E-mail: marwan.alamrani@slu.se

Spring wheat (Triticum aestivum L.) is one of the most important crops in northern Europe, particularly in regions where winter wheat cultivation is challenging. Climate change is expected to exacerbate the occurrence of pests and diseases, including the emergence of new pathogen races. To address this challenge, the CResWheat project has been established as a collaborative pre-breeding initiative involving Nordic spring wheat breeders and researchers.

The primary goal is to enhance the climate resilience of Nordic spring wheat by improving grain yield and its stability across different environments (sites and years), and self-sufficiency. CResWheat project evaluated more than 20 characteristics of 184 breeding lines and cultivars in 24 field trials at seven locations across four Nordic countries from 2021 to 2023. Most of the material was of European origin except for a few cultivars from the USDA and CIMMYT.

The focus was on agronomic traits, host plant resistance to various pathogens, and pre-harvest sprouting resistance. Yellow rust, caused by (Puccinia striiformis f.sp. tritici), a disease that has a severe effect on the yield of spring wheat, is one of the traits evaluated.. During 2022 and 2023 the screening was done at four different sites: Svalöv in Sweden, Holeby and Horsens in Denmark, and Vollebekk in Norway. Results from a genome wide association study (GWAS) across locations revealed quantitative trait loci (QTL) on wheat chromosomes 4A, 5B and 6A for resistance to yellow rust. Excluding the breeding lines from CIMMYT, two additional QTL were found on chromosomes 3B and 7A. Additionally, four and eight QTL were found in separate GWAS for Vollebekk and Holeby, respectively. The QTL on chromosome 6A has previously been identified incultivars and breeding lines with Nordic origin.

Based on the results of their phenotypic performance and further genetic analyses, genotypes were selected as parents for the development of segregating populations. These populations are currently under development and will be evaluated in multi-environment trials in the Nordic Region and Baltic States in the next years.

The project’s main outcomes will be DNA markers associated with important characteristics, populations and lines with combinations of beneficial characteristics as well as exchange of knowledge and material between the project partners, thus greatly benefiting breeding for climate-resilient spring wheat in northern Europe.