ANATOMICAL ANALYSIS OF DOUBLE-FLOWER MORPHOGENESIS IN A NICOTIANA-ALATA MUTANT

Anatomical analysis was performed using a double-flowered mutant of Ni cotiana alata Link & Otto. Flower doubleness resulted from petaloid mo dification of the androecium. Vascularized petal-like outgrowths arose from the anther, connective, and filament of the stamen. The vasculat ure in petaloid outgrowths from the anther and upper part of the filam ent originated from and was continuous with the vascular bundle of the filament. In contrast, the vascular bundles formed in the outgrowths from the lower part of the filament developed independently of the vas cular bundle of the filament and were not connected to it at any time. Emergences consisting of epidermal and ground parenchyma tissue and l acking vascularization arose from the filament.