assimilate translocation; Biological and medical sciences; breeding; carbon; Carbon fixation; Chloroplasts; Climate models; Drought; Drought resistance; drought tolerance; Droughts; Environmental stress; filling period; Flowering; Fundamental and applied biological sciences. Psychology; genetic engineering; genetically modified organisms; Genetics; genomics; Global climate; grain filling; Grains; leaves; marker-assisted selection; Morphology; Photosynthesis; Physiology; Plant breeding; Plant morphology; plant stress; Precipitation; resistance mechanisms; Strategy; Stresses; terminal drought; Terminals; water stress; Wheat; Translocation; terminal drought; Monocotyledones; Metabolite; assimilate translocation; Grain filling; Review; Water stress; Terminal; Triticum; Gramineae; Angiospermae; Flowering; Spermatophyta; Genetic engineering; Plant sciences; Photosynthesis; Drought; breeding
• ISSN: 0735-2689; 1549-7836; 1549-7836
• DOI: 10.1080/07352689.2014.875291

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 critical for improving drought resistance in wheat, with marker-assisted selection being increasingly employed in breeding for this resistance. The limited success of molecular breeding and physiological strategies suggests a more holistic approach, including interaction of drought with other stresses and plant morphology. Furthermore, integration of physiological traits, genetic and genomic tools, and transgenic approaches may also help to improve resistance against drought in wheat. In this review, we describe the influence of terminal drought on leaf senescence, carbon fixation, grain set and development, and explain drought resistance mechanisms. In addition, recent developments in integrated approaches such as breeding, genetics, genomics, and agronomic strategies for improving resistance against terminal drought in wheat are discussed.