Effects of Plant Growth Regulators on Callus Proliferation, Plantlet Regeneration and Growth of Plantlets of Doritaenopsis Orchid

Supplement of 2,4-D and BAP into New Phalaenopsis (NP) medium was not effective for the growth of callus in Doritaenopsis orchid. Among the different combinations of BAP and NAA, 5.0 mg l-1 BAP + 0.1 mg l-1 NAA highly enhanced PLB formation from calli. For plantlet initiation from PLBs 0.5 mg l-1 BAP was suitable and higher concentration was inhibitory. Similar effect to that of BAP was found for NAA (0.5 mg l-1) and BAP + NAA (0.5 mg l-1 + 0.5 mg l-1) in plantlet initiation. For in vitro growth of plantlets, 0.5 mg l-1 of BAP was the best for leaf and shoot growth compared to that of for BAP and NAA. However, for root growth of plantlets 1.0 mg l-1 BAP + 1.0 mg l-1 NAA was the most suitable.