Nodes with dormant buds from flower stalks of orchid Phalaenopsis sp. were plated on six
culture media. The composition of the culture media affected the induction, regeneration,
number and form of Phalaenopsis regenerants. We managed to obtain direct shoot
regeneration without callus formation on all media except for medium F. Medium A,
supplemented with 2 mg/l of 6-benzylaminopurine (BAP) and 0.5 mg/l of α–naphtalenacetic
acid (NAA) was found to be the most appropriate of all the media used for rapid
micropropagation of a large number of vegetative shoots (multiplication factor 8.35 per node)
without roots 160 days after inoculation. We found medium B, supplemented with 4.41 mg/l
BAP and 1 mg/l NAA less appropriate for vegetative shoot production (multiplication factor
2.08 per node) also because the regenerants ceased to elongate.