Light Intensity Affects Growth, Photosynthetic Capability, and Total Flavonoid Accumulation of Anoectochilus Plants

Anoectochilus formosanus, a medicinal plant used to treat hypertension, lung disease, and liver disease, was grown to maximize biomass and secondary metabolite production in a controlled environment under four levels of photosynthetic photon flux (PPF), namely, 10, 30, 60, or 90 μmol·m−2·s−1, that is L10, L30, L60, and L90 treatments, respectively. On Day 45, all growth values were greatest for the L30 plants. Dry weight was lowest for the L10 plants. Leaf area, stem length, and fresh weight were lowest for the L90 plants. The chlorophyll concentration was highest in the L10 treatment and decreased with increasing PPF. Electron transport ratios of leaves were highest in the L30 treatment and lowest in the L90 for the second leaf (counted down from the apex) and in the L10 for the third leaf. An increase in light intensity from 10 to 60 μmol·m−2·s−1 increased the superoxide dismutase activity and was associated with an increase in the total flavonoid concentration. The total flavonoid concentration (mg·g−1 DW) was greatest in the L60 and lowest in the L90. However, the total flavonoid content (mg/plant) was highest in the L30 plants as a result of great biomass. The results indicated that A. formosanus is a typical shade plant suitable to grow under low light intensity at PPF of 30 to 50 μmol·m−2·s−1 for both growth and production of total flavonoid. A light intensity of 90 μmol·m−2·s−1 induced stress on plant growth and reduced photosynthetic capability and the flavonoid accumulation.

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Morphological acclimation to light intensity in Douglas-fir seedlings

Canadian Journal of Botany ◽

10.1139/b77-229 ◽

1977 ◽

Vol 55 (15) ◽

pp. 2033-2042 ◽

Cited By ~ 17

Author(s):

Allan P. Drew ◽

William K. Ferrell

Keyword(s):

Light Intensity ◽

Root Growth ◽

Dry Weight ◽

Frost Damage ◽

Douglas Fir ◽

Stem Length ◽

Low Light ◽

Spring Frost ◽

Terminal Bud ◽

Leaf Surface Area

Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings were grown outdoors under 9, 44, and 100% light intensity and were sampled periodically over their first growing season for stem, leaf, and root dry weights, and the data were analyzed allometrically. In addition, seedlings were assessed for number of needles per stem length, ratio leaf surface area: leaf dry weight, and maximum seedling dry weight. The experiment was repeated during a 2nd, warmer, year.Maximum growth occurred under partial shade and moderate temperatures. In the 1st year, seedlings allocated progressively more dry matter to shoot than to root growth as light intensity decreased. In the 2nd year, root growth was favored at the expense of shoot growth. In both years, shoot structural alterations were such as to favor enhanced photosynthesis under low light. Acclimative changes are explained in terms of an interaction between light, temperature, and seedling size.A second experiment showed that seedlings grown under low light set a terminal bud sooner in the fall and broke bud sooner the next spring than seedlings preconditioned to high light. They also suffered more spring frost damage and showed greater incidence of lammas growth in the 2nd year. No effect of 1st-year preconditioning on timing of budbreak was evident in the 3rd year.

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Effects of Light Quality on Growth and Quality of in Vitro Plantlets during Low-temperature Storage

HortScience ◽

10.21273/hortsci.30.4.809c ◽

1995 ◽

Vol 30 (4) ◽

pp. 809C-809

Author(s):

Chieri Kubota ◽

Nihal C. Rajapakse ◽

Roy E. Young

Keyword(s):

