Micropropagation of Dendrobium kingianum Bidwill orchid

For the development of aseptic culture, Dendrobium kingianum Bidwill orchid pseudobulbs (2.0-3.0 cm long) with one or two terminal leaves were surface sterilized with 0.1% mercuric chloride solution and transferred to initial MSmedium, supplemented with auxin lAA at 0.5 mg dnr^ and cytokinin BA at1.0 mg dm-3. New shoots, which developed after 4-6 weeks of culture at thebase of pseudobulbs or at their upper nodes, were transferred to basal MS medium suplemented with an auxin (lAA or NAA) at 0.5 and 1.0 mg drn ^ and cytokinin Kinetin or 6-benzylaminopurine (BA) at 0.5, 1.0 and 2.0 mg dm'^ in differentcombinations. The responses of orchid cultures varied according to concentrations and type of growth regulators. From tested growth regulators, BA in concentration 2.0 mg dm-3 in combination with 0.5 mg dnr^ lAA was the most effective for shoot induction. At 0.5 mg dm^ both lAA and NAA strongly stimulatedshoots multiplication in comparison to 1.0 mg dnr^. NAA-BA combinations positively influenced the shoot length. For roots induction, the NAA-Kinetin combinations were better than the remaining ones. Kinetin stimulated the increase ofthe root length.