Among the traits that may add commercial value to maize (Zea mays L.), those related to nutritional quality, specially protein and oil content, are of great interest to the feed industry. The objective of this work was studying the variability of protein and oil content, as well as yield, in a group of maize testcrosses. One hundred and twenty S1 families of the ESA23B maize population were crossed with two testers, an open-pollinated population (BR108) and an exotic line (CML269). Testcrosses were evaluated at two locations under a completely randomized block design with three replications. Ear and grain yield, protein and oil content were evaluated. The three-way interaction location x tester x progeny was significant for all traits, except for oil content. Differences among progenies were detected for all traits. Testcross means varied from 8.40% to 11.82% for protein content and from 3.77% to 5.10% for oil content. Hybrids with similar or superior means to the best check were identified for protein content, ear yield, and grain yield. Estimates of the interpopulation additive variance ranged from 0.553 to 1.124 for protein content; 0.034 to 0.057 for oil content (percent data); 132.13 to 521.74 for ear yield and 116.33 to 381.73 for grain yield (data in grams per plant). The population ESA23B can potentially be improved for all the traits studied. Associations among traits were weak, thus concomitant selection of quality and yield can be feasible.
Zea mays; breeding; topcross; nutritional quality; grains
