Underwater light climate and the growth and pigmentation of planktonic blue-green algae (Cyanobacteria) II. The influence of light quality

1986 ◽  
Vol 227 (1248) ◽  
pp. 381-393 ◽  
Keyword(s):  
Growth Rate ◽  
Flux Density ◽  
Green Algae ◽  
White Light ◽  
Light Quality ◽  
Red Light ◽  
Green Light ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Blue Green Algae

The influence of light quality on the growth and chlorophyll and phycobiliprotein composition of eight strains of planktonic blue-green algae has been investigated. Growth rate in chromatic (red, green, blue) light (12 μE m -2 s -1 ) (1 μE = 6 × 10 17 photons) is a general function of the light absorption capacity of the cell. In all strains examined growth rate is enhanced in red light, and in Oscillatoria redekei and Gloeotrichia echinulata CC1 it exceeds the maximum growth rate possible in white light of a higher photon flux density under otherwise similar experimental conditions. In green light the growth rate of six phycocyanin-rich strains is approximately 60–75% of that in white light (12 μE m -2 s -1 ), but growth rate is enhanced in O. agardhii 7821 and G. echinulata CC1, which synthesize the green-light-absorbing phycobiliprotein, phycoerythrin. With the exception of these two phycoerythrin-producing strains, incubation in blue light results in a pronounced reduction in growth rate, which in the majority of strains is associated with a specific decline in cell chlorophyll concentrations. In all strains cell chlorophyll and phycobiliprotein content is similar in both white and green light. Associated with the enhancement of growth rate in red light there is a general decline in cell pigment concentrations. An increase in the cell chlorophyll: phycobiliprotein ratio also occurs in a number of strains in red light. This qualitative variation in pigmentation occurs where growth rate is at or near its maximum rate and in Gloeotrichia echinulata CC1 is the result of a specific reduction in the rate of phycoerythrin synthesis. In contrast to other blue-green algae capable of chromatic adaptation, the modulation of phycoerythrin synthesis in this strain is influenced considerably by the photon flux density of red light.

scholarly journals Photosynthetic Physiology of Blue, Green, and Red Light: Light Intensity Effects and Underlying Mechanisms

2021 ◽  
Vol 12 ◽  
Author(s):  
Jun Liu ◽  
Marc W. van Iersel
Keyword(s):  
Blue Light ◽  
Interactive Effect ◽  
Red Light ◽  
Green Light ◽  
Photosynthetic Photon Flux Density ◽  
Interactive Effects ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Light Spectrum ◽  
Response Curves

Red and blue light are traditionally believed to have a higher quantum yield of CO2 assimilation (QY, moles of CO2 assimilated per mole of photons) than green light, because green light is absorbed less efficiently. However, because of its lower absorptance, green light can penetrate deeper and excite chlorophyll deeper in leaves. We hypothesized that, at high photosynthetic photon flux density (PPFD), green light may achieve higher QY and net CO2 assimilation rate (An) than red or blue light, because of its more uniform absorption throughtout leaves. To test the interactive effects of PPFD and light spectrum on photosynthesis, we measured leaf An of “Green Tower” lettuce (Lactuca sativa) under red, blue, and green light, and combinations of those at PPFDs from 30 to 1,300 μmol⋅m–2⋅s–1. The electron transport rates (J) and the maximum Rubisco carboxylation rate (Vc,max) at low (200 μmol⋅m–2⋅s–1) and high PPFD (1,000 μmol⋅m–2⋅s–1) were estimated from photosynthetic CO2 response curves. Both QYm,inc (maximum QY on incident PPFD basis) and J at low PPFD were higher under red light than under blue and green light. Factoring in light absorption, QYm,abs (the maximum QY on absorbed PPFD basis) under green and red light were both higher than under blue light, indicating that the low QYm,inc under green light was due to lower absorptance, while absorbed blue photons were used inherently least efficiently. At high PPFD, the QYinc [gross CO2 assimilation (Ag)/incident PPFD] and J under red and green light were similar, and higher than under blue light, confirming our hypothesis. Vc,max may not limit photosynthesis at a PPFD of 200 μmol m–2 s–1 and was largely unaffected by light spectrum at 1,000 μmol⋅m–2⋅s–1. Ag and J under different spectra were positively correlated, suggesting that the interactive effect between light spectrum and PPFD on photosynthesis was due to effects on J. No interaction between the three colors of light was detected. In summary, at low PPFD, green light had the lowest photosynthetic efficiency because of its low absorptance. Contrary, at high PPFD, QYinc under green light was among the highest, likely resulting from more uniform distribution of green light in leaves.

