Photosynthesis system
Encyclopedia
Photosynthesis systems are electronic
scientific instruments designed for non-destructive measurement of photosynthetic rates in the field. Photosynthesis systems are commonly used in agronomic and environmental
research, as well as studies of the global carbon cycle.
. Atmospheric carbon dioxide
is taken up by leaves in the process of photosynthesis
, where is used to generate sugars in a molecular pathway known as the Calvin cycle
. This draw-down of induces more atmospheric to diffuse through stomata into the air spaces of the leaf. While stoma are open, water vapor can easily diffuse out of plant tissues, a process known as transpiration
. It is this exchange of and water vapor that is measured as a proxy of photosynthetic rate.
The basic components of a photosynthetic system are the leaf chamber, infrared
gas analyzer (IRGA), batteries and a console with keyboard, display and memory. Modern 'open system' photosynthesis systems also incorporate miniature disposable compressed gas cylinder and gas supply pipes. This is because external air has natural fluctuations in and water vapor content, which can introduce measurement noise. Modern 'open system' photosynthesis systems remove the and water vapour by passage over soda lime and Drierite, then add at a controlled rate to give a stable concentration. Some systems are also equipped with temperature control and a removable light unit, so the effect of these environmental variables can also be measured.
The leaf to be analysed is placed in the leaf chamber. The concentrations is measured by the infrared gas analyzer. The IRGA shines infrared light through a gas sample onto a detector. in the sample absorbs energy, so the reduction in the level of energy that reaches the detector indicates the concentration. Modern IRGAs take account of the fact that absorbs energy at similar wavelengths as . Modern IRGAs may either dry the gas sample to a constant water content or incorporate both a and a water vapour IRGA to assess the difference in and water vapour concentrations in air between the chamber entrance and outlet.
The Liquid Crystal Display
on the console displays measured and calculated data. The console may have a PC card slot. The stored data can be viewed on the LCD display, or sent to a PC. Some photosynthesis systems allow communication over the internet using standard internet communication protocols.
Modern photosynthetic systems may also be designed to measure leaf temperature, chamber air temperature, PAR (Photosynthetically Active Radiation
), and atmospheric pressure
. These systems may calculate water use efficiency (A/E), stomatal conductance (gs
), intrinsic water use efficiency (A/gs), and sub-stomatal concentration (Ci). Chamber and leaf temperatures are measured with a thermistor sensor. Some systems are also designed to control environmental conditions.
In an ‘open system’, air is continuously passed through the leaf chamber to maintain in the leaf chamber at a steady concentration. The leaf to be analysed is placed in the leaf chamber. The main console supplies the chamber with air at a known rate with a known concentration of and . The air is directed over the leaf, then the and concentration of air leaving the chamber is determined. The out going air will have a lower concentration and a higher concentration than the air entering the chamber. The rate of uptake is used to assess the rate of photosynthetic carbon assimilation, while the rate of water loss is used to assess the rate of transpiration. Since intake and release both occur through the stomata, high rates of uptake are expected to coincide with high rates of transpiration. High rates of uptake and loss indicates high stomatal conductance.
Because the atmosphere is renewed, 'open' systems are not seriously effected by outward gas leakage and adsorption
or absorption by the materials of the system.
In contrast, in a ‘closed system’, the same atmosphere is continuously measured over a period of time to establish rates of change in the parameters. The concentration in the chamber is decreased, while the concentration increases. This is less tolerant to leakage and material ad/absorption.
For CO2 to diffuse into the leaf, stomata must be open, which permits the outward diffusion of water vapour. Therefore, the conductance of stomata influences both photosynthetic rate (A) and transpiration (E), and the usefulness of measuring A is enhanced by the simultaneous measurement of E. The internal concentration (Ci) is also quantified, since Ci represents an indicator of the availability of the primary substrate (CO2) for A.
A leaf is placed in the leaf chamber, then the rate of photosynthetic carbon assimilation is determined by measuring the rate at which the leaf assimilates . The change in is calculated as flowing into leaf chamber, in μmol
mol−1 , minus flowing out from leaf chamber, in μmol mol-1. The photosynthetic rate (Rate of exchange in the leaf chamber) is the difference in concentration through chamber, adjusted for the molar flow of air per m2 of leaf area, mol m−2 s−1.
The change in H2O vapour pressure is water vapour pressure out of leaf chamber, in mbar, minus the water vapour pressure into leaf chamber, in mbar. Transpiration rate is differential water vapour concentration, mbar, multiplied by the flow of air into leaf chamber per square meter of leaf area, mol s−1 m−2, divided by atmospheric pressure, in mBar.
