Diallel Mating to Determine Combining Ability for Important Economic, Agronomic, and Compositional Traits in a Diverse Set of Colored (Red, Blue, Purple) Maize [Z. Mays].

Maize genetic diversity includes an array of kernel colors (red, blue, purple) with blue concentrated in the aleurone and red primarily in the pericarp. These are minimally-utilized specialty corns when compared to the yellows and whites commonly grown. Red, blue, and purple pigments are antioxidant phytochemicals produced by the plant as secondary metabolites. Antioxidants have been linked to various anti-cancer and other anti-inflammatory health benefits. These alternate colors have been the subject of little breeding research and the potential for high grain yield and high phenolic content from the same hybrid has not been previously investigated. We evaluated 84 maize hybrids from a diallel mating design of 11 diverse colored inbred parents. A large portion of the observed genetic variation for total phenolics was general combining ability (additive gene effects), leading to a high narrow-sense heritability of 0.80. Importantly, very little genotype by environment (GxE) interaction was observed for phenolics, even when comparing diverse Texas and Iowa environments. This proved the trait analysis procedure to be robust in detecting and separating genotypes. Top combiners for phenolics were the purple corn ‘maize morado’ and red lines, with blue, yellow and white corn performing in descending order.