scholarly journals The influence of light quality on the shoot proliferation and rooting of Gerbera jamesonii in vitro

2013 ◽  
Vol 48 (2) ◽  
pp. 105-111 ◽  
Author(s):  
Eleonora Gabryszewska ◽  
Ryszard Rudnicki
Keyword(s):  
White Light ◽  
Light Quality ◽  
Red Light ◽  
Green Light ◽  
Shoot Proliferation ◽  
Gerbera Jamesonii ◽  
Fresh Weight ◽  
Axillary Shoots ◽  
The Media

The effect of white, blue, green, red and UV + white light on the growth and development of shoots and roots of Gerbera jamesonii cv. Queen Rebecca in relation to the presence of kinetin or IAA were investigated. The highest number of axillary shoots was obtained in red and green light on the medium with 5 mg l<sup>-1</sup> kinetin. Also, green and red light markedly increased the number of leaves developed on the plantlets on the medium supplemented with kinetin. Light quality and IAA added to culture medium variously affected the development of root system: roots were regenerated under all light treatments, higher root number was recorded under red light when 5 mg l<sup>-1</sup> IAA was added to the media, the shortest roots were found in red light on the medium supplemented with IAA. The greatest fresh weight of shoots was found under white light on the medium with kinetin. Red light markedly decreased shoot fresh weight on hormone-free medium. Blue and white light caused increase in fresh weight of roots.

scholarly journals Growth and Energy Use Efficiency of Grafted Tomato Transplants as Affected by LED Light Quality and Photon Flux Density

Agriculture ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 816
Author(s):  
Jianfeng Zheng ◽  
Peidian Gan ◽  
Fang Ji ◽  
Dongxian He ◽  
Po Yang
Keyword(s):  
Energy Use ◽  
Light Quality ◽  
Red Light ◽  
Electrical Energy ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Red Led ◽  
Use Efficiency ◽  
Led Lights

This study was conducted to compare the effects of broad spectrum during the whole seedling period and photon flux density (PFD) in the healing stage on the growth and energy use efficiency of grafted tomato (Lycopersicon esculentum Mill.) transplants in a plant factory. Fluorescent lights, white LED lights, and white plus red LED lights were applied at the growth processes of grafted tomato transplants from germination of rootstock and scion to post-grafting. Three levels of PFD (50, 100, 150 μmol m−2 s−1) were set in the healing stage under each kind of light quality. The results indicated that the growth and quality of grafted tomato transplants under different broad spectrums were influenced by the ratio of red to blue light (R/B ratio) and the ratio of red to far-red light (R/FR ratio). A higher R/B ratio was beneficial to total dry matter accumulation, but excessive red light had a negative effect on the root to shoot ratio and the seedling quality index. The higher blue light and R/FR ratio suppressed stem extension synergistically. The LED lights had good abilities to promote plant compactness and leaf thickness in comparison with fluorescent lights. The plant compactness and leaf thickness increased with the increase in daily light integral in the healing stage within a range from 2.5 to 7.5 mol m−2 d−1 (PFD, 50 to 150 μmol m−2 s−1). Compared to fluorescent lights, the LED lights showed more than 110% electrical energy saving for lighting during the whole seedling period. Higher PFD in the healing stage did not significantly increase the consumption of electric power for lighting. White plus red LED lights with an R/B ratio of 1.2 and R/FR ratio of 16 were suggested to replace fluorescent lights for grafted tomato transplants production considering the high quality of transplants and electrical energy saving, and PFD in the healing stage was recommended to be set to 150 μmol m−2 s−1.

scholarly journals Effect of Light Quality with Different Red/Far-red Photon Flux Density Ratio on Elongation of Pak-choi Seedlings Grown under High Temperatures.

