scholarly journals THE EFFECT OF TEMPERATURE ON CARBON GAIN IN ALSTROEMERIA

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 649e-649
Author(s):  
E.D. Leonardos ◽  
M.J. Tsujita ◽  
B. Grodzinski ◽  
T.J. Blom
Keyword(s):  
Gas Exchange ◽  
Dark Respiration ◽  
Leaf Gas Exchange ◽  
Carbon Assimilation ◽  
Net Photosynthesis ◽  
Stomatal Resistance ◽  
Effect Of Temperature ◽  
Carbon Gain ◽  
Leaf Transpiration ◽  
Whole Plant

Leaf and whole plant gas exchange (net photosynthesis Pn, dark respiration Dr, transpiration Tr, and resistance R) of `Jacqueline' Alstroemeria, grown in pots inside a greenhouse, were measured under lab conditions using an openflow and a semi-closed system respectively. Temperature responses of apical fully expanded leaves, on flowering and non-flowering shoots, showed an optimum range for net photosynthesis (Pn) from 15 to 20 °C. Above 25 °C Pn dropped considerably as temperature increased. Leaf transpiration rates over the same range of temperature showed a similar decrease, indicating that low leaf Pn rates at higher temperatures were due in part to increased stomatal resistance. Whole plant photosynthetic response to temperature was similar to that of leaf gas exchange. The optimum temperature range for whole plant Pn was from 12 to 17 °C. These results show that moderately low temperatures are essential for carbon assimilation and efficient water use in Alstroemeria. Temperature interactions with other environmental factors will also be presented in models describing Pn rates as a function of irradiance, CO2 concentration, and temperature.

Influence of temperature on net CO2 exchange in roses

1991 ◽  
Vol 71 (1) ◽  
pp. 235-243 ◽  
Author(s):  
J. Jiao ◽  
M. J. Tsujita ◽  
B. Grodzinski
Keyword(s):  
Dark Respiration ◽  
Net Photosynthesis ◽  
Co2 Exchange ◽  
Effect Of Temperature ◽  
Flower Bud ◽  
Temperature Range ◽  
Whole Plant ◽  
Optimal Temperature Range ◽  
Influence Of Temperature On ◽  
Whole Plants

The effect of temperature on net CO2 exchange of source and sink tissues of the flowering shoots and of whole plants was examined using single-stemmed Samantha roses. At all stages of shoot development, the optimal temperature range for whole-plant carbon (C) gain at saturating irradiance and ambient CO2 level was between 20° and 25 °C, narrower than the temperature range for optimal leaf net photosynthesis. Dark respiration increased more dramatically than photosynthesis with temperatures between 15 and 35 °C. At 25 °C, C loss due to respiration from the flower bud at colour bud stage accounted for 45% of the C loss of the flowering shoot. At low irradiance levels (e.g. 200 μmol m−2 s−1) whole-plant net photosynthesis was greater at 16° than at 22 °C because of a greater reduction in respiration. Lowering the night temperature from 27 to 17 °C also increased daily C gain due to a reduction in the C lost at night. Whole-plant net photosynthesis of plants grown and measured at enriched (1000 ± 100 μL L−1) CO2 was greater than that of plants grown and measured at ambient (350 ± 50 μL L−1) level at temperatures between 15° and 35 °C. Furthermore, the optimal temperatures for whole-plant net photosynthesis in CO2 enrichment was higher than at ambient CO2 level. Key words: Dark respiration, net photosynthesis, Rosa hybrida, temperature

CARBON GAIN IN COFFEA ARABICA DURING CLEAR AND CLOUDY DAYS IN THE WET SEASON

2006 ◽  
Vol 42 (2) ◽  
pp. 147-164 ◽  
Author(s):  
J. C. RONQUIM ◽  
C. H. B. A. PRADO ◽  
P. NOVAES ◽  
J. I. FAHL ◽  
C. C. RONQUIM
Keyword(s):  
Gas Exchange ◽  
Coffea Arabica ◽  
Leaf Gas Exchange ◽  
Photochemical Efficiency ◽  
Vapour Pressure Deficit ◽  
Net Photosynthesis ◽  
Photon Flux ◽  
Photon Flux Density ◽  
Carbon Gain ◽  
Wet Season

