Dimorphism in bud regeneration in flax (Linum usitatissimum)

Abstract

The study of the expression of morphogenetic potential in stem segments of flax (Linum usitatissimum L.) was undertaken as a function of donor plant age and level (basal, median, or apical) on the stem axis and in the absence of growth regulatory substances. Neoformation of normal buds (resembling seedlings) gave rise to shoots with no visible axillary buds, and a few roots were obtained from explants taken from young, vegetative plants; these organs were more numerous on basal than on apical explants. If the donor plant was in a prefloral or floral state, thus older and at a different physiological stage, a "modified" bud was formed, characterized by its slow growth, short thick stem and leaves, and sometimes with visible axillary buds. This type of bud was more numerous in apical than in basal segments. Callus was also formed and was reduced in size and limited to the cut extremities of explants when the donor plant was young, but was large and covered almost all the explant when the plant was older.