Author
 |
Pollak, Linda |
|
Submitted to: Latin American Maize Project Final Report
Publication Type: Book / Chapter Publication Acceptance Date: 7/1/1997 Publication Date: N/A Citation: N/A Interpretive Summary: Maize is extremely important to the U.S. economy due to the amount produced, its value to industry, and its export value. In 1983 a comprehensive survey on the use of exotic germplasm in commercial corn revealed that less than 1% of the U.S. germplasm base consisted of exotic germplasm, and tropical exotic germplasm accounted for only a fraction of that. It is prudent to develop alternate breeding populations from exotic sources to insure against unanticipated threats to production, or to accommodate alternate uses. The Latin American Mazie Project (LAMP) provided the evaluation information necessary to efficiently select exotic germplasm for enhancement. The U.S. Germplasm Enhancement of Maize project (GEM) was organized as a cooperative public/private effort to enhance LAMP germplasm. GEM will provide to the corn industry materials developed using germplasm enhancement of useful exotic germplasm. This germplasm will improve and broaden the germplasm base of maize hybrids grown by American farmers. Technical Abstract: More than half of the germplasm used in U.S. hybrids descended from a strain of the open pollinated variety, Reid's Yellow Dent. The second most important open pollinated variety is Lancaster, which had a very similar origin to Reid's Yellow Dent. Although perhaps several hundred U.S. maize varieties were sampled by corn breeders in the early twentieth century, very few of them contributed to modern hybrid corn. While many have advocated the use of tropical maize germplasm for U.S. breeding purposes, little has filtered through commercial or public breeding programs and reached farmers' fields. Tropical accessions were selected from LAMP for use in U.S. breeding programs based on yield results from Stage 4 testcross experiments conducted in Puerto Rico and Mexico, Stage 4 testcross experiments conducted in all Homologous Area 1 countries, and testcross experiments conducted with Caribbean accessions and Corn Belt testers. Temperate LAMP accessions were selected based on yield results of Stage 4 testcross experiments (Oh43xMol7 and Bl4xB73 testers because these are the heterotic patterns used in the USA). In the U.S., the value of exotic germplasm will be recognized, leading to better funding for collection and maintenance of maize genetic resources. Maize breeders will cooperate to enhance the best LAMP accessions by developing breeding lines with both high yield and combinations of disease resistance, insect resistance, or superior values for maize users. By focusing on evaluating source material for value-added traits and releasing breeding lines with these data, maize hybrids will be developed with superior value for their ultimate use. |
