In Vitro Shoot Proliferation and Phytochemical Characterization of Wild and In Vitro-Propagated Kaempferia chayanii Koonterm

Establishing a suitable propagation protocol is important for the conservation and potential utilization of Kaempferia chayanii (Zingiberaceae). However, no studies have reported on its micropropagation or phytochemical profiling. Explant initiation from rhizome buds was carried out on Murashige and Skoog (MS) medium (1962), supplemented with various exogenous plant growth regulators in both solid and liquid media. In addition, the phytochemical profile was assessed, with particular emphasis on HPLC analysis, to evaluate the antioxidant activity of different organs under varying growth conditions. In solid medium, the highest mean shoot proliferation (4.90 ± 0.38 shoots/explant) was obtained with 4 mg/L BA and 2 mg/L kinetin, representing 2.93 times the control value. In liquid medium, 2 mg/L BA combined with 1 mg/L TDZ produced the highest numerical mean shoot number (6.80 ± 0.47 shoots/explant), representing 1.89 times the corresponding control value. However, no significant differences were observed among the PGR-supplemented liquid-medium treatments. Principal component analysis (PCA) provided a clear overview of plant responses to plant growth regulators (PGRs). Wild leaves had the highest total phenolic content (TPC) (188.27 ± 3.49 mg GAE/g DW), rhizomes had the highest total flavonoid content (TFC) (19.99 ± 1.77 mg RE/g DW), while leaves from micropropagated plants (Ms1 medium treatment) showed high TPC (186.08 ± 5.94 mg GAE/g DW). Antioxidant activity revealed strong radical scavenging capacity, particularly in micropropagated plants, as determined by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay and the ferric reducing antioxidant power (FRAP) assay. High-performance liquid chromatography (HPLC) analysis revealed distinct phenolic acid and flavonoid profiles among plant samples. This study represents the first report on the micropropagation and phytochemical profiling of K. chayanii, providing information for its sustainable propagation and potential utilization.