Estimates of heterosis and potence through model fitting of ten quantitative traits in onion

Abstract

This investigation was undertaken to measure the heterotic effects and adequacy of the additive-dominance model in onion. Maximum crosses exhibited significant heterosis over mid and better-parents for most of the characters indicating good sign for improvement onion varieties. Potence found to be non-significant in maximum crosses indicating the absence of dominance. Significant and non-significant χ2 values with [h] and without [h] were noted in different crosses for different characters. In all the crosses for number of leaves except P1  P3 with dominance showed non-significant χ2 values indicated that the model is adequate. Besides, P1  P3 and P1  P5 for bulb weight, P2  P5 for bulb yield/plot with dominance showed non-significant χ2 values as well as significant potence indicated the adequacy of the model. Again, crosses P2  P3 and P3  P4 without dominance for bulb weight and bulb yield/plot showed the adequacy of the model. A similar trend was recorded for bulb volume in all the crosses except P1  P4 and P2  P5. The adequacy of the model indicated that only additive and dominant genes are responsible for controlling these traits. From this study, it may conclude that crosses P1  P3 ,P1  P5, P2  P5, P3  P4 and P3  P5 are promising in respect of bulb weight, bulb yield/plot and bulb volume and indicate that they would likely help do successful breeding plan easily for the improvement of potential varieties in onion.