Author
Duvick, Susan | |
Pollak, Linda | |
Edwards, Jode | |
WHITE, PAMELA - ISU |
Submitted to: Maydica
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 6/1/2005 Publication Date: 6/1/2006 Citation: Duvick, S.A., Pollak, L.M., Edwards, J.W., White, P.J. 2006. Altering the fatty acid composition of Corn Belt corn through Tripsacum introgression. Maydica. 51:409-416. Interpretive Summary: Corn oil has many uses and is known to have good flavor quality but its nutritional quality would be improved by altering the fatty acid composition. Increasing the level of oleic acid in the oil would offer many health benefits, like reducing coronary disease. On the other hand, increasing the level of saturated fatty acids could possibly lead to a margarine spread made without trans fatty acids, which contribute to poor cholesterol profiles in the blood. Adapted corn has little variation for levels of these fatty acids, so other germplasm sources are needed in order to develop corn with altered fatty acid levels. By using corn with genes from a grassy wild relative, we developed lines with high oleic and high total saturated fatty acids. We used traditional plant breeding methods to develop the lines. There is great potential in this germplasm to make additional gains in breeding for high oleic and high total saturated fatty acids, as well as new unique combinations with nutritional importance such as high oleic with high stearic acids. Oil from hybrids of these lines can lead to healthier oils, healthier food products, and new uses for corn. Technical Abstract: Corn breeders need sources of genes for altering the fatty acid content of corn oil that are not available in Corn Belt germplasm. Previously we determined that lines developed from corn introgressed with genes from Tripsacum dactyloides had useful variation for fatty acid composition. We conducted this study to validate that the trait could be transferred to Corn Belt inbreds using traditional plant breeding techniques to create lines with altered fatty acid composition useful for an oil quality breeding program. Based on their fatty acid profiles, corn lines were selected from an open pollinated population that was introgressed with genes from Tripsacum dactyloides. These introgressed corn lines were both selfed and backcrossed to Corn Belt lines while undergoing selection for various fatty acid compositions. The lines and S1 and S3 progeny from the backcrosses were compared to commercial Corn Belt hybrids and inbreds in an experiment using a randomized complete block design with two replications at two locations near Ames, Iowa. The plants were hand pollinated and hand harvested. The fatty acid compositions were analyzed by using gas chromatography to characterize the fatty acid methyl esters made from the corn oil of 5 individual kernels from each ear. Levels of the two types of fatty acids we targeted, oleic acid and saturated fatty acids (palmitic and stearic acids), were greatly increased by selective breeding within the Tripsacum introgressed corn germplasm. New corn oil products with more healthful fatty acid compositions and products with reduced trans fats can be developed from these corn lines. |