Black rice, also known as forbidden or imperial rice, has long been cultivated throughout Asia, though its origin remains disputed. The black colour trait is due to the accumulation of anthocyanins in the pericarp, which shows significant phenotypic variation. Based on indigenous knowledge, black rice has been incorporated into treatments for several diseases such as diarrhoea, vomiting, fever and kidney disorders. Recent scientific studies support the health benefits of black rice, including anti-oxidant, anti-diabetic, anti-hyperlipidemic and anti-cancer properties. While major structural and regulatory loci involved in grain pigmentation have been identified, it remains unknown how natural genetic variation and environmental effects, such as temperature and ultra-violet (UV) radiation, modulate black rice trait expression. It is suspected that UV radiation, particularly UVB, is a contributor to grain pigmentation. This may bring an interesting advantage to black rice cultivation in Australia, where high UV radiation prevails. Understanding the relationship between the genetics of anthocyanin regulation and UV radiation can assist breeding activities such as marker-assisted selection of varieties with high anthocyanin in response to UV. Therefore, this research aims to i) characterise phenotypic variations of a diversity panel of 191 black rice accessions with respect to the accumulation and composition of anthocyanin content under different UV regimes; ii) conduct a genome-wide association study (GWAS) to identify quantitative trait loci (QTL) for anthocyanin accumulation in response to UV treatment. Collectively, this will shed light on the genotype-by-environment (GxE) interactions of the black rice trait and pinpoint potential candidate genes for variety improvement.