High-frequency shoot multiplication in Curcuma longa L. using thidiazuron

The effects of plant growth regulators, explant types, and culture regimens were investigated on in vitro shoot proliferation from terminal bud explants of Curcuma longa. Each bud was longitudinally divided into four equal pieces, each 1 cm in length, and used as explants. These were then cultured on MS medium supplemented with 18.17 muM thidiazuron for 4 weeks prior to transfer to MS medium without growth regulator for 8 weeks. Under these conditions, a shoot induction rate of 18.22+/-0.62 shoots/explant was obtained after 12 weeks of cultures. Spontaneous rooting was achieved. The regenerated plants were transferred to soil under greenhouse conditions and subsequently grown successfully in the field.