A leaf is placed in the leaf-chamber, with a known area of leaf enclosed. Once the chamber is closed, carbon dioxide concentration gradually declines. When the concentration decreases past a certain point a timer is started, and is stopped as the concentration passes at a second point. The difference between these concentrations gives the change in carbon dioxide in ppm. Net photosynthetic rate in micro grams carbon dioxide s−1 is given by;
(V • p • 0.5 • FSD • 99.7) / t
where V = the chamber volume in liters, p = the density of carbon dioxide in mg cm−3, FSD = the carbon dioxide concentration in ppm corresponding to the change in carbon dioxide in the chamber, t = the time in seconds for the concentration to decrease by the set amount. Net photosynthesis per unit leaf area is derived by dividing net photosynthetic rate by the leaf area enclosed by the chamber.
, estimates of these parameters can be used to investigate numerous aspects of plant biology
. The plant-scientific community has generally accepted photosynthetic systems as reliable and accurate tools to assist research. There are numerous peer-reviewed articles in scientific journals which have used a photosynthetic system. To illustrate the utility and diversity of applications of photosynthetic systems, below you will find brief descriptions of research using photosynthetic systems;
Electronics
Electronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...
scientific instruments designed for non-destructive measurement of photosynthetic rates in the field. Photosynthesis systems are commonly used in agronomic and environmental
Environmental science
Environmental science is an interdisciplinary academic field that integrates physical and biological sciences, to the study of the environment, and the solution of environmental problems...
research, as well as studies of the global carbon cycle.
How photosynthesis systems function
Photosynthesis systems function by measuring gas exchange of leavesLeaves
-History:Vocalist Arnar Gudjonsson was formerly the guitarist with Mower, and he was joined by Hallur Hallsson , Arnar Ólafsson , Bjarni Grímsson , and Andri Ásgrímsson . Late in 2001 they played with Emiliana Torrini and drew early praise from the New York Times...
. Atmospheric carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
is taken up by leaves in the process of photosynthesis
Photosynthesis
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...
, where is used to generate sugars in a molecular pathway known as the Calvin cycle
Calvin cycle
The Calvin cycle or Calvin–Benson-Bassham cycle or reductive pentose phosphate cycle or C3 cycle or CBB cycle is a series of biochemical redox reactions that take place in the stroma of chloroplasts in photosynthetic organisms...
. This draw-down of induces more atmospheric to diffuse through stomata into the air spaces of the leaf. While stoma are open, water vapor can easily diffuse out of plant tissues, a process known as transpiration
Transpiration
Transpiration is a process similar to evaporation. It is a part of the water cycle, and it is the loss of water vapor from parts of plants , especially in leaves but also in stems, flowers and roots. Leaf surfaces are dotted with openings which are collectively called stomata, and in most plants...
. It is this exchange of and water vapor that is measured as a proxy of photosynthetic rate.
The basic components of a photosynthetic system are the leaf chamber, infrared
Infrared
Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...
gas analyzer (IRGA), batteries and a console with keyboard, display and memory. Modern 'open system' photosynthesis systems also incorporate miniature disposable compressed gas cylinder and gas supply pipes. This is because external air has natural fluctuations in and water vapor content, which can introduce measurement noise. Modern 'open system' photosynthesis systems remove the and water vapour by passage over soda lime and Drierite, then add at a controlled rate to give a stable concentration. Some systems are also equipped with temperature control and a removable light unit, so the effect of these environmental variables can also be measured.
The leaf to be analysed is placed in the leaf chamber. The concentrations is measured by the infrared gas analyzer. The IRGA shines infrared light through a gas sample onto a detector. in the sample absorbs energy, so the reduction in the level of energy that reaches the detector indicates the concentration. Modern IRGAs take account of the fact that absorbs energy at similar wavelengths as . Modern IRGAs may either dry the gas sample to a constant water content or incorporate both a and a water vapour IRGA to assess the difference in and water vapour concentrations in air between the chamber entrance and outlet.
The Liquid Crystal Display
Liquid crystal display
A liquid crystal display is a flat panel display, electronic visual display, or video display that uses the light modulating properties of liquid crystals . LCs do not emit light directly....
on the console displays measured and calculated data. The console may have a PC card slot. The stored data can be viewed on the LCD display, or sent to a PC. Some photosynthesis systems allow communication over the internet using standard internet communication protocols.
