In Vitro Propagation of Curcuma lampangensis Saensouk, Maknoi & Rakarcha, Critically Endangered Species from North Thailand

Curcuma lampangensis Saensouk, Maknoi & Rakarcha is a member of the family Zingiberaceae within the genus Curcuma L. This species is endemic to Thailand and is classified as critically endangered due to its restricted distribution and the ongoing degradation of its natural habitats. The species predominantly occurs in areas that are increasingly impacted by anthropogenic activities, particularly agricultural expansion, which contributes to habitat fragmentation and poses a significant risk to its persistence in the wild. In addition, propagation by rhizomes or seeds shows relatively low propagation efficiency. Therefore, plant tissue culture techniques are considered important for improving propagation efficiency. In this study, shoot and root induction of C. lampangensis were investigated by culturing on solid and liquid MS medium for 8 weeks, supplemented with different plant growth regulators including BA, kinetin, IAA, IBA, NAA, 2,4-D, TDZ, mT and Ads. The results showed that solid MS medium supplemented with 2 and 3 mg/L mT induced the highest mean number of shoots of 7.26 to 7.63 shoots per explant, a mean roots number of 18.57 to 19.88 roots per explant, and 30 to 60% callus formation. Meanwhile, liquid MS medium without plant growth regulators induced the highest mean number of roots of 34.73 roots per explant, with a mean root length of 3.49 cm. Acclimatized rooted plantlets transferred to sandy soil showed 85% survival rate.