Blue Light ◽

Chlorophyll Concentration ◽

Dry Weight ◽

Stem Length ◽

Photon Flux ◽

Spectral Quality ◽

Low Temperature Storage ◽

Light Spectra ◽

Plantlet Quality

Broccoli `Green Duke' plantlets, which were ready for transplanting after 2 weeks of photoautotrophic (sugar-free) culture under the conditions of 1100 μmol·mol–1 CO2 (outside the vessel), 22±4C air temperature, and 140 μmol·m–2·s–1 photosynthetic photon flux (PPF), were stored for 6 weeks at 5C in darkness or in white, red, or blue light at 2 μmol·m–2·s–1 PPF. Photoperiod was set at 24 h/day during storage. Spectral quality significantly affected plantlet quality: stem length was longer and chlorophyll concentration of leaves was lower in red or in blue light than in white light or in darkness after 6 weeks in storage. Regardless of the spectral quality, light in storage maintained plantlet dry weight at a level comparable to that before storage, while dry weight was reduced significantly in dark-stored plantlets. Spectral quality did not significantly affect the photosynthetic and regrowth potential of plantlets. All plantlets stored in light, regardless of light spectra, showed comparably high photosynthetic ability after storage and had similar dry weight, number of leaves, and stem length after 9 weeks of transplanting to the greenhouse under natural light.

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LOW-TEMPERATURE STORAGE OF MICROPROPAGATED PLANTLETS UNDER SELECTED LMHT SPECTRA

HortScience ◽

10.21273/hortsci.30.3.440c ◽

1995 ◽

Vol 30 (3) ◽

pp. 440c-440

Author(s):

Chieri Kubota ◽

Nihal C. Rajapakse ◽

Roy E. Young

Keyword(s):

Blue Light ◽

Chlorophyll Concentration ◽

Dry Weight ◽

Stem Length ◽

Photon Flux ◽

Spectral Quality ◽

Low Temperature Storage ◽

Light Spectra ◽

Plantlet Quality ◽

Temperature Storage

`Green Duke' broccoli plantlets, which were ready for transplanting after 2 weeks of photoautotrophic (sugar free) culture under the conditions of 1100 μmol·mol–l CO2 (outside the vessel), 22 + 4C air temperature, and 140 μmol·m–2·s–1 photosynthetic photon flux (PPF), were stored for 6 weeks at 5C in darkness or in white, red, or blue light at 2 μmol·m–2·s–l PPF (light compensation point at 5C). Photoperiod was set at 24 hour/day during storage. Spectral quality significantly affected plantlet quality: stem length was longer and chlorophyll concentration of leaves was lower in red or in blue light than in white light or in darkness after 6 weeks in storage. Regardless of the spectral quality, light in storage maintained plantlet dry weight at a level comparable to that before storage; dry weight was reduced significantly in dark-stored plantlets. Spectral quality did not significantly affect the photosynthetic and regrowth potential of plantlets. All plantlets stored in light, regardless of light spectra, grew preferably and had similar dry weight and stem length after 9 weeks of transplanting to the greenhouse under natural light.

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The Effect of Low Light Intensity and Temperature on Growth of Schefflera arboricola in Interior Landscapes

HortScience ◽

10.21273/hortsci.42.1.65 ◽

2007 ◽

Vol 42 (1) ◽

pp. 65-67 ◽

Cited By ~ 4

Author(s):

Astrid Kubatsch ◽

Heiner Grüneberg ◽

Christian Ulrichs

Keyword(s):

Light Intensity ◽

Chlorophyll Content ◽

Dry Weight ◽

Leaf Thickness ◽

Photon Flux ◽

Photon Flux Density ◽

Low Light ◽

Light Intensities ◽

Temperature Regimes ◽

Schefflera Arboricola

Schefflera arboricola was held in light- and temperature-controlled chambers for 6 months under three light intensities of 10 μmol·m–2·s–1, 20 μmol·m–2·s–1, and 80 μmol·m–2·s–1 measured as photon flux density (PFD). Plants also received three temperature regimes: 15 °C, 20 °C, and 25 °C. Reduced light intensity significantly decreased fresh and dry weight and increased chlorophyll content, but did not affect leaf thickness and palisade and spongy mesophyll parenchyma. High temperatures reduced fresh weight and significantly increased chlorophyll content and leaf thickness. The authors conclude that reduced photosynthetic energy flow at low light intensities (10 μmol·m–2·s–1, 20 μmol·m–2·s–1) could not be buffered by a downregulation of energy-consuming processes. Therefore the life span and quality of S. arboricola is reduced at such PFD values, especially at higher temperatures. Plants lose their marketability within 6 months.

