Abstract

Anoectochilus formosanus Hayata, a species of jewel orchid, possesses significant medicinal and economic value. Investigating the application of organic compounds in in vitro cultivation to generate a safe source of medicinal materials is crucial. This study examined the effects of oligo alginate with different molecular weights (20471 Da and 5666 Da) and concentrations (1, 5, 10, 50, 75 mg/L) on the regeneration of A. formosanus shoots and the concentration (0.5, 1, 5, 10, 50 mg/L) on plant growth. The total flavonoid and phenolic contents of regenerated shoots were evaluated. At the shoot regeneration stage, the MS medium supplemented with 50 mg/L oligo alginate (20471 Da) gave the best results (80% shoot regeneration rate, fresh weight of 0.626 g/explant, dry weight of 0.028 g/explant, and improved shoot morphology after 4 weeks of culture). In this treatment, the total flavonoid and phenolic contents were also significantly higher compared to the control (82.07 mg quercetin/dry weight and 23.49 mg gallic acid/dry weight, respectively). At the shoot growth stage, the half-strength MS medium supplemented with 0.5 mg/L of oligo alginate 20471 Da enhanced various growth parameters, including rooting rate, root length, plant height, fresh weight, dry weight, and overall plant morphology after five weeks of culture. Thus, oligo alginate stimulated the growth of Anoectochilus formosanus and promoted the accumulation of secondary compounds.