2001 ◽  
Vol 70 (6) ◽  
pp. 774-776 ◽  
Author(s):  
Tatsuya Hayashida ◽  
Yasushi Shibato ◽  
Yuji Hamachi ◽  
Youichi Yamato ◽  
Hiroko Yamazaki ◽  
...  
Keyword(s):  
Flux Density ◽  
High Temperatures ◽  
Light Quality ◽  
Density Ratio ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Pak Choi ◽  
Effect Of Light

scholarly journals Blue Light Monochromatic Irradiation for 12 Hours in Lighting Pattern with Combinations of Blue and Red Light Elongates Young Cos Lettuce Leaves and Promotes Growth under High Daily Light Integral

HortScience ◽  
2021 ◽  
pp. 1-6
Author(s):  
Tomohiro Jishi ◽  
Ryo Matsuda ◽  
Kazuhiro Fujiwara
Keyword(s):  
Flux Density ◽  
Blue Light ◽  
Light Emitting Diode ◽  
Red Light ◽  
Dry Weight ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Photosynthetic Photon Flux ◽  
Leaf Elongation

Cos lettuce was grown under different spectral photon flux density distribution (SPFD) change patterns with blue- and/or red light-emitting diode (LED) irradiation with a 24-hour cycle. Twelve treatments were designed with a combination of four relative SPFD (RSPFD) change patterns and three photosynthetic photon flux density (PPFD) levels. The RSPFD change patterns were as follows: BR/BR, simultaneous blue- and red-light irradiation (BR) for 24 h; R/BR, red-light monochromatic irradiation (R) for 12 h followed by 12 hours of BR; B/BR, blue-light monochromatic irradiation (B) for 12 hours followed by 12 hours of BR; and B/R, 12 hours of B followed by 12 hours of R. Each RSPFD change pattern was conducted at three daily average photosynthetic photon flux densities (PPFDave) of 50, 100, and 200 µmol·m−2·s−1. The RSPFD change patterns that included B (B/BR and B/R) resulted in elongated leaves. A low ratio of active phytochrome to total phytochrome under B was considered the reason for leaf elongation. Shoot dry weight was significantly greater under the RSPFD change patterns that included B when the PPFDave was 200 µmol·m−2·s−1. The leaf elongation caused by B would have increased the amount of light received and thereby promoted growth. However, excessive leaf elongation caused the plants to fall, and growth was not promoted under the RSPFD change patterns that included B when the PPFDave was 50 µmol·m−2·s−1. Thus, 12-hour B promoted growth under conditions in which leaf elongation leads to increases in the amount of light received.

scholarly journals Effects of Blue and Red Light On Growth And Nitrate Metabolism In Pakchoi

2019 ◽  
Vol 17 (1) ◽  
pp. 456-464
Author(s):  
Xiao-Xue Fan ◽  
Feng Xue ◽  
Bo Song ◽  
Long-Zheng Chen ◽  
Gang Xu ◽  
...  
Keyword(s):  
Blue Light ◽  
White Light ◽  
Red Light ◽  
Glutamate Synthase ◽  
Photosynthetic Photon Flux Density ◽  
Continuous Illumination ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Key Enzymes ◽  
Chlorophyll Contents

AbstractThis study investigated the effects of blue and red light on metabolites of nitrate, key enzymes, and the gene expression of key enzymes in pakchoi plants (Brassica campestris L. var. Suzhouqing). Plants were grown under three light quality treatments, namely, white light (W), red light (R) and blue light (B), at the same photosynthetic photon flux density (PPFD) of approximately 150 μmol m-2 s-1 for 48 hours of continuous illumination, and W was set as the control. The dynamics of net photosynthetic rate in pakchoi subjected to different light treatments were the same as the total chlorophyll contents: blue light > white light > red light. The nitrate reductase (NR) activity, nitrite reductase (NiR) activity, glutamine synthetase (GS) activity and glutamate synthase (GOGAT) activity were highest under blue light. Further, the expression levels of NR, NiR and GS genes were significantly higher under blue light. Under continuous illumination, the auxin content (IAA) in pakchoi leaves was highest under blue light, whereas the abscisic acid (ABA) content was highest under red light. In contrast, there was no significant effect for gibberellin (GA) under any type of light treatment.

scholarly journals LED Lighting Strategies Affect Physiology and Resilience to Pathogens and Pests in Eggplant (Solanum melongena L.)

