Heterosis and combining ability studies for quality protein maize

Ten maize inbreds were crossed as lines to eight testers (Quality Protein Maize donors) in Line X Tester mating design to generate eighty F1 crosses. The ninety-nine genotypes including 80 F1 hybrids along with their 18 parents and a check were evaluated in Randomized Block Design to estimate the General Combining Ability (GCA), Specific Combining Ability (SCA) and Heterosis of F1 crosses. Analysis of Variance revealed significant differences among genotypes, parents and crosses for all the traits. The interaction of Line × Tester was highly significant for all the traits. Both, non-additive and additive types of gene action were observed to influence the expression of traits among the crosses. Among the lines, CM 141, V335 and V351 were promising as observed to be the superior general combiner. Cross CM 141 × CML 161 was among the best cross as the cross recorded positive and significant SCA effect, high heterosis and high per se performance for grain yield and other important traits. Standard heterosis for grain yield ranged from -56.45 to 53.31 %. Based on combining ability and hybrid vigour, the lines V335 and V351 figured to be potential lines to be converted in to QPM lines to develop local QPM hybrids. The QPM donor CML 141 based on its GCA, SCA and heterosis estimates seems to be most promising donor for conversion programme