Estimates magnitude of heterosis, nature of gene action and combining ability in maize using Line ×Tester method for yield and attributing traits

Aim: This study aimed to evaluate genetic variability and heterotic potential among maize genotypes Zea mays (L.) for key agronomic traits, with a focus on kernel yield and related characteristics, to enhance hybrid development strategies. Methodology: Maize genotypes were assessed for growth, yield and quality traits. Analysis of variance (ANOVA) was conducted to identify significant differences, heterosis, and the combining ability was analyzed to determine the genetic potential of parent lines and hybrids. Results: Significant genetic variability was observed for all traits. The inbred line BLD 203, tester WNC 40108, and their hybrid BLD 203 × WNC 40108 performed best for kernel yield. The crosses BLD 176 × WNC 40108, BLD 226 × WNC 40108, and BLD 246 × WNC 40223 demonstrated the highest heterotic effects for kernel yield and improvements in several agronomic traits. The ratio of general combining ability (GCA) to specific combining ability (SCA) was less than one for all traits, indicating dominance of non-additive gene action. Interpretation: The study reveals substantial genetic diversity and hybrid potential in maize. WNC 40108 was identified as an excellent parent for kernel yield improvement, and the maize F1 hybrids BLD 176 × WNC 40108, BLD 226 × WNC 40108, and BLD 246 × WNC 40223 were found promising for yield related traits. These hybrids should be further evaluated across diverse environments for commercialization and their use in further maize improvement programs. Key words: Combining ability, Gene action, Heterosis, Kernel yield, Maize F1 hybrids