Heterosis and Combining ability for yield and quality traits in Quality Protein Maize (Zea mays L.)

Abstract

A study of diallel analysis (excluding reciprocal cross) involving 10 maize inbreds (P1 to P10)  was carried out to identify high heterotic crosses and their relationship in terms of general and specific combining ability (GCA and SCA) for yield and quality traits in quality protein maize under  four different environments. Analysis of variance exhibited highly significant difference among them for all the traits in all the environments. The ratio of gca/sca was less than unity there by indicating the preponderance of non-additive gene action in the expression of all the characters studied. The parents P1, P4 and P10 for kernel yield, P1, P3 and P4 for oil content, P6 and P9 for protein content as well as tryptophan content, P2, P6 and P9 for lysine content were identified as most promising parents due to having good general combining ability in all environments. Among the crosses significant and desirable sca effects were found in P1 x P9, P1 x P10, P2 x P7, P4 x P5, P5 x P9, P6 x P8 and P7 x P9 for kernel yield, P2 x P7, P3 x P5 and P1 x P7 for oil content and P1 x P8 and P5 x P9 for protein, tryptophan and lysine content, respectively. On the basis of heterosis, the hybrids P1 x P10, P2 x P7, P4 x P5 for kernel yield per plant, P3 x P5 for oil, P5 x P9 for protein as well as tryptophan and P1 x P10 for lysine content gave consistent performance in all the environments. Therefore, these crosses could be utilised for further selection of high kernel yield and quality progenies to achieve quantum jump in quality protein maize improvement.