Abstract:
Withania somnifera (L.) Dunal (Solanaceae) is
normally propagated by seeds. The percentage germination is
low, due to the presence of certain inhibitory compounds in the
fruit. Among the local and Indian cultivars, the Indian cultivar
is preferred by the pharmaceutical industry due to the starchy
nature of roots. The local cultivar is listed as a threatened
plant. In the present study, W. somnifera was successfully
mass propagated in vitro, acclimatized and compared with seed
raised plants.
The best callus production was observed in Murashige and
Skoog (MS) medium supplemented with 1.0 μM kinetin (Kin),
4.5 μM benzyl amino purine (BAP), and 1.5 μM naphthelene
acetic acid (NAA) within a 14 day dark period. Shoot initiation
was observed in calli produced from shoot tips and nodal
segments cultured in the above medium but not from the calli
produced from leaf pieces. The highest shoot multiplication
was observed in calli from nodal segments cultured in the
presence of 9.0 μM BAP and 1.0 μM indole-3-actic acid
(IAA) (11.30±1.60). Growth regulator free MS medium was
the best medium for rooting. In vitro produced plants were
acclimatized successfully (80%) in a potting mixture of river
sand: top soil: compost (2: 1: 1). The rate of photosynthesis was
higher in tissue cultured plants at three months (4.86±0.40 and
5.67±0.31 for morning and noon respectively) and six months
(6.20±0.52 and 6.67±0.33 for morning and noon respectively),
while stomatal resistance showed the opposite of that. TLC
fingerprints indicated that there was no significant difference in
chemical identities (steroids) present in tissue cultured and seed
raised plants.
