Patel RM and Shah RR, Journal of Herbal Medicine and Toxicology 1: 27-29 (2007)
Summary
In vitro regeneration was achieved in liquorice using nodal segments as an explants. The establishment of explants was noticed satisfactorily in all the treatments. However, it was recorded cent per cent on MS medium supplemented with BAP (0.5 mg/l) and NAA (0.05 mg/l). Earlier sprouting of explants as well as maximum length of shoot and number of nodes/shoot were reported on MS medium fortified with 1.0 mg/l BAP and 0.05 mg/l NAA. On other hand, maximum number of shoots/explant was produced on MS medium containing higher BAP (2.0 mg/l) level combined with NAA (0.05 mg/l). In vitro rooting was found better on full strength MS medium supplemented with IBA (0.5 - 1.0 mg/l). Maximum number of root and length of shoot were noticed in 0.5 mg/l IBA treatment. Further, rooted plantlets were hardened better in soil + leaf mould medium (1:1, v/v) and 72 per cent survival rate was obtained in this potting mixture. The technique developed may be utilized efficiently for producing true type and disease free planting materials during any time of the year.
Objectives
Standardization of the technique for rapid in vitro clonal
propagation of liquorice to obtain true to type planting
materials in large quantity
Materials
Glycyrrhiza glabra
Explant
Nodal segments
Initial culture
The explants (nodal segments) were washed thoroughly in running tape water for about 30 minutes and then cleaned with 10 per cent solution of detergent for 5 minutes. After rinsing thoroughly with double distilled water, the explants were surfaced sterilized by treating them with 0.1 per cent mercuric chloride solution for 3 minutes under aseptic condition in a laminar air flow cabinet. The traces of mercuric chloride were thoroughly washed with sterile double distilled water. Further, explants were trimmed of to the size of about 1.0 cm. Then, explants were quickly
inoculated on MS medium supplemented with 30g/l sucrose, hormones and gelled with 8 g/l agar. The culture was incubated at 25 ± 2℃ temperature with 1000 lux light intensity from fluorescence cool tube light in culture room for 16 h. The establishment of explants varies from 72 % to 100 %. Cent per cent establishment was recorded on MS medium fortified with BAP (0.5 mg/l) + NAA (0.05 mg/l) treatment, which was reported superior among all the treatments. Buds sprouted within 4 days of inoculation on BAP treatments up to 1.0 mg/l, whereas, it took 7 days on higher BAP level. Though higher BAP (2.0 mg/l) supported significantly maximum number of shoots per explant, length of shoot and number of nodes per shoot was the lowest in this treatment. However, which were found significantly higher on MS medium fortified with BAP (1.0 mg/l) + NAA (0.05 mg/l) treatment.
Shoot multiplication
The established explants were recultured on the same medium for 4 weeks for further
multiplication. Treatment BAP 0.5 mg/l in combination with NAA 0.05 mg/l was found statistically superior among all the treatments, which showed maximum multiplication rate as well as length of the shoot.
Rooting
The regenerated shoots were excised and transferred to rooting medium (different levels of IBA supplemented on half MS and full strength MS medium and cultured for 3 weeks. Rooting was significantly influenced by strength of medium and different levels of IBA. Rooting response on full strength MS supplemented with 0.5 to 1.0 mg/l IBA was found to be better than other treatments. Maximum rooting percentage, number
of roots/plant and length of shoot (cm) were registered on full strength MS supplemented with 0.5 mg/l IBA. There was no rooting response recorded at higher levels (0.5 and 1.0 mg/l) of IBA on half strength MS medium. The trend was reverse on full strength MS medium; no rooting response was being
observed at lower level of IBA.
Acclimation
Rooted plantlets were hardened and raised in
polybags. Survival of the plantlets was significantly
influenced by different potting mixtures. Among the various potting mixtures tested, soil + leaf mould medium (1:1, v/v) was found to be the best with 72% survival of the plantlets.