Abstract

Determination of gene effects and combining abilities is a critical stage in maize hybrid breeding. In the present study, eight lines as female and two inbred lines (K3615.2 and A679) as tester were crossed and the resulting test cross progenies were evaluated in a randomized complete block design with three replications in 2011. During the growing period, several agronomic characters including grain yield were measured. Effects of lines and testers were significant on all the characters except for the grain yield, grains per row and days to maturity. This indicated the importance of additive gene effect in controlling most of the traits under investigation. Inbred lines L5, L10 and L14 were identified as good general combiners for grain yield because they showed significant positive GCA for this trait. L14 was superior compared with L1 and L5 because of significant positive GCA for most of the agronomic characters. These lines, especially L14, have potential additive gene effects to be utilized in the breeding programmes. T3 tester showed favourable additive gene effects for forage yield, its components, early maturity and shorter stature. Promising crosses were selected based on per se performance, standard heterosis and sca effects. The highest grain yield (107.313) belonged to L6 × A679 combination. The superiority of L6 × A679 hybrid can be attributed to its days to physiological maturity and more ears per plant. Higher grain yield and sca for forage yield were also observed in L7 × A679 and L14 × K3615.2. The cross L14 × K3615.2 had also large positive sca for grain rows per cob. Furthermore, negative sca of ear height, number of leaves above ear and grains per row were observed for L6 × A679, while positive sca of these characters was determined for L7 × A679. However, none of the scas for these combinations was significant. On the basis of grain yield, the genotypes L6 × A679, L7 × A679 and L14 × K3615.2 may be regarded as promising hybrids and should be evaluated further for grain yield and other desirable characters.