Corrigendum - Effects of a water stress on the photosynthesis and respiration of wheat ears

1980 ◽  
Vol 31 (5) ◽  
pp. 857
Author(s):  
B Marshall ◽  
RH Sedgley ◽  
PV Biscoe
Keyword(s):  
Carbon Dioxide ◽  
Water Stress ◽  
Maximum Rate ◽  
Dark Respiration ◽  
Light Response ◽  
Grain Filling ◽  
Response Curves ◽  
Rectangular Hyperbola ◽  
Wheat Leaves ◽  
Days After Anthesis

An experiment was conducted on Huntsman winter wheat to investigate the effects of a water stress applied at anthesis on the carbon dioxide exchange of the ears during grain filling. The water stress was created by excluding rain from the soil, not the foliage, of plants growing in the field. Control plants were well watered throughout the period when the treatment was imposed. At intervals for 32 days after anthesis, detailed measurements were made of the photosynthetic rate of ears at different irradiances and rates of ear dark respiration. The measurements were analysed by using the photosynthesis-light response model developed by Marshall and Biscoe (1980) for wheat leaves with a modification for the pathway of respiration from the grains to the glumes. The model is a non-rectangular hyperbola and uses four parameters: Pn,max (maximum rate of net photosynthesis), Rd (rate of dark respiration), � (photochemical efficiency at low light), and F (ratio of physical to total resistance to diffusion of carbon dioxide). Analysis showed that in wheat ears during grain filling, photosynthesis can be treated as occurring predominantly in the glumes and respiration in the grains. The shape of the photosynthesis-light response curves for ears from both treatments were similar, but differed from those for wheat leaves because the maximum rates of photosynthesis were reached more gradually with increasing irradiance. However, the measured response curves were still better fitted by the model than a rectangular hyperbola which has often been used in the past. The water stress at anthesis decreased the maximum rate of ear photosynthesis by 0.8 g carbon dioxide m-2 h-1 throughout the grain-filling period. Initially, the rates of ear respiration were the same, but 32 days after anthesis the treatment had decreased ear respiration rate from 0.04 to 0.01 g carbon dioxide h-1/grain.

Effects of a water stress on the photosynthesis and respiration of wheat ears

1980 ◽  
Vol 31 (5) ◽  
pp. 857
Author(s):  
B Marshall ◽  
RH Sedgley ◽  
PV Biscoe
Keyword(s):  
Carbon Dioxide ◽  
Water Stress ◽  
Maximum Rate ◽  
Dark Respiration ◽  
Light Response ◽  
Grain Filling ◽  
Response Curves ◽  
Rectangular Hyperbola ◽  
Wheat Leaves ◽  
Days After Anthesis

An experiment was conducted on Huntsman winter wheat to investigate the effects of a water stress applied at anthesis on the carbon dioxide exchange of the ears during grain filling. The water stress was created by excluding rain from the soil, not the foliage, of plants growing in the field. Control plants were well watered throughout the period when the treatment was imposed. At intervals for 32 days after anthesis, detailed measurements were made of the photosynthetic rate of ears at different irradiances and rates of ear dark respiration. The measurements were analysed by using the photosynthesis-light response model developed by Marshall and Biscoe (1980) for wheat leaves with a modification for the pathway of respiration from the grains to the glumes. The model is a non-rectangular hyperbola and uses four parameters: Pn,max (maximum rate of net photosynthesis), Rd (rate of dark respiration), � (photochemical efficiency at low light), and F (ratio of physical to total resistance to diffusion of carbon dioxide). Analysis showed that in wheat ears during grain filling, photosynthesis can be treated as occurring predominantly in the glumes and respiration in the grains. The shape of the photosynthesis-light response curves for ears from both treatments were similar, but differed from those for wheat leaves because the maximum rates of photosynthesis were reached more gradually with increasing irradiance. However, the measured response curves were still better fitted by the model than a rectangular hyperbola which has often been used in the past. The water stress at anthesis decreased the maximum rate of ear photosynthesis by 0.8 g carbon dioxide m-2 h-1 throughout the grain-filling period. Initially, the rates of ear respiration were the same, but 32 days after anthesis the treatment had decreased ear respiration rate from 0.04 to 0.01 g carbon dioxide h-1/grain.

scholarly journals Photosynthetic model for citrus cultivar Huangguogan

2020 ◽  
Vol 41 (1) ◽  
pp. 61
Author(s):  
Ling Liao ◽  
Yi Ronga ◽  
Xia Qiua ◽  
Tiantian Donga ◽  
Zhihui Wang
Keyword(s):  
Photosynthetic Rate ◽  
Dark Respiration ◽  
Light Response ◽  
Exponential Model ◽  
Photosynthetic Parameters ◽  
Response Curves ◽  
Effective Measure ◽  
Rectangular Hyperbola ◽  
Light Response Curves ◽  
Citrus Cultivar

