Influence of Fe(III) source, light quality, photon flux and presence of oxygen on photoreduction of Fe(III)-organic complexes – Implications for light-influenced coastal freshwater and marine sediments

2022 ◽  
pp. 152767
Author(s):  
Ulf Lueder ◽  
Bo Barker Jørgensen ◽  
Markus Maisch ◽  
Caroline Schmidt ◽  
Andreas Kappler
Keyword(s):  
Marine Sediments ◽  
Light Quality ◽  
Photon Flux ◽  
Organic Complexes

scholarly journals Effects of Light Quality on the Chlorophyll Degradation Pathway in Rice Seedling Leaves

2016 ◽  
Vol 44 (2) ◽  
pp. 393-398
Author(s):  
Chang-Chang CHEN ◽  
Kuan-Hung LIN ◽  
Meng-Yuan HUANG ◽  
Wen-Dar HUANG ◽  
Chi-Ming YANG
Keyword(s):  
Light Quality ◽  
Protoporphyrin Ix ◽  
Degradation Pathway ◽  
Photosynthetic Photon Flux Density ◽  
Rice Seedling ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Rice Seedlings ◽  
Rice Varieties ◽  
Enriched Environments

The objective of this study was to investigate the dynamics of chlorophyll (Chl), biosynthetic intermediates (protoporphyrin IX, magnesium protoporphyrin IX, and protochlorophyllide), degradation intermediates [chlorophyllide (Chlide), pheophytin (Phe), and pheophorbide (Pho)], and carotenoids (Car) in leaves of rice seedlings. Two rice varieties, 'Taichung Shen 10' ('TCS10') and 'IR1552', were grown under different light quality conditions controlled by light emitting diodes (LED). Lighting treatments for rice seedlings were included by red (R), blue (B), green (G), and red + blue (RB), with fluorescent lighting (FL) as the control and photosynthetic photon flux density being set at 105 µmol m-2 s-1. The results show that lower levels of Chl and Car in leaves were detected under G lighting, and light quality did not mediate porphyrins in biosynthetic pathways. Rice seedling leaves took Chl→Phe→Pho and Chl→Chlide→Pho as the major and minor degradation routes, respectively. Furthermore, higher Phe/Chlide ratios were observed under G and FL lighting conditions, indicating that green-enriched environments can up-regulate the minor degradation route in leaves.

scholarly journals 263 Photoselective Films Influence Flowering of Photoperiodic Species

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 436E-436
Author(s):  
Teresa A. Cerny ◽  
Nihal C. Rajapakse ◽  
Ryu Oi
Keyword(s):  
Plant Species ◽  
Light Quality ◽  
Red Light ◽  
Photon Flux ◽  
Crop Species ◽  
Plastic Films ◽  
Spectral Filters ◽  
Short Day ◽  
Long Day ◽  
Air Temperatures

Growth chambers constructed from photoselective plastic films were used to investigate the effects of light quality on height manipulation and flowering of photoperiodic plant species. Three types of treatment films were used; control, a far-red light intercepting film (YXE-10) and a red light intercepting film (SXE-4). The red (600-700 nm):far-red (700-800 nm) ratios and phytochrome photoequilibrium estimates for the control, YXE-10 and SXE-4 films were 1.0 and 0.71, 1.5 and 0.77, and 0.71 and 0.67, respectively. The photosynthetic photon flux was adjusted to uniformity among chambers using neutral density filters. Spectral filters did not effect minimum and maximum air temperatures. Experiments were conducted using quantitative long day (Antirrhinum majus and Petunia × hybrida), quantitative short day (Zinnia elegans and Dendranthema × grandiflorum) and day-neutral (Rosa × hydrida) plant species under natural short-day conditions. Plants produced under the YXE-10 filters were significantly shorter than the control plants, while plants produced under the SXE-4 films had similar or increased height compared to the control plants. However, both height response and flowering times varied with the crop species. Flowering time of Rosa × hybrida plants was uniform among all treatments. Flowering of quantitative long-day plants was delayed by at least 10 days under the YXE-10 film and was most responsive to the filtered light. Flowering of quantitative short-day plants was delayed by 2 days under the YXE-10. Days to flower for plants produced under the SXE-4 film were similar to the control plants for all species tested.

