Combining ability analysis for grain yield and yield related traits in quality protein maize (zea mays l.)

Maize is a major cereal crop for human nutrition in Ethiopia. For communities that rely heavily on maize as the staple, development of maize cultivars with enhanced quality protein can be one means to fight protein malnutrition. Development of single cross hybrids significantly boosted up the grain yield potential of maize. Estimation of combining ability is main step in the development and evaluation of hybrids. Thus this study was conducted to estimate general combining ability (GCA) of parents and specific combining ability (SCA) of the crosses of quality protein maize (QPM).The crosses were made during 2016 by 6x6 half diallel mating design which produced 15 F1 single crosses. These single crosses along with three checks were evaluated in two replications of the alpha lattice design at Bako and Arsi Negelle during the 2017 main cropping season for their grain yield (GY) and related agronomic traits. Significant mean squares due to general combining ability (GCA) were observed for plant height, ears per plant, thousand kernel weight, ear length, ear diameter, kernel rows per ear and grain yield in across location results; indicating the importance of additive gene action in the inheritance of these traits. Inbred lines L3, L4 & L6 had high positive GCA effects for grain yield. Furthermore, the finding of this study indicates the possibility of developing high yielding QPM varieties for the mid-altitude agro-ecology of Ethiopia from the QPM inbred lines included in this study.