ARS | Publication request: Evaluation of the Methionine Content of Maize (Zea mays L.) Germplasm in the Germplasm Enhancement of Maize Program

Submitted to: Plant Genetic Resources
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 28, 2009
Publication Date: February 27, 2009
Citation: Scott, M.P., Blanco, M.H. 2009. Evaluation of the Methionine Content of Maize (Zea mays L.) Germplasm in the Germplasm Enhancement of Maize Program. Plant Genetic Resources. 7:237-243.

Interpretive Summary: Livestock and poultry diets in the US are made of corn that has been supplemented to create a nutritionally balanced diet. Amino acids such as lysine, tryptophan and methionine are among the nutrients that must be added as supplements in this way. Corn with increased content of these amino acids would require less supplementation, making diets less expensive to produce. Plant breeders use germplasm to improve corn, however, little germplasm has been characterized for it's content of amino acids. The GEM program seeks to develop novel germplasm as a resource for plant breeders. We characterized the aminoa acid content of GEM germplasm and identified lines that with superior amino acid content. This information is valuable to plant breeders who will apply it in developing new varieties. This ultimately benefits consumers and producers of livestock and poultry products by reducing the cost of animal feed.

Technical Abstract: The GEM (Germplasm Enhancement of Maize) program is a cooperative effort between the USDA-ARS, private industry and public researchers to broaden and enhance the germplasm base of maize. In this program, selected accessions from the Latin American Maize Project (LAMP), and seven tropical hybrids donated by Dekalb to the GEM Project, were crossed to elite proprietary inbred lines contributed by commercial plant breeding programs. In most cases, the resulting hybrids were crossed to a second commercial inbred line and the resulting 25% exotic hybrids were used as breeding crosses for further development. We developed a process for evaluating the content of the essential amino acids methionine, lysine and tryptophan in the grain of GEM germplasm that balances the need for multi-year evaluations with the constantly changing entry list of this germplasm screening program. Very little variation was observed for tryptophan and lysine content, but a number of GEM lines had methionine or lysine levels that were significantly better than corn-belt checks and some were competitive high-amino acid checks.