Apical Growth and Modification of the Development of Primordia During Re-flowering of Reverted Plants of Impatiens balsamina L

Impatiens balsamina L. was induced to flower by exposure to 5 short days and then made to revert to vegetative growth by return to long days. After 9 long days reverted plants were induced to re-flower by returning them to short days. Petal initiation began immediately and seven primordia already present developed into petals instead of into predominantly leaf-like organs. However, the arrangement of primordia at the shoot apex, their rate of initiation and size at initiation remained unchanged from the reverted apex, as did apical growth rate and the length of stem frusta at initiation. The more rapid flowering of the reverted plants than of plants when first induced, and the lack of change in apical growth pattern, imply that the reverted apices remain partially evoked, and that the apical growth pattern and phyllotaxis typical of the flower, and already present in the reverted plants, facilitate the transition to flower formation.