THE MODE OF INHERITANCE OF GRAIN YIELD IN TWO SINGLE-CROSS MAIZE (ZEA MAYS L.) HYBRIDS

Efficacy of maize breeding program based on maize grain and choice of breeding method depend on effects of genes included in expression of this trait. The objective of this study was to determine genetic parameters for grain yield using generation mean analysis (GMA) in two maize single-cross hybrids with one parent in common. Dominance gene effects were the most important in the inheritance of the grain yield. Significant values of two-gene epistasis were obtained. Interaction between dominant genes was in most instances of duplicate type, and was associated to a smaller effect of dominant genes. Less importance was estimated for epistatic effects between additive genes and additive and dominant genes which varied a large degree depending on the hybrid under consideration and on the environment. Higher values obtained for the interaction with the environment of the dominant in comparison to additive genes showed that it is not possible to predict with greater confidence the performances of the grain yield in both hybrids, so that successful estimation of the value of each inbred line can be derived only based on its performance in the particular hybrid combination.