Objectives

Our current project aims to develop a genome level understanding of the causal variants that determine the levels of five essential and limiting dietary micronutrients in maize grain, and most other cereal crops: the four B vitamins (B₁, thiamine; B₂, riboflavin; B₃, niacin; B₆, pyridoxine) and vitamin E. This research will develop the fundamental knowledgebase needed to enhance these micronutrient levels in grain such that diets in which maize is a major staple will provide a more balanced nutritional content. This work will provide guiding principles for undertaking analogous efforts in other agricultural crops and enable predictive breeding for diet-based micronutrients.

Specific objectives are:

1. Perform genome-wide association studies (GWAS) with the maize Ames inbred line panel (n~2,000) to identify and resolve quantitative trait loci (QTL) controlling accumulation of these five micronutrients.
2. Assess the role of rare alleles by generating and analyzing segregating F2 populations derived from Ames lines that are extreme outliers for traits.
3. Determine the contribution of expression QTL (eQTL) and PAVs to vitamin composition using whole transcriptome data obtained from grain 24 days after pollination (DAP) in a 500 inbred line panel that represents the phenotypic extremes of the Ames panel.
4. Perform genomic prediction with the Ames panel to accelerate the efficiency of breeding improved grain micronutrient composition in developing countries.
5. Disseminate the impact of this project to the broader scientific community and public through a set of activities that engage students, postdoctoral associates, scientists and the public.