Heterosis and Combining Ability in Urdbean

The present study on a 6 × 6 diallel cross of urdbean (Phaseolus mungo L.) revealed high manifestation of heterosis for plant height, pods per plant and yield per plant. The predominant gene action appeared to be additive for plant height and non-additive for the other two characters. H70-1 was a good combiner for dwarfness and L35-5 was the best combiner for pods per plant and yield per plant. Three crosses have been identified as promising in terms of breeding value, based on their heterosis and sea estimates as well as gca effects of the parents. Non-additive variation observed in this material has been attributed to the genetic diversity of the parents selected on the basis of D² analysis. Significance of non-additive variation in self pollinated crops like urdbean has been discussed.