Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/15/1997
Publication Date: N/A
Citation: Interpretive Summary: Farmers continue to demand higher-yielding corn hybrids with improved disease and insect resistance and agronomic characteristics. In addition, value-added traits, such as corn with higher feed value, offer new opportunities. One way to meet these needs is through introduction of new genes into the existing gene pool. An international project was conducted in Argentina, Chile, Uruguay and the USA which evaluated more than 12,000 landrace corn populations from germplasm banks. The objective was to identify germplasm with potential to improve commercial hybrids. After two evaluation stages, countries selected and interchanged a total of 69 populations. These 69 were crossed to adapted materials and evaluated among all countries to select the best for each country. Results showed that preliminary evaluation needs to be done in the country in which the accession will be used. The project identified populations that performed well in all countries. Using these populations in a cooperative improvement effort would benefit commercial corn companies in the Western Hemisphere. This information will be of most interest to those interested in corn improvement.
Technical Abstract: The Latin American Maize Project (LAMP) evaluated more than 12,000 accessions (mostly landrace collections) in 11 Latin American countries and the USA. The objective of LAMP was to identify useful germplasm to use in breeding programs for improving the productivity of commercial hybrids and varieties. Temperate locations in Argentina, Chile, Uruguay and the USA (HA5) evaluated throughout the Americas 1692, 988, and 69 accessions in th first, second, and third stages respectively. In general, the accessions per se showed silk delay indicating lack of adaptability of the material. The 69 selected accessions were topcrossed with B73 x B14A, Oh43 x Mo17 and SR76. Topcrosses were evaluated at locations in the four countries. The topcross results in each country identified germplasm equal or superior to the performance of the checks, indicating that selected germplasm has broad adaptability and could be used to increase yield and improve combining ability. Even though topcrosses showed significant improvement for silk delay and stalk lodging, additional improvement is needed to facilitate wider use of the material. The results show high correlation between the performance of the accessions per se and topcrosses in each country indicating that preliminary evaluation needs to be done in the country in which accessions will be used. Some accessions performed well in almost all the countries and should be utilized in a cooperative enhancement effort. The best accessions should be crossed with the best lines of similar background to form breeding crosses for using in recurrent and pedigree selection.