Flint-Garcia Lab

Corn For The People:
Using Genetics, Genomics, and Breeding to Explore Maize Diversity for Food and Flavor

We are interested in various aspects of genetic diversity in maize:

How levels of genetic diversity affect our understanding of the genes controlling agronomic traits.
How selection impacted kernel composition, including protein, oil, starch, and amino acid content.
Apply this knowledge to improving maize for human interests such as food and beverage flavor, aroma, and texture.
Diversify the genetic base of US maize by utilizing landraces and teosinte.

Maize was domesticated from teosinte (Zea mays ssp. parviglumis) in southern Mexico around 9,000 years ago. Early selection on a handful of genes resulted in large changes in plant, ear, and kernel morphology. As the early domesticate was carried north and south across the Americas, this primitive maize adapted to diverse environments and human uses. This adaptation resulted in open-pollinated populations called landraces, heirlooms, or heritage varieties. In the early 1900’s, studies of inbreeding and heterosis launched the era of hybrid corn and the commercial hybrid seed industry. Intense selection during modern breeding resulted in inbred lines and hybrids derived from only a handful of productive heirloom varieties.

Large-scale sequencing projects indicate that approximately 2% (1,000 genes) of the ~50,000 genes of maize have been selected during domestication and/or plant breeding (improvement). Genes that have experienced artificial selection have greatly reduced genetic diversity in modern germplasm, and therefore cannot contribute to variation for agronomically important traits. Also of significance, selected genes will not be identified through conventional genetic analyses such as QTL analysis and association mapping.

Hybrid yellow dent corn was bred to be very productive and rapidly replaced existing heirloom varieties in the 1950’s in the United States. There is very wide genetic and phenotypic diversity in landraces that was lost during this process. This is true for many genes involved in kernel composition traits as these traits were targets of selection during modern breeding, but most importantly for food quality traits as these traits are largely neglected by seed companies in the United States.

My research program focuses on seed traits and seeks to integrate research on inbreeding and adaptation of landraces to develop better tasting and more nutritious food corn. We have initiated multiple projects to characterize the landraces (heirlooms) from the US and other regions around the world, improve US heirlooms for agronomic characteristics, and explore food properties of heirlooms to increase corn use in the human diet.

"Of all creation

by all civilization,

the highest praise

belongs to maize.

Ablaze in phase

with admiring craze,

we forever raise

this amazing maize."

Walton C. Galinat,

1995.