Two major QTL for Cadmium accumulation in oat (Avena sativa L.) grains

Cadmium (Cd) is a heavy-metal that accumulates in the environment, in cereal grains and ultimately in humans posing significant health risks. With the increased demand on plant-based products, the production of oats for food products has increased as well, and with it the risk of uptake of Cd. However, limited research exists on the genetic control of Cd accumulation in oat grains. This study evaluated a panel of 620 Nordic spring oat breeding lines in field trials in Sweden during 2015–2021. GWAS was conducted for 596 lines for Cd grain content, thousand kernel weight (tkw), and hectolitre weight (hlw). Fifteen and six significant marker trait associations were identified for tkw and hlw, respectively. Some of which corresponded to previously reported QTL and some of which represent putatively new loci. Two new major QTL were identified associated with Cd grain accumulation located on chromosomes 3D (432.54 Mbp) and 4A (381.23 Mbp), explaining 34.69% and 27.92% of the phenotypic variation, respectively. Key message A total of 596 oat breeding lines were analysed for Cadmium accumulation in the grains. Genome-wide association studies identified two major QTL as well as strong candidate genes.