Carbon Dioxide Exchange in Response to Change of Environment and to Defoliation in a Tobacco Crop

DM Whitfield; DJ Connor; PJM Sale

doi:10.1071/pp9800473

Carbon Dioxide Exchange in Response to Change of Environment and to Defoliation in a Tobacco Crop

Functional Plant Biology ◽

10.1071/pp9800473 ◽

1980 ◽

Vol 7 (4) ◽

pp. 473 ◽

Cited By ~ 4

Author(s):

DM Whitfield ◽

DJ Connor ◽

PJM Sale

Keyword(s):

Carbon Dioxide ◽

Dark Respiration ◽

Leaf Age ◽

Early Flowering ◽

Carbon Dioxide Exchange ◽

Long Term Effects ◽

Short Term ◽

Photosynthetic Responses ◽

Response To Change ◽

Response To Temperature

Rates of carbon dioxide exchange of field-grown tobacco crops at early flowering and maturity were measured using a pair of large closed-system field chambers. Photosynthetic responses to irradiance and temperature were investigated on both occasions. Rate of dark respiration and its response to temperature were measured during the night. Defoliation treatments were employed to disrupt the correlation between leaf age and light environment in the canopy. In these experiments, the short-term photosynthetic response to irradiance was determined for crops that were progressively defoliated upwards or downwards. Long- term effects of varying intensities of downward defoliation were also investigated. Maximum photosynthetic rates of 3.7 g CO2 m-2 h-1 were achieved at early flowering. These had fallen to 1.9 g CO2 m-2 h-1at maturity. Maximum rates occurred at an irradiance of approximately 700 W m-2. Short-term shifts in temperature in the range 10-32°C had little effect during the day, but dark respiration was strongly dependent on temperature. Defoliation experiments demonstrated that lower leaves retained a significant potential for photosynthesis but their contri- bution to the total exchange of CO2 of mature crops was only small. This was attributed in part to the poorer light regime in the lower canopy. Results are discussed in the context of the development of yield and quality in flue-cured tobacco.

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CARBON DIOXIDE EXCHANGE OF A WHEAT STAND GROWN IN NASA'S BIOMASS PRODUCTION CHAMBER

HortScience ◽

10.21273/hortsci.25.9.1151d ◽

1990 ◽

Vol 25 (9) ◽

pp. 1151d-1151

Author(s):

K.A. Corey ◽

R.M. Wheeler ◽

J.C. Sager ◽

R.P. Prince

Keyword(s):

Carbon Dioxide ◽

Triticum Aestivum ◽

Biomass Production ◽

Mass Flow ◽

Compensation Point ◽

Carbon Dioxide Exchange ◽

Film Culture ◽

Short Term ◽

Photosynthesis And Respiration

A wheat (Triticum aestivum cv. Yecora Rojo) stand was grown using nutrient film culture in the closed conditions of NASA's Biomass Production Chamber. Rates of photosynthesis and respiration of the entire stand (about 20 m2) were determined daily using a regime of 20 hr light/4 hr dark, 20 C light/16 C dark an average PPF of 600 μmol/m2/s from HPS lamps, and a CO2 cone of 1000 ppm. Fractional interception of PPF by the stand reached a maximum of 0.96 at 24 days from planting. Rates of photosynthesis were constant throughout the photoperiod as determined by short term drawdowns of CO2 throughout the photoperiod. Drawdown rates of CO2 were correlated with rates determined by logging of mass flow of CO2 injected during chamber closure. Photosynthetic drawdowns of CO2 indicated that photosynthesis was not saturated at 1000 ppm CO2 and that the CO2 compensation point was about 50 ppm. Whole stand light compensation points were 200 to 250 μmol/m2/s between days 13 and 70 and then increased rapidly during senescence.

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Photosynthetic Responses of Swiss Chard, Kale, and Spinach Cultivars to Irradiance and Carbon Dioxide Concentration

HortScience ◽

10.21273/hortsci11799-17 ◽

2017 ◽

Vol 52 (5) ◽

pp. 706-712 ◽

Cited By ~ 6

Author(s):

John Erwin ◽

Esther Gesick

Keyword(s):