scholarly journals 569 Photoselective Filters Affect Flowering and Stem Extension In Viola ×wittrockiana and Pisum sativum

HortScience ◽  
1999 ◽  
Vol 34 (3) ◽  
pp. 544D-544 ◽  
Author(s):  
Erik S. Runkle ◽  
Royal D. Heins
Keyword(s):  
Pisum Sativum ◽  
Light Quality ◽  
Stem Elongation ◽  
Plant Morphology ◽  
Photon Flux ◽  
Spectral Filters ◽  
Density Control ◽  
Long Day ◽  
Long Day Plants ◽  
Peduncle Length

For many plants, light quality has a pronounced effect on plant morphology; light with a low red (R, 600 to 700 nm) to far-red (FR, 700 to 800 nm) ratio promotes stem elongation and a high R: FR, or blue light (B, 400 to 500 nm), suppresses it. In addition, FR light is required for rapid flowering in some species, particularly for long-day plants. Our objective was to quantify how flexible spectral filters, which selectively reduce FR, B, or R, influence plant height and flowering of the quantitative long-day plants Pisum sativum L. `Utrillo' and Viola ×wittrockiana Gams. `Crystal Bowl Yellow'. Plants were grown at 20 °C with reduced FR, B, or R environments or with a neutral density control (C) filter. Calculated phytochrome photoequilebria were 0.78, 0.73, 0.71, or 0.46 for the altered FR, B, C, or R environments, respectively. All filter treatments transmitted a similar photosynthetic photon flux. Sixteen-hour photoperiods were created with natural daylight supplemented with high-pressure sodium lamps positioned above filters. Viola grown under the FR filter never reached 100% flowering within 8 weeks, and visible bud appearance was delayed by at least 17 days compared to all other filters. The R and B filters enhanced peduncle length by at least 25% compared to the C or FR filters. In Pisum, average internode length was 2.2, 2.9, 3.4, and 3.7 cm under the FR, C, B, and R filters, respectively, all statistically different. Fresh and dry shoot weights were similar under the C and FR filters but were at least 35% greater under the B filter and 35% lower under the R filter.

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.

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 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 Regulation of Chrysanthemum Growth by Spectral Filters

1992 ◽  
Vol 117 (3) ◽  
pp. 481-485 ◽  
Author(s):  
Nihal C. Rajapakse ◽  
John W. Kelly
Keyword(s):  
Light Quality ◽  
Leaf Size ◽  
Experimental Period ◽  
Internode Length ◽  
Photon Flux ◽  
Average Height ◽  
Dry Matter Accumulation ◽  
Water Control ◽  
Spectral Filters

The role of light quality and quantity in regulating growth of vegetative Dendranthema × grandiflorum (Ramat.) Kitamura was evaluated using CuSO4 solutions and water (control) as spectral filters. Copper sulfate filters increased the red (R): far-red (FR) and the blue (B): R ratios (R = 600 to 700 nm; FR = 700 to 800 nm; B = 400 to 500 urn) of transmitted light. Photosynthetic photon flux (PPF) under 4%, 8% and 16% CuSO4 filters was reduced 26%, 36%, and 47%, respectively, from natural irradiance in the greenhouse, which averaged ≈ 950 μmol·m-2·s-1. Control treatments were shaded with Saran plastic film to ensure equal PPF as the corresponding C uSO4 chamber. Average daily maxima and minima were 26 ± 3C and 16 ± 2C. At the end of the 4-week experimental period, average height and internode length of plants grown under CuSO4 filters were ≈ 40% and 34% shorter than those of plants grown under control filter. Reduction in plant height and internode length was apparent within 1 week after the beginning of treatment. Total leaf area (LA) was reduced by 32% and leaf size (LS) was reduced by 24% under CuSO4 filters. Specific leaf weight (SLW) was higher under CuSO4 filters than for the controls. Irradiance transmitted through CuSO4 filters reduced fresh and dry leaf weights by 30%. Fresh and dry stem weights of plants grown under CuSO4 filters were 60% lower than those of controls. Relative dry matter accumulation into leaves was increased in plants grown under CuSO4 filters while it was reduced in stems. A single application of GA3 before irradiation partially overcame the height reduction under CuSO4 filters, suggesting GA biosynthesis/action may be affected by light quality. Our results imply that alteration of light quality could be used to control chrysanthemum growth as an alternative method to conventional control by chemical growth regulators. Chemical names used: gibberellic acid (GA)

