Combining ability of the genotypes/lines is a major factor in planning the breeding programme and for development of Heterotic hybrids. In the present study, twenty maize inbred lines were crossed to three diverse testers CM-111, GPM-549 and GPM-581 and the resultant F1 hybrids were evaluated in an alpha lattice design. General combining ability of lines which is representation of additive gene action was found to be significant for all the quantitative traits. Specific combining ability which is indication of non-additive gene action was found to be significant for the traits number of kernel rows per cob, number of kernels per row, cob girth, cob length, test weight and grain yield. Lines VL-058725, VL-1018527 and VL-108723 produced heterotic hybrids in cross combination with any of the tester due to their high GCA effects. Whereas, the lines VL-0536, SNL-1574 and VL-109086 interacted positively with their testers thus producing heterotic hybrids with high positive SCA. GGE biplot analysis was helpful in visualizing the combining ability effects and identify heterotic pattern among theinbred lines. Heterotic grouping based on SCA and mean grain yield was able to classify thirteen of the twenty inbred lines into two distinct heterotic groups i.e., Heterotic group A and B consisting of six and seven lines respectively. Heterotic group A consisted of lines with high GCA whereas, heterotic group B with low GCA lines. SCA effect showed significant positive correlation with all the quantitative traits and played a prominent role in determining the performance of hybrids, thus indicating the importance of non-additive gene action in developingheterotic hybrids
