Effects of thidiazuron on in vitro propagation of Phalaenopsis and Doritaenopsis (Orchidaceae)

Phalaenopsis or Doritaenopsis (Orchidaceae) flower stem sections cultivated in vitro on media containing 0.23–11.35 M of N-phenyl-N-1,2,3-thiadiazol-5-ylurea (thidiazuron, TDZ) developed generally multiple shoots with the higher levels producing also protocorm-like bodies (PLB). Shoot and root development were reduced while proliferation increased with increasing concentration of TDZ. Similar effects were observed with Phalaenopsis protocorms at a lower range (0.23–1.14 M) of TDZ.