Combining ability for tassel characteristics in corn (Zea mays L.)

Fourty-five hybrids of a 10-entry diallel cross involving five Corn Belt inbreds and five tropical inbreds were tested to study the combining abilities for eight tassel characteristics. Corn Belt inbreds B 37, B 68, Mo 17 and Oh 545 produced hybrids with long or short tassel and a few branches, while tropical inbreds Hi 27, Hi 28 and Mp 68 : 616 produced hybrids with long or short tassel and many branches. Bath general and specific combining ability effects were highly significant for all tassel characteristics studied, indicating that both additive and nonadditive gene effects are involved. However, the predominance of GCA effects indicated the possible selection of hybrids with small tassel based on the individual inbreds. Two Corn Belt inbreds B 37 and B 68 appeared as the best combiners for the small tassel size in hybrids. Insignificant phenotypic correlations between length traits and branch number traits indicated the possible independent inheritance of these two tassel characters.