Induction of "filamentous structures" in wild type Antirrhinum majus flowers by benzylaminopurine

The cytokinin, N-6-benzylaminopurine (BAP), when applied to young infloresc ences of wild-type Antirrhinum majus L., resulted in the formation of chime ric "filamentous structures" in the dorsal region of the third whorl, the p osition where a stamen primordium is suppressed in wild-type flowers. In ad dition, BAP induced similar filamentous structures in between the first and second whorls, and this response was concentration dependent. The basal re gion of the filamentous structures was similar to the filament of a stamen, while the distal portion resembled a petal. These observations suggest tha t cytokinins may be site-specific factors involved in the regulation of flo ral organ identity genes or genes that control floral symmetry, i.e., the C YCLOIDEA gene.