Current maize (Zea mays L.) breeders prefer genetically narrow base populations. The F-2 of commercial single cross hybrids provide germplasm for extracting recombinant lines. In the present study a mating design was proposed for maize hybrids evaluation as source germplasm. The commercial single-cross hybrids, Constanza, Prezia and Nubia, distributed by the Commercial Company Pioneer Hi-Bred Int., were evaluated for their usefulness as germplasm. According to mating design three criteria were used: the percentage of inbreeding depression, the general combining ability and the specific combining ability. All experiments were conducted in honeycomb design, i.e., in 2002 the comparison of each hybrid with its F-2; and in 2003 the comparison of each hybrid with its diallel crosses and its testcross with an inbred line. Prezia had a lower percentage of inbreeding depression (28.9%), which also was combined with positive general combining ability (+7.5) and negative specific combining ability (-34.5). The estimated percentage of inbreeding depression was greater in Constanza (44.3%) and in Nubia (54.7%). Constanza also had negative general combining ability (-35.5), while Nubia had positive specific combining ability (+75.0). Therefore, the evaluation through mating designs showed that the commercial hybrid Prezia posseses more desirable genes and that its F-2 may be a more profitable germplasm for developing elite inbred lines. An additional criterion of genetic analysis of yield potential and its components, based on honeycomb design, showed that the commercial hybrid Prezia possesses a greater frequency of partially dominant alleles.