Modern photosynthetic systems may also be designed to measure leaf temperature, chamber air temperature, PAR (Photosynthetically Active Radiation
Photosynthetically active radiation
Photosynthetically active radiation, often abbreviated PAR, designates the spectral range of solar radiation from 400 to 700 nanometers that photosynthetic organisms are able to use in the process of photosynthesis. This spectral region corresponds more or less with the range of light visible to...
), and atmospheric pressure
Atmospheric pressure
Atmospheric pressure is the force per unit area exerted into a surface by the weight of air above that surface in the atmosphere of Earth . In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point...
. These systems may calculate water use efficiency (A/E), stomatal conductance (gs
GS
-Places:* South Georgia and the South Sandwich Islands ** .gs, an Internet country code top-level domain-Science:* g-force , multiples of the acceleration due to gravity* Guanosine synthetase-Technologies:* Glideslope* Ground Speed...
), intrinsic water use efficiency (A/gs), and sub-stomatal concentration (Ci). Chamber and leaf temperatures are measured with a thermistor sensor. Some systems are also designed to control environmental conditions.
'Open' systems or 'closed' systems
There are two distinct types of photosynthetic system; ‘open’ or ‘closed’. This distinction refers to whether or not the atmosphere of the leaf-enclosing chamber is renewed during the measurement.In an ‘open system’, air is continuously passed through the leaf chamber to maintain in the leaf chamber at a steady concentration. The leaf to be analysed is placed in the leaf chamber. The main console supplies the chamber with air at a known rate with a known concentration of and . The air is directed over the leaf, then the and concentration of air leaving the chamber is determined. The out going air will have a lower concentration and a higher concentration than the air entering the chamber. The rate of uptake is used to assess the rate of photosynthetic carbon assimilation, while the rate of water loss is used to assess the rate of transpiration. Since intake and release both occur through the stomata, high rates of uptake are expected to coincide with high rates of transpiration. High rates of uptake and loss indicates high stomatal conductance.
Because the atmosphere is renewed, 'open' systems are not seriously effected by outward gas leakage and adsorption
Adsorption
Adsorption is the adhesion of atoms, ions, biomolecules or molecules of gas, liquid, or dissolved solids to a surface. This process creates a film of the adsorbate on the surface of the adsorbent. It differs from absorption, in which a fluid permeates or is dissolved by a liquid or solid...
or absorption by the materials of the system.
In contrast, in a ‘closed system’, the same atmosphere is continuously measured over a period of time to establish rates of change in the parameters. The concentration in the chamber is decreased, while the concentration increases. This is less tolerant to leakage and material ad/absorption.
Calculations used in 'open system' systems;
For CO2 to diffuse into the leaf, stomata must be open, which permits the outward diffusion of water vapour. Therefore, the conductance of stomata influences both photosynthetic rate (A) and transpiration (E), and the usefulness of measuring A is enhanced by the simultaneous measurement of E. The internal concentration (Ci) is also quantified, since Ci represents an indicator of the availability of the primary substrate (CO2) for A.
A leaf is placed in the leaf chamber, then the rate of photosynthetic carbon assimilation is determined by measuring the rate at which the leaf assimilates . The change in is calculated as flowing into leaf chamber, in μmol
Mol
-Places:* City Municipality of Ljubljana, known after the acronym MOL in Slovene language * Märkisch-Oderland, a rural district of Brandenburg, Germany* Mol, Belgium, a municipality in Belgium* Mol, Serbia, a town in Serbia...
mol−1 , minus flowing out from leaf chamber, in μmol mol-1. The photosynthetic rate (Rate of exchange in the leaf chamber) is the difference in concentration through chamber, adjusted for the molar flow of air per m2 of leaf area, mol m−2 s−1.
The change in H2O vapour pressure is water vapour pressure out of leaf chamber, in mbar, minus the water vapour pressure into leaf chamber, in mbar. Transpiration rate is differential water vapour concentration, mbar, multiplied by the flow of air into leaf chamber per square meter of leaf area, mol s−1 m−2, divided by atmospheric pressure, in mBar.
