ABSTRACT

Maize is considered as Queen of cereals, accounting to its global importance, genetic variability, combining ability, and molecular diversity were assessed in two sets of experiments during the kharif and rabi 2023. In the first experiment, inbred lines were evaluated using an augmented design to estimate genetic variability and trait correlations related to growth, grain yield, and yield-attributing characteristics. In the second experiment, 75 hybrids developed using line × tester design were evaluated alongside parental lines and checks using a simple lattice design to estimate general combining ability (GCA), specific combining ability (SCA), and heterosis.
The analysis of genetic variability revealed significant treatment effects across traits. Maturity traits registered high heritability with low genetic advance, while yield and related traits exhibited moderate to high genetic variation, indicating predominance of additive gene action in controlling these traits. Correlation analysis highlighted a positive association between yield-contributing traits and grain yield, supporting the potential for indirect selection to enhance yield.
Combining ability analysis revealed significant gca effects, particularly in inbred lines, IMLSB 883 and KDMI 15 for maturity traits and in BGUDI 135 and MAI 283 for yield-related traits. Among the hybrids, MAI-769 × CML 286, MAI-313 × CML 286, and MAI-283 × CML 451 recorded significant sca effects and high grain yield.
Parental molecular diversity analysis using 25 SSR markers, 20 markers generated polymorphism and 60 alleles, with an average PIC value of 0.45. UPGMA clustering grouped inbreds into eight major clusters, highlighting the sufficient genetic diversity.
Overall, the findings highlighted the presence of significant genetic variability, strong combining ability, and considerable molecular diversity in the inbred lines and hybrids studied. These results provide a valuable genetic foundation for future maize breeding programmes aimed at enhancing grain yield and other desirable traits.