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Influences of Shading and Fall Fertilization on Fluorescence, Freeze Resistance, Flower Production and Growth of Rhododendron ×kurume ‘Pink Pearl’

Journal of Environmental Horticulture ◽

10.24266/0738-2898.30.1.28 ◽

2012 ◽

Vol 30 (1) ◽

pp. 28-34

Author(s):

Frank P. Henning ◽

Timothy J. Smalley ◽

Orville M. Lindstrom ◽

John M. Ruter

Keyword(s):

Light Intensity ◽

Dry Weight ◽

Fertilizer Application ◽

High Rate ◽

Photon Flux ◽

Photon Flux Density ◽

Freeze Resistance ◽

Time Period ◽

Shade Cloth ◽

Main Plot

We investigated the influences of fall fertilization and light intensity on photosynthesis and freeze resistance of Rhododendron ×kurume ‘Pink Pearl’, an evergreen azalea cultivar, grown outdoors in containers under nursery conditions. The study included two main-plot fall fertilization treatments: 1) 0.5 liter solution containing 75 mg·liter−1 N applied for 60 days from August 1 through September 29 and 2) 0.5 liter solution containing 125 mg·liter−1 N applied for 120 days from August 1 through November 28, and four subplot light intensity treatments 1) 100% ambient photon flux density (PPFD) from May 1, 2004, through May 1, 2005, 2) shade fabric rated to reduce PPFD by 50% from May 1 through September 30, 2004, followed by 100% PPFD from October 1, 2004, through May 1, 2005, 3) 100% PPFD from May 1 through September 30, 2004, followed by 50% PPFD from October 1, 2004, through May 1, 2005, and 4) 50% PPFD from May 1, 2004, through May 1, 2005. Fertilizer application and shade treatments did not interact in their effects on stem freeze resistance or the timing of anthesis. The high rate of extended fertigation (125 mg·liter−1 N applied August 1 through September 28) reduced freeze resistance of azalea stems and advanced anthesis by 4.9 days compared to plants that received moderate fertigation (75 mg·liter−1 N from August 1 through September 29). The high rate of extended fall fertigation failed to increase leaf or stem dry weight compared to plants that received the moderate rate of fertigation. Plants grown in 50% PPFD from May 1 through September 30 produced 163% more above ground dry weight compared to plants grown in 100% light during the same time period. The addition or removal of shade cloth beginning October 1 failed to enhance azalea stem freeze resistance compared to plants that were only exposed to 100 or 50% PPFD respectively. Shade treatments affected the chlorophyll fluorescence ratio (Fv · Fm−1) of leaves, but leaf fluorescence was unrelated to stem freeze resistance. Shade treatments affected azalea growth and photosynthetic stress, but shade neither interacted with fall fertilization to increase stem freeze resistance, nor had a biologically significant effect on stem freeze resistance.

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Photochemical Acclimation of Three Contrasting Species to Different Light Levels: Implications for Optimizing Supplemental Lighting

Journal of the American Society for Horticultural Science ◽

10.21273/jashs04188-17 ◽

2017 ◽

Vol 142 (5) ◽

pp. 346-354 ◽

Cited By ~ 7

Author(s):

Shuyang Zhen ◽

Marc W. van Iersel

Keyword(s):

Electron Transport ◽

Light Intensity ◽

Photochemical Efficiency ◽

Light Response ◽

High Light ◽

Photon Flux ◽

Ambient Light ◽

Response Curves ◽

Low Light ◽

Supplemental Lighting

Photosynthetic responses to light are dependent on light intensity, vary among species, and can be affected by acclimation to different light environments (e.g., light intensity, spectrum, and photoperiod). Understanding how these factors affect photochemistry is important for improving supplemental lighting efficiency in controlled-environment agriculture. We used chlorophyll fluorescence to determine photochemical light response curves of three horticultural crops with contrasting light requirements [sweetpotato (Ipomea batatas), lettuce (Lactuca sativa), and pothos (Epipremnum aureum)]. We also quantified how these responses were affected by acclimation to three shading treatments-full sun, 44% shade, and 75% shade. The quantum yield of photosystem II (ΦPSII), a measure of photochemical efficiency, decreased exponentially with increasing photosynthetic photon flux (PPF) in all three species. By contrast, linear electron transport rate (ETR) increased asymptotically with increasing PPF. Within each shading level, the high-light-adapted species sweetpotato used high light more efficiently for electron transport than light-intermediate lettuce and shade-tolerant pothos. Within a species, plants acclimated to high light (full sun) tended to have higher ΦPSII and ETR than those acclimated to low light (44% or 75% shade). Nonphotochemical quenching (NPQ) (an indicator of the amount of absorbed light energy that is dissipated as heat) was upregulated with increasing PPF; faster upregulation was observed in pothos as well as in plants grown under 75% shade. Our results have implications for supplemental lighting: supplemental light is used more efficiently and results in a greater increase in ETR when provided at low ambient PPF. In addition, high-light-adapted crops and crops grown under relatively high ambient light can use supplemental light more efficiently than low-light-adapted crops or those grown under low ambient light.

