Genetic potential of tropical sweet corn hybrids and combining ability among parental inbred lines

Superiority of sweet corn (Zea mays L. saccharata) hybrid varieties is reflected by their performance per se, heterosis they reveal and combining ability of their inbred parents. This study was conducted to investigate performance, combining ability, heterosis and heritability revealed by 15 F1 tropical sweet corn hybrids from a half-diallel cross involving six diverse inbred lines, at two locations in Malaysia. At each location, the hybrids were evaluated for ear yield and yield components in a randomised complete block design, in comparison with their inbred parents and a commercial hybrid variety Hybrid 530 as control. Hybrids H11, H12 and H15 were found to be the most superior for yield and yield components, hence could be further tested in large-scale trials before release. Inbred lines FTT-1, EE0-2 and HAW-1 showed high positive GCA effects for yield and yield-related traits at both locations. Cross combinations HAV-2 × NTS-2, HSE-4 × NTS-2, NTS-2 × EE0-2 and EE0-2 × HAW-1 revealed high positive SCA effects for fresh ear yield and yield related traits at both location. Crosses among unrelated lines were found to produce superior hybrids. Both additive and non-additive gene effects were found important, although additive effects were predominating. The hybrids revealed substantially high heterosis, the highest being for number of ears per hectare and ear height. Moderate to high broad- and narrow-sense heritabi1ity estimates were displayed by the different traits measured