Caralluma edulis (Edgew.) Benth. & Hook. f., (family Asclepiadaceae), rich source of antioxidants, is an
edible and nutraceutically important plant of the extreme arid regions of the Thar Desert. Anthropogenic
activities on established sand dunes, habitat destruction and harvesting/grazing of complete plant prior
to its reproductive maturity restrict the propagation by sexual means. Poor reproduction and seed set
have put adverse pressure on native populations of this endemic and slow multiplying plant of Indian
Thar Desert. Though it is categorized as endangered plant species, there is need for revision of its status as
this species can be spotted rarely in its habitat. There is also need for development of non-conventional
methods for propagation and conservation of C. edulis. Therefore, in vitro methods are good alternative
for multiplication, propagation and germplasm conservation of this nutraceutically important plant.
We used nodal segments obtained from field grown plants as explant for culture initiation. Murashige
and Skoog (1962) medium containing 6-benzyladenine (BA) (2.0 mg l−1) + additives proved optimum for
axillary shoot bud induction and produced 3–4 shoots. Shoots were amplified by repetitive transfer of
original explant and by subculturing of in vitro raised shoots on various concentrations of cytokinins
(BA and Kinetin [Kn]) alone and in combination with auxin (-naphthaleneacetic acid [NAA]). A high
rate (35.30
±
1.55 per culture vessel) of shoot multiplication was achieved on MS medium fortified with
0.5 mg l−1 BA + 0.5 mg l−1 Kn + 0.1 mg l−1 NAA and additives. In vitro produced shoots were rooted under
in vitro as well as ex vitro conditions. Half strength MS medium containing 1.5 mg l−1 indole-3-butyric
acid (IBA) was optimal for root induction under in vitro conditions. More than 95% shoots were rooted ex
vitro, when in vitro raised shoots were treated with IBA (300 mg l−1) for 4 min. Rooted plantlets by both
methods were hardened under different conditions of humidity and temperature in the greenhouse. The
percentage survival rate of ex vitro rooted plants was higher (97.1
±
2.02%) in comparison to in vitro rooted
plants (87.6
±
2.45%). The described protocol can be efficiently used for the large scale propagation and
conservation of germplasm of this edible, endemic and endangered plant.