MUTATIONS IN RUBUS: THEIR VALUE IN BREEDING AND PROBLEMS FOR PROPAGATION

Gene mutations from the recessive to the dominant in Rubus often have certain properties: they sometimes affect several characteristics of the plant, they often revert to the original form and their inheritance is often aberrant.
The extent to which these properties occur and limit the usefulness of gene L₁ and five dominant genes for spinelessness is described and discussed.

Mutations from the dominant to the recessive are not affected in these ways, but they are rarely expressed unless the parent cultivar is heterozygous for them.
Several examples of undesirable mutations are described.
They affect fertility or fruiting-lateral morphology and are a hazard to propagation, because they are seen only at the fruiting stage and are unwittingly multiplied in vegetative material.
Recessive mutations in polyploid blackberries are particularly unlikely to be discovered, but one is described that may have occured as a correlated response to selection fir spinelessness.

VI International Symposium on Rubus and Ribes

D.L. Jennings

https://doi.org/10.17660/ActaHortic.1993.352.50