Similar yield of modern maize hybrids under drought is provided by different physiological and metabolic mechanisms.

Evaluating the stability and drought tolerance of maize hybrids using multi-environment and multi-trait analyses

Abstract Drought remains a major constraint on maize productivity in tropical environments. Consequently, maize requires the identification of hybrids that combine high yield with stability across variable conditions. Ten tropical maize hybrids (eight promising candidates and two commercial checks) were evaluated across five environments (three optimal and two drought-stressed) using a randomized complete block design. Significant genotype, environment, and G × E effects (p < 0.01) were detected for nearly all traits, confirming substantial phenotypic variability. Drought stress reduced grain yield by 32.34%, primarily due to declines in ear weight and kernel size. Based on stress tolerance indices, GGE biplot, and WAASB analysis, hybrids G01, G02, and G08 were identified as the most drought-tolerant genotypes with broad stability. MGIDI further confirmed these selections, with G01 specifically achieving the lowest multi-trait distance to the ideotype under both optimal (1.12) and drought conditions (0.56). These results support the recommendation of these superior hybrids for deployment in tropical maize production systems prone to water deficit.

Stronger drought tolerance in C4 compared to C3 grass crops is achieved via both avoidance and resistance strategies.

Grasses comprise many of the world's major cereal crops, yet the physiological mechanisms underlying their resilience to environmental stress remain unclear. While C4 grasses tend to display higher water use efficiency than C3 grasses, little is known about the underlying physiological and structural dynamics during mild and severe dehydration. We tested the sequence of decline with dehydration in leaf, root and whole plant hydraulic functions, and in leaf gas exchange and photochemistry (Fv/Fm) across three C3 and three C4 grass crop species, along with their rehydration capacity post-dehydration. We observed distinct strategies between the C3 and C4 species in response to water stress. The three C4 species experienced their peak intrinsic water-use efficiency earlier during dehydration, displayed greater hydraulic supply relative to demand, and had higher turgor loss points. The three C4 species also showed greater resistance to photochemical damage and embolism under severe dehydration. The three C4 species had higher leaf capacitance, and experienced greater leaf shrinkage than the three C3 species. Our findings reveal that variation among photosynthetic types can be associated with contrasts in both drought avoidance and resistance traits, contributing to a broader understanding of how different photosynthetic pathways influence plant performance under stress.

Phenotypic and biochemical responses of high-yield tomato varieties to salinity and drought stress

Abiotic stresses can influence plant growth and productivity by causing physiological, biochemical, molecular, and morphological changes. Salinity and drought are increasing in frequency and intensity because of climate change. Therefore, this study assessed four high-yield tomato cultivars under 150 mM NaCl and 260 mM mannitol treatments to characterize physiological (i.e., chlorophyll level, root/shoot length, and relative water content) and biochemical responses (i.e., GLY I/II and DLDH enzyme activities, proline, and hydrogen peroxide). Results indicated that the four BARI tomato varieties showed genotype- and treatment-specific physiological and biochemical responses rather than a single uniform tolerance pattern. BARI tomato 2 maintained relatively higher shoot growth and showed strong proline accumulation under stress, whereas BARI tomato 16 showed higher chlorophyll retention, RWC, and lower H2O2 accumulation. GLY I, GLY II, and DLDH activities were significantly affected by variety, treatment, and their interaction, with reduced activities in several stress treatments after 120 h exposure. Moreover, there was a significant accumulation of proline and hydrogen peroxide in the plant leaves. These results showed that MG detoxification-related enzyme activities are useful biochemical markers for comparing tomato responses to salinity and drought. Thus, this research can provide stress-response profiles of high-yielding BARI tomato varieties at the seedling stage and reveal DLDH as an unexplored downstream component of MG detoxification-related metabolism during salinity and drought stress.

Reducing wheat yield loss under drought: A review of physiological mechanisms and practical countermeasures

Drought increasingly constrains global wheat production, reducing photosynthetic capacity, accelerating senescence, and shortening grain-filling periods. This review analyses current knowledge on physiological responses (root architecture, reactive oxygen species dynamics, photosystem stability, and abscisic acid signaling) and evaluates agronomic, chemical, nutritional, and genetic countermeasures that aim to protect yield under water deficit. We compare evidence from controlled experiments and field trials to assess which interventions deliver consistent yield benefits, and we highlight trade-offs between water conservation and carbon assimilation. Root traits that access deeper soil moisture, robust antioxidant systems, and balanced hormonal regulation emerge as key biological targets; meanwhile, seed priming, targeted nutrient management, and selected biochemical treatments show promise as near-term, scalable practices. Genetic approaches, including marker-assisted selection and introgression of drought-adaptive alleles, offer longer-term gains but require multi-environment validation. We identify gaps in cross-scale evidence, notably a shortage of multi-location, farmer-level trials that quantify the cost-effectiveness and environmental safety of chemical agents. Finally, we propose an integrated research agenda combining trait-based breeding, optimized nutrient regimes, and pragmatic agronomy to improve wheat resilience to drought. Implementing coordinated strategies across breeding and management is essential to sustain wheat yields as climate variability intensifies.

Differential response of wild and domesticated Solanum genotypes to water stress

Mechanisms of drought tolerance in legumes: physiological impacts, adaptive responses, and phenotyping strategies

A comprehensive analysis of drought-induced effects across various developmental stages in legumes, detailing the signaling networks that facilitate stress perception and response and analyzing the revolutionary role that high-throughput phenotyping could play in stress assessment and precision breeding.