The effect of colored plastic films on the photosynthetic characteristics and content of active ingredients of Dysosma versipellis

Abstract

Light intensity and quality affect photosynthesis, plant morphology, and the synthesis of primary and secondary metabolites. Dysosma versipellis (Hance) M. Cheng is an endangered species endemic to China, and a highly valued medicinal and ornamental plant. In this study, we discuss the effects of different light spectrums conferred by colored plastic films on photosynthesis and the contents of active ingredients of D. versipellis. D. versipellis plants were cultured for 90 days under white, red, yellow, or blue film. The blue film treatment generally increased the chlorophyll content, photosynthetic rate (Pn), maximal photochemical efficiency of PSII (Fv/Fm), actual photochemical efficiency of PSII (ФPSII), photochemical quenching (qP), and the podophyllotoxin content of the rhizomes. The blue film treatment also decreased the maximum net photosynthetic rate (Amax), apparent photosynthetic quantum efficiency (AQY), and podophyllotoxin contents of the stems. The yellow film treatment resulted in a decline of the Amax, AQY, Fv/Fm, ФPSII, qP, chlorophyll contents, and podophyllotoxin contents of the leaves and rhizomes; however, the light compensation point (LCP), light saturation point, and minimum fluorescence (Fo) were increased. There were no significant differences in chlorophyll content, Amax, LCP, AQY, Fv/Fm, ФPSII, or qP between the white and red film treatments. These results suggest that in D. versipellis, blue film treatments promote photosynthesis and the accumulation of podophyllotoxin, while yellow film treatments inhibit photosynthesis and the accumulation of podophyllotoxin.