Changes in end-use quality parameters of two bread wheat cultivars under water stress and heatwave conditions

The baking industry requires a high level of uniformity in flour quality to meet its demands. Cereal production and nutritional traits are tightly conditioned by genotype and environmental factors. In the current study, the impact of temperature and rainfall on yield and end-use quality of two bread wheat (Triticum aestivum L.) cultivars (Camargo and Marcopolo) was analysed under field conditions. To do that a 2-year experiment (2018–2019) was carried out in three contrasting agro-climatic environments in Navarra (northern Spain). The results revealed that year (Y) (linked with temperature and precipitation) was the main factor controlling most crop agronomic performance parameters. Further, genotype (G), G x E, G x Y and the triple interaction had significant effects in the studied grain quality parameters, suggesting a well-differentiated response to different environments between both cultivars. More specifically, Marcopolo was more affected by drought, decreasing grain yield and starch but increasing quality parameters (protein, gluten and N content and dough extensibility (alveograph L) and dough baking strength (alveograph W). On the other hand, only heatwave affected protein and N and gluten content in the Camargo cultivar. Nitrogen content in grain was selected as a potential small-scale rapid parameter to predict quality traits due to its high correlation with protein and gluten content and alveograph W with correlations higher than r = 0.85. Finally, the C isotopic discrimination (Δ¹³C) and N isotope composition (δ¹⁵N) determinations showed that while Δ¹³C was the best trait predicting grain yield, δ¹⁵N was significantly correlated with some important end-use quality parameters. In summary, the current study underscores the fact that alongside a direct impact on crop yield, heat and water stress are target factors conditioning wheat grain quality traits.