Abstract:
The present work developed an efficient plant regen
eration and propagation system
via
direct organogenesis for
Morinda officinalis
How., a valuable endangered medicinal plant.
The effects of explant types on shoot induction, pl
ant growth regulators on shoot
proliferation
and
elongation and the subsequent rooting ability of sh
oots were examined.
Among the various types of explant, direct shoot pr
oliferation was successfully achieved
from shoot tips and nodal stem segments with around
95%
of the explants producing
approximately 5 shoots per explant after 8 weeks of
culture on optimal medium. On the
other hand, leaf and internodal explants did not pr
oduce any shoots. The most effective
cytokinin on shoot proliferation was 6-benzyladenin
e. When the concentration of 6-
benzyladenine was at 1.0-2.0 mg L
-1
, a high mean shoot number (about 5 shoots per
explant) was achieved. Shoot elongation was obtaine
d satisfactorily by transferring the
shoots to Murashige and Skoog basal media containin
g 2.0-3.0 mg L
-1
gibberellic acid-3
within 2 weeks. Rooting was 100%
on half-strength Murashige and Skoog medium
containing 0.2 mg L
-1
indole-3-butyric acid after 3 weeks of culture. Th
e plantlets were
acclimatized in the greenhouse and subsequently tra
nsferred to the field with 90%
survival rate.
Keywords:
Direct regeneration, Explants, Plant growth regula
tors.