Grafting is an effective measure to improve the photosynthetic rate of citrus. The light responses of photosynthesis in leaves of two-year old grafted Huangguogan (citrus cultivar Huangguogan), Huanggougan / Trifoliate (HG/PT), Huanggougan / Tangerine (HG/CR), and Huanggougan / Ziyang Xiangcheng (HG/CJ) were studied using the LI-COR 6400 portable photosynthesis system. Light-response curves and photosynthetic parameters were analyzed and fitted using the rectangular hyperbola model (RHM), the exponential model (EM), the non rectangular hyperbola model (NRHM), and the modified rectangular hyperbola model (MRHM). The results showed that: (1) Grafting can change the photosynthetic characteristics of Huangguogan, and the value of photosynthesis rate of HG/CJ is the greatest; (2) The light-response curves of net photosynthetic rate (PN), the light compensation point (LCP), and the dark respiration rate (RD) were well fitted using the above four models. The modified rectangular hyperbola was the best model in fitting the data; the nonrectangular hyperbola model was the second, and the rectangular hyperbola model was the poorest one.

scholarly journals Photosynthetic Rate, Flowering, and Yield Component Alteration in Hazelnut in Response to Different Light Environments

1996 ◽  
Vol 121 (6) ◽  
pp. 1103-1111 ◽  
Author(s):  
Cheryl R. Hampson ◽  
Anita N. Azarenko ◽  
John R. Potter
Keyword(s):  
Photosynthetic Rate ◽  
Dark Respiration ◽  
Stomatal Density ◽  
Chlorophyll Concentration ◽  
Light Response ◽  
Dry Weight ◽  
Yield Component ◽  
Response Curves ◽  
Photosynthetic Rates ◽  
Light Response Curves

In hazelnut (Corylus avellana L.), vigorous vegetative growth and traditional orchard practices that include little or no pruning combine to produce a dense, shady canopy. A study designed to quantify the effect of shade on reproduction and photosynthetic rate in this shade-tolerant species was undertaken to assess whether some degree of pruning might improve productivity. Shade cloth was used to exclude 30%, 47%, 63%, 73%, or 92% of ambient sunlight from whole `Ennis' and `Barcelona' trees from mid-May until harvest. Photosynthetic light response curves were obtained for leaves that had developed in full sunlight, deep inside the canopy of unshaded trees, or in 92% shade. Light-saturated net photosynthetic rates were 12.0, 6.1, and 9.3 μmol·m-2·s-1 of CO2 and dark respiration rates were 2.0, 1.1, and 0.7 μmol·m-2·s-1 of CO2, respectively, for the three light regimes. Light-saturated photosynthetic rates of leaves from 30% or 63% shade differed little from the control (0% shade). Area per leaf increased by 49% and chlorophyll concentration (dry weight basis) by 157% as shading increased from 0% to 92%. Shading to 92% reduced specific leaf weight (68%), stomatal density (30%), light compensation point (69%), and dark respiration rate (63%) compared to controls. Female inflorescence density declined by about one-third and male inflorescence density by 64% to 74% in the most heavily shaded trees of both cultivars compared to controls. Shade was more detrimental to yield than flowering: yield per tree dropped by >80%, from 2.9 to 3.4 kg in full sun to 0.6 to 0.9 kg in 92% shade. Shade reduced yield primarily by decreasing nut number and secondarily by decreasing nut size. The incidence of several kernel defects increased as shade increased. Therefore, hazelnut leaves showed considerable capacity to adapt structurally and functionally to shade, but improving light penetration into the canopy would probably increase orchard productivity.

scholarly journals Shading Affects Morphology, Dry-matter Partitioning, and Photosynthetic Response of Greenhouse-grown `Chardonnay' Grapevines

HortScience ◽  
2004 ◽  
Vol 39 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Justine E. Vanden Heuvel ◽  
John T.A. Proctor ◽  
K. Helen Fisher ◽  
J. Alan Sullivan
Keyword(s):  
Dry Matter ◽  
Dark Respiration ◽  
Light Response ◽  
Leaf Size ◽  
Dry Weight ◽  
Volume Density ◽  
Response Curves ◽  
Dry Matter Partitioning ◽  
Light Response Curves ◽  
Whole Plant

In order to gain an understanding of the capacity of severely shaded leaves to be productive in dense canopies, the effects of increased shading on morphology, dry-matter partitioning, and whole-plant net carbon exchange rate (NCER) were investigated on greenhouse-grown Vitis vinifera L. `Chardonnay' grapevines. Vines were subjected to whole-plant shading levels of 0%, 54%, 90%, and 99% of direct sun 3 weeks after potting. Data were collected 8 to 10 weeks after potting. Nonlinear regression was used to investigate the relationship of leaf morphological traits and organ dry weights to increased shading. Leaf size was maintained with increased shading to approximately the 90% shading level, while leaf fresh weight, volume, density, and thickness were immediately reduced with increased shading. Root dry weight was most affected by increased shading, and root to shoot ratio was reduced. When nonlinear regressions were produced for light response curves, light compensation point was reduced by approximately 49% by moderate shading, and 61% by severe shading. Shaded leaves approached the asymptote of the light response curve more quickly, and had reduced dark respiration rates, indicating that the morphological compensation responses by the vine allow shaded leaves to use available light more efficiently. However, the long-term ramifications of reduced root growth in the current year on vines with shaded leaves may be significant.

