Kaempferia galanga (L) is an aromatic perennial herb, which is widely used in Ayurvedic medicine. Dry tubers are imported in large scale to Sri Lanka due to lack of mass production in Sri Lanka. Disease susceptibility and higher cost of production have restricted its cultivation. Propagation of Kaempferia galanga is normally by rhizome cuttings but disease susceptibility of tender rhizomes restricts propagation in large scale. Propagation through other vegetative methods is not possible. Rahman et al. (2004) reported the possibility of obtaining plants through somatic embryogenesis but the survival rate was low. Therefore an attempt was made to develop a protocol for mass propagation of Kaempferia galanga through direct organogenesis. Leaf discs and axillary buds were used as explants. Axillary buds isolated from rhizomes of Kaempferia galanga mother plants were sprayed with 0.2% Captanä 2-3 days before collection. After that, they were placed on a wet paper lined tray and covered again with another wet paper. Five to six days later young axillary buds were emerged from nodes and they were used as explants. For leaf disc explants leaves were washed with soap and soaked in a solution of Teepolä for 15 minutes, and washed with running tap water for 45 minutes.
Both leaf discs and axillury buds were dipped in 5% Chloroxä (5.25% Sodium hyperclorite v/v) for 10-15 minutes under sterile conditions. Then they were washed 10% Cloroxä for 3 minutes and 70% ethanol for one minute each followed by two successive washings in sterile distilled water. Explants were cultured on MS basal medium (Murashige and Skoog, 1962) supplemented with different concentrations of Benzyl amino purine (BAP) and Indole acetic acid (IAA) (2.00 mgl-1 – 2.25 mgl-1 and 0.30 mgl-1 – 0.70 mgl-1 respectively). Sucrose 3% (w/v) and 0.8% agar were added to the media. pH was adjusted to 5.8.
Cultures were incubated under 16 hr light /8 hr dark at 26 + 1 0C temperature for 21 days. Callusing was not observed from both tested explants in any of the media tested. After 15 –18 days of incubation axillary buds were elongated in all combinations tested. MS supplemented with 2.25 mgl-1 BAP and 0.5 mgl-1 IAA showed the highest elongation (490 ± 10 mm). After 25-30 days of incubation in vitro grown shoots were cut and separated from the explant. Then they were subcultured on the same medium and incubated in 16 hr light at 26 + 1 0C temperature for shoot multiplication. MS medium was used as basal medium with above combinations of growth regulators.
The highest multiplication was observed in 2.25 mgl-1 BAP and 0.5 mg-1 IAA (7.0 + 0.02) shoots per explant. Further sub culturing on to the same medium induced roots. Seven-weeks old plantlets were removed from culture vessels, washed well to remove all agar and transferred to small plastic pots containing sand, soil and compost in 1:1:1 proportion by volume and kept in shade house covered with polythene bags, for acclimatization. 100% survival was observed when acclimatized plants were transferred to the field.
K M R T Wijekoon and W T P S K Senarath
Department of Botany, University of Sri Jayewardenepura, Sri Lanka