Regenerative Studies on the Excised Bulb Tissue of Various Tunicated-bulbous Ornamentals

II. Morphological Observations on Bulblet Formation from Bulb-scale Segments

Abstract

In the basal part of bulb-scale of 17 genera (20 species) in the Amaryllidaceae and 2 genera (4 species) in the Liliaceae, the vascular system consists of a number of parallel abaxial strands. Opposite to that, the system in 8 genera (11 species) belonging to the Liliaceae is composed of the adaxial ones.
When the basal parts were cultured aseptically on nutrient medium without growth regulators, the cultures from the former genera and the latter ones formed bulblets mostly on the abaxial side and the adaxial side, respectively, of the proximal end of the scale, though both sides had the capacity to regenerate bulblets.
Morphological observations of the scale base with the genera in the both families indicated that the bulblets were predominantly arised from the epidermal and subepidermal cells in the nearest location to each vascular strand.
The results suggest that the cells nearest to the strand contain more cell division stimuli, which move basipetally in the vascular tissue, than the cells at a distance from the strand.