Genetic variation and possible SNP markers for breeding wheat with low-grain asparagine, the major precursor for acrylamide formation in heat-processed products

BACKGROUND: In products made from wheat (Triticum aestivum) flour, acrylamide formation is almost exclusively determined by the level of free asparagine in the grain. Genetic variability for grain asparagine content was evaluated in order to assess the potential for acrylamide mitigation by breeding. RESULTS: Free asparagine levels in the grains of 92 varieties varied from 137 to 471mgkg-1, representing an approximate threefold difference between the low- and high-asparagine genotypes. Heritability was low, with a value of 32%, indicating that breeding cultivars with inherently low grain asparagine would be a challenge. A genome-wide scan with single-nucleotide polymorphism (SNP) markers identified nine SNPs that were significantly (P < 0.001) associated with variation in free asparagine. The significant SNPs were localized on chromosome 5A, and explained between 14% and 24% of the observed variation. These putative SNPs are candidates for further studies to develop molecular markers. CONCLUSION: Significant genetic variation exists for reducing acrylamide precursors in wheat flour, indicating that breeding and genetics could play an important role in mitigating the acrylamide risk in wheat products. The study identified a region on chromosome 5A that could provide a basis for further research to develop functional markers.