Establishment of a protocol for micropropagation of Clausena guillauminii Tanaka

Song Fa (Clausena guillauminii Tanaka) is a native medicinal plant that has properties to cure flatulence, discoloration, feces, sore eyes, fever, headaches, and it also has anticancer, anti-HIV, and anti-inflammatory activity. Song Fa can be propagated only by seeds with a small number of seeds and low germination rate. The Thai Traditional Medical Center, Phana Hospital has the demand to use it as raw material in developing new unique products. Because of low quantity in nature, tissue culture was applied to increase their quantity to meet the demand. Firstly, young shoots and seeds were surface sterilization with Clorox^® and hydrogen peroxide. After culturing on semi-solid Murashige and Skoog (MS) medium for 4 and 8 weeks, 50% of shoot segments and 100% of seeds were recorded for uncontaminated explants. Of these, all seeds were germinated within 4 weeks on MS media added with 2 and 4 mg L^‑1 BA. Next, the lateral bud explants were induced for multiple shoot formation on semi-solid MS media added with 0, 2 and 4 mg L^‑1 BA. After culture for 8 weeks, the highest average number of shoots (3.7 shoots) and lateral bud (21.7±10.35 buds explant^‑1) were formed on semi-solid MS medium added with 2 mg L^‑1 BA. Approximately a 21-time multiplication rate could be produced from a lateral bud within 8 weeks of each subculture. Then, the rooted plantlets were induced on semi-solid MS medium added with 0, 0.1, 0.3 and 0.5 mg L^‑1 NAA. After culture for 8 weeks, the highest average root numbers were achieved on semi-solid MS medium added with 0.1 and 0.3 mg L^‑1 NAA as 3.81 roots and 1.6 roots, respectively. Finally, all rooted plantlets survived after acclimatization and transplanting to the greenhouse. Consequently, this first protocol could be applied for mass propagation of Song Fa for commercial use and conservation.