Light‐Emitting Diodes: Progress in Plant Micropropagation

Abstract

In commercial micropropagation laboratories, the light source is one of the most important factors controlling plant morphogenesis and metabolism of plant cells and tissue and organ cultures. Lamp manufacturers have begun to rate lamps specifically for plant needs. The traditional light source used for in vitro propagation is fluorescent lamps (FLs). However, power consumption in FL use is expensive and produces a wide range of wavelengths (350-750 nm) unnecessary for plant development. Light-emitting diodes (LEDs) have recently emerged as an alternative for commercial micropropagation. The flexibility of matching LED wavelengths to plant photoreceptors may provide more optimal production, influencing plant morphology and chlorophyll content. Although previous reports have confirmed physiological effects of LED light quality on morphogenesis and growth of several plantlets in vitro, these study results showed that LED light is more suitable for plant morphogenesis and growth than FLs. However, the responses vary according to plant species. This chapter describes the applications and benefits of LED lamps on chlorophyll in plant micropropagation. Two study cases are exposed, Anthurium (Anthurium andreanum) and moth orchids (Phalaenopsisis sp.), both species with economic importance as ornamental plants, where LEDs have a positive effect on in vitro development and chlorophyll content.

Application of wide-spectrum light-emitting diodes in micropropagation of popular ornamental plant species: a study on plant quality and cost reduction

“…It was previously reported that blue LED light alone increased chlorophyll content in F. benjamina, Anthurium andraeanum Linden ex André, and Phalaenopsis sp. (Werbrouck et al 2012;Bello-Bello et al 2017). However, in the present study, the NS1 lamp, with an increased blue light content, did not improve the results.…”

“…To date, several light sources have been utilized in plant tissue culture laboratories including high-pressure sodium, metal halide, and fluorescent lamps, with the latter light sources being most popular (Gupta and Jatothu 2013). Fluorescent lamps (FLs) are versatile, as they provide a wide light spectrum (350-750 nm), which is applicable to numerous plant species, although their disadvantages include high electricity consumption, unstable radiation parameters, and considerable heat emission (Bello-Bello et al 2017). Light-emitting diodes (LEDs), on the other hand, have the flexibility to deliver specific wavelengths that may yield faster or more favorable results for plant researchers and growers.…”

LED Lights Affecting Morphogenesis and Isosteroidal Alkaloid Contents in Fritillaria cirrhosa D. Don—An Important Chinese Medicinal Herb

“…Similar to our results, the beneficial effects of some LED light sources on the induction of embryogenesis in Oncidium have been reported [ 39 ]. Due to these beneficial effects, LED light systems are being increasingly used to boost the horticulture industry in Taiwan and several other countries [ 40 , 41 , 42 ].…”

Towards a tailored indoor horticulture: a functional genomics guided phenotypic approach

“…Chlorophyll a content was significantly higher in the blue LED treatment (0.2813 mg g −1 fresh weight), while chlorophyll b content was higher in blue and the combination of blue and red LED treatments, yielding 0.1368 and 0.1468 mg g −1 fresh weights, respectively. Total chlorophyll (0.421875 mg g −1 fresh weight) was highest under blue LED while the lowest total chlorophyll content was found in FL treatments and white LEDs yielding 0.1810 and 0.2500 mg g −1 fresh weights, respectively 29 . We have summarized the effects of electric lights on the growth and development of other ornamentals studied in recent years in Supplementary Table S1 .…”

“…Ornamental plants serve as good case studies for the testing of narrow-bandwidth electric lights such as LEDs, because they are in general smaller in size, consume fewer resources, have easily amenable features of broad esthetic values and are already accustomed to growth under indoor (home- or office-spaces) conditions compared to crop plants. In the case of Anthurium ( Anthurium andreanum ) and moth orchids ( Phalaenopsisis ), they not only displayed positive development but also yielded higher biochemical content when grown under LED lights (white light at 460 and 560 nm peaks; red at 660 nm peak and blue at 460 nm peak) compared to those grown under fluorescent lights (545–610 nm) (FL) 29 . In this study, the PPFD was maintained at 25 μmol m −2 s −1 under a 16 h photoperiod.…”