scholarly journals Optimization of Photosynthetic Photon Flux Density and Light Quality for Increasing Radiation-Use Efficiency in Dwarf Tomato under LED Light at the Vegetative Growth Stage

Plants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 121
Author(s):  
Xinglin Ke ◽  
Hideo Yoshida ◽  
Shoko Hikosaka ◽  
Eiji Goto
Keyword(s):  
Vegetative Growth ◽  
Growth Stage ◽  
Light Quality ◽  
Dry Mass ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Photosynthetic Photon Flux ◽  
Use Efficiency ◽  
Radiation Use

Dwarf tomatoes are advantageous when cultivated in a plant factory with artificial light because they can grow well in a small volume. However, few studies have been reported on cultivation in a controlled environment for improving productivity. We performed two experiments to investigate the effects of photosynthetic photon flux density (PPFD; 300, 500, and 700 μmol m−2 s−1) with white light and light quality (white, R3B1 (red:blue = 3:1), and R9B1) with a PPFD of 300 μmol m−2 s−1 on plant growth and radiation-use efficiency (RUE) of a dwarf tomato cultivar (‘Micro-Tom’) at the vegetative growth stage. The results clearly demonstrated that higher PPFD leads to higher dry mass and lower specific leaf area, but it does not affect the stem length. Furthermore, high PPFD increased the photosynthetic rate (Pn) of individual leaves but decreased RUE. A higher blue light proportion inhibited dry mass production with the same intercepted light because the leaves under high blue light proportion had low Pn and photosynthetic light-use efficiency. In conclusion, 300 μmol m−2 s−1 PPFD and R9B1 are the recommended proper PPFD and light quality, respectively, for ‘Micro-Tom’ cultivation at the vegetative growth stage to increase the RUE.

scholarly journals Growth of Impatiens, Petunia, Salvia, and Tomato Seedlings under Blue, Green, and Red Light-emitting Diodes

HortScience ◽  
2014 ◽  
Vol 49 (6) ◽  
pp. 734-740 ◽  
Author(s):  
Heidi Marie Wollaeger ◽  
Erik S. Runkle
Keyword(s):  
Light Quality ◽  
Light Emitting Diode ◽  
Red Light ◽  
Morphological Characteristics ◽  
Photon Flux ◽  
Fluorescent Light ◽  
Flower Bud ◽  
Specialty Crops ◽  
Light Emitting ◽  
Shoot Weight

Plant growth and architecture are regulated in part by light quality. We performed experiments to better understand how young plants acclimate to blue (B), green (G), and red (R) light and how those responses can be used to produce plants with desirable morphological characteristics. We grew seedlings of impatiens (Impatiens walleriana), salvia (Salvia splendens), petunia (Petunia ×hybrida), and tomato (Solanum lycopersicum) under six sole-source light-emitting diode (LED) treatments or one cool-white fluorescent treatment that each delivered a photosynthetic photon flux (PPF) of 160 µmol·m−2·s–1 for 18 h·d−1. Leaf number was similar among treatments, but plants grown under 25% or greater B light were 41% to 57% shorter than those under only R light. Plants under R light had 47% to 130% greater leaf area and 48% to 112% greater fresh shoot weight than plants grown under treatments with 25% or greater B. Plants grown under only R had a fresh shoot weight similar to that of those grown under fluorescent light for all species except tomato. In impatiens, flower bud number at harvest generally increased with B light, whereas in tomato, the number of leaflets with intumescences decreased with B light. This research discusses how light quality can be manipulated for desired growth characteristics of young plants, which is important in the production of specialty crops such as ornamentals, herbs, and microgreens.

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