Heterosis and combining ability for grain yield and its component characters in quality protein maize (Zea mays L.) hybrids

A Line X Tester mating set of eight newly developed Quality Protein Maize inbred lines were utilized to evaluate combining ability and heterosis for yield and its components characters, at Field Experimentation Centre, Department of Genetics and Plant Breeding, SHUATS, Allahabad, during kharif-2017. Analysis of variance revealed that significant differences among the parents and experimental hybrids for all the characters except anthesis silking interval. Combining ability analysis revealed that estimate of specific combining ability (sca) variances were higher than general combining ability (gca) variances for maximum traits under study, indicating predominance of non-additive gene action of these traits. The parents LM-13 and DMR-N21 were identified as best combiners for yield and its related traits. The best experimental hybrid, on the basis of per se performance, sca effect and standard heterosis for grain yield per plant and its component was LM-13 X IC32809 was followed by DMR-N21 X IC-32809 and LM-13 X IC-31899. Parents BBB-B2-NBBB, TSK-194and DMR-N21 recorded positive significant GCA for protein content indicating these parents are good combiner for protein content. Further, the study of analysis of variance for combining ability revealed the preponderance of non-additive gene action for all of the traits favouring the exploitation of heterosis breeding.