Towards stable wheat grain yield and quality under climatic instability

Global wheat production is likely to be affected by projected warming and water scarcity. As climate changes faster than breeding, we focused on genotypic and environmental effects on grain production and quality of present wheat cultivars. To mimic the continuous challenges farmers face given the erratic rainy seasonal and temperature pattern of the Eastern Mediterranean, 15 commercial hard spring wheat (HSW) cultivars were evaluated at Gilat Research Center, Israel, over four seasons constituting 33 independent dryland field environments. Grains of HSW samples from commercial and experimental nurseries across Israel over three seasons were also analyzed to represent the Eastern Mediterranean wheat agroclimatic span. Samples were analyzed for grain yield and quality traits. High humidity and mild temperature during grain filling were associated with higher production, flour extraction, and dough extensibility; whereas high precipitation was mainly associated with lower protein, lower gluten content, and dough tenacity. Correlation between grain protein content and wet gluten was affected by environment and is cultivar dependent, as precipitation during a specific phase plays a major factor for some cultivars, while others are affected more by temperature, humidity, or other factors. Test weight and gluten index showed the clearest relation between performance and variation, enabling to identify cultivar stability across environments. Stable cultivars are more acceptable in the market, however, if a specific quality parameter is highly important for the millers and/or the bakers then the stability of this parameter under multiple growth conditions might serve as a decision support tool for on-farm commercial cultivar selection.