RESUMO
Successful shoot regeneration of Dendrobium nobile was achieved using thin shoot tip sections and triacontanol (TRIA) for the first time. Protocorm-like bodies (PLBs) or proliferating shoot buds were observed when thin shoot tip sections were cultured on the basal medium of Mitra et at. (Indian J. Exp. Biol. 14 (1976) 350) supplemented with 4.0 microg L(-1) TRIA. The highest percentage of explants (93%) produced PLBs or proliferating shoot buds (21) at 4.0 microg L(-1) TRIA-supplemented basal medium. All the newly formed PLBs or proliferating shoot buds survived and ultimately produced healthy shoots with 2-3 leaves. Shoots produced roots when cultured on basal medium supplemented with 2.0 microg L(-1) TRIA. The well-rooted shoots were transferred to pots containing charcoal chips, coconut husk and broken tiles (2:2:1), and a 92% survival rate was achieved. This work reveals that TRIA can be used as an effective growth regulator in the micropropagation and conservation of D. nobile.
