Genetic Analysis of Yield and Some Associated Characters in Crosses of Six Open-Pollinated Varieties of Maize (Zea Mays L.)

Various genetic parameters like combining ability, components of variation and heritability for eleven characters including yield of four exotic and two local open-pollinated varieties of maize were studied over a period of three years. Significant differences existed between varieties for all the eleven traits studied. Combining ability analysis indicated that both additive non-additive components of variation were important for days to tassel, silk and maturity, plant height; ear height, length and weight; kernel row number and kernel number per ear; 1000 kernel weight and yield per plant. Components of genetic variance analysis also indicated additive genetic effects for days to tassel, silk and maturity and yield per plant but non-additive for kernel number per ear. Both additive and non-additive effects were important for plant height; ear height, length and weight; kernel row number per and 1000-kernel weight. Heritability in narrow-sense was slightly above 60 percent for yield per plant, between 50 to 60 percent for days to silk and maturity and below 50 percent for all the remaining characters. In Fz! BC1 and BC2 generations the characters days to tassel, silk and maturity; kernel row number per ear and 1000- kernel weight showed heritability between 50 to 60 percent it was below 50 percent for the other characters.