Combining Ability in Quality Protein Maize Using Diallele Crosses Among Five Inbred Lines

A study was conducted to assess the magnitude of combining ability in a half diallel cross. Materials involving 10 hybrids and 5 parents of quality protein maize (QPM) were evaluated in 2013/2014 at the Institute for Agricultural Research farms, IAR. Ahmadu Bello University, Zaria. The analysis of variance for the seven agronomic traits viz: days to 50% tasseling days to 50% silking, plant height, ear weight, ear height, ears per plant and grain yield indicated significant (p < 0.05) amount of variability among the genotypes for all the seven traits studied, variances for general combining ability (GCA) were highly significant for all traits except ear height and ear weight. Variance for specific combining ability (SCA) were highly significant for days to 50% tasseling, plant height, ear height, ears per plant and ear weight. Among the parents sammaz 17 was the best general combiner with high GCA effects for grain yield, as well as negative GCA value for days to 50% tasseling and days to 50% silking. Among the hybrids Sammaz 14 x Sammaz 32 and Sammaz 37 x Sammaz 36 showed significant SCA effect in the desired direction. The hybrid with the best yielding quality and earliness to tasseling and silking was sammaz 14 x Sammaz 32 followed by sammaz 37 x Sammaz 36. Key Words: Combining ability, quality protein maize, diallel.