Genetic Factors Underlying Dry‐Milling Efficiency and Flaking‐Grit Yield Examined in US Maize Germplasm

A small but important proportion of US maize (Zea mays L.) grain is channeled to create breakfast cereals and other food products; yet, little focus has been devoted to genetic improvement of corn hybrids to meet needs of dry millers and other end users in the cereal pipeline. This study was designed to evaluate a broad range of US maize germplasm for key dry‐milling traits: dry‐milling efficiency (DME), the proportion of flaking grits produced from dry‐milled maize grain, and flaking‐grit yield (FGY), the amount of flaking grits produced per unit land. Genetic parameters for DME and FGY were characterized based on grain produced over 3 yr, and the associations between dry‐milling, agronomic, ear, and kernel traits were assessed. Means for DME among experimental hybrids ranged from 24.0 to 36.0%. The DME was negatively correlated with grain yield and positively correlated with test weight; associations with other ear and kernel traits were weak despite being statistically significant in some cases. The DME is moderately heritable (h2 = 0.53) and controlled largely by additive gene action. A moderate amount (31%) of the variation in FGY was explained by multiple linear regression of grain yield and simple physical kernel properties: test weight, kernel thickness, and 100‐kernel volume. Genetic variation for DME in US maize germplasm was demonstrated, which could be exploited to develop new maize hybrids with improved DME and, ultimately, FGY. However, more work is needed to develop indirect selection approaches to predict DME and FGY at or before harvest.