The Q-Box CO650 Plant CO₂ Analysis Package may be used to measure photosynthesis, respiration and photorespiration in attached or detached leaves maintained in a leaf chamber attached to an open flow gas exchange system.

Operation of the Q-Box CO650 involves the use of an infrared CO2 gas analyzer (Q-S151) to measure, at different times, the concentration of CO2 in a gas entering a leaf chamber, and the concentration of CO2 in the same gas after it leaves the chamber. Measurement of the difference between influx and efflux CO2 concentration (differential CO2) and measurement of the flow of gas through the chamber, allow calculation of photosynthetic CO2 fixation rate.  The method can also be used to measure CO2 evolution from the leaf in the dark (dark respiration) or in the light (photorespiration).

The Q-Box CO650 includes a Humidity/Temperature sensor (Q-S161) which measures relative humidity of the air before and after it has passed through the leaf chamber, and the temperature of the air at the RH sensor.  The RH differential between influx and efflux air, the air temperature, and the flow rate through the leaf chamber, allow calculation of leaf transpiration rates.

An LED Light Source (A113) supplies photosynthetically active radiation to the leaf with minimum heat load.  The LED light source can deliver approximately 1400 µmol photons/m2/s at maximum output.
For calculations of leaf conductance, leaf temperature measurements are required.  An optional S171 Leaf Thermistor can be added to the package and fitted in the bottom portion of the leaf chamber for measurements of leaf temperature during experiments.  If S171 is not included an assumption that the leaf temperature is the same as air temperature can be made.
Analog signals from all of the sensors are converted to digital signals via two integrated LabQuest mini interfaces (6 channels).  Data is displayed, recorded and manipulated on a PC or Macintosh computer using Logger Pro software.

The Q-Box CO650 Plant CO2 Analysis Package contains:

• Q-A101 laboratory stand (free standing or integrated into Q-Box)
• A113 LED Light Source
• Q-P651 Gas pump (4L/min no load)
• G112 Flow Through Leaf Chamber
• G122 Large Gas Bags (2)
• Q-G266 Flow Monitor (0-1L/min)
• Q-S151 CO2 Analyzer (0-2000ppm) (Includes CO2 and H2O scrubbers)
• Q-S161 RH/temperature sensor
• C610 two integrated LabQuest Mini data interfaces 
• C901 Logger Pro Software
• C404 Customized Setup Software
• Q-Box Accessory Kit
• Rugged Water-proof case housing the sensors and analyzers
• Manual
• individual power supplies for stand alone use of the sensors and analyzers

optional components:

• S171 Leaf chamber thermistor (for leaf conductance calculations)
• A248 Battery pack and charger (for field use)

Sample of data from a detached leaf:

Q-Box CO650 software provides a calculation template page so photosynthetic rate, transpiration rate, leaf conductance can be easily determined.

Contact Qubit for more information on Q-Box CO650 package.

The Q-Box SR1LP Soil Respiration Package provides the user with all of the materials required to measure soil respiration using an open-flow gas exchange system when the rate of respiration is high, or as a closed-flow recirculation system when the rate of respiration is low.  The Battery Pack and Charger allow the use of the package in the field conditions.  Air is pumped at a known flow rate through the soil chamber and sensors.  The concentration of CO2 in the air is determined using the Q-S151 CO2 Analyzer.   In the open-flow system the difference in CO2 concentration entering the flow through the cuvette holding the soil sample and exiting it is used to calculate the rate of respiration.  In a closed-flow system the initial rate of CO2 accumulation in the soil chamber (placed on top of the soil surface) is used to determine the rate of respiration. 

 In addition to soil respiration Q-Box SR1LP package allows measurements of soil temperature with the S132 temperature probe and water loss from the soil with the S161 Temperature/Relative Humidity sensor.  The flow through the system is monitored by the Q-G266 Flow Monitor.  The Analog signals from all of the sensors and analyzers are converted to digital signals via two integrated LabQuest mini interfaces (6 channels).  Data is displayed, recorded and manipulated on a PC or Macintosh computer using Logger Pro software.

The Q-Box SR1LP Soil Respiration Package includes:

• Q-P651 Gas Pump (!L/min no load)
• G180 Soil Chamber with collar (10.2cm x 20cm high)
• G115 Flow Through Chamber (3.8 x 20cm)
• Q-S151 CO2 Analyzer (0-2000 ppm) (Includes CO2 and H2O scrubbers)
• S132 Temperature Probe
• Q-S161 RH/Temperature Sensor
• Q-G266 Flow Monitor (0-1L/min)
• G122 Gas Bags Large (30L x 2)
• A248 Battery Pack and Charger
• C610 Two integrated LabQuest Mini interfaces
• C901 Logger Pro Software
• C404 Customized Setup Software
• Q-Box Accessory Kit
• Rugged water proof case housing all sensors and analyzers
• Manual
• individual power supplies for stand alone use of analyzers and sensors

Sample soil respiration data from a closed-flow system:

Q-Box SR1LP software provides calculation templated for determination of soil respiration rates.

There are many other potential applications for Q-Box SR1LP package both in open flow and closed gas exchange systems.  For example, it can be used to measure CO2 exchange from any organism or sample maintained in a flow-through chamber.  In addition, it can be used to examine respiration or fermentation in aqueous suspensions when air or N2 is bubbled through the suspension and the outflow gas is analyzed using the CO2 Analyzer.  Provided that CO2 production rates are in the correct range, the package can be used to measure CO2 production of virtually any biological system. For more information on Q-Box SR1LP package please contact Qubit.

