scholarly journals Effects of Frequency and Duty Ratio on the Growth of Potato Plantlets In Vitro Using Light-emitting Diodes

HortScience ◽  
2004 ◽  
Vol 39 (2) ◽  
pp. 375-379 ◽  
Author(s):  
Ruey-Chi Jao ◽  
Wei Fang

Effects of intermittent light on photomixotrophic growth of potato plantlets in vitro and the electrical savings that could be realized by adjusting the frequency and duty ratio of light-emitting diodes (LEDs) were investigated and compared to the use of conventional tubular fluorescent lamps (TFLs). TFLs provide continuous fluctuating light at 60 Hz and LEDs provide continuous nonfluctuating or intermittent/pulse light depend on the preset frequency and duty ratio. In total, eight treatments were investigated with varying light source, frequency, duty ratio and photoperiod. Results indicated that if growth rate is the only concern, LEDs at 720 Hz [1.4 milliseconds (ms)] and 50% duty ratio with 16-h light/8-h dark photoperiod stimulated plant growth the most. However, if energy consumption is the major concern, using LEDs at 180 Hz (5.5 ms) and 50% duty ratio with 16-h light/8-h dark photoperiod would be the best choice for illuminating potato plantlets without significantly sacrificing plant growth, especially when energy for heat removal is also considered.

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1477
Author(s):  
Woo-Suk Jung ◽  
Ill-Min Chung ◽  
Myeong Ha Hwang ◽  
Seung-Hyun Kim ◽  
Chang Yeon Yu ◽  
...  

Light is a key factor that affects phytochemical synthesis and accumulation in plants. Due to limitations of the environment or cultivated land, there is an urgent need to develop indoor cultivation systems to obtain higher yields with increased phytochemical concentrations using convenient light sources. Light-emitting diodes (LEDs) have several advantages, including consumption of lesser power, longer half-life, higher efficacy, and wider variation in the spectral wavelength than traditional light sources; therefore, these devices are preferred for in vitro culture and indoor plant growth. Moreover, LED irradiation of seedlings enhances plant biomass, nutrient and secondary metabolite levels, and antioxidant properties. Specifically, red and blue LED irradiation exerts strong effects on photosynthesis, stomatal functioning, phototropism, photomorphogenesis, and photosynthetic pigment levels. Additionally, ex vitro plantlet development and acclimatization can be enhanced by regulating the spectral properties of LEDs. Applying an appropriate LED spectral wavelength significantly increases antioxidant enzyme activity in plants, thereby enhancing the cell defense system and providing protection from oxidative damage. Since different plant species respond differently to lighting in the cultivation environment, it is necessary to evaluate specific wavebands before large-scale LED application for controlled in vitro plant growth. This review focuses on the most recent advances and applications of LEDs for in vitro culture organogenesis. The mechanisms underlying the production of different phytochemicals, including phenolics, flavonoids, carotenoids, anthocyanins, and antioxidant enzymes, have also been discussed.


2020 ◽  
Vol 66 (6) ◽  
pp. 754-760 ◽  
Author(s):  
Natane A Miranda ◽  
Aloisio Xavier ◽  
Wagner C Otoni ◽  
Ricardo Gallo ◽  
Kellen C Gatti ◽  
...  

Abstract The quality and quantity of light are important factors in controlling in vitro plant growth in photoautotrophic systems. The aim of this study was to evaluate the influence of light quality (fluorescent, white, red, blue, red/blue, and distant red) on microstumps of a Eucalyptus urophylla clone in an in vitro photoautotrophic system, as well as the intensity of fluorescent light (60, 85, 100, and 140 μmol m–2 s–1) in the growth and production of microcutting. The number of shoots and microcutting, the size of the largest shoot, the stomatal density, chlorophyll, and carotenoid content were analyzed. Light quality altered plant growth, and fluorescent light intensity did not affect the microstumps’ production during the evaluation period. In white light-emitting diode (LED) light, there was higher production of carotenoids, with a lower initial production of microcuttings. A smaller number of shoots were obtained in blue LED. In general, the different qualities and light intensities tested allowed for the growth of the Eucalyptus urophylla clone grown in vitro, making it possible to obtain microcuttings under photoautotrophic cultivation. Study Implications In vitro propagation is a stressful process for plants and has limitations for commercial-scale Eucalyptus production. Fluorescent lamps, closed containers, and high sucrose concentrations are traditionally used. To reduce costs and improve production, the use of efficient light sources and photoautotrophic cultivation systems become alternatives. This study investigated the influence of light on the in vitro growth of a Eucalyptus clone in a photoautotrophic system. The quality was more important than the intensity of light. Foresters will be able to indicate the use of LEDs (light-emitting diodes) as a replacement for fluorescent lamps. This approach is useful in enhancing micropropagation techniques.


HortScience ◽  
2004 ◽  
Vol 39 (7) ◽  
pp. 1617-1622 ◽  
Author(s):  
Hyeon-Hye Kim ◽  
Gregory D. Goins ◽  
Raymond M. Wheeler ◽  
John C. Sager

Plants will be an important component of future long-term space missions. Lighting systems for growing plants will need to be lightweight, reliable, and durable, and light-emitting diodes (LEDs) have these characteristics. Previous studies demonstrated that the combination of red and blue light was an effective light source for several crops. Yet the appearance of plants under red and blue lighting is purplish gray making visual assessment of any problems difficult. The addition of green light would make the plant leave appear green and normal similar to a natural setting under white light and may also offer a psychological benefit to the crew. Green supplemental lighting could also offer benefits, since green light can better penetrate the plant canopy and potentially increase plant growth by increasing photosynthesis from the leaves in the lower canopy. In this study, four light sources were tested: 1) red and blue LEDs (RB), 2) red and blue LEDs with green fluorescent lamps (RGB), 3) green fluorescent lamps (GF), and 4) cool-white fluorescent lamps (CWF), that provided 0%, 24%, 86%, and 51% of the total PPF in the green region of the spectrum, respectively. The addition of 24% green light (500 to 600 nm) to red and blue LEDs (RGB treatment) enhanced plant growth. The RGB treatment plants produced more biomass than the plants grown under the cool-white fluorescent lamps (CWF treatment), a commonly tested light source used as a broad-spectrum control.


Author(s):  
Jinmeng Xiang ◽  
Xiaoqi Zhao ◽  
Hao Suo ◽  
Minkun Jin ◽  
Xue Zhou ◽  
...  

Controlling the light environment of plant growth using phosphor-converted light-emitting diodes (pc-LEDs) is an important means to regulate the growth rhythm and enhance the yield, in which bluish violet light...


Author(s):  
Marcela Leticia Leal Gonçalves ◽  
Elaine Marcílio Santos ◽  
Ana Cláudia Muniz Renno ◽  
Anna Carolina Ratto Tempestini Horliana ◽  
Matheus de Almeida Cruz ◽  
...  

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