MICROPROPAGATION OF STEMONA CURTISII HOOK F., A THAI MEDICINAL PLANT

Stemona curtisii Hook f., named Non Tai Yak, is a medicinal plant belonging to the family Stemonaceae. The roots of several species in the genus Stemona are widely used as insecticide and for medicinal purposes due to the occurrence of various alkaloids. The most important alkaloid is stemofoline which possesses interesting bio-insecticide properties. However, indiscriminate collection of wild growing plants might soon result in a threat to the natural populations. What is more, considerable variability of the crude drug quality can be assumed due to genotypically dependent fluctuations in alkaloid content, and due to difficulties in distinguishing the various species. A micropropagation protocol for S. curtisii was developed using shoot cultures. Formation of shoots was induced in vitro from axillary bud explants on solid MS medium supplemented with 20 µM BAP. For the step of shoot multiplication, shoots were cultured on MS media supplemented with various types of cytokinins (2iP, BAP, kinetin, TDZ, zeatin) at concentrations between 0-20 µM. The highest shoot multiplication rate (i.e. shoot and node number) could be observed on MS medium containing 20 µM BAP. Shoots were subsequently cultured on medium without plant growth regulators for 1 month before transfer to MS media supplemented with various types of auxins (IAA, IBA, NAA) at concentrations between 0-20 µM. Shoots were successfully rooted with any type of auxin treatment, however, the highest root numbers were achieved on MS medium supplemented with 10 µM IAA. Plantlets could be hardened and grew well after transplanting to the greenhouse.