Phenotypic diversity of key adaptive traits in advanced Nordic and Baltic spring wheat (Triticum aestivum L) breeding material

Wheat ( Triticum aestivum L.) has become the most widely grown cereal crop in the Nordic-Baltic region, however, due to climate change its yields are under increasing risk. Here we present results of international effort harnessing available wheat germplasm in the region for identification of tools and genotypes for breeding wheat varieties with improved yield stability. We formed a panel comprising 300 spring wheat genotypes from Nordic-Baltic region and studied their phenotypic diversity across different environments to identify genotypes with high potential for adaptation to changing climate. Field experiments were carried out in 2021 and 2022 in Estonia, Latvia, Lithuania and Norway. The performance and stability of yield (GY), protein content (PC), thousand kernel weight (TKW), test weight (TW), length of growing period (GP), and nine other traits – were studied. Drought and excessive rainfall occurred in the Baltic countries in 2021–2022, whereas weather was more stable in Norway. High variability for most, and significant GxE effect for all the studied traits was identified. We found out genotypes combining yield and quality with stability using the AMMI model-based Weighted Average of Absolute Scores index (WAASB). Finally, we selected nineteen superior genotypes that combined high yield with high values of important quality traits. Thus, combining broad Nordic-Baltic wheat germplasm with extensive field phenotyping, we identified promising breeding material to develop climate ready spring wheat varieties for the region.