Carbon Dioxide ◽

Dark Respiration ◽

Carbon Dioxide Concentration ◽

Controlled Environment ◽

Plant Responses ◽

Whole Plant ◽

Swiss Chard ◽

Spinacea Oleracea ◽

Photosynthetic Responses ◽

The Impact

The impact of irradiance (0–1200 μmol·m−2·s−1) and carbon dioxide concentration (CO2; 50–1200 ppm) on kale (Brassica oleracea and B. napus pabularia; three cultivars), Swiss chard (chard, Beta vulgaris; four cultivars), and spinach (Spinacea oleracea; three cultivars) photosynthetic rate (Pn; per area basis) was determined to facilitate maximizing yield in controlled environment production. Spinach, chard, and kale maximum Pn were 23.8, 20.3, and 18.2 μmol CO2·m−2·s−1 fixed, respectively, across varieties (400 ppm CO2). Spinach and kale had the highest and lowest light compensation points [LCPs (73 and 13 μmol·m−2·s−1, respectively)] across varieties. The light saturation points (LSPs) for chard and kale were similar at 884–978 μmol·m−2·s−1, but for spinach, the LSP was higher at 1238 μmol·m−2·s−1. Dark respiration was lowest on kale and highest on spinach (−0.83 and −5.00 μmol CO2·m−2·s−1, respectively). The spinach CO2 compensation point (CCP) was lower (56 ppm) than the chard or kale CCP (64–65 ppm). Among varieties, ‘Red Russian’ kale Pn saturated at the lowest CO2 concentration (858 ppm), and ‘Bright Lights’ chard saturated at the highest (1266 ppm; 300 μmol·m−2·s−1). Spinach Pn was more responsive to increasing irradiance than to CO2. Kale Pn was more responsive to increasing CO2 than to irradiance, and chard Pn was equally responsive to increasing CO2 or irradiance. Implications and limitations of this work when “upscaling” to whole-plant responses are discussed.

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Short-term carbon dioxide exchange and environmental factors in a boreal fen

SIL Proceedings 1922-2010 ◽

10.1080/03680770.1998.11901476 ◽

2000 ◽

Vol 27 (3) ◽

pp. 1446-1450 ◽

Cited By ~ 1

Author(s):

Anu Kettunen

Keyword(s):

Carbon Dioxide ◽

Environmental Factors ◽

Carbon Dioxide Exchange ◽

Short Term

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Medium-incorporated PEG-8000 Reduces Elongation, Growth, and Whole-canopy Carbon Dioxide Exchange of Marigold

HortScience ◽

10.21273/hortsci.41.1.124 ◽

2006 ◽

Vol 41 (1) ◽

pp. 124-130 ◽

Cited By ~ 1

Author(s):

Stephanie E. Burnett ◽

Marc W. van Iersel ◽

Paul A. Thomas

Keyword(s):

Carbon Dioxide ◽

Polyethylene Glycol ◽

Dark Respiration ◽

Net Photosynthesis ◽

Carbon Dioxide Exchange ◽

Seedling Height ◽

Tagetes Patula ◽

Whole Plant ◽

Growing Medium ◽

Peg 8000

French marigold (Tagetes patula L. `Boy Orange') was grown in a peat-based growing medium containing different rates (0, 15, 20, 30, 42, or 50 g·L–1) of polyethylene glycol 8000 (PEG-8000) to determine if PEG-8000 would reduce seedling height. Only 28% to 55% of seedlings treated with 62, 72, or 83 g·L–1 of PEG-8000 survived, and these treatments would be commercially unacceptable. Marigolds treated with the remaining concentrations of PEG-8000 had shorter hypocotyls, and were up to 38% shorter than nontreated controls at harvest. Marigold cotyledon water (ψw), osmotic (ψs), and turgor (ψp) potentials were significantly reduced by PEG-8000, and ψp was close to zero for all PEG-treated seedlings 18 days after seeding. Whole-plant net photosynthesis, whole-plant dark respiration, and net photosynthesis/leaf area ratios were reduced by PEG-8000, while specific respiration of seedlings treated with PEG-8000 increased. Marigolds treated with concentrations greater than 30 g·L–1 of PEG-8000 had net photosynthesis rates that were close to zero. Fourteen days after transplanting, PEG-treated marigolds were still shorter than nontreated seedlings and they flowered up to 5 days later. Concentrations of PEG from 15 to 30 g·L–1 reduced elongation of marigold seedlings without negatively affecting germination, survival, or plant quality. It appears that marigold seedlings were shorter because of reduced leaf ψp and reductions in net photosynthesis.

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Net Carbon Dioxide Exchange Rates and Predicted Growth Patterns in Alstroemeria `Jacqueline' at Varying Irradiances, Carbon Dioxide Concentrations, and Air Temperatures

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.119.6.1265 ◽

1994 ◽

Vol 119 (6) ◽

pp. 1265-1275 ◽

Cited By ~ 17

Author(s):

E.D. Leonardos ◽

M.J. Tsujita ◽

B. Grodzinski

Keyword(s):

