In plant-based foods, tocochromanols and specific carotenoids (beta-carotene, beta-cryptoxanthin, and alpha-carotene) are dietary sources of vitamin E and provitamin A, respectively. As with all essential nutrients, vitamins A and E are required at minimal levels in the human diet to maintain optimal health. Even though sweet corn is the third most commonly consumed vegetable (24.1 lb/person) in the U.S. after tomato (86.3 lb/person) and potato (83 lb/person) (USDA-ERS, 2011), the sweet corn varieties routinely consumed in the U.S. still do not provide adequate daily levels of these two essential nutrients. Processed foods are routinely fortified with synthetic vitamins in the U.S., but this is not possible for fresh-market vegetables such as sweet corn.
While the vitamin A requirement in the U.S. is largely met through fortification, surprisingly large proportions of the U.S. population still do not obtain the daily recommended dietary amount of vitamin E and the two non-provitamin A carotenoids, lutein and zeaxanthin, that delay onset of age-related macular degeneration― a leading cause of irreversible blindness in elderly populations of Western societies. Carotenoids and tocochromanols are also antioxidants and provide additional health benefits related to heart disease, vision, and specific cancers. Improving the nutritional quality of crops through plant breeding, termed biofortification, is a cost-effective and sustainable approach to potentially help address such nutritional deficiencies in the human population.
As the 4th highest producer of fresh-market sweet corn in the nation, New York’s sweet corn crop had a value of $68.4 million in 2012. Breeders, growers, processors, and consumers of sweet corn in NY and throughout the U.S. will benefit from locally adapted, superior-performing orange-grain sweet corn germplasm with high provitamin A and vitamin E content. Ultimately, this work is intended to serve, promote, and benefit the health and nutrition of residents of New York State and beyond. In collaboration with Margret Smith (Cornell University), William Tracy (University of Wisconsin-Madison), and Dean DellaPenna (Michigan State University), the two major objectives of this research are to (i) conduct a genome-wide association study to identify genes and favorable alleles responsible for quantitative variation of grain carotenoid and tocochromanol levels in a sweet corn diversity panel; and (ii) develop and validate marker-based prediction models to convert locally adapted sweet corn germplasm to dark orange grain with high provitamin A and vitamin E content.