Non-additive gene effects for creeping-root in lucerne (Medicago sativa L.).

Both general and specific combining abilities for creeping-rootedness of lucerne were found to be highly significant although there were substantial differences among genotypes for both parameters. These results indicate that both "additive" and "non-additive" gene effects are involved in the genetic substrate of creeping-rootedness; hence utilization of heterosis would seem to be the most appropriate procedure for further improvement in this trait.