Role of polarity in de novo shoot bud initiation from stem disc explants of Curculigo orchioides Gaertn. and its encapsulation and storability

The occurrence of strong polarity towards
shoot bud induction and the effect of cytokinin(s) on each
segment of stem axis, encapsulation and storability of de
novo Shoot buds of Curculigo orchioides Gaertn.
(Hypoxidaceae) have been documented in the present
communication. Maximum number of shoot buds arising
de novo from the stem discs (cross section) explanted from
proximal end on MS medium fortified with BAP and KIN
1 mg/L each. Stem discs from distal end were less efficient
in shoot bud induction. A combination of two cytokinins
(BAP and KIN) as a synergistic effect on shoot buds
induction from each segment of stem axis. Stem discs in
inverted position produced shoot buds from the lower
surface, showing strong polarity within the explant. Further,
storability and shoot development of sodium alginate
encapsulated shoot buds of Curculigo orchioides were
tested on half-strength Murashige and Skoog (MS) basal
medium fortified with coconut water (10% v/v). The frequency
of regeneration from encapsulated shoot buds was
affected significantly by concentration of sodium alginate
and the duration of exposure to calcium chloride. Shoot
buds encapsulated with 2.5% sodium alginate dissolved in
MS basal salts solution recorded significantly higher shoot
development than other treatments. A relatively short
(5 min) incubation with calcium chloride solution provided
uniform encapsulation of shoot buds that gave the highest
percentage (68%) of shoot development. Encapsulated
shoot buds could be stored at 4�C for 50 days without
reduction in viability as oppose to non-encapsulated shoot
buds, which showed 9.5% viability after 20 days at 4�C.
Encapsulated shoot bud developed into normal shoots.
Based on the present observations an improved protocol
may be developed for the rapid multiplication and conservation
of the endangered species—C. orchioides.