scholarly journals Canopy Position Affects Light Response Curves for Gas Exchange Characteristics of Apple Spur Leaves

1992 ◽  
Vol 117 (3) ◽  
pp. 467-472 ◽  
Author(s):  
Richard J. Campbell ◽  
Richard P. Marini ◽  
Jeffrey B. Birch
Keyword(s):  
Gas Exchange ◽  
Dark Respiration ◽  
Incident Light ◽  
Light Response ◽  
Net Photosynthesis ◽  
Response Curves ◽  
Light Response Curves ◽  
Light Levels ◽  
Canopy Position ◽  
Gas Exchange Characteristics

Light response curves for gas exchange characteristics were developed for spur leaves of `Stayman' and `Delicious' apple (Malus domestica Borkh.) from interior, intermediate, and exterior canopy positions throughout the season. At full bloom (FB), before full leaf expansion, exterior leaves had higher maximum rates of net photosynthesis (Pn), and a statistically different Pn light response curve than the interior leaves. Intermediate leaves had intermediate Pn rates and light response curves. Pn light response curves for all three `Delicious' canopy positions differed from each other from FB + 6 weeks until the end of the season. Interior leaves had maximum Pn rates of only 50% to 60% of those for the exterior leaves from FB + 10 weeks until the end of the season. Light saturation levels were higher for the exterior leaves than for interior or intermediate leaves. Exterior leaves had a tendency throughout the season for higher quantum efficiency of Pn at subsaturating light levels than interior or intermediate leaves. Stomatal conductance was higher for the exterior than the interior or intermediate leaves of `Delicious' on all dates. Water-use efficiency was equivalent among all leaves. Exterior leaves had higher specific leaf weight, dark respiration rates, and incident light levels on all dates than interior or intermediate leaves.

scholarly journals Ecophysiology ofpotentilla gracilisdouglas ex hook (rosaceae): effects of night temperature and water stress on photosynthetic gas exchange

2019 ◽  
Author(s):  
Madhav P. Nepal ◽  
Virginia S. Berg
Keyword(s):  
Water Stress ◽  
Stomatal Conductance ◽  
Gas Exchange ◽  
Light Intensity ◽  
Light Response ◽  
Growing Season ◽  
Night Temperature ◽  
Response Curves ◽  
Photosynthetic Gas Exchange ◽  
Light Response Curves

ABSTRACTPlants in stressful environments have evolved strategies to cope with fluctuating environmental conditions.Potentilla gracilis, also known as Alpine Cinquefoil, grows in alpine meadows of the Rocky Mountains (USA), and is subjected to wide ranges of temperature, light intensity and water availability on a time scale of minutes to days during the growing season. Leaves often freeze to a brittle state at night, are exposed to high radiation while still frosty, dehydrate to wilting during the following light period, and then repeat the cycle the following day. The main objective of this research was to determine the effect of night temperature on subsequent photosynthetic gas exchange inP. gracilis. We used a photosynthetic gas exchange system to compare assimilation and stomatal conductance from light response curves of cold-acclimatedP. gracilisfollowing warm and chilling nights, and for plants at different water potentials. From the light response curves, dark respiration, light compensation point, maximum assimilation, light saturation point, and inhibition of photosynthesis were determined and were compared among the same plants under varying conditions. Assimilation and stomatal conductance decreased with the fall in measurement temperature, following chilling nights, and with the severity of water stress. Low night temperature and high photon flux density during the daytime, which are very common during the growing season in the field, cause a reduction in photosynthesis of the plant. The probable underlying damage during inhibition is likely repairable indicating protection rather than damage. The cold nocturnal temperature, with its less efficient biochemical repair capabilities, may partly be responsible for the reduction in assimilation of the following day.P. gracilisspecies exhibited persistent acquired freezing tolerance; substantial photosynthetic productivity over a wide range of light intensity and temperature; and significant tolerance of, and rapid recovery from, severe drought; making a maximum use of often challenging resources.

scholarly journals Comparison of Models Describing Light Dependence of N2 Fixation in Heterocystous Cyanobacteria

2002 ◽  
Vol 68 (9) ◽  
pp. 4679-4683 ◽  
Author(s):  
Marc Staal ◽  
Sacco te Lintel Hekkert ◽  
Peter Herman ◽  
Lucas J. Stal
Keyword(s):  
Process Parameters ◽  
Cyanobacterial Bloom ◽  
Light Response ◽  
Enzymatic Process ◽  
The Baltic Sea ◽  
Response Curves ◽  
Heterocystous Cyanobacterium ◽  
Rectangular Hyperbola ◽  
Light Response Curves ◽  
The Baltic

ABSTRACT The abilities of four models to describe nitrogenase light-response curves were compared, using the heterocystous cyanobacterium Nodularia spumigena and a cyanobacterial bloom from the Baltic Sea as examples. All tested models gave a good fit of the data, and the rectangular hyperbola model is recommended for fitting nitrogenase-light response curves. This model describes an enzymatic process, while the others are empirical. It was possible to convert the process parameters between the four models and compare N2 fixation with photosynthesis. The physiological meanings of the process parameters are discussed and compared to those of photosynthesis.

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