Understanding combining ability, heterosis and relationships of pod yield and yield contributing traits in groundnut (Arachis hypogaea L.)

The study was conducted to estimate the magnitude of heterosis and combining ability effects in groundnut for yield attributing traits. Fifty-six F1 hybrids developed through Line × Tester mating fashion were evaluated along with the parents in RCBD with two replicates during kharif-2022. Analysis of variance showed significant differences among genotypes for all the studied traits. The hybrids K 6 × ICGV 15402, VRI 10 × ICGV 15402, VRI 10 × ICGV 15426 exhibited positive heterosis for traits number of primary branches, pods/plant, kernel yield, 100 kernel weight and shelling percentage. Significant negative heterosis was observed for plant height in these crosses namely, CO 7 × ICGV 15412, VRI 7 × ICGV 15408 and VRI 8 × ICGV 15402. The study recorded significantly higher SCA variances compared to GCA variances, indicating a predominant role of non-additive gene action for all the traits studied. Line VRI 7 showed significant gca effects for all the traits except shelling % and hundred kernel weight and was identified as a best general combiner. The hybrids VRI 8 × ICGV15426 and VRI 7 × ICGV15402 revealed superior performance in terms of pod yield per plant. Notably, the cross VRI 7 × ICGV15402 exhibited outstanding performance across all traits, highlighting the prominence of a parent with strong SCA. Pod yield was significantly correlated with kernel yield/plant and sound mature kernel. Path analysis highlighted the direct and indirect effects of traits on pod yield, emphasizing the importance of kernel yield and sound mature kernel. This study underscores the utility of heterosis breeding in improving groundnut for enhanced yield and suggests specific parent combinations for future breeding.