Three cultivars of Coffea arabica, Catuaí Vermelho IAC 81, Icatu Amarelo IAC 2944 and Obatã IAC 1669–20, were evaluated in relation to leaf gas exchange and potential photochemical efficiency of photosystem II under field conditions on clear and cloudy days in the wet season in southeast Brazil. Independent of levels of irradiance, leaf water potential (υleaf) values were always higher than the minimum required to affect daily net photosynthesis (PN). PN, stomatal conductance (gs), leaf transpiration (E) and the index of photochemical efficiency (Fv/Fm) declined on a clear day in all cultivars. The depression of leaf gas exchange and Fv/Fm (specially around midday) caused a strong decrease (about 70 %) in daily carbon gain on a clear day. Under cloudless conditions, gs and PN were correlated with the air vapour pressure deficit (VPDair), but not with photosynthetic photon flux density (PPFD) values. On a cloudy day, the daily carbon gain was barely limited by PPFD below 800 μmol m−2 s−1, the Fv/Fm values showed a slight decrease around midday, and gs and PN were positively correlated with PPFD but not with VPDair. By contrast, irrespective of the contrasting irradiance conditions during the day, PN and E were correlated with gs.

Inhibition of gas exchange in bean leaves by NO2

1975 ◽  
Vol 53 (5) ◽  
pp. 466-474 ◽  
Author(s):  
H. S. Srivastava ◽  
P. A. Jolliffe ◽  
V. C. Runeckles
Keyword(s):  
Gas Exchange ◽  
Exposure Time ◽  
Gas Flow ◽  
Dark Respiration ◽  
Leaf Gas Exchange ◽  
Leaf Growth ◽  
Stomatal Resistance ◽  
Air Pollutant ◽  
Phaseolus Vulgaris L ◽  
Rate Of Absorption

An open gas-flow system was used to examine the effects of the air pollutant NO2 on gas exchange by primary leaves of bean (Phaseolus vulgaris L.). Apparent photosynthesis and dark respiration were both inhibited by NO2 concentrations between 1.0 and 7.0 ppm. The degree of inhibition was increased by increasing NO2 concentration and increasing exposure time. Leaf susceptibility to NO2 varied during leaf growth. NO2 was most inhibitory at the ages when maximum rates of apparent photosynthesis or respiration were observed in the NO2-free controls (11 or 12, or 8 days after sowing, respectively). The rate of absorption of NO2 by leaves increased in direct proportion with the NO2 concentration and declined with increasing exposure time. The NO2 uptake rate in the dark was about half of its rate during illumination because of greater stomatal resistance to NO2 absorption in the dark. Transpiration rate was less affected by NO2 than was photosynthesis or respiration. Accordingly, it is suggested that the principal effects of NO2 on leaf gas exchange are exerted in the leaf mesophyll and are not on the stomata.

scholarly journals A COMPARISON OF LEAF AND WHOLE PLANT NET PHOTOSYNTHESIS IN ALSTROEMERIA

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 576c-576
Author(s):  
E.D. Leonardos ◽  
M.J. Tsujita ◽  
B. Grodzinski ◽  
T.J. Blom
Keyword(s):  
Dark Respiration ◽  
Net Photosynthesis ◽  
Stomatal Resistance ◽  
Gas Analysis ◽  
Whole Plant ◽  
Plant Photosynthesis ◽  
Mutual Shading ◽  
Photosynthetic Responses ◽  
Analysis System ◽  
Two Stages

Gas exchange (net photosynthesis Pn, dark respiration, transpiration, and stomatal resistance) of `Jaqueline' Alstroemeria, grown in pots in a greenhouse, were measured. Measurements were made under laboratory conditions using an open-flow infrared gas analysis system for leaf studies, and a semi-closed computer controlled whole plant photosynthesis system for whole plant studies. Apical fully expanded leaves on non-flowering and flowering (at two stages) shoots had similar photosynthetic responses in respect to photosynthetically active radiation (PAR) and to CO2 concentration. Light saturation occurred at 600 umol/m2/s PAR with maximum leaf Pn rates ranging from 9 to 11 umol CO2/m2/s. CO2 saturation was estimated at approximately 1100 to 1200 ppm with maximum leaf Pn rates from 17 to 22 umol CO2/m2/s. Whole plant Pn rates increased with increased PAR. Maximum rates 4 to 5 umol CO2/m2/s (half that of individual leaves) occurred at approximately 1000 to 1100 umol/m2/s PAR. CO2 saturation was estimated at 1100 to 1200 ppm, with maximum whole plant Pn rates ranging from 7 to 8 umol CO2/m2/s. These data will be discussed in relation to respiration and mutual shading at the leaf canopy.

