Estimation of Combining Ability in Maize (Zea mays L.) for Yield Using Half Diallel Method

The present set of investigation was conducted during Kharif, 2008 at Crop Research Centre, Pantnagar. The experimental material consisted of 12 maize inbred lines crossed in half diallel fashion to evaluate F_1s to estimate the genetic parameters for grain yield. All the 12 parents, 66 F₁’s along with two checks, Him 129 and Vivek Hybrid 9, were evaluated in randomized complete block design. Analysis of variance revealed that these genotypes differed significantly indicating the presence of adequate amount of variability among genotypes. Analysis of Variance of combining ability for GCA and SCA were highly significant indicating importance of both additive and non-additive genetic variances. The magnitude of SCA variance was greater than GCA variance showing preponderance of non-additive variances and suitability of material for hybrid breeding. The parental line, P12 (POB. 45 C8-2511-1-2-6) recorded maximum GCA effect and was found the best general combiner. On the basis of the GCA of the parents in 66 specific crosses, 68.18% of crosses were of ‘average/average’ parental combination. The maximum SCA effects were observed in crosses, P6 × P10, P9 × P11 and P10 × P12. These findings revealed that the crosses between high GCA parents did not always result in good F₁ combinations.