Combining Ability of Yield and Yield Related Traits in Maize (Zea mays L.) Using Diallel Analysis

The present study was aimed to estimate the general combining ability (GCA) of inbred lines and the specific combining ability (SCA) of their crosses, to estimate the magnitude of heterosis in hybrid maize and to identify superior hybrids for yield and its component traits in maize. Seven inbred lines were crossed with diallel method II mating design. The resulting twenty-one crosses and standard check (CP 808) along with seven parents were evaluated at Other Cereal Crops Research Section, Department of Agricultural Research (DAR), Yezin (for plain region) and Aungban Regional Research Farm (DAR) (for hilly region) from May to September, 2023 in a randomized complete block design with three replications. Highly significant differences were observed in both locations for all traits, confirming the potential for effective selection to improve yield and yield‑related characteristics in ANOVA. Parent P6 (YZSI 21‑006) consistently emerged as the most valuable donor for both locations, contributing positively to a wide range of traits including ear length, row length, kernels per row, 1000 grain weight, shelling percentage, and grain yield, while also promoting earlier maturity through negative GCA values for tasseling and silking. In Aungban, P4 (YZSI 21‑032) demonstrated region‑specific superiority, combining high grain yield with reduced plant height, thereby enhancing lodging resistance. Among the hybrid combinations, P4×P5 proved to be the most promising cross in both regions, exhibiting superior SCA effects and favorable standard heterosis for grain yield, ear length, row length, and 1000 grain weight. Its positive heterosis for grain yield in Aungban, surpassing the commercial check CP 808, validates its potential for commercial exploitation. Other crosses such as P1×P2 and P1×P4 also showed stable yield advantages and desirable kernel traits in SCA effect in the same region. Therefore, these crosses can be utilized for developing high yielding hybrid varieties in maize.