CHIMERAL NATURE OF THE PINWHEEL FLOWERING AFRICAN VIOLETS (SAINTPAULIA, GESNERIACEAE)

Pinwheel flowering African violets are bicolor forms that have a patterned arrangement of colors on the corolla segments. A median band of one color extends radially from the central portion of the corolla on each corolla segment and contrasts with the marginal color. In vitro culture of various tissues was accomplished, and observation of the flowering patterns of the regenerated plants supports the hypothesis that the cultivars ‘Valencia’, ‘Dardevil’, and ‘Desert Dawn’ are periclinal chimeras. Adventitious plants display a high proportion of monochromatic flowers of the same color as the lateral margin of the corolla segments. Petiole cultures from which the epidermal layers were removed yielded plants with flowers of the color of the central stripe of the corolla segments. Pinwheel flowering plants were regenerated through short‐term culture of whole inflorescences, suggesting that the African violet inflorescence may possess axillary vegetative meristems. These results support the contention that adventitious shoots may arise from the epidermal layer only (L.I), or with the participation of the epidermal and subjacent layers (L.I and L.II). These results contradict the recent conclusion that all three histogen layers of African violet participate in adventitious shoot organization.