Combining ability for grain yield and some important agronomic traits in Maize (Zea mays L.)

The 15 hybrids along with the parents evaluated in field under normal condition to determine the combining ability for grain yield and other agronomic traits in maize (Zea mays L.) at two years 2011 and 2012, using RCBD with three replications. Results of combined ANOVA revealed that year effect was significant for all the parameters. Based on diallel cross analysis according to Griffing method 2, the general combining ability (GCA) and Significant specific combining ability (SCA) were significant for all the traits and so in the inheritance of all the parameters, additive and non additive gene action are important. The GCA×year interaction effects were significant for plant height, ASI and grain yield. The SCA×year interaction effects were significant for days taken to tasseling, ASI and grain yield. This indicates high variability among the parents and crosses in their responses to different conditions changes in both years. The GCA/SCA variance ratio exhibited that all traits were predominantly under non-additive control and non-additive effects played a more important role than additive effects in all the parameters. Based on GCA effects (gi), σ 2 gi , σ 2 si and per se performance for each parent, SD\17 line for 100 grain weight, ASI and grain yield, SD\15 line for number of rows per ear, SD\10 line for number of kernels per row was suitable resources to increase grain yield. Therefore these inbred line probably have potential as parents of hybrid varieties, as well as for inclusion in breeding programmes, since they may contribute superior alleles in new populations for high grain yield. Furthermore, SD\3×SD\704 and SD\17×SD\704 proved to be the best crosses to increase grain yield.