LIGHT RESPONSE CURVES OF SELECTED PLANTS UNDER DIFFERENT LIGHT CONDITIONS

2012 ◽  
pp. 291-298 ◽  
Author(s):  
N. Domurath ◽  
F.-G. Schroeder ◽  
S. Glatzel
Keyword(s):  
Light Response ◽  
Light Conditions ◽  
Response Curves ◽  
Light Response Curves

scholarly journals Net Carbon Exchange Rate of Fragaria Species, Synthetic Octoploids, and Derived Germplasm

2012 ◽  
Vol 137 (3) ◽  
pp. 202-209 ◽  
Author(s):  
Rebecca M. Harbut ◽  
J. Alan Sullivan ◽  
John T.A. Proctor ◽  
Harry J. Swartz
Keyword(s):  
Exchange Rate ◽  
Light Response ◽  
Research Station ◽  
Carbon Exchange ◽  
Light Conditions ◽  
Response Curves ◽  
Low Light ◽  
Light Response Curves ◽  
Single Leaf ◽  
Net Carbon Exchange

The net carbon exchange rate (NCER) of Fragaria species, synthetic octoploids [SO (interspecific hybrids)], F1 (SO × cultivar), and first outcross [OC1 (F1 × cultivar)] hybrids were evaluated in both field and greenhouse conditions. Plants were grown in a field trial at the Elora Research Station in Ontario, Canada, for one season and then plants were dug and moved into a greenhouse where the trial was repeated during the next season. Single leaf photosynthesis measurements and light response curves were generated at different stages of plant development. Photosynthetic capacity of the species was related to the ecological background of the species with sun-adapted species having higher rates compared with the shade-adapted species. The Fragaria species and introgressed hybrids (F1 and OC1) had significantly higher NCERs compared with the cultivars with rates 28% and 23% higher, respectively. Species and hybrids also appear to have increased adaptability to both high and low light conditions. These increases in NCER may be a heterotic effect because NCER of the hybrids were consistently higher compared with the midparent values and in some cases, they were higher than the high parent. These results suggest that the introgression of lower-ploidy Fragaria species into the cultivated strawberry (Fragaria ×ananassa) may lead to increased NCER and light adaptability.

Photosynthetic light-response curves

Planta ◽  
1993 ◽  
Vol 189 (2) ◽  
Author(s):  
E. �gren ◽  
J.R. Evans
Keyword(s):  
Light Response ◽  
Response Curves ◽  
Light Response Curves

scholarly journals Temperature response of photosynthesis and its interaction with light intensity in sweet orange leaf discs under non-photorespiratory condition

2006 ◽  
Vol 30 (4) ◽  
pp. 670-678 ◽  
Author(s):  
Rafael Vasconcelos Ribeiro ◽  
Eduardo Caruso Machado ◽  
Ricardo Ferraz de Oliveira
Keyword(s):  
Sweet Orange ◽  
Photochemical Efficiency ◽  
Temperature Response ◽  
Light Response ◽  
Photon Flux ◽  
O2 Evolution ◽  
Response Curves ◽  
Leaf Discs ◽  
Light Response Curves ◽  
Heat Effects

This study aimed to evaluate the response of photosynthesis (A), given by photosynthetic O2 evolution, to increasing temperature from 25 to 50ºC in sweet orange (Citrus sinensis (L.) Osbeck) leaf discs under non-photorespiring conditions. In order to evaluate the response of gross photosynthesis to temperature and the balance between photosynthetic and respiratory activities, respiration (Rd) rates were also measured, i.e. the O2 uptake in each temperature. In addition, light response curves of photosynthesis were performed by varying the photosynthetic photon flux density (PPFD) from 0 to 1160 µmol m-2 s-1 at 25 and 40ºC. The highest A values were observed at 35 and 40ºC, whereas the highest Rd values were noticed at 50ºC. A higher relationship A/Rd was found at 30 and 35ºC, suggesting an optimum temperature of 35ºC when considering the balance between photosynthesis and respiration under non-photorespiring condition. Overall, heat effects on plant metabolism were more evident when evaluating the relationship A/Rd. In light response curves, higher A values were also found at 40ºC under PPFD higher than 300 µmol m-2 s-1. Light saturation point of photosynthesis was increased at 40ºC, without significant change of quantum efficiency under low PPFD. Respiration was also enhanced at 40ºC, and as a consequence, the light compensation point increased. The better photosynthetic performance at 35-40ºC was supported by higher photochemical efficiency in both light and temperature response curves. The temperature-dependence of photosynthesis was affected by growth temperature, i.e. a high air temperature during plant growth is a probable factor leading to a higher photosynthetic tolerance to heat stress.

