Combining Ability, Gene Action and Heterosis Estimation in Quality Protein Maize (Zea mays L.)

A field study was conducted using eight parents and 28 F1 cross combinations of quality protein maize during rabi 2012–13 with objective to identify the best parental genotypes and cross combinations. None of the tested parents were found good for general combiner with respect to yield attributing traits and yield. Inbred lines I-07-6-4-4(P₂), I-07-65-18-3 (P₅) and I-07-65-13-1(P₆) were found good general combiners for direct yield attributing traits whereas inbreds I-07-13-1-3(P₁), I-07-65-13-1(P₆) and I-07-595 (P₇) contributed maximum genes for protein and its related traits. Among the hybrids, P₇ x P₈, P₂ x P₃ and P₆ x P₈ exhibited positive and significant specific combining ability effects for ear weight. High standard heterosis values were observed for lysine content whereas low values of heterosis were observed for tryptophan in protein over standard check HQPM1.