2021 ◽  
Vol 11 ◽  
Author(s):  
J. Anja Dieleman ◽  
H. Marjolein Kruidhof ◽  
Kees Weerheim ◽  
Kirsten Leiss
Keyword(s):  
Powdery Mildew ◽  
Flux Density ◽  
Blue Light ◽  
Red Light ◽  
Solanum Melongena ◽  
Spectral Composition ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Led Lighting ◽  
Greenhouse Horticulture

Over the last decade, LED lighting has gained considerable interest as an energy-efficient supplemental light source in greenhouse horticulture that can change rapidly in intensity and spectral composition. Spectral composition not only affects crop physiology but may also affect the biology of pathogens, pests, and their natural enemies, both directly and indirectly through an impact on induced plant resistance. In this study, we investigated the effects of light spectrum against a background of sunlight on growth and development of Solanum melongena. These effects were related to the spectral effects on the establishment of populations of the predatory mite Amblyseius swirskii and plant resilience against the biotrophic fungus powdery mildew, the necrotrophic fungus botrytis, and the herbivorous arthropod Western flower thrips. The effects of a reduced red/far-red (R:FR) ratio were studied under two ratios of red to blue light. Far-red light either was supplied additionally to the photosynthetic photon flux density (PPFD) or partially replaced PPFD, while maintaining total photon flux density (PFD). Effects of white light or additional UV-B light on plant resilience was tested, compared to the reference (5% blue, 5% green, and 90% red light). Plant biomass in the vegetative phase increased when additional far-red light was supplied. Stem length increased with far-red, irrespective of PPFD and the percentage of blue light. In the generative phase, total shoot biomass and fruit fresh weights were higher under additional far-red light, followed by the treatments where far-red partly replaced PPFD. Far-red light increased biomass partitioning into the fruits, at the expense of the leaves. There were no differences in population growth of A. swirskii mites between light treatments, nor did light treatment have an effect on the vertical distribution of these predatory mites in the plants. The treatments with additional far-red light reduced the infection rate of powdery mildew, but increased botrytis infection. These differences might be due to the plant defenses acting against these pathogens evolving from two different regulatory pathways. These results show that positive effects of altered spectral compositions on physiological responses were only moderately compensated by increased susceptibility to fungal pathogens, which offers perspective for a sustainable greenhouse horticulture.

scholarly journals Application of an Automatic Control System of Photosynthetic Photon Flux Density for LED-Low Light Irradiation Storage of Green Plants

2005 ◽  
Vol 15 (4) ◽  
pp. 781-786 ◽  
Author(s):  
Kazuhiro Fujiwara ◽  
Toshinari Sawada ◽  
Yoshikatsu Kimura ◽  
Kenji Kurata
Keyword(s):  
Flux Density ◽  
Blue Light ◽  
Red Light ◽  
Dry Weight ◽  
Photosynthetic Photon Flux Density ◽  
Light Irradiation ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Photosynthetic Photon Flux ◽  
Low Light

A light-emitting diode (LED)-low light irradiation (LLI) storage system was developed for suppressing the change in dry weight and maintaining the quality of green plants during long-term storage. In this system, the carbon dioxide (CO2) exchange rate was maintained at zero by automatically adjusting the photosynthetic photon flux density (PPFD) with a proportional-integralderivative (PID) controller. The voltage supplied to the LEDs was controlled by the difference between the inflow (400 μmol·mol-1) and outflow CO2 concentrations in the storage case. Grafted tomato (Lycopersicon esculentum; scion = `House Momotaro'; rootstock = `Anchor T') plug seedlings were stored at 10 °C for 35 days under four different LLI conditions as a system operating test: fixed red light irradiation at 2 μmol·m-2·s-1, PID-controlled red light irradiation with no blue light, and PID-controlled red light irradiation with blue light at 0.2 or 1.0 μmol·m-2·s-1. The results showed that the automatic PPFD control during LED-LLI helped suppress changes in dry weight during storage as expected. Furthermore, it was found that addition of a low percentage of blue light improved the morphological appearance of the seedlings and reduced the PPFD required to suppress the change in dry weight.

