Submitted to: Maydica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/20/2006
Publication Date: 8/8/2006
Citation: Scott, M.P., Edwards, J.W., Bell, C.P., Schussler, J.R., Smith, J.S. 2006. Grain composition and amino acid content in maize hybrids representing 80 years of commercial maize varieties. Maydica. 51:417-423. Interpretive Summary: Maize has undergone intense selection resulting in tremendous increases in yields over the past 80 years. Little is known about the impact that this selection has had on grain composition. Maize is an important source of food, feed, and energy and it's composition determines how well suited it is to these purposes. In this study, we compare varieties that were widely grown in different eras ranging from 1920 to present. We identified changes in grain composition that have occurred over the course over this time period. While these changes are small, they have resulted in grain that is slightly better for some uses and slightly worse for others. Plant breeders will benefit by being aware of these trends. This study contributes to the body of knowledge used by breeders to decide the best way to improve the quality and quantity of corn produced.
Technical Abstract: In order to determine how development of modern hybrids has impacted grain composition and amino acid content, we characterized a set of cultivars that were widely grown in different eras from the 1920s through 2001. Grain composition exhibited clear trends with time, with protein decreasing and starch increasing. We examined the content of the nutritionally limiting essential amino acids lysine, methionine and tryptophan. On a per tissue mass basis, the levels of these amino acids dropped with time while on a per protein basis, their levels were not significantly changed. We conclude that the development of modern hybrids has resulted in maize with reduced protein content, but protein quality has not changed.