| Abstract: | Young excised floral buds of Aquilegia were grown on defined medium containing kinetin, indoleacetic acid (IAA), or gibberellic acid (GA3). Only when 10−6 or 10−7 m kinetin was added to the basal medium was there a significant increase in the number of initiated whorls of primordia. Buds on the basal medium or on medium with IAA or GA3 failed to initiate carpels. On medium with 10−6 or 10−7 m kinetin, buds successfully initiated a normal whorl of five carpels. A high level of inorganic nitrogen was also required for the initiation of carpels. With 10−5 m kinetin, individual buds initiated from 6–18 carpels. Staminodial primordia of these buds were replaced with carpels, or the floral apex enlarged to accommodate a single whorl of many carpels. Kinetin did not support the further differentiation of the floral organs. Sepals, petals, and carpels did differentiate on medium with GA3, but stamens aborted. However, on medium with GA3 and kinetin, stamen primordia differentiated into short filaments and anthers. Further unknown growth factors appear to be required for the complete differentiation of floral primordia into mature organs. |
