Blue and red light proportion affects growth, nutritional composition, antioxidant properties and volatile compounds of Toona sinensis sprouts

Abstract

The aim of this study was to evaluate the effects of different proportions of red and blue light on Toona sinensis sprouts. To this end, white light (WL) was taken as control and various light qualities were compared. Vegetative parameters, bioactive components, antioxidant properties, and volatile organic compounds (VOCs) were examined. Results showed that red light (RL) significantly increased hypocotyl elongation by 59.8% compared with WL. Under blue light (BL), the fresh weight (FW) was the lowest but the contents of ascorbic acid (AsA), total phenolics (TP), total flavonoids (TF) were the highest and also antioxidant properties. The effect of BL on increasing AsA content was the most significant, with an increase of 75.1% compared with WL. Our innovation was that we found light quality had significant effects on VOCs. The content of sulfur compounds increased significantly under BL, while the terpenes increased significantly when the ratio of RL to BL spectrum was 3R1B. Conclusively, our results proved that application of proper proportion of RL and BL was an effective strategy to improve the yield, nutritional quality and even the characteristic aroma. In the production of horticultural crops, adjusting lighting conditions is an effective method to enable on-purpose cultivation.