Calculations used in 'closed system' systems;
A leaf is placed in the leaf-chamber, with a known area of leaf enclosed. Once the chamber is closed, carbon dioxide concentration gradually declines. When the concentration decreases past a certain point a timer is started, and is stopped as the concentration passes at a second point. The difference between these concentrations gives the change in carbon dioxide in ppm. Net photosynthetic rate in micro grams carbon dioxide s−1 is given by;
(V • p • 0.5 • FSD • 99.7) / t
where V = the chamber volume in liters, p = the density of carbon dioxide in mg cm−3, FSD = the carbon dioxide concentration in ppm corresponding to the change in carbon dioxide in the chamber, t = the time in seconds for the concentration to decrease by the set amount. Net photosynthesis per unit leaf area is derived by dividing net photosynthetic rate by the leaf area enclosed by the chamber.
Applications
Since photosynthesis, transpiration and stomatal conductance are an integral part of basic plant physiologyPhysiology
Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...
, estimates of these parameters can be used to investigate numerous aspects of plant biology
Biology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...
. The plant-scientific community has generally accepted photosynthetic systems as reliable and accurate tools to assist research. There are numerous peer-reviewed articles in scientific journals which have used a photosynthetic system. To illustrate the utility and diversity of applications of photosynthetic systems, below you will find brief descriptions of research using photosynthetic systems;
- Researchers from the Technion - Israel Institute of TechnologyTechnion - Israel Institute of TechnologyThe Technion – Israel Institute of Technology is a research-intensive institute of technology in Haifa, Israel. Originally called the Technikum, it was founded in 1912...
and a number of US institutions studied the combined effects of drought and heat stress on Arabidopsis thalianaArabidopsis thalianaArabidopsis thaliana is a small flowering plant native to Europe, Asia, and northwestern Africa. A spring annual with a relatively short life cycle, arabidopsis is popular as a model organism in plant biology and genetics...
. Their research suggests that the combined effects of heat and drought stress cause sucrose to serve as the major osmoprotectant. - Plant physiologists from The University of Putra Malaysia and The University of EdinburghUniversity of EdinburghThe University of Edinburgh, founded in 1583, is a public research university located in Edinburgh, the capital of Scotland, and a UNESCO World Heritage Site. The university is deeply embedded in the fabric of the city, with many of the buildings in the historic Old Town belonging to the university...
investigated the relative effects of tree age and tree size on the physiological attributes of two broadleaf species. A photosynthetic system was used by to measure photosynthetic rate per unit of leaf mass. - Researchers at University of California-Berkeley found that water loss from leaves in Sequoia sempervirens is ameliorated by heavy fog in the Western US. Their research suggests that fog may help the leaves retain water and enable the trees to fix more carbon during active growth periods.
- The effect of CO2 enrichment on the photosynthetic behavior of an endangered medicinal herb was investigated by this team at Garhwal University, India. Photosynthetic rate (A) was stimulated during the first 30 days, then significantly decreased. TranspirationTranspirationTranspiration is a process similar to evaporation. It is a part of the water cycle, and it is the loss of water vapor from parts of plants , especially in leaves but also in stems, flowers and roots. Leaf surfaces are dotted with openings which are collectively called stomata, and in most plants...
rate (E) decreased significantly throughout the CO2 enrichment, whereas stomatal conductance (gsGS-Places:* South Georgia and the South Sandwich Islands ** .gs, an Internet country code top-level domain-Science:* g-force , multiples of the acceleration due to gravity* Guanosine synthetase-Technologies:* Glideslope* Ground Speed...
) significantly reduced initially. Overall, it was concluded that the medicinally important part of this plant showed increased growth. - Researchers at the University of Trás-os-Montes and Alto DouroUniversity of Trás-os-Montes and Alto DouroThe University of Trás-os-Montes and Alto Douro is a public university located in Vila Real, Portugal. It was created in 1986 from the structure of the former Instituto Politécnico de Vila Real, a polytechnic institution dating from 1974. Today UTAD has campuses in Chaves and Miranda do Douro...
, Portugal grew Grapevines in outside plots and in Open-Top Chambers which elevated the level of CO2. A photosynthetic system was used to measure CO2 assimilation rate (A), stomatal conductance (gs), transpiration rate (E), and internal CO2 concentration/ambient CO2 ratio (Ci/Ca). The environmental conditions inside the chambers caused a significant reduction in yield. - A study of Nickel bioremediationBioremediationBioremediation is the use of microorganism metabolism to remove pollutants. Technologies can be generally classified as in situ or ex situ. In situ bioremediation involves treating the contaminated material at the site, while ex situ involves the removal of the contaminated material to be treated...
involving poplar (Populas nigra), conducted by researchers at the Bulgarian Academy of Sciences and the National Research Institute of Italy (Consiglio Nazionale delle RicercheConsiglio Nazionale delle RicercheThe Consiglio Nazionale delle Ricerche or National Research Council, is an Italian public organization set up to support scientific and technological research. Its headquarters are in Rome.-History:The institution was founded in 1923...
