Acclimatization ofCodiaeum variegatumL. ‘Aucubaefolia’ to changes in photon flux density. II. Net photosynthesis, dark respiration and chlorophyll content

1988 ◽  
Vol 63 (2) ◽  
pp. 279-286 ◽  
Author(s):  
N. T. Welander ◽  
O. Hellgren
Keyword(s):  
Chlorophyll Content ◽  
Flux Density ◽  
Dark Respiration ◽  
Net Photosynthesis ◽  
Photon Flux ◽  
Photon Flux Density

Genotypic Variation in Light and Temperature Response of Photosynthesis in Nothofagus solandri Var. cliffortioides and N. menziesii

1996 ◽  
Vol 23 (4) ◽  
pp. 421 ◽  
Author(s):  
OJ Sun ◽  
GB Sweet
Keyword(s):  
New Zealand ◽  
Dark Respiration ◽  
Genotypic Variation ◽  
Temperature Response ◽  
Light Response ◽  
Net Photosynthesis ◽  
Photosynthetic Photon Flux Density ◽  
Ecosystem Dynamics ◽  
Photon Flux ◽  
Photon Flux Density

Responses of photosynthesis to light and temperature were studied in two Nothofagus species native to New Zealand: N. solandri var. cliffortioides (Hook. f.) Poole and N. menziesii (Hook. f.) Oerst.. Measurements of leaf photosynthesis were made in a controlled environment growth chamber at photosynthetic photon flux density between 0 and 700 μmol m-2 s-1 with temperatures set for 10, 20 and 25�C, on seedlings previously grown in a glasshouse from seed of three different origins. In both species, pronounced intraspecific variation was shown in dark respiration, light compensation point and light-saturated net photosynthesis (Amax). Seedlings of N. solandri showed higher dark respiration and light compensation levels than N. menziesii seedlings, but the two species did not differ in Amax. Change in temperature resulted in significant change in the response of photosynthesis to light in both N. solandri and N. menziesii. The differences between N. solandri and N. menziesii in light response of photosynthesis are discussed in terms of ecosystem dynamics of Nothofagus forests in New Zealand.

Loss of chlorophyll with limited reduction of photosynthesis as an adaptive response of Syrian barley landraces to high-light and heat stress

1999 ◽  
Vol 26 (6) ◽  
pp. 569 ◽  
Author(s):  
Michel Havaux ◽  
Florence Tardy
Keyword(s):  
High Temperature ◽  
Chlorophyll Content ◽  
Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Arid Environments ◽  
Strong Light ◽  
Carotenoid Concentration ◽  
High Solar Radiation ◽  
Barley Landraces

The Syrian barley landrace Tadmor is adapted to semi-arid environments and characterized by a reduced chlorophyll content (ca −25% on a leaf area basis) compared to improved barley genotypes, such as the European variety Plaisant. Tadmor leaves had reduced stomatal conductance (gS ) compared to Plaisant leaves both under well-watered conditions and during water stress. Both Tadmor and Plaisant barley seedlings were progressively acclimated to high temperature (39°C) and high photon flux density (1600 µmol photons m −2 s −1 ). During acclimation, the chlorophyll content of Tadmor leaves further decreased whereas the carotenoid concentration remained virtually unchanged, leading to a marked increase in the carotenoid:chlorophyll ratio. The chlorophyll content of acclimated Tadmor leaves was reduced to approximately half of the chlorophyll content of Plaisant leaves grown under the same conditions. Loss of chlorophyll in Tadmor leaves was not observed when only one environmental factor was increased (temperature or photon flux density). In the improved variety, both chlorophylls and carotenoids accumulated during acclimation to heat and strong light, leading to an almost constant carotenoid:chlorophyll ratio. The loss of chlorophyll in the Syrian landrace was associated with limited changes in the photosynthetic characteristics of the leaves (oxygen evolution, electron transport quantum yield, chlorophyll antenna size of photosystem II). Plaisant leaves, but not Tadmor leaves, exhibited symptoms of oxidative damage during growth in strong light at high temperature. When the stomata were closed, sudden exposure to bright light caused a smaller increase in leaf temperature in Tadmor than in Plaisant. Taken together, our results suggest that the ‘low chlorophyll’ feature of Syrian barley landraces is related to their drought adaptation which is manifested by a low g S : the very low chlorophyll content decreases leaf absorbance which, in turn, reduces the potentially damaging heating effect of high solar radiation in droughted plants whose stomata are closed.

