Combining ability and heterosis of tropical maize under acidic soil conditions

This title will be presented on Friday, December 15, 2023 at 15.55-16.05 GMT+7.

Abstract

This title will be presented on Friday, December 15, 2023 at 15.55-16.05 GMT+7.

The selection of inbred lines by combining ability is an essential step towards the development of maize hybrids under abiotic stress.  This study aimed to determine the general combining ability (GCA) and specific combining ability (SCA) of tropical maize inbred lines and heterosis of their hybrids under acidic soil conditions. Six inbred lines as parents were crossed in the incomplete half-diallel mating design method Griffing II and then were evaluated using an augmented RCBD with three blocks and six hybrid checks repeated across blocks. The results revealed that GCA and SCA were significant for all traits 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) were significant for yield and several agronomic traits, followed by high positive heterosis of the hybrids. Similar to combining ability, the multi-trait genotype-ideotype distance index (MGIDI) suggested L152 x L26 (G03) and L15 x B4B (G05) as the highest-performing hybrids, determined by grain yield and six other traits. These findings can be utilized in maize breeding programs to develop a new variety of tolerance in acidic soils.