Growth and anthocyanin concentration of Perilla frutescens var. acuta Kudo as affected by light source and DIF under controlled environment

The effect of light source and DIF (difference between light and dark-period temperatures) on the growth and anthocyanin concentration of Perilla frutescens var. acuta Kudo grown in a growth chamber was examined. The plant was grown under 140 mu mol center dot m(-2)center dot s(-1) PPF provided by either cool white fluorescent lamps (FL, the control), white (W) light emitting diodes (LEDs), or a 8:1:1 mixture of red, blue and white (RBW) LEDs. Temperatures during the light-/dark-period were maintained at either 24/16 (+8 DIF), 22/18 (+4 DIF), or 20/20A degrees C (0 DIF) with a daily mean temperature of 20A degrees C in all treatments. Plant height increased in the FL as compared to the W and RBW LEDs treatments with +8 and +4 DIF. The RBW LEDs treatment promoted vegetative growth of the shoot and root. Chlorophyll fluorescence (Fv/Fm) was not significantly affected by the light source and DIF. Total anthocyanin concentration per leaf in the +8 DIF was higher in the RBW LEDs treatment than the other treatments. The results suggested that the RBW LEDs was the most suitable light source not only for vegetative growth, but also for the accumulation of anthocyanin under a controlled environment.