scholarly journals Mulching of Ornamental Trees: Effects on Growth and Physiology

2008 ◽  
Vol 34 (3) ◽  
pp. 157-162
Author(s):  
Francesco Ferrini ◽  
Alessio Fini ◽  
Piero Frangi ◽  
Gabriele Amoroso
Keyword(s):  
Gas Exchange ◽  
Tree Growth ◽  
Leaf Gas Exchange ◽  
Carbon Assimilation ◽  
Pine Bark ◽  
First Year ◽  
Trunk Diameter ◽  
Whole Plant ◽  
Growth Differences ◽  
Ornamental Trees

Two organic mulching materials applied to newly planted Tilia × europaea and Aesculus × carnea trees were evaluated for effects on tree growth and physiology. Both mulches were efficient in maintaining a cleared area around newly planted trees, although pine bark was more durable than coarse compost from mixed green material. Trees mulched with compost generally had greater height, trunk diameter, and current-year shoot growth. Differences were more evident in the first year in Aesculus and in the second year in Tilia. Mulching with compost increased carbon assimilation of linden leaves in 2005 when compared with pine bark and chemical weeding. Both mulching materials increased transpiration of horsechestnut in 2005. Little effect on gas exchange was found in 2006 in both species. However, because mulched trees were larger with longer shoots, whole plant leaf gas exchange was probably greater. Mulching had very limited effects on chlorophyll fluorescence. Results of this project have shown that mulching materials applied around trees after planting can positively affect tree growth without significantly affecting tree physiology.

scholarly journals (143) Drought Acclimation of Leaf Gas Exchange in Jalapeno and Big Chili Pepper

HortScience ◽  
2006 ◽  
Vol 41 (4) ◽  
pp. 1058B-1058
Author(s):  
Frank Williams ◽  
Alexis Barbarin ◽  
Donald Hauber ◽  
Harish Ratnayaka
Keyword(s):  
Gas Exchange ◽  
Photosystem Ii ◽  
Cropping Systems ◽  
Leaf Gas Exchange ◽  
Carbon Assimilation ◽  
Net Photosynthesis ◽  
Photosystem Ii Efficiency ◽  
Drought Acclimation ◽  
Greenhouse Study ◽  
Relative Water

Drought is a major constraint to chili production in a variety of cropping systems worldwide. A greenhouse study was conducted to understand mechanisms underlying drought acclimation of leaf gas exchange in two popular chili cultivars, `Big Chili' and `Jalapeno'. Unstressed `Big Chili' had 27% greater net photosynthesis (Pnet), 60% higher stomatal conductance (gw), and 18% higher transpiration (E), but only 3% greater intercellular CO2 concentration (Ci) than `Jalapeno'. Light compensation point was 43.3 and 31.6 μmol·m-2·s-1 in `Big Chili' and `Jalapeno', respectively, although light-saturated assimilation (Amax) and photosystem II efficiency (F'v/F'm) were the same in the two cultivars. Maximum rubisco-mediated carboxylation, Vcmax, was 66.3 and 69.1 μmol·m-2·s-1 in `Big Chili' and `Jalapeno', respectively. During drought, 50% of plants wilted to zero Pnet in 5 days in `Big Chili', and 7 days in `Jalapeno'. However, at wilting, relative water content was the same at 66%, with 97% less gw than unstressed plants, in each cultivar. `Jalapeno' had 9% greater F'v/F'm than `Big Chili', at wilting. Four days after rewatering, Pnet, gw and F'v/F'm were 27%, 47%, and 8% less in `Big Chili', but only 11%, 19%, and 4% less in `Jalapeno', than unstressed plants, respectively. `Jalapeno' shows greater acclimation of gas exchange to drought than `Big Chili' through rapid recovery of photosystem II, carbon assimilation and stomatal activity.

scholarly journals Growth, Foliar Mineral Relations, and Gas Exchange of Mammea americana as Influenced by Salinity

HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 685e-685
Author(s):  
Thomas E. Marler ◽  
Yasmina Zozor
Keyword(s):  
Gas Exchange ◽  
Mineral Content ◽  
Dark Respiration ◽  
Leaf Gas Exchange ◽  
Fold Increase ◽  
Dry Mass ◽  
Apparent Quantum Yield ◽  
Cross Sectional ◽  
Whole Plant ◽  
Relative Tolerance

