bioRxiv preprint doi: https://doi.org/10.1101/2021.09.01.458275; this version posted September 3, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. TITLE: Simultaneous Dissection of Grain Carotenoid Levels and Kernel Color in Biparental Maize Populations with Yellow-to-Orange Grain AUTHORS AND ADDRESSES: Mary-Francis LaPorte1, Mishi Vachev1†, Matthew Fenn2†, Christine Diepenbrock1* 1University of California, Davis, Department of Plant Sciences, Davis, CA 95616. 2Cornell University, Plant Breeding and Genetics Section, School of Integrative Plant Science, Ithaca, NY 14853. †Indicates equal contribution. *For correspondence:
[email protected], +1(530)754-0666. ABSTRACT: Maize enriched in provitamin A carotenoids could be key in combatting vitamin A deficiency in human populations relying on maize as a food staple. Consumer studies indicate that orange maize may be regarded as novel and preferred. This study identifies genes of relevance for grain carotenoid concentrations and kernel color, through simultaneous dissection of these traits in 10 families of the U.S. maize nested association mapping population that have yellow to orange grain. Quantitative trait loci (QTL) were identified via joint-linkage analysis, with phenotypic variation explained for individual kernel color QTL ranging from 2.4 to 17.5%. These QTL were cross-analyzed with significant marker-trait associations in a genome-wide association study that utilized ~27 million variants. Nine genes were identified: four encoding activities upstream of the core carotenoid pathway, one at the pathway branchpoint, three within the α- or β-pathway branches, and one encoding a carotenoid cleavage dioxygenase.