Plant regeneration through callus initiation from anthers and ovules of Scabiosa columbaria

Anthers and ovules of Scabiosa columbaria L. were cultured in vitro to determine whether gametophytic cells would proliferate and/or a protocol for plant regeneration could be developed. Several factors were tested, including explant type, donor plant, cold pre-treatment, and medium composition. Callus induction frequency varied among treatments, indicated by significant effects of explant type, medium composition, and their interactions. Histological analysis revealed numerous sites of callus induction, however, gametophytic cells did not proliferate. Stepwise removal of growth regulators and simultaneous lowering of sucrose from the nutrient medium, resulted in initiation of embryogenesis or shoot organogenesis, and allowed plant regeneration. Under the conditions tested, regeneration capacity was donor related, because only material of one donor responded. Regenerants were diploid (except one mixoploid individual), but showed various types of flower heads. They were probably of sporophytic origin.