), found that Ni-induced stress reduced photosynthesis rates, and that this effect was dependent upon leaf Ni content. In mature leaves, Ni stress led to emission of cis-β-ocimene, where as in developing leaves, it led to enhanced isopreneIsopreneIsoprene , or 2-methyl-1,3-butadiene, is a common organic compound with the formula CH2=CCH=CH2. Under standard conditions it is a colorless liquid...
emissions. - Plant physiologists in Beijing measured photosynthetic rate, transpiration rate and stomatal conductance in plants which accumulate metal and those that do not accumulate metal. Seedlings were grown in the presence of 200 or 400 μM CdCl2Cadmium chlorideCadmium chloride is a white crystalline compound of cadmium and chlorine, with the formula CdCl2. It is a hygroscopic solid that is highly soluble in water and slightly soluble in alcohol. Although it is considered to be ionic, it has considerable covalent character to its bonding...
. This was used to elucidate the role of antioxidative enzyme in the adaptive responses of metal-accumulators and non-accumulators to Cadmium stress. - In a study of drought resistance and salt tolerance of a rice variety, researchers at the National Center of Plant Gene Research and the Huazhong Agricultural UniversityHuazhong Agricultural UniversityHuazhong Agricultural University . a.k.a. Central China Agricultural University, HZAU/HAU) is a multi-disciplinary comprehensive university giving priority to agriculture, characterized by life sciences and supplemented by the combination of agriculture, basic sciences, engineering, liberal arts,...
in Wuhan, China found that a transgenic rice variety showed greater drought resistance than a conventional variety. Over expression of the stress response gene SNAC1 led to reduced water loss, but no significant change in photosynthetic rate. - This Canadian team examined the dynamic responses of Stomatal conductance (gs) net photosynthesis (A) to a progressive drought in nine poplar clones with contrasting drought tolerance. gs and A were measured using a photosynthetic system. Plants were either well-watered or drought preconditioned.
- Researchers at Banaras Hindu UniversityBanaras Hindu UniversityBanaras Hindu University is a public university located in Varanasi, India and is one of the Central Universities of India. It is the largest residential university in Asia, with over 24,000 students in its campus. BHU was founded in 1916 by Pandit Madan Mohan Malviya under the Parliamentary...
, India, investigated the potential of sewage sludge to be used in agriculture as an alternative disposal technique. Agricultural soil growing rice had sewage sludge added at different rates. Rates of photosynthesis and stomatal conductance of the rice were measured to examine the biochemical and physiological responses of sewage addition. - Researchers from Lancaster UniversityLancaster UniversityLancaster University, officially The University of Lancaster, is a leading research-intensive British university in Lancaster, Lancashire, England. The university was established by Royal Charter in 1964 and initially based in St Leonard's Gate until moving to a purpose-built 300 acre campus at...
, The University of LiverpoolUniversity of LiverpoolThe University of Liverpool is a teaching and research university in the city of Liverpool, England. It is a member of the Russell Group of large research-intensive universities and the N8 Group for research collaboration. Founded in 1881 , it is also one of the six original "red brick" civic...
, and The University of EssexUniversity of EssexThe University of Essex is a British campus university whose original and largest campus is near the town of Colchester, England. Established in 1963 and receiving its Royal Charter in 1965...
, UK, measured isoprene emission rates from a oil palm tree. Samples were collected using a photosynthetic system that controlled PAR and leaf temperature (1000 μmol m−2 s−1; 30 °C). It had thought that PAR and temperature are the main controls of isoprene emission from the biosphere. This research showed that isoprene emissions from oil palm tree are under strong circadian control. - The ecophysiological diversity and the breeding potential of wild coffee populations in Ethiopia was evaluated as a thesis submitted to The Rheinischen Friedrich-Wilhelms-UniversityUniversity of BonnThe University of Bonn is a public research university located in Bonn, Germany. Founded in its present form in 1818, as the linear successor of earlier academic institutions, the University of Bonn is today one of the leading universities in Germany. The University of Bonn offers a large number...
of Bonn, Germany. Complementary field and garden studies of populations native to a range of climatic conditions were examined. Plant ecophysiological behavior was assessed by a number of system parameters, including gas exchange, which was measured using a photosynthetic system. - A collaborative project between researchers at the University of CambridgeUniversity of CambridgeThe University of Cambridge is a public research university located in Cambridge, United Kingdom. It is the second-oldest university in both the United Kingdom and the English-speaking world , and the seventh-oldest globally...
