Plantlet regeneration and multiple shoot induction from protocorm-like bodies (PLBs) of medicinal orchid species, dendrobium crumenatum Sw.

Abstract

To investigate the suitable medium for in vitro shoot regeneration and plantlet growth of Dendrobium crumenatum Sw., individual protocorm-like bodies (PLBs) (about 4-5 mm in diameter) of Dendrobium crumenatum Sw. derived from MS medium supplemented with 0.5 mg/L TDZ for 60 days of culture were cultured on 6 culture media; Murashige and Skoog (MS) medium, MS medium supplemented with 15 % (v/v) CW, MS medium supplemented with 15 % (v/v) CW and 0.2 % (w/v) AC, Vacin and Went (VW) medium, VW medium supplemented with 15 % (v/v) CW, VW medium supplemented with 15 % (v/v) CW and 0.2 % (w/v) AC. After 4 months of culture, MS medium containing 15 % coconut water (CW) gave the highest percentage of shooting and number of shoots per explant of 96.0 and 9.5, respectively with a significant difference from other media. The addition of 0.2 % (w/v) activated charcoal (AC) significantly increased the number of leaves and roots. PLBs developed into complete plantlets. MS medium supplemented with 15 % (v/v) CW and 0.2 % (w/v) AC and VW medium supplemented with 15 % (v/v) CW and 0.2 % (w/v) AC gave the highest number of roots per plantlet and root length at 5.3 roots and 34.9 mm, respectively. After the transfer of rooted shoots to the greenhouse, 95 % of the regenerated plantlets survived and grew vigorously. Plantlets grown in vitro were successfully acclimatized in the greenhouse and showed normal development.