Floral determination in the terminal and axillary buds of Nicotiana tabacum L

Abstract

The terminal and axillary buds of the day-neutral plant, Nicotiana tabacum cv. Wisconsin 38, become determined for floral development during the growth of the plant. This state of determination can be demonstrated with a simple experiment: buds determined for floral development produce the same number of nodes in situ and if rooted. After several months of growth and the production of many leaves, the terminal bud became determined for floral development within a period of about 2 days. After the terminal bud became florally determined, it produced four nodes and a terminal flower. The buds located in the axils of leaves borne just below the floral branches became florally determined 5 to 9 days after the terminal bud became florally determined. Since florally-determined axillary buds were not clonally derived from a florally-determined terminal meristem, axillary buds and the terminal bud acquired the state of floral determination independently. These data indicate that a pervasive signal induced a state of floral determination in competent terminal and axillary buds.