ASSESSMENT OF COMBININGABILITYAND HETEROSIS FOR YIELD AND YIELD RELATED TRAITS IN MAIZE ( ZEA MAYS L.) J.B. Wadhavane, Harshal A. Avinashe* and Nidhi Dubey Department of Genetics and Plant Breeding, Lovely Professional University, Phagwara-144411 (Punjab) India Abstract The present investigation was conducted at Department of Genetics and Plant Breeding, School of Agriculture, Lovely Professional University, Jalandhar, Punjab during 2015-2016. The experimental material consisted of 7 inbreed lines with 3 tester in maize and 21 F 1 s, along with one check (P-1543). All these are were grown in a Randomized Block Design (RBD) with three replications. The hybrids were evaluated to know the extent of heterosis and combining ability for grain yield per plant, yield contributing characters in maize. Considerable variability existed among the genotypes for all the characters studied as observed from the significant mean squares due to genotypes. Combining ability analysis showed the predominant role of non-additive gene action for all characters studied. The line I-07-19-6 was found to be good general combiner and tester CML-269 was found average combiners for grain yield per plant. Crosses I-07-19-6 x CM-140, I-07-19-5 x CML-269 and I-07- 26-7 × CML-269 revealed high specific combining ability effects for grain yield per plant. The hybrids I-07-19-6 × CM-140, I- 07-19-2 × HKI-193-1 and I-07-19-5 × CML-269 were identified as superior hybrids as it recorded high percentage of relative heterosis, heterobeltiosis and standard heterosis for grain yield per plant along with other characters. These hybrids were identified as potential hybrids for widespread cultivation and commercial exploitation. Key words: Combining ability, Heterosis, Maize. Introduction Maize is the third most important cereal grain in world and it’s mainly utilized for direct human consumption and livestock feed. One of the most important objectives of maize breeding is the production of high yielding hybrids. Good results have been achieved in increasing maize yield through the successful exploitation of heterosis. Maize is a highly cross pollinated crop and the scope for the exploitation of hybrid vigor will depend on the magnitude of heterosis and direction, biological feasibility and the type of gene action involved. Maize is one of the world’s leading crops cultivated over an area of about 161.0 million ha with a production of about 822.0 million tons and average productivity is 5100 kg/ha -1 (Food Corporation of India, 2015). Maize is not only used as food, feed and fodder but also used for some five hundred different industrial purposes for manufacturing. Maize has been widely cultivated as a rainfed crop in India. Recent studies have shown that maize can be successfully grown during rabi in many parts of the country due to evolution of new improved cultivars and assured irrigation facility as well. The yield level of maize during rabi season is considerably higher than that of kharif due to its higher water and fertilizer use efficiencies. More over recent emphasis on development of hybrids meant for both the seasons, has paid rich dividends in terms of higher maize production and productivity in the country. Material and methods The experimental materials consisted of seven lines I-07-21-3, I-07-26-7, I-07-27-9, I-07-19-2, I-07-19-4, I- 07-19-5, I-07-19-6 and three testers HKI-193-1, CML- 269, CM-140 of maize with diverse genetic base. Their 21 cross combinations were recovered through Line × Tester mating design. The 21 F 1 s, 10 parents and one standard checks (P-1543) were grown in a randomized block design with three replications with spacing of 60 × 20 cm at Department of Genetics and Plant Breeding, Lovely Professional University, Jalandhar, Punjab during 2016. Five randomly selected plants in each replication for each cross were used for recording observations viz., Plant Archives Vol. 18 No. 2, 2018 pp. 1756-1760 e-ISSN:2581-6063 (online), ISSN:0972-5210 *Author for correspondence : E-mail : havinashe@gmail.com