scholarly journals Supplemental Far-red Light-emitting Diode Light Increases Growth of Foxglove Seedlings Under Sole-source Lighting

2020 ◽  
Vol 30 (5) ◽  
pp. 564-569
Author(s):  
Claudia Elkins ◽  
Marc W. van Iersel
Keyword(s):  
Flux Density ◽  
Plant Height ◽  
Light Emitting Diode ◽  
Red Light ◽  
Dry Weight ◽  
Sole Source ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Light Emitting ◽  
Light Intensities

Seedlings may be grown indoors where environmental conditions can be precisely controlled to ensure consistent and reliable production. The optimal spectrum for production under sole-source lighting is currently unknown. Far-red light (λ = 700–800 nm) typically is not a significant part of the spectrum of light-emitting diode (LED) grow lights. However, far-red light is photosynthetically active and can enhance leaf elongation, which may result in larger leaves and increased light interception. We hypothesized that adding far-red light to sole-source lighting would increase the growth of ‘Dalmatian Peach’ foxglove (Digitalis purpurea) seedlings grown under white LED lights, potentially shortening production times. Our objective was to evaluate the effect of far-red light intensities, ranging from 4.0 to 68.8 µmol·m−2·s−1, on the growth and morphology of foxglove seedlings. Foxglove seedlings were grown in a growth chamber with a photosynthetic photon flux density (PPFD) of 186 ± 6.4 μmol·m−2·s−1 and supplemental far-red light intensities ranging from 4.0 to 68.8 µmol·m−2·s−1. As far-red light increased, shoot dry weight, root dry weight, plant height, and plant height/number of leaves increased by 38% (P = 0.004), 20% (P = 0.029), 38% (P = 0.025), and 34% (P = 0.024), respectively, while root weight fraction decreased 16% (P = 0.034). Although we expected supplemental far-red light to induce leaf and/or stem expansion, specific leaf area and compactness (two measures of morphology) were unaffected. Because a 37% increase in total photon flux density (PPFD plus far-red light) resulted in a 34.5% increase in total plant dry weight, the increased growth likely was due to increased photosynthesis rather than a shade-acclimation response. The growth response was linear across the 4.0 to 68.8 µmol·m−2·s−1 range of far-fed light tested, so we were unable to determine a saturating far-red photon flux density.

Effects of Photon Flux Density on Nutrient Productivity in Eucalyptus grandis Seedlings

1991 ◽  
Vol 18 (3) ◽  
pp. 307 ◽  
Author(s):  
MUF Kirschbaum
Keyword(s):  
Growth Rate ◽  
Flux Density ◽  
Relative Growth Rate ◽  
Eucalyptus Grandis ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Phosphorus Concentration ◽  
Phosphorus Addition ◽  
Relative Growth ◽  
Nutrient Productivity

In plants in which growth is limited by the availability of phosphorus, phosphorus productivity is defined as the plants' relative growth rate divided by their internal phosphorus concentration. An experiment was conducted to assess whether phosphorus productivity was dependent on photon flux density, or whether photon flux density only set an upper maximum relative growth rate below which phosphorus productivity remained constant with changing photon flux density. Eucalyptus grandis seedlings were grown in growth units in which plants were suspended in air while continuously being sprayed with nutrient solution (aeroponic system). Plants were grown at five different relative phosphorus addition rates, and under natural lighting over the period from late summer to mid-winter when daily photon flux density decreased from about 30 to 10 mol quanta m-2 d-1. Relative growth rate was then plotted as a function of internal phosphorus concentration for a series of harvests. For the three highest relative phosphorus addition rates, there was a negative relationship between relative growth rate and internal phosphorus concentration. For the two lowest phosphorus addition rates, the internal phosphorus concentration increased throughout the experiment, while relative growth rate remained almost constant. This meant that phosphorus productivity changed throughout the experiment. When phosphorus productivity was expressed as a function of daily photon flux density, a linear relationship between phosphorus productivity and photon flux density was obtained. That relationship had a positive intercept on the axis of photon flux density which was interpreted as the plants' light compensation point. This finding has important implications for applications of the concept of nutrient productivity to the modelling of ecosystems in which growth is limited by nutrient availability.

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