Estimation of Combining Ability of Maize Inbreds

The present study was conducted to assess the combining ability for grain yield and its related components by crossing six diverse maize inbred lines using a half-diallel mating design. A total of 15 F1 hybrids, along with their six parental lines, were evaluated in a randomized complete block design (RCBD) with three replications. Combining ability analysis indicated that both general combining ability (GCA) and specific combining ability (SCA) variances were significant for all studied traits, highlighting the importance of both additive and non-additive gene actions. Grain yield was found to be influenced by both types of gene effects. Most of the crosses exhibited significant and positive SCA effects for several traits, particularly those involving low × average and average × average general combiners. Parent P4 showed high GCA effects and demonstrated good general combining ability for most traits, except for number of rows per cob and number of grains per row. A comparison of SCA effects with the GCA effects of the respective parents revealed that crosses with high SCA effects for maturity, number of grains per cob, and grain yield per plant generally involved high × low general combiners. The majority of high-yielding crosses with superior SCA effects for grain yield and grains per cob also involved high × low GCA parents. Based on GCA performance, parents P3 and P4 were identified as promising genotypes and may be utilized as potential sources in future maize hybridization programs.