Effects of supplemental light quality on growth and phytochemicals of baby leaf lettuce

The effects of red, blue, and white light-emitting diodes on the growth, development, and edible quality of hydroponically grown lettuce (Lactuca sativa L. var. capitata)

Effects of LEDs on net photosynthetic rate, growth and leaf stomata of chrysanthemum plantlets in vitro

Physiological responses of cucumber seedlings under different blue and red photon flux ratios using LEDs

Providing an adequate quantity and quality of food for the escalating human population under changing climatic conditions is currently a great challenge. In outdoor cultures, sunlight provides energy (through photosynthesis) for photosynthetic organisms. They also use light quality to sense and respond to their environment. To increase the production capacity, controlled growing systems using artificial lighting have been taken into consideration. Recent development of light-emitting diode (LED) technologies presents an enormous potential for improving plant growth and making systems more sustainable. This review uses selected examples to show how LED can mimic natural light to ensure the growth and development of photosynthetic organisms, and how changes in intensity and wavelength can manipulate the plant metabolism with the aim to produce functionalized foods.

https://royalsocietypublishing.org/doi/pdf/10.1098/rstb.2013.0243

Photosynthesis under artificial light: the shift in primary and secondary metabolism

The effects of light generated by monochromic blue, red or mixed radiation from a fluorescent lamp (FL) with light emitting diodes (LEDs) (blue, red, or far-red) on growth and morphogenesis of marigold and salvia seedlings were investigated and the responses compared with those of plantlets grown under a broad spectrum conventional fluorescent lamp (a 16 h photoperiod per day). Dry weight of marigold seedlings was significantly increased in monochromic red light (R), fluorescent light plus red LED (FLR) or fluorescent light (FL) but reduced when monochromic blue light (B) was used, whereas in salvia dry weight was significantly greater under fluorescent light plus blue LED (FLB), fluorescent light plus red LED (FLR) and fluorescent light plus far-red LED (FLFr) as compared to other treatments. Stem length in marigold was greatest in monochromic blue light, being three times greater than in FLR or FL treatments. In salvia, FLFr increased stem length but this was significantly decreased by R as compared to other treatments. The number of visible flower buds in marigold was much higher in FLR as well as in the control (FL), and it was about five times greater than in B or R. However, the number of open flowers in salvia varied slightly in all the treatments. Different light qualities also influenced the duration of the blooming period in both the species. No flower buds were formed when monochromic B or R was used in salvia and FLFr inhibited flower bud formation in marigold. In comparison with monochromic blue or red light, the number of stomata was greater in mixed radiation of FL with LEDs in both the plants. Our study demonstrates the effectiveness of a LED system for plantlet growth and morphogenesis in space-based plant research chambers.

Growth responses of marigold and salvia bedding plants as affected by monochromic or mixture radiation provided by a Light-Emitting Diode (LED)

The influence of light quality on growth and development of in vitro grown Doritaenopsis hort. (Orchidaceae) plants was investigated. Growth parameters like leaf and root fresh/dry mass and leaf area were highest with plants grown under red plus blue light emitting diodes (LEDs). Leaf length was greater with the plants grown under red LED. Carbohydrate (starch, sucrose, glucose and fructose) and leaf pigment (chlorophylls and carotenoids) biosynthesis of the plants was significantly increased in plants grown under red plus blue LEDs compared to red or blue LED and fluorescent light treatments. This study suggests that the production of quality Doritaenopsis plants is possible by culturing the plants in vitro under a mixture of blue plus red light sources.

The effect of light quality on the growth and development of in vitro cultured Doritaenopsis plants

The aim of the study was to establish whether the quantity and the quality of light affect growth and development of Withania somnifera plantlets. We have studied growth and histo-physiological parameters [stomatal characteristics, chloroplastic pigments concentrations, photosynthesis, and transpiration (E)] of W. somnifera plantlets regenerated under various light intensities, or monochromatic light or under a mixture of two colors of light in tissue culture conditions. Plantlets grown under a photon flux density (PFD) of 30 μmol m-2 s-1 showed greater growth and development than those raised under other PFDs. Chlorophylls and carotenoids, numbers of stomata, rate of photosynthesis (PN) and transpiration (E), stomatal conductance (gs), and water use efficiency (WUE) increased with increasing the PFD up to 60 μmol m-2 s-1. Light quality also affected plantlets growth and physiology. Highest growth was observed under fluorescent and in a mixture of blue and red light. Very few stomata were developed in any of the monochromatic light but under fluorescent or under a mixture of two colors stomatal numbers increased. Similarly, gs, E, PN, and WUE were also higher under fluorescent light and under a mixture of red and blue light. Regressional analysis showed a linear relationship between PN (r2 = 70) and gs and between E (r2 = 0.95) and gs. In conclusion, both the quality and the quantity of light affect growth of plantlets, development of stomata and physiological responses differently depending on the intensity and the wavelength of light.

Photon flux density and light quality induce changes in growth, stomatal development, photosynthesis and transpiration of Withania Somnifera (L.) Dunal. plantlets

Kee-Yoeup Paek

Papers

Effects of LEDs on net photosynthetic rate, growth and leaf stomata of chrysanthemum plantlets in vitro

Growth responses of marigold and salvia bedding plants as affected by monochromic or mixture radiation provided by a Light-Emitting Diode (LED)

The effect of light quality on the growth and development of in vitro cultured Doritaenopsis plants

Photon flux density and light quality induce changes in growth, stomatal development, photosynthesis and transpiration of Withania Somnifera (L.) Dunal. plantlets

Effects of light emitting diodes (LEDs) on the in vitro induction and growth of bulblets of Lilium oriental hybrid ‘Pesaro’