Abstract:
Information on the combining ability and heterotic patterns of maize germplasm is of great value to maize breeders. The objective of this study was to determine the heterosis and combining ability of seven yellow University Maize inbreds (UMI) as lines and five Quality Protein Maize as testers (QPM) lines in a line x tester fashion to understand the genetic architecture, breeding behavior, recombination potential and prediction of progeny performance. Significant differences among the hybrids were observed for all 18 characters indicating the existence of genetic variability. The line x-tester analysis revealed the importance of dominance gene action for all the characters. Parents CML 144, CML 145 in lines, and UMI 524 in testers have superior gca effects and per se performance. On the basis of per se performance, sca effects, and standard heterosis the hybrids CML 145 / UMI 189, CML 146 / UMI 427, CML 147/ UMI 427, and CML 147 / UMI 426 appeared to be best for heterosis breeding. Evaluation of hybrids based on significant gca and non-significant sca resulted in the identification of CML 143 / UMI 427, CML 144 / UMI 524, CML 145 / UMI 189, CML 145 / UMI 427, CML 145 / UMI 524 , CML 146 / UMI 189, CML 147/ UMI 524 as worthy genotypes for commercial exploitation and further utilization in recombination breeding programs. Maximum desirable heterosis over mid-parent was observed for carotene (78.68%) and Tryptophan (62.07 %) followed by single plant grain yield (56.61 %). For heterosis over better parent was observed for protein (54.47%) carotene (78.68%) followed by single plant grain yield (59.99%) . Among the hybrids, CML 143 x UMI189 recorded highly significant standard heterosis for carotene (41.66), lysine (13.29), and tryptophan (34.29), and also this hybrid was considered to be the best one for moderate yield (31.25 %) and moderate starch (4.92) and low protein(1.63%), which indicates that heterosis in general, can be commercially exploited especially in maize to improve nutritional qualities along with yield to suit the farmers so the exploitation of heterosis is the best method to increase the qualitative like lysine and tryptophan along with increase in the grain yield in maize.