The impact of red and blue light-emitting diode illumination on radish physiological indices

Abstract

The objective was to evaluate the effect of different combinations of red (638 nm) and blue (455 nm) light produced by solid-state light-emitting diodes (LEDs) on physiological indices (net assimilation rate, hypocotyl-to-leaf ratio, leaf area, leaf dry weight, hypocotyl length and diameter, plant length, developed leaves), variation of photosynthetic pigments and non-structural carbohydrates in radish (Raphanus sativus L., var. ‘Faraon’). Lighting experiments were performed under controlled conditions (total PPFD - 200 μmol m−2 s−1; 16 h photoperiod; 14/18°C night/day temperature). The LED conditions: 638 nm; 638 + 5% 455 nm; 638 + 10% 455 nm; 638 + 10% 455 + 731 nm; 638 + 10% 455 + 731 + 669 nm. Our results showed that radishes grown under red (638 nm) alone were elongated, and the formation of hypocotyl was weak. The net assimilation rate, hypocotyl-to-leaf ratio, and leaf dry weight also were low due to the low accumulation of photosynthetic pigments and non-structural carbohydrates in leaves. The supplemented blue (455 nm) light was necessary for the non-structural carbohydrates distribution between radish storage organs and leaves which resulted in hypocotyl thickening. Red alone (638 nm) or in combination with far-red (731 nm), or red669 for radish generative development was required.

The Evaluation of Growth Performance, Photosynthetic Capacity, and Primary and Secondary Metabolite Content of Leaf Lettuce Grown under Limited Irradiation of Blue and Red LED Light in an Urban Plant Factory

“…The lower leaf LA and plant height in treatments with high B/R light ratios may be associated with a B light-mediated inhibition of cell expansion [46]. A similar result was reported by Samuoliene et al [47], who showed that an optimal combination of B/R light ratios enhances the plant growth rate in controlled conditions. However, the optimal B/R ratio differed according to plant species, growth periods, and the targeted qualities [48].…”

Transcriptomic and metabolomic profiling reveals the effect of LED light quality on morphological traits, and phenylpropanoid-derived compounds accumulation in Sarcandra glabra seedlings

“…Speci cally, compared to white light, the red light signi cantly increased the plant height and decreased the stem diameter and leaf area, whereas blue light signi cantly suppressed the height and leaf area of S. glabra. Similar ndings were also obtained in previous studies, for instance, radish stems were found to be thin and elongated under red light [38]. In experiments on the effects of blue and red light on stem elongation of tomato seedlings and other species, results showed that stem length decreased with increasing blue to red light ratio [39,40].…”

Transcriptome and mebabolomic profiling: the effect of LED light quality on morphological traits, and phenylpropanoid-derived compounds accumulation in Sarcandra glabra seedlings

“…Speci cally, red light enhanced plant growth while blue light restricted it. Similar ndings were also obtained in previous studies; for instance, radish stems were found to be thin and elongated under red light [38]. In experiments on the effects of blue and red light on stem elongation of tomato seedlings and other species, results showed that stem length decreased with increasing blue to red light ratio [39,40].…”