Whole plant growth, foliage mineral content, and leaf gas exchange were measured on Mammea americana seedlings exposed to salinity ranging from 0 to 8 dS·m–1 to determine relative tolerance of this species. In one study, growth measured as leaf area, trunk cross-sectional area, and total dry mass was reduced by 23 weeks of exposure to salinity. Growth of plants exposed to 8 dS·m–1 was ≈30% below that of control plants. Leaf gas exchange was reduced by salinity to a greater degree than the growth variables. Stomatal conductance of plants exposed to 8 dS·m–1 was ≈70% below that of control plants. Plants exposed to 8 dS·m–1 exhibited a seven-fold increase in leaf chloride and 13-fold increase in leaf sodium compared to the control plants. In a second study, 8 weeks of exposure to 8 dS·m–1 reduced net CO2 assimilation and apparent quantum yield to ≈50% of the values for the control plants. Dark respiration was not influenced by salinity. The results indicate that Mammea americana is moderately sensitive to salinity stress.

Seasonal and diurnal patterns in leaf gas exchange of Eucalyptusglobulus trees growing in Portugal

1986 ◽  
Vol 16 (2) ◽  
pp. 177-184 ◽  
Author(s):  
J. S. Pereira ◽  
J. D. Tenhunen ◽  
O. L. Lange ◽  
W. Beyschlag ◽  
A. Meyer ◽  
...  
Keyword(s):  
Stomatal Conductance ◽  
Gas Exchange ◽  
Leaf Gas Exchange ◽  
Carbon Assimilation ◽  
Net Photosynthesis ◽  
Severe Drought ◽  
Midday Depression ◽  
Diurnal Patterns ◽  
Use Efficiency ◽  
Photosynthetic Carbon Assimilation

Gas exchange of adult leaves of Eucalyptusglobulus Labill. trees growing in Portugal was monitored during weekly periods between September 1982 and August 1983. Photosynthetic carbon assimilation rates and leaf water use efficiency were highest (maximum instantaneous values, ca. 12 μmol CO2 m−2 s−1 and ca. 7 mmol CO2 mol H2O−1, respectively) in the spring, somewhat reduced in the winter, and strongly depressed by the middle of the summer, when severe drought conditions prevailed. Diurnal patterns of variation in stomatal conductance and net photosynthesis rates showed a marked seasonal variation. With the transition from winter to spring and summer, as the environmental conditions became warmer and drier, there was an increasing tendency for a midday depression in gas exchange rates as well as a decreasing capacity in the afternoon for recovery to the same net photosynthesis rates measured in the morning. Midday depression in gas exchange and stomatal conductance occurred in leaves positioned both vertically and horizontally inside the measurement cuvettes. Leaf dark respiratory rates also changed with the season; the temperature necessary to evoke similar rates increased with the transition from winter to summer.

Diurnal Time Course of Leaf Gas Exchange Rates and Related Characters in Drought-Acclimated and Irrigated Trifolium Subterraneum.

1995 ◽  
Vol 22 (3) ◽  
pp. 461 ◽  
Author(s):  
J Vadell ◽  
C Cabot ◽  
H Medrano
Keyword(s):  
Gas Exchange ◽  
Exchange Rates ◽  
Water Use Efficiency ◽  
Water Use ◽  
Leaf Gas Exchange ◽  
Trifolium Subterraneum ◽  
Co2 Assimilation ◽  
Carbon Gain ◽  
Assimilation Rate ◽  
Use Efficiency

The effects of drought acclimation on the diurnal time courses of photosynthesis and related characters were studied in Trifolium subterraneum L. leaves during two consecutive late spring days. Leaf CO2 assimilation rate and transpiration rate followed irradiance variations in irrigated plants. Under drought, a bimodal pattern of leaf CO2 assimilation rate developed although stomatal conductance remained uniform and low. Instantaneous water-use efficiency was much higher in droughted plants during the early morning and late evening, while during the middle of the day it was close to the value of irrigated plants. Net carbon gain in plants under drought reached 40% of the carbon gain in irrigated plants with a significant saving of water (80%). Average data derived from midday values of leaf CO2 assimilation rates and instantaneous water-use efficiency did not provide good estimates of the daily carbon gain and water-use efficiency for droughted leaves. Coupled with the morphological changes as a result of acclimation to progressive drought, modifications of diurnal patterns of leaf gas exchange rates effectively contribute to a sustained carbon gain during drought. These modifications significantly improve water-use efficiency, mainly by enabling the plant to take advantage of morning and evening hours with high air humidity.

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