Abstract

Drought is one of the most severe abiotic stresses in many regions of the world, and it is one of the most urgent issues in the current climate scenario. Drought-tolerant varieties are in high demand, which appears to be a challenging task for plant breeders. However, difficulties are complicated by crop production challenges on genetic and physiological bases. Drought is one of the most major environmental factors affecting crop productivity and quality around the world. Drought mostly impacts crops that thrive in wetland conditions, which account for 80% of all farmed land in the world. Climate change raises the likelihood of increased drought in many regions of the world in the next decades, causing crop damage as a result of abnormal metabolism and perhaps reducing crop growth, crop death, or crop development death. Drought resistance is defined as the mechanism(s) that cause the crop to lose the least amount of yield in a drought environment compared to the highest yield in a constant-free of optimal environment. Drought stress reduces the size of the leaves, stem extension, and root proliferation inside the soil; it also disrupts plant water relations and reduces water-use efficiency, reducing the plant’s yielding ability. Therefore, breeding for drought resistance is a good approach, combining both conventional and molecular approaches to develop a drought resistant variety. Root morphology research, proline estimates, and leaf rolling are all factors to take into account. Breeding improved drought-tolerant cultivars may be more effective if selection is based on a comprehensive approach to testing. Water stress also affects the crop’s physiological activity by inhibiting photosynthesis and assimilates consumption in the growing leaves. Plant hormones play a key role in transducing the stress signal, with abscisic acid (ABA) being the most important among them. To alleviate suitable crop productivity under environmental stresses, scientists developed various breeding strategies, such as conventional breeding, which works for both self-pollinated and cross-pollinated crops and is used to develop or improve cultivars using a basic conservative tool for manipulating plant genomes within the natural genetic boundaries of species. Pedigree, recurrent selection, back-crossing, and mutation breeding are among the conventional breeding strategies used to generate cultivars that can withstand drought stress.

Keywords: Drought; Conventional breeding; Photosynthesis; Crop yield