Influence of light spectra and elicitors on growth and ascaridole content using in vitro cultures of Dysphania ambrosioides L.

Abstract

Dysphania ambrosioides L. is a medicinal plant with anti-helmintic potential. The aim of this study was to evaluate separately the effect of light spectra and elicitors on Dysphania ambrosioides growth and volatile constituents in vitro. Thus, plantlets were first cultured under blue (B), red (R), white, combinations of B:R (1:1, 2:1, 1:2) from LEDs and fluorescent lamps. Secondly, nodal segments were inoculated in the medium supplemented with chitosan (0, 50, 100, 150, and 200 mg L⁻ ¹) and salicylic acid (0, 3, 6, 9, and 12 mg L⁻ ¹). After 40 days of cultivation, the growth parameters and chemical composition of volatile constituents were evaluated. The light spectra significantly influenced in vitro growth of D. ambrosioides. The best growth occured using white LED or a blue:red combination of 2:1. It was also observed that the blue LEDs inhibited the synthesis of Z-ascaridole, while fluorescent light promoted a greater conversion of α-terpinene into ascaridole. The elicitors, chitosan and salicylic acid had a negative effect on the growth of nodal segments. However, the highest Z-ascaridole content was obtained at 50 to 100 mg L⁻ ¹ of chitosan and with 6 to 9 mg L⁻ ¹ of salicylic acid. The present study demonstrates that shoots regenerated from nodal segments exposed to different light spectra or on MS medium containing chitosan and salicylic acid can exhibit an altered growth and increased volatile constituents of interest.