QTL mapping and candidate gene analysis of element accumulation in rice grains via genome-wide association study and population genetic analysis.

Background: Toxic heavy metal elements in soils are major global environmental issues and easily migrate to crop grains to cause severe problems in human health, whereas moderately essential elements such as selenium are beneficial for human health. The accumulation of heavy metals and essential elements in rice grains and their genetic mechanisms are still poorly understood.

Results: We conducted genetic dissection of four toxic heavy metal elements (lead, cadmium, mercury, and chromium), one quasi metallic element (arsenic), and one essential element (selenium) in grains of 290 Xian and 308 Geng rice accessions through a genome-wide association study (GWAS) based on three statistical models and assays of element concentrations from three environments.