Genomic insights and breeding strategies for nixtamalization moisture content in hybrid maize (Zea mays)

Abstract

Nixtamalization moisture content, a measure of the quantity of water absorbed during the nixtamalization of a grain, has a large impact on the end-quality of masa-based products. An application to predict nixtamalization moisture content from raw inbred and hybrid maize (Zea mays L.) grain was recently developed, but its utility in a breeding context has not been assessed. Here, important breeding considerations such as partitioning of variation, genetic architecture, and relationship with yield were assessed in diverse maize hybrids (n = 560), modern commercial hybrids (n = 10), and historically high-acreage hybrids (n = 15) grown in up to three environments across 2 years. This study demonstrated that nixtamalization moisture content is heavily influenced by growing conditions, but sufficient genetic variance is present to allow breeders to make gains from selection. There was not a substantial correlation between nixtamalization moisture content and yield, suggesting breeders can select for both traits without negatively impacting either trait. Both additive and dominant genetic action was observed, and genomic prediction was able to predict nixtamalization moisture content in hybrids with an average Spearman's rank correlation coefficient between 0.253 and 0.451 and a root mean square error between 0.00579 and 0.00691. The findings suggest that nixtamalization moisture content can be selected for early in breeding generations, allowing breeders to develop improved food-grade maize germplasm without negatively impacting yield.