Micropropagation of Oncidium orchid by PLB techniques

Abstract

Auxin group and cytokinin group were examined for the effects of micropropagation of Oncidium orchid by PLBs techniques, with purposes of preservation of Vietnam breeds and supplement for demand of customers. MS was used for all experiments. It contained essentials elements, 10% (v/v) coconut water and 20 g/L of sucrose. Callus induction from shoot clusters of Onc. orchid obtained from 2,4D with concentration of 1 mg/L for the highest frequency induction (76.19%) and 0.25 mg/L for the biggest size of callus (8.02 mm). At the concentration of 0.75 mg/L NAA, the highest number of PLBs was achieved (98 PLBs) from callus clusters of Onc. orchid after 90 days of culture. Besides, 28.18 PLBs were the best result obtained from combination of 0.50 mg/L NAA and 0.50 mg/L BA from shoot cluster of Onc. orchid. Moreover, PLBs micropropagation could be gotten maximum number of PLBs at 1 mg/L NAA (79.21 PLBs) from start protocorm - like - bodies explants. Shoot induction and regeneration were afterward initiated. The best result was recorded at 1 mg/L BA (12.42 shoots) and combination of 0.25 mg/L BA and 0.25 mg/L NAA (11.66 shoots) from shoot explants. Shoots were 3 - 5 cm height and had 6 - 9 leaves. Finally, root generation was performed. NAA at 0.75 mg/L gave the highest number of root formation (2.64 roots) and at 1 mg/L NAA, it gave the longest length of root (12.58 mm).

Key words: 2,4D, BA, callus, micropropagation, NAA, PLBs, root, shoot