Carbon Dioxide ◽

Dark Respiration ◽

Net Photosynthesis ◽

Growth Patterns ◽

High Yield ◽

Carbon Dioxide Exchange ◽

Air Temperatures ◽

Temperature Regimes ◽

Whole Plant ◽

Whole Plants

The influence of irradiance, CO2 concentration, and air temperature on leaf and whole-plant net C exchange rate (NCER) of Alstroemeria `Jacqueline' was studied. At ambient CO2, leaf net photosynthesis was maximum at irradiances above 600 μmol·m-2·s-1 photosynthetically active radiation (PAR), while whole-plant NCER required 1200 μmol·m-2·s-1 PAR to be saturated. Leaf and whole-plant NCERs were doubled under CO2 enrichment of 1500 to 2000 μl CO2/liter. Leaf and whole-plant NCERs declined as temperature increased from 20 to 35C. Whereas the optimum temperature range for leaf net photosynthesis was 17 to 23C, whole-plant NCER, even at high light and high CO2, declined above 12C. Dark respiration of leaves and whole plants increased with a Q10 of ≈2 at 15 to 35C. In an analysis of day effects, irradiance, CO2 concentration, and temperature contributed 58%, 23%, and 14%, respectively, to the total variation in NCER explained by a second-order polynomial model (R2 = 0.85). Interactions among the factors accounted for 4% of the variation in day C assimilation. The potential whole-plant growth rates during varying greenhouse day and night temperature regimes were predicted for short- and long-day scenarios. The data are discussed with the view of designing experiments to test the importance of C gain in supporting flowering and high yield during routine harvest of Alstroemeria plants under commercial greenhouse conditions.

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Net Carbon Dioxide Exchange Rates of Raspberries at Varying Irradiances, Carbon Dioxide Concentrations, and Air and Soil Temperatures

HortScience ◽

10.21273/hortsci.30.4.881e ◽

1995 ◽

Vol 30 (4) ◽

pp. 881E-881

Author(s):

David C. Percival ◽

John T.A. Proctor ◽

M.J. Tsujita

Keyword(s):

Carbon Dioxide ◽

Soil Temperature ◽

Dark Respiration ◽

Net Photosynthesis ◽

Rubus Idaeus ◽

Carbon Dioxide Exchange ◽

Whole Plant ◽

Carbon Dioxide Concentrations ◽

Soil Temperatures ◽

Variation Explained

The influence of irradiance, CO2, and temperature on whole-plant net C exchange rate (NCER) of micropropagated raspberries (Rubus idaeus L. cv. `Heritage') was examined in 1994. Irradiances >1000 μmol–m–2–s–1 PAR were required for light saturation, and net photosynthesis (Pn) greatly increased under CO2 enrichment (up to 2000 μl–liter–1) and was optimum at 17C. Temperature effects were separated in another experiment using varying air and soil temperatures (15, 20, 25, 30, and 35C) under saturated light and ambient CO2 levels (350 μl–liter–1). Both air and soil temperature influenced net Pn, with maximum rates occurring at an air/soil temperature of 17/25C and each contributing 71.2% and 26.7%, respectively, to the total variation explained by a polynomial model (R2 = 0.96). Dark respiration and root respiration rates also increased significantly with elevated air and soil temperatures. Therefore, results from this study indicate that maximum net Pn occurred at an air/soil temperature of 17/25C and that irradiance, CO2 levels, and shoot and root temperatures are all important factors in examining NCER in raspberries.

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Measurement of Carbon Fixation and Allocation Using 11C-Labeled Carbon Dioxide

Radiocarbon ◽

10.1017/s0033822200005737 ◽

1983 ◽

Vol 25 (2) ◽

pp. 441-446 ◽

Cited By ~ 2

Author(s):

Boyd R Strain ◽

John D Goeschl ◽

Charles H Jaeger ◽

Youhanna Fares ◽

Charles E Magnuson ◽

...

Keyword(s):

Carbon Dioxide ◽

Carbon Fixation ◽

Dark Respiration ◽

Net Photosynthesis ◽

Time Measurement ◽

Carbon Dioxide Exchange ◽

Carbon Dioxide Assimilation ◽

Real Time Measurement ◽

Infra Red ◽

The Subject

The real-time measurement of net photosynthesis and dark respiration of plants has been possible since the development of the infra-red analyzer and its application in the 1940's. This technique has allowed intensive investigations of the mechanisms and dynamics of carbon dioxide assimilation by green plants (Sestak, Catsky, and Jarvis, 1971). As a result, physiologic and ecologic aspects of net carbon dioxide exchange are the subject of much research (eg, Osmond, Bjorkman and Anderson, 1980).

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Ultrastructural investigations of MDL 19,660-induced effects on the canine platelet and megakaryocyte

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100159412 ◽

1990 ◽

Vol 48 (3) ◽

pp. 374-375

Author(s):

D.E. Loudy ◽

J. Sprinkle-Cavallo ◽

J.T. Yarrington ◽

F.Y. Thompson ◽

J.P. Gibson

Keyword(s):

Antidepressant Drug ◽

Beagle Dogs ◽

Long Term Effects ◽

Short Term ◽

Platelet Counts ◽

Toxicological Studies ◽

Induced Aggregation ◽

Internal Architecture

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.

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