Impact of Drought and Genetic Drought Resistance in Crop Plants

Among abiotic stresses, drought is the most severe abiotic stress in many parts of the world and is a grand problem in present-day climatic scenario. Drought is the prominent environmental stress, which is significantly hampering crop yield and its quality in the world. Climate change increases the odds of worsening drought in many parts of the world in the decades ahead, it damages the crop that has occurred because of abnormal metabolism and may reduce growth and death of crop development. The physiological activity of the crop is also influenced by water stress through suppressing photosynthesis and the consumption of assimilates in the expanding leaves. Crop production is determined by the existence of sufficient rain fall, especially in areas where crop production totally rely on rain fall, there is always risk of crop failure or yield loss due to moisture stress. In severe cases, moisture stress could lead to total crop loss. Drought stress occurs at different stages of growth and adversely affect yield and yield related traits, which leads to reduction in yield. The effect of drought stress is mainly depending on the developmental stage of the plant, degree and duration of the stress, genotypic capacity of species and environmental interactions. Crop plants have adaptation strategies to survive under drought stress by the development of various morphological, physiological and biochemical mechanisms. However, a plant may exhibit more than one strategy to cope with drought stress. Drought resistance is the mechanism(s) causing minimum loss of yield in a drought condition. Drought escape, dehydration avoidance, reduced transpiration or physiological factors are some drought resistance mechanisms. Eventually, global food security is threatened by climate change and the most challenging in the 21st century, affecting the supply of sufficient food for the increasing world population. The use of well-adapted and high-yielding varieties with resistance to drought stress is important to reach maximum yield potential as long as possible through minimizing the risk of climate change. Climate-smart agriculture is the only way to reduce the negative impact of climate variations on crop adaptation, before it might affect global crop production drastically.