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High frequency callus
induction and plantlet regeneration from different explants
of Picrorhiza kurroa
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a medicinal herb
of Himalayas
H. Sood and R.
S. Chauhan*
Departmet
Of
Biotechnology and Bioinformatics, Japee University of
Information Technology, Waknaghat,
Solan-173 215 H. P. India.
*Corresponding author. E-mail:
rajinder.chauhan@rediffmail.com.
Tel.: 91-1792-239231.
Abbreviations: BA, 6-benzyladenine; IAA,
indole-3-aceticacid; NAA, 1-naphthyleneacetic acid;
IBA, indole-3-butyric acid; KN, kinetin; MS,
Murashige and Skoog (1962) medium.
Accepted
26 January, 2009 |
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Picrorhiza kurroa is a medicinal herb prevalent in the North-Western Himalayan
region at an altitude of 3000 - 4300 m. It is a rich source
of hepatoprotective picrosides; picroside-i and picroside-ii
and other medicinal metabolites such as picroside-iii,
picroside-iv, apocynin, androsin, catechol, kutkoside, etc.
Being pharmacologically important and listed as an
endangered herb, optimization of in vitro conditions
for callusing and regeneration is of paramount importance
not only for the selection of cell lines with enhanced
content of phytopharmaceuticals or in the genetic
transformation of P. kurroa. Moreover, the
regeneration hold a great promise in the production of
metabolites in cell cultures. Callus cultures were
established from different explants such as leaf discs,
nodal and root segments of P. kurroa. Callus
induction was highest (70%) in root segments followed by
leaf discs (56.3%) and nodal segments (38.3%) on MS medium
supplemented with 2,4-D (2 mg/l) + IBA (0.5 mg/l) + sucrose
3% (w/v) + agar-agar 0.8% (w/v). The callus cultures derived
from different explants were differentiated into multiple
shoots on MS medium containing different concentrations and
combinations of BA, KN and IBA. Regeneration was highest in
the calli derived from root segments and leaf discs on MS +
BA (2 mg/l) + KN (3 mg/l) + sucrose 3% (w/v) + agar-agar
0.8% (w/v) with 76.7 and 72.2% calli forming shoot primordia,
respectively. Most of the nodal segment derived calli got
differentiated into roots rather shoots. Comparative
callusing and shoot regeneration from different explants
revealed that root segments are the best explant for in
vitro studies in P. kurroa. The rooted plantlets
were acclimatized to the external environment through
hardening and eventually transferred to pots.
Key
words:
Explants, callusing, regeneration, Picrorhiza kurroa. |
