Bud formation in leaves, leaf fragments and midrib pieces ofHeloniopsis orientalis (Liliaceae)

摘要

Isolated leaves, leaf fragments and pieces of the midrib portion devoid of lamina, ofHeloniopsis orientaliswere grown on an inorganic nutrient medium without organic nutrients and growth regulators in order to investigate their regenerative ability. Bud formation in intact, attached leaves occurs only at the tip, in isolated leaves at the tip and the base, whereas leaf fragments cut transversely at a distance from the tip and isolated midrib pieces form numerous shoot buds in a random distribution. Lamina fragments lacking midrib frequently fail to regenerate even after a long time of culture. It is suggested that endogeneous growth regulators in the leaf, especially the vascular tissues, play an important role in bud initiation. Very young leaves ofHeloniopsisare capable forming buds and roots when isolated from the mother plants.