Light-emitting diode spectra modify nutritional status, physiological response, and secondary metabolites in Ficus hirta and Alpinia oxyphylla

Abstract

Lighting spectrum is one of the key factors that determine biomass production and secondary-metabolism accumulation in medicinal plants under artificial cultivation conditions. Ficus hirta and Alpinia oxyphylla seedlings were cultured with blue (10% red, 10% green, 70% blue), green (20% red, 10% green, 30% blue), and red-enriched (30% red, 10% green, 20% blue) lights in a wide bandwidth of 400-700 nm. F. hirta seedlings had lower diameter, fine root length, leaf area, biomass, shoot nutrient (N) and phosphorus concentrations in the blue-light spectrum compared to the red- and green-light spectra. In contrast, A. oxyphylla seedlings showed significantly higher concentrations of foliar flavonoids and saponins in red-light spectrum with rare responses in N, chlorophyll, soluble sugars, and starch concentrations. F. hirta is easily and negatively impacted by blue-light spectrum but A. oxyphylla is suitably used to produce flavonoid and saponins in red-light spectrum across a wide bandwidth.

Keywords

• chlorophyll
• flavonoid
• light-emitting diode
• medicinal plants
• saponin
• non-structural carbohydrate