Photosynthetic light and temperature responses of Eucalyptus cloeziana and Eucalyptus argophloia

2003 ◽  
Vol 51 (5) ◽  
pp. 573 ◽  
Author(s):  
Michael R. Ngugi ◽  
Mark A. Hunt ◽  
David Doley ◽  
Paul Ryan ◽  
Peter J. Dart
Keyword(s):  
Quantum Yield ◽  
Dark Respiration ◽  
Temperature Response ◽  
Net Photosynthesis ◽  
Photosynthetic Photon Flux Density ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Response Curves ◽  
Growth Environment ◽  
Eucalyptus Cloeziana

Acclimation of gas exchange to temperature and light was determined in 18-month-old plants of humid coastal (Gympie) and dry inland (Hungry Hills) provenances of Eucalyptus cloeziana F.Muell., and in those of a dry inland provenance of Eucalyptus argophloia Blakely. Plants were acclimated at day/night temperatures of 18/13, 23/18, 28/23 and 33/28�C in controlled-temperature glasshouses for 4 months. Light and temperature response curves were measured at the beginning and end of the acclimation period. There were no significant differences in the shape and quantum-yield parameters among provenances at 23, 28 and 33�C day temperatures. Quantum yield [μmol CO2 μmol–1 photosynthetic photon flux density (PPFD)] ranged from 0.04 to 0.06 and the light response shape parameter ranged from 0.53 to 0.78. Similarly, no consistent trends in the rate of dark respiration for plants of each provenance were identified at the four growth temperatures. Average values of dark respiration for the plants of the three provenances ranged from 0.61 to 1.86 μmol m–2 s–1. The optimum temperatures for net photosynthesis increased from 23 to 32�C for the humid- and from 25 to 33�C for the dry-provenance E. cloeziana and from 21 to 33�C for E. argophloia as daytime temperature of the growth environment increased from 18 to 33�C. These results have implications in predicting survival and productivity of E. cloeziana and E. argophloia in areas outside their natural distribution.

Photosynthetic Productivity of Mayweed Chamomile (Anthemis cotula)

Weed Science ◽  
1991 ◽  
Vol 39 (1) ◽  
pp. 18-26 ◽  
Author(s):  
David R. Gealy ◽  
Sheila A. Squier ◽  
Alex G. Ogg
Keyword(s):  
Pacific Northwest ◽  
Dark Respiration ◽  
Cropping Systems ◽  
Net Photosynthesis ◽  
Compensation Point ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Photosynthetic Photon Flux ◽  
Photosynthetic Productivity ◽  
Maximum Net Photosynthesis

Photosynthetic productivity parameters were determined for mayweed chamomile, a troublesome annual weed of the cropping systems in the Pacific Northwest. At a photosynthetic photon flux density of 1800 μE m−2s–1, maximum net photosynthetic rate of greenhouse-grown plants was 35 mg CO2dm−2h–1and maximum transpiration rate was 6.7 μg H2O cm−2s–1. Dark respiration rate was 1.4 mg CO2dm−2h–1and the light compensation point was 17.5 μE m−2s–1. Carbon dioxide compensation point increased from 25 ppm at 15 C to 43 ppm at 30 C. At saturating photosynthetic photon flux densities, optimum leaf temperature for net photosynthesis was about 25 C. Maximum net photosynthesis of leaves of field-grown plants averaged 15.8 mg CO2dm−2h–1. After a 24-h exposure to 0.075 kg ha–1metribuzin, maximum net photosynthesis and transpiration were reduced 85 and 40%, respectively. Soil water deficits reduced maximum net photosynthesis about 50%.

scholarly journals Production and Postproduction Irradiance Affects Acclimatization and Longevity of Potted Chrysanthemum and Poinsettia

1990 ◽  
Vol 115 (2) ◽  
pp. 262-265 ◽  
Author(s):  
Terril A. Nell ◽  
Ria T. Leonard ◽  
James E. Barrett
Keyword(s):  
Flux Density ◽  
Dark Respiration ◽  
Photosynthetic Photon Flux Density ◽  
Compensation Point ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Euphorbia Pulcherrima ◽  
Total Chlorophyll ◽  
Photosynthetic Photon Flux ◽  
Light Compensation Point

