In vitro Propagation of Curcuma lithophila Škorničk. & Soonthornk., an Endemic Species of Thailand with High Potential to be used as Ornamental Plant

Abstract

Curcuma lithophila Škorničk. & Soonthornk. is an endemic zingiberaceous plant of Thailand that is found only in Kanchanaburi Province. This plant has a high potential for becoming a new economic cut-flower or ornamental plant because it produces long peduncles coupled with colorful inflorescences. For these reasons, C. lithophila is collected from its natural habitat for trading. In addition, some distribution areas of this plant are being disrupted from human activities, making this plant is became a threatened and potentially extinct species in the future. Therefore, this research aimed to establish the propagation method using plant tissue culture technique for conservation this plant. Seeds of C. lithophila were subjected to surface sterilization process before inoculating onto Murashige & Skoog (MS) medium. After culturing until in vitro young shoots with the height of 6 – 7 cm were obtained, these axenic shoots were excised to obtain 1.5 cm high leafy-shoot bases. Then, these explants were cultured onto MS medium supplemented with 0 – 20 µM N⁶-benzyladenine (BA) or meta-Topolin for 8 weeks and later transferred to MS medium for another 4 weeks. The results revealed that MS medium supplemented with 10 µM BA produced the highest new shoots number (6.90 shoots/explant). Plants regenerated from this medium exhibited 100% of survival rate after planting ex vitro for 4 weeks. These presented outcomes are not only helpful for preservation this endemic species, but they could be applied for commercial cultivation, which will reduce bringing plants out of the forest. Moreover, it could be used for C. lithophila breeding, which will increase value and support this plant to become a new economic ornamental plant of Thailand.