Linking Anthocyanin Diversity, Hue, And Genetics In Purple Corn

While maize with anthocyanin-rich pericarp (purple corn) is rising in popularity as a source of natural colorant for foods and beverages, information on color range and stability—factors associated with anthocyanin decorations and compositional profiles—are currently limited. Using the natural anthocyanin diversity present in a purple corn landrace, Apache Red, we generated a population with variable flavonoid profiles—flavonol-anthocyanin condensed forms (0-83%), acylated anthocyanins (2-72%), pelargonidin-derived anthocyanins (5-99%), and C-glycosyl flavone co-pigments up to 1904 µg/g—all of which contributed in part to the absorbance profile, used here as a proxy for hue. This variability offers targets of selection for breeders looking to expand both stability and the available range of colors that can be sourced from purple corn. With genotyping-by-sequencing of this population we mapped these anthocyanin profile traits. Major QTL for anthocyanin type were found near loci previously identified only in aleurone-pigmented maize varieties [ Purple aleurone1 ( Pr1 ) and Anthocyanin acyltransferase1 ( Aat1 )]. A QTL near P1 ( Pericarp color1 ) was found for both flavone content and flavanol-anthocyanin condensed forms. A significant QTL associated with peonidin-derived anthocyanins near a candidate S-adenosylmethionine-dependent methyltransferase was also identified, warranting further investigation. This population represents the most anthocyanin diverse pericarp-pigmented maize variety characterized to date. Moreover, the candidates identified here will serve as branching points for future research studying the genetic and molecular processes determining anthocyanin profile in pericarp.