Production irradiance levels on growth, light compensation point (LCP), dark respiration (DR), and interior longevity of potted chrysanthemum (Demfranthema grandiflora Tzvelev. cvs. Iridon and Mountain Peak) and poinsettia (Euphorbia pulcherrima Wind. cvs. Annette Hegg Dark Red and Gutbier V-10 Amy) were determined. LCP and DR were measured at anthesis and during acclimatization to interior conditions (10 μmol·s-1·m-2). Days to flowering, inflorescence diameter, total chlorophyll, and interior longevity of chrysanthemum increased when maintained at a mean maximum photosynthetic photon flux density (PPFD) of 500 μmol·s-1·m-2 compared to plants shifted to 300 or 100 μmol·s-1·m-2 8 weeks after planting. LCP and DR were highest at anthesis and were reduced 38% and 49%, respectively, for chrysanthemum and 19% and 42%, respectively, for poinsettia within 3 days in interior conditions. Chrysanthemum plants shifted to 300 μmol·s1·m-2 during production had lower LCP and DR rates at anthesis and throughout time in interior conditions compared to plants maintained at 500 μmol·s-1·m-2. The acclimatization of chrysanthemum to reduced production PPFD is of little significance because interior longevity is reduced. No differences were found in the LCP or DR of poinsettia or chrysanthemum cultivars that differ in interior performance, demonstrating that these physiological characteristics are not good indicators of interior longevity for chrysanthemum and poinsettia.

scholarly journals Oxygen and radiation effects on C02 exchange in fight and in darkness of decaploid and hexaploid tall fescue (Festuca arundinacea Schreb.)

2014 ◽  
Vol 55 (1) ◽  
pp. 35-43
Author(s):  
Jerzy W. Poskuta ◽  
Curtis J. NELSON
Keyword(s):  
Linear Function ◽  
Flux Density ◽  
Tall Fescue ◽  
Festuca Arundinacea ◽  
Radiation Effects ◽  
Dark Respiration ◽  
Closed Circuit ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Infra Red

Rates of apparent photosynthesis (APS). photorespiration (PR), CO<sub>2</sub> compensation (I) and dark respiration (DR) were determined on attached shoots of decaploid (70 chromosomes) and a hexaploid (42 chromosomes) genotype of tall fescue (Festuca arundinacea Schreb.) using an infra red CO<sub>2</sub> analyzer arranged in a closed circuit system. Plants were grown at a photon flux density 500 µmol m<sup>-2</sup>s<sup>-1</sup> (400-700 nm) and at 25°C. Measurements were made at 25°C in O<sub>2</sub> concentrations of l, 21 and 100% and at irradiance of 500 or 1800 µmol m<sup>-2</sup>s<sup>-1</sup>. The decaploid exhibited rates of APS that was from 26 to 46% higher in 1 and 21% O<sub>2</sub> but not in 100% O<sub>2</sub>, than those of hexaploid. Rates of PR were positively related to rates of APS. Values of r were very similar for both genotypes, they were little affected by irradiance, and were a linear function of O<sub>2</sub> Concentration. The percentages of PR in true photosynthesis (TPS = APS+ PR) were also similar for the two genotypes, and were a linear function of O<sub>2</sub> concentration. Alternatively, rates of DR were by 16-26% higher in the hexaploid than decaploid genotype, and were little affected by O<sub>2</sub> concentration or by previous rates of APS.

Effect of leaf age on photosynthesis and transpiration of cassava (Manihot esculenta)

1977 ◽  
Vol 55 (17) ◽  
pp. 2288-2295 ◽  
Author(s):  
M. Aslam ◽  
S. B. Lowe ◽  
L. A. Hunt
Keyword(s):  
Chlorophyll Content ◽  
Manihot Esculenta ◽  
Leaf Age ◽  
Gas Analysis ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Genotypic Differences ◽  
Specific Leaf Weight ◽  
Manihot Esculenta Crantz ◽  
Leaf Weight

The effect of plant and leaf age on CO2-exchange rates (CER) and transpiration rates in 15 genotypes of cassava (Manihot esculenta Crantz) was measured in situ by infrared gas analysis. The plants were grown in a controlled-environment room with a 14-h photoperiod, day–night temperatures of 29–24 °C, and 60–70% relative humidity.Plant age had no effect on leaf CER, whereas transpiration rates in 14-week-old plants were significantly greater than those in 7-week-old plants. Both CER and transpiration rates decreased with leaf age. The decline was negligible when measured at low photosynthetic photon flux density. At saturating light, however, both CER and transpiration rates decreased significantly in most of the genotypes. Significant genotypic differences were observed in the pattern of decline. Both stomatal (rs) and residual (rr) resistances to the diffusion of CO2 increased with leafage in all the genotypes. The relative increase in rr was much greater than the increase in rs. In all the genotypes the ratio rr:rs was greater than unity, suggesting that rr is the major component of the total resistance to photosynthesis. Chlorophyll content and specific leaf weight also varied significantly among the genotypes. However, chlorophyll content decreased and specific leaf weight increased with leaf age.

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