The amount of free asparagine in grain of a wheat genotype determines its potential to form harmful acrylamide in derivative food products. Here, we explored the variation in the free asparagine, aspartate, glutamine and glutamate contents of 485 accessions refecting wheat worldwide diversity to defne the genetic architecture governing the accumulation of these amino acids in grain. Accessions were grown under high and low nitrogen availability and in water-defcient and well-watered conditions, and plant and grain phenotypes were measured. Free amino acid contents of grain varied from 0.01 to 1.02 mg g−1 among genotypes in a highly heritable way that did not correlate strongly with grain yield, protein content, specifc weight, thousand-kernel weight or heading date. Mean free asparagine content was 4% higher under high nitrogen and 3% higher in water-defcient conditions. After genotyping the accessions, single-locus and multi-locus genome-wide association study models were used to identify several QTLs for free asparagine content located on nine chromosomes. Each QTL was associated with a single amino acid and growing environment, and none of the QTLs colocalised with genes known to be involved in the corresponding amino acid metabolism. This suggests that free asparagine content is controlled by several loci with minor efects interacting with the environment. We conclude that breeding for reduced asparagine content is feasible, but should be frmly based on multi-environment feld trials. Key message: Diferent wheat QTLs were associated to the free asparagine content of grain grown in four diferent conditions. Environmental efects are a key factor when selecting for low acrylamide-forming potentialRead less <