, UK, the Australian Research Council Center of Excellence, and the Australian National UniversityAustralian National UniversityThe Australian National University is a teaching and research university located in the Australian capital, Canberra.As of 2009, the ANU employs 3,945 administrative staff who teach approximately 10,000 undergraduates, and 7,500 postgraduate students...
resulted in validation of a model that describes carbon isotope discrimination for crassulacean acid metabolism using Kalanchoe daigremontiana. - Instruments of this type can also be used as a standard for plant stress measurementPlant stress measurementPlant stress measurement is the quantification of environmental effects on photosynthesis, and plant health.When plants are subjected to less than ideal growing conditions, plants are considered to be under stress. Plant stress can affect plant growth, plant survival and crop yields...
. Difficut to measure types of plant stress such as Cold stress, and water stress can be measured with this type of instrumentation. See the Desk top Stress guide for more details
Alphabetical list of system models
- The ADC BioscientificADC BioscientificADC Bioscientific is a UK-based company that designs and manufactures scientific instruments for research into plant physiology, environments, soils, and for monitoring carbon dioxide...
model LCi uses an ‘open’ system design. It is a slimmed-down photosythesis system, which can only measure the environment within the leaf chamber, and calculate the photosynthetic activity of the leaf. - The ADC Bioscientific model LCpro+ uses an ‘open’ system design. This instrument can control temperature, light levels, concentration and concentration within the leaf chamber. It can measure photosynthetic parasystems. The LCpro+ comes with a range of interchangeable chamber heads which allows it to be adapted to the plant of interest.
- The ADC BioscientificADC BioscientificADC Bioscientific is a UK-based company that designs and manufactures scientific instruments for research into plant physiology, environments, soils, and for monitoring carbon dioxide...
model LCi-SD is a new system that uses an ‘open’ design. It is an highly portable ambient photosynthesys system designed for differential leaf photosynthesis work. - ADC Bioscientific model LCpro-SD is a new system that uses an ‘open’ system design. This is also a highly portable field instrument that allows environmental control of temperature, light levels, concentration and concentration within the leaf chamber. It can also measure other photosynthetic parameters. The LCpro-SD comes with a range of interchangeable chamber heads which allows it to be adapted to the plant of interest.
- The CID Bio-Science model CI-340 Handheld Photosynthesis System measures, (in an open or closed system) photosynthesis, transpiration, stomatal conductance, PAR and internal CO2 in a single handheld instrument. The chamber is connected directly to the CO2 / H2O differential gas analyzer, so there is virtually no delay when measuring CO2 / H2O in the chamber. The optional environmental control modules enable the researcher to create green house conditions in the field. The device can simultaneously measure chlorophyll fluorescence and gas exchange over the same leaf area, in the chamber.
- The LI-COR BiosciencesLI-COR BiosciencesLI-COR Biosciences designs, manufactures, and markets instruments for biological and environmental research. It is ISO 9001 certified, meaning that it demonstrates "its ability to consistently provide products that enhance customer satisfaction and meet applicable statutory and regulatory...
models LI-6000 and LI-6200 were of the 'closed' system design. - LI-COR BiosciencesLI-COR BiosciencesLI-COR Biosciences designs, manufactures, and markets instruments for biological and environmental research. It is ISO 9001 certified, meaning that it demonstrates "its ability to consistently provide products that enhance customer satisfaction and meet applicable statutory and regulatory...
model LI-6400/LI-6400XT uses an 'open' system design. This device can simultaneously measure fluorescence and gas exchange over the same leaf area, and it provides control over temperature, light levels, concentration, and concentration in the chamber. - The PP Systems model CIRAS-1 used an 'open' system design.
- PP Systems TPS-2 uses an 'open' system design.
- The PP Systems model CIRAS-2 uses an 'open' system. It can control , , temperature and light. It can also measure chlorophyll fluorescence.
External links
- http://www.ipipotash.org/udocs/CO2_Gas_exchange_parasystems_paper.pdf
- http://www.ncbi.nlm.nih.gov/pmc/articles/PMC425915/pdf/plntphys00537-0205.pdf
- http://jxb.oxfordjournals.org/content/47/11/1629.full
- http://www.optisci.com/adc_co2.htm
- http://www.optisci.com/datasheet/lcprosd.pdf
- http://www.optisci.com/datasheet/lcisd.pdf