2026/07/02 by Jatinder S. Sangha, Ron Knox, Andre G. Duarte +5 · 1 voice
Agricultural and Biological Sciences · Environmental Science · #Wheat and Barley Genetics and Pathology #Plant Water Relations and Carbon Dynamics #Plant Stress Responses and Tolerance
paper · pdf · doi:10.3389/fsufs.2026.1840301
openalex publication_date 2026/07/02 · openalex created_date 2026/07/03 · openalex updated_date 2026/07/23
Heat and water stress increasingly threaten wheat ( Triticum aestivum L.) productivity worldwide, underscoring the need for robust physiological markers that enable the identification of genotypes with stable yield performance across contrasting environments. Stable isotope signatures in plant tissues provide integrative measures of carbon assimilation and plant water relations and therefore offer potential as functional markers for crop improvement. Here, we evaluated grain Δ 13 C/δ 18 O ratio as a potential integrative physiological indicator of yield performance in a doubled haploid bread wheat population (genotypes) consisting of 208 lines and two parents grown under irrigated and rainfed conditions at a semi-arid location in Saskatchewan, Canada. Grain yield exhibited a positive association with the Δ 13 C/δ 18 O ratio, and this relationship remained a highly significant predictor of yield even after accounting for variation among genotypes and years. Genotypes with higher Δ 13 C/δ 18 O ratios also exhibited cooler flag leaf temperatures and higher canopy greenness (NDVI), indicating improved canopy function and plant water status. Together, these findings demonstrate that grain Δ 13 C/δ 18 O ratio integrates key physiological processes related to carbon assimilation and transpiration with potential to serve as a practical marker for selecting high-yielding Canadian wheat germplasm across contrasting water regimes.