Breeding Plants for Future Climates

Water Deficit Stress Tolerance Potential of Newly Developed Wheat Genotypes for Better Yield Based on Agronomic Traits and Stress Tolerance Indices: Physio-Biochemical Responses, Lipid Peroxidation and Antioxidative Defense Mechanism

“…In crop plants, the selection of high-yielding crop varieties by agronomists for growth and better production under such abruptly changing environmental conditions is mainly based on agronomic traits [ 56 ]. However, very little importance was given to physiological and biochemical mechanisms; their activity appears in phenotypic characteristics, including agronomic traits, due to their firm genetic attachment, especially under changing environmental conditions [ 19 , 57 , 58 ]. The morphological adaptations under water deficit stress include denser, deeper, and extended roots; reduced shoot growth to maintain a high root/shoot ratio; and delayed senescence, while the high content of chlorophyll, lower osmotic potential, and waxy leaf coverings indicate biochemical adjustments.…”

“…The crop genotypes that show tolerance against the adverse environmental conditions have a better capacity of cellular osmotic adjustment for maintaining plant–water relations, as well as reduced lipid peroxidation by maintaining the antioxidative defense mechanism. Therefore, the tolerance in crop plants against stressful environments is the combined effect of genotypic expression and physiological alterations that lead to phenotypic modulations with better agronomic performance [ 19 , 61 ].…”

“…Plant biomass production under water deficit conditions is linked with the better adjustment of water relations to maintain physiological and biochemical processes [ 19 , 28 , 62 ]. It is known that, to survive under water deficit stress, wheat experiences phenotypic changes and altered dry matter partitioning, e.g., a reduced biomass production and leaf area, a smaller decrease in root growth and reduced injury [ 63 ] that shows the adoptability for balancing the water status of plant tissues [ 64 , 65 ].…”

“…Plant physio-biochemical responses under water deficit stress include a decreased photosynthetic activity due to membrane disruptions by oxidative stress, the accumulation of toxic metabolites, and perturbations in cellular water relations, leading to a loss of turgidity, and reduction in growth rates and productivity. It is reported that, in crop plants, different physiological responses are linked with their resistance functions under drought, such as a high amount of relative water content, water potential and integrity of membranes [ 18 , 19 , 20 ]. Perturbations in biomass production are considered as one such important process which is sensitive to drought and linked with the disturbances in cellular water relations [ 21 ].…”

“…In this regard, the major focus of the breeders is to increase the productivity of wheat at a global level as it faces the serious threat of ongoing and increasing adverse environmental conditions. Due the various abiotic stress constraints, including drought, wheat production was compromised [ 19 , 28 ]. Therefore, the primary goal of wheat breeders is developing drought-tolerant wheat cultivars.…”