Line × Tester Analysis of Early Generation Inbred Lines for some Agronomic Traits in Maize

Maize (Zea mays L.) is the most versatile crop among cereals that grows well in a wide range ofenvironments. Promising maize populations (and their hybrids) could be used as a source for inbred line developmentas well as cost-effective alternatives to single-cross hybrids. This study was aimed at determiningcombining ability and grain yield performance of S1 lines derived from ten maize populations. These populationswere crossed in half diallel design and the resulting 45 cross combinations were further explored for theiruse as source of elite inbred line development in a line × tester experiment conducted at Cereal Crops ResearchInstitute, Pirsabak and Maize and Millet Research Institute, Yousaf wala during Kharif 2016. A total of 164testcrosses from four testers were evaluated for yield and other traits (days to anthesis, kernels ear-1, 100-grainsweight) in RCB design with two replications. Analysis of variance showed significant differences among hybrids,lines and testers. Differences due to site × hybrid interaction for grain yield were also significant. Non-additivegene action was predominant for the inheritance of the studied traits. Tester, T-4 was the best general combinerwith desirable GCA for kernels ear-1 and grain yield. The testcrosses i.e. (P8 × P10-3) × T4, (P6 × P10-1) ×T4, (P8 × P10-1) × T4, (P6 × P9-2) × T4, (P2 × P3-1) × T1, (P1 × P5-2) × T1 and (P4 × P10-3) × T3 were thebest performers in terms of maximum grain yield (above checks) and desirable SCA effects. Another 33 crossesexhibited positive SCA effects for 100-grains weight and grain yield and could possibly be utilized in maizebreeding programs for developing high yielding maize hybrids accompanied with other desirable attributes.