Light response of photosynthesis and stomatal conductance of rose leaves in the canopy profile: the effect of lighting on the adaxial and the abaxial sides

2020 ◽  
Vol 47 (7) ◽  
pp. 639
Author(s):  
Roberta Paradiso ◽  
Pieter H. B. de Visser ◽  
Carmen Arena ◽  
Leo F. M. Marcelis
Keyword(s):  
Stomatal Conductance ◽  
Light Transmission ◽  
Model Simulation ◽  
Light Response ◽  
Substantial Part ◽  
Response Curves ◽  
Abaxial Side ◽  
Area Index ◽  
Light Response Curves ◽  
Light Absorbance

We investigated the light response of leaf photosynthesis, stomatal conductance and optical properties in rose plants grown in a glasshouse with bending technique. Leaves were lighted from the adaxial or the abaxial side during measurements, performed in four positions in the upright and bent shoots: top leaves, middle leaves, bottom leaves, and bent shoot leaves. Moreover, the effect of the irradiation on the adaxial or abaxial leaf side on whole canopy photosynthesis was estimated through model simulation. No significant differences were found in light transmission, reflection and absorption of leaves and in photosynthesis light response curves among the four positions. In all the leaf positions, light absorption, stomatal conductance and photosynthesis were higher when leaves were lighted from the adaxial compared with the abaxial side. The model showed that a substantial part of the light absorbed by the crop originated from light reflected from the greenhouse floor, and thus the abaxial leaf properties have impact on whole crop light absorbance and photosynthesis. Simulations were performed for crops with leaf area index (LAI) 1, 2 and 3. Simulation at LAI 1 showed the highest reduction of simulated crop photosynthesis considering abaxial properties; however, to a lesser extent photosynthesis was also reduced at LAI 2 and 3. The overall results showed that the model may be helpful in designing crop systems for improved light utilisation by changing lamp position or level of leaf bending and pruning.

Drought Enhances Stomatal Closure in Response to Shading in Sorghum (Sorghum bicolor) and in Millet (Pennisetum americanum)

1995 ◽  
Vol 22 (1) ◽  
pp. 1 ◽  
Author(s):  
HG Jones ◽  
DO Hall ◽  
JE Corlett ◽  
A Massacci
Keyword(s):  
Sorghum Bicolor ◽  
Water Status ◽  
Stomatal Closure ◽  
Light Response ◽  
Pennisetum Americanum ◽  
Crop Water ◽  
Response Curves ◽  
Early Stages ◽  
Light Response Curves ◽  
Sorghum Bicolor L

When field-grown sorghum (Sorghum bicolor (L.) Moench) and millet (Pennisetum americanum (L.) Leeke) plants are subjected to drought, the speed of stomatal closure in response to darkness is enhanced in comparison with the speed observed in well-irrigated control plants. This shade-induced closure is most apparent at early stages of desiccation and is not rapidly reversible. These results need to be considered when developing protocols for the measurement of photosynthetic light response curves in the field. The sensitivity to crop water status of this stomatal closure response potentially provides a very valuable means for detection of the early stages of soil drying, and may also provide opportunities for screening different varieties for their adaptation to drought conditions.

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