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Growth and Photosynthetic Capability of Momordica grosvenori Plantlets Grown Photoautotrophically in Response to Light Intensity

HortScience ◽

10.21273/hortsci.44.3.757 ◽

2009 ◽

Vol 44 (3) ◽

pp. 757-763 ◽

Cited By ~ 11

Author(s):

Meijun Zhang ◽

Duanduan Zhao ◽

Zengqiang Ma ◽

Xuedong Li ◽

Yulan Xiao

Keyword(s):

Callus Formation ◽

Dry Weight ◽

Control Treatment ◽

Photon Flux ◽

Photon Flux Density ◽

Naphthaleneacetic Acid ◽

Ms Medium ◽

Light Intensities ◽

Four Levels

Momordica grosvenori plantlets were cultured in vitro for 26 d on sucrose- and hormone-free Murashige and Skoog (MS) medium with four levels of photosynthetic photon flux density (PPFD), namely 25, 50, 100, or 200 μmol·m−2·s−1, and a CO2 concentration of 1000 μmol·mol−1 in the culture room [i.e., photoautotrophic micropropagation (PA) treatments]. The control treatment was a photomixotrophic culture using MS medium containing sucrose and NAA with a CO2 concentration of 400 μmol·mol−1 in the culture room and a PPFD of 25 μmol·m−2·s−1. Based on the results, a second experiment was conducted to investigate the effects of α-naphthaleneacetic acid (NAA) and sucrose on callus formation. For this, plantlets were grown in the absence and presence of either NAA or sucrose. Compared with the control, the PA plantlet had a well-developed rooting system, better shoot, greater chlorophyll content, and higher electron transport rate and the ex vitro survival percentage was increased by 31%. Both sucrose and NAA stimulated callus formation on the shoot bases of control plantlets, whereas calluses did not form on the plantlets grown in sucrose- and hormone-free medium. The stronger light intensities increased the fresh and dry weight of plantlets. A PPFD of 100 μmol·m−2·s−1 was more suitable for the growth of M. grosvenori plantlets. Therefore, photoautotrophic plantlets grown at high light intensities would be better suited to the intense irradiance found in sunlight.

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Interaction of Light Intensity and CO2 Concentration Alters Biomass Partitioning in Chrysanthemum

Journal of Horticultural Research ◽

10.2478/johr-2021-0015 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Maral Hosseinzadeh ◽

Sasan Aliniaeifard ◽

Aida Shomali ◽

Fardad Didaran

Keyword(s):

Light Intensity ◽

Growth Management ◽

Growth Yield ◽

Dry Weight ◽

Co2 Concentration ◽

Photosynthetic Photon Flux Density ◽

Biomass Partitioning ◽

Photon Flux ◽

Photon Flux Density ◽

Vegetative Organs

Abstract Biomass partitioning is one of the pivotal determinants of crop growth management, which is influenced by environmental cues. Light and CO2 are the main drivers of photosynthesis and biomass production in plants. In this study, the effects of CO2 levels: ambient 400 ppm (a[CO2]) and elevated to 1,000 ppm (e[CO2]) and different light intensities (75, 150, 300, 600 μmol·m−2·s−1 photosynthetic photon flux density – PPFD) were studied on the growth, yield, and biomass partitioning in chrysanthemum plants. The plants grown at higher light intensity had a higher dry weight (DW) of both the vegetative and floral organs. e[CO2] diminished the stimulating effect of more intensive light on the DW of vegetative organs, although it positively influenced inflorescence DW. The flowering time in plants grown at e[CO2] and light intensity of 600 μmol·m−2·s−1 occurred earlier than that of plants grown at a[CO2]. An increase in light intensity induced the allocation of biomass to inflorescence and e[CO2] enhanced the increasing effect of light on the partitioning of biomass toward the inflorescence. In both CO2 concentrations, the highest specific leaf area (SLA) was detected under the lowest light intensity, especially in plants grown at e[CO2]. In conclusion, elevated light intensity and CO2 direct the biomass toward inflorescence in chrysanthemum plants.

