Combining ability and heterosis of tropical maize under acidic soil conditions

Abstract

The selection of inbred lines by combining abilities is an essential step for developing maize hybrids under abiotic stress. This research aimed to estimate the combining ability and heterosis of tropical maize under acidic soil conditions. Six inbred parental lines were crossed using the incomplete half-diallel mating design method Griffing II and evaluated using an augmented RCBD with three blocks and six hybrid checks replicated across blocks. The results revealed that combining ability variances affect all traits of maize, except GCA in grain yield. P13, P42, and L15 tended to have the best GCA in agronomic and yield components. Meanwhile, SCA of L152 x L26 (G03), L15 x B4B (G05), L26 x P13 (G08), and P42 x L15 (G10) had a significant effect on yield and several agronomic traits, followed by high positive heterosis of the hybrids. Similar to combining ability, selection based on MGIDI suggested that L152 × L26 (G03) and L15 × B4B (G05) were the best hybrids, determined by grain yield and six other traits. These findings can be used in maize breeding programs to tolerate acidic soil conditions.