Breeding Potential of Maize Accessions from Argentina, Chile, USA, and Uruguay

Abstract

The Latin American Maize Project (LAMP) evaluated nearly 12 000 maize (Zea mays L.) accessions in 12 countries to select germplasm that can be used in breeding programs to improve commercial materials. In Argentina, Chile, Uruguay, and the USA, 1692 and 988 native accessions were evaluated in the first and second period, respectively. Sixty‐nine selected accessions were evaluated in all countries in the third stage. Accessions per se showed silk delay, indicating a lack of adaptation. The 69 selected accessions topcrossed with B73 × B14A, Oh43 × MolT, and SR76 were evaluated in the four countries to (i) identify temperate accessions from Latin America and the USA that could enhance yield, tassel and silk synchronization, lodging resistance, and maturity; and (ii) identify the U.S. heterotic group to which the accessions belong. The topcross results identified germplasm equal or superior to the performance of the checks in all countries, indicating that selected germplasm could be used to increase yield. Even though topcrosses showed significant improvement for silk delay and stalk lodging across the accessions, additional improvement is needed to facilitate wider use of the material. The Argentinean accessions had the best mean per se and topcross performance. Some accessions performed well in most countries and should be included in cooperative enhancement efforts.