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Combined effects of light reduction and ammonia nitrogen enrichment on the submerged macrophyte Vallisneria natans

Marine and Freshwater Research ◽

10.1071/mf17146 ◽

2018 ◽

Vol 69 (5) ◽

pp. 764 ◽

Cited By ~ 4

Author(s):

Zhengjie Zhu ◽

Siyuan Song ◽

Yaner Yan ◽

Pengshan Li ◽

Nasreen Jeelani ◽

...

Keyword(s):

Light Intensity ◽

Ammonia Nitrogen ◽

Combined Effects ◽

Submerged Plants ◽

Low Light ◽

Underwater Light ◽

Vallisneria Natans ◽

High Ammonia ◽

N Enrichment ◽

Four Levels

The decline of submerged plants resulting from low light and high ammonia nitrogen (ammonia-N) has become a serious problem worldwide. In the present study, three levels of ammonia-N concentrations (0, 3 and 6mgL–1) and four levels of light intensity (control, 15, 2.5 and 0.75% underwater light) were designed to investigate the combined effects of low light and high ammonia-N stress on the submerged plant Vallisneria natans. The effects of low light and ammonia-N were examined by measuring the relative growth rate (RGR), chlorophyll content and superoxide dismutase (SOD) and peroxidase (POD) activity in response to the stressors. The decline in RGR and increase in SOD and POD activity in high ammonia-N water were more significant than under low light conditions, indicating that the stress imposed on submerged plants due to ammonia-N enrichment is stronger. Moreover, the combination of ammonia-N enrichment and low light had a greater effect on submerged plants. This study indicates that V. natans were tolerant to ammonia-N concentrations <6mgL–1. Moreover, low light intensity (0.75% underwater light) amplified the toxic effects of ammonia-N, reducing ammonia-N tolerance from <6 to <3mgL–1.

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Growth kinetics of Marquis wheat. II. Carbon dioxide dependence

Canadian Journal of Botany ◽

10.1139/b72-106 ◽

1972 ◽

Vol 50 (4) ◽

pp. 883-889 ◽

Cited By ~ 9

Author(s):

F. D. H. Macdowall

Keyword(s):

Carbon Dioxide ◽

Light Intensity ◽

Carbon Dioxide Concentration ◽

Dry Weight ◽

Maximum Growth ◽

Carbon Dioxide Enrichment ◽

Low Light ◽

Growth Coefficient ◽

Light Intensities ◽

Wide Range

Marquis wheat was grown in growth rooms with four different concentrations of carbon dioxide and four to seven different intensities of light in a 16-h photoperiod at 25 °C. Growth was expressed quantitatively as the pseudo-first-order rate coefficient. Carbon dioxide stimulated growth, but the effect was greater the lower the light intensity in opposition to the known effect on photosynthesis. Carbon dioxide and light, in effect, did not influence the "rate" of growth of wheat additively but, rather, mutually compensated over a wide range. The growth coefficient of the roots was a little less than that of the shoots at all carbon dioxide concentrations and light intensities, probably owing to the cost of translocation. However, root growth benefited most from carbon dioxide enrichment at low light intensities. At intermediate light intensity there appeared to be a carbon dioxide concentration optimal for shoot growth. Carbon dioxide enrichment did not influence the maximum growth coefficient of Marquis wheat with respect to light intensity. The light-using efficiency of growth, calculated for vanishingly low light intensity at which it is maximal, was maximal for shoots at 1300 ppm CO2 but that for laminal area and root dry weight increased with CO2 to 2200 ppm at which the value for "leaves" was nearly fourfold that for roots. Unlike photosynthesis, the stimulation of growth by raised CO2 concentration was accomplished by increased efficiency of, and not capacity for, the net photosynthetic use of light.

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