XVI International Botanical Congess
In Nicotiana, leaf blades are initiated along the lateral edges of the dorsal surface of the leaf primordium. A codominant mutation was isolated that displaces leaf blade initiation ventrally. Currently, we are determining if the blade is initiated on the ventral domain or if the dorsal domain is extended ventrally. Leaf mesophyll orientation is unaffected with normal adaxial palisade and abaxial spongy mesophyll in typical locations. Heterozygous plants produce ectopic leaf blades from stem tissue. Carpels are inverted and plants almost always female sterile although male-fertile. Homozygous plants are semi-lethal. The meristem becomes disorganized and hyperinitiation of leaves appears to consume it. Implications of this mutation on the concept of dorsoventrality will be presented.