The PH1LP Photosynthesis teaching Package may be used to measure photosynthesis in attached or detached leaves maintained in a sealed leaf chamber. O2 is produced by the light reactions of photosynthesis causing an accumulation of O2 in the chamber, which is measured by a gas phase O2 sensor. The rate at which O2 concentration in the chamber increases provides a measurement of the rate of photosynthesis.

The PH1LP Photosynthesis Package includes everything you require to conduct numerous experiments investigating photosynthetic physiology in a teaching laboratory. You supply only the computer and the plant! Equipment specifications and experimental designs are fully documented in an Instructor’s Manual. A separate Student’s Manual guides undergraduates through experimental protocols and data handling. Minimal set-up time is required and experiments are easy to perform.

The PH1LP Package Includes:

• A101 Laboratory Stand
• A102 Accessories Bracket
• A111 Halogen Light Source
• A112 Voltage Regulator
• A211 Leaf Chamber Accessories Kit
• G111 Leaf Chamber
• G121 Small Gas Bags
• G123 12 Straws
• S101 Diffusion Based O2 Sensor
• S141 Light Sensor
• C410 LabPro Interface
• C901 Logger Pro Software
• C404 Customized Setup Software
• Instructor’s and Student’s Manuals

Photosynthesis requires both light and CO2. In the PH1LP Photosynthesis Package, light is provided by a halogen light source (A111), the intensity of which, may be varied by a sliding dimmer control (A112) . The amount of light passing through the leaf is measured by a photosensor (S141) placed beneath the transparent leaf chamber. CO2 is supplied from a gas bag (G121), which the user inflates with exhaled breath, the breath providing sufficient CO2 (usually about 3%) to saturate photosynthesis. The concentration of CO2 in the chamber declines as it is fixed in photosynthesis, and its rate of fixation is directly related to the rate of O2 production. Eventually, the CO2 concentration declines to a level that will not support net fixation, and O2 production ceases as a consequence. At this point (the CO2 compensation point) the O2 concentration in the chamber remains stable unless processes are activated that inhibit photosynthesis or stimulate respiratory O2 consumption.

The photosynthesis package is best used to measure photosynthetic O2 production under CO2-saturated conditions, and the experiments described in the manuals reflect its capability under these optimal conditions. However, there is great scope for measuring the effects on photosynthesis of other environmental parameters such as light quantity and quality. In addition, plants may be pre-treated in various ways that affect their photosynthetic rate and the effects of these treatments may be measured under conditions of both CO2 and light saturation.

The photosynthesis package may also be used to measure leaf respiration. If the flux of light to the leaf chamber is maintained below the light compensation point, respiratory O2 consumption will exceed photosynthetic O2 evolution, and the O2 concentration in the chamber will decline. The O2 sensor is able to measure this decline in O2 concentration, and the rate of decline provides a measurement of leaf “dark respiration”.

Applications

The Photosynthesis Package is suitable for use in both entry-level undergraduate courses and in research-based upper level courses. The Instructor’s Manual provides step-by-step protocols for each experiment. It includes suggested variations to make experiments more or less challenging.

Experiments Include:

• Photosynthetic rate
• Light compensation point
• Light saturation point
• Photochemical efficiency
• Wavelength dependence of photosynthesis
• Temperature effects on photosynthesis
• Photoinhibition
• CO2 limitation of photosynthesis
• Comparison of sun and shade plants
• Comparison of C3 and C4 species

A leaf is enclosed in a transparent chamber incorporating a sensor that measures photosynthetic O2 evolution. Calibration of the O2 sensor requires only that its output be adjusted to read atmospheric O2 level (20.9%). The student fills a gas bag with exhaled air (approximately 17% O2 and 3% CO2) which is then pumped through the chamber. The chamber is then sealed and the leaf illuminated with a halogen light source. Chamber O2 concentration increases as photosynthesis progresses.

Light level may be varied using a voltage regulator control. The light level used in the experiment is monitored by a light sensor situated beneath the leaf chamber. Light sensor output is given in µmol quanta/m²/s and no calibration is required. Analog outputs from both the O2 sensor and the light sensor are converted to digital signals by a LabPro Interface. They are recorded and displayed to the screen using Logger Pro data-acquisition software. The software is also used for subsequent data analysis.

In the following graph, the derivative of O2 concentration against time has been calculated to produce a data set representing photosynthetic rate (%O2 increase per minute). This derivative has been plotted against irradiance to generate a photosynthetic light response curve.

Dr. Steven Spilatro of Marietta College, Marietta, Ohio, has put together a great Photosynthesis Investigation Study Guide. It is definitely worth a look!

Qubit Systems produces the only complete experimental package Q-Box NF1LP for measurement of nitrogen fixation in H2 producing legume symbioses. The unique flow-through H2 sensor (Q-S121) measures the production rate of H2 from N2-fixing tissues, allowing in vivo measurement of nitrogenase activity in real time. Measurement of H2 evolution as a means of determining nitrogenase activity overcomes all the problems of the traditional acetylene reduction assay. The Q-Box NF1LP Nitrogen Fixation Package is perfectly safe, non-invasive and allows changes in nitrogenase activity to be observed