Combining Ability Studies over Environments in High Altitude Elite Inbred Lines of Maize (Zea mays L.)

The experimental material comprised of 66 F1’s generated by crossing twelve diverse inbred lines of maize(Zea mays L.) in a half diallel fashion and their parents were evaluated in RBD in two replications at two locations during Kharif, 2008. The pooled analysis revealed that both gca and sca were influenced by environments, which suggested that studies are being conducted over the environments to get unbiased estimates. The sca x e interaction was greater than gca x e interaction for most of the traits. The compassion of relative magnitude of gca and sca variances indicated greater magnitude of sca variances for all the traits, indicating greater importance of non additive gene action for the inheritance of these traits. PMI- 298, PMI-67, PMI-69, PMI-117, PMI-224 and PMI-118 were best general combiners for grain yield and yield attributing traits. The most promising crosses, in order of merit for grain yield, were PMI-67 × PMI-69, PMI-48 × PMI-224, PMI-360 × PMI-401, PMI-118 × PMI-360, PMI-03 × PMI-64, PMI-64 × PMI-67, PMI-64 × PMI-118, PMI-117 × PMI-298, PMI-224 × PMI-298, PMI-117 × PMI-360, PMI-224 × PMI-298, PMI- 117 × PMI-360 and PMI-69 × PMI-401. The result of the present investigation revealed that in general there was no relationship between GCA effects of the parents and the SCA effects of the single crosses. However mean performance of single crosses was largely dependent upon the mean performance of the parents involved so high gca value of parents is no guarantee of high SCA effects of their crosses