CHARACTERIZATION OF A NEW GIBBERELLIN RELATED DWARFING LOCUS IN POTATO (SOLANUM-TUBEROSUM L)

Gibberellins have been shown to be involved in such important processes as seed germination, flowering, maturation and tuberization in potato. Parents from Solanum tuberosum Groups Andigena and Tuberosum were found to produce progeny containing dark green, rosette dwarf individuals which could be completely restored to normal appearance by exogenous GA3. Test crosses indicated that this phenomenon can be explained by the action of a single locus, the dwarfing characteristic being conferred by the nulliplex condition. The gene symbol "ga1" is proposed. Group Andigena dwarfs demonstrated much greater tuberization compared to their normal full sibs or dwarfs restored to normal phenotype by exogenous GA3. The possibility that such gibberellin mutants may be involved in the long day adaptation of Gp. Tuberosum is discussed. This character may also be a useful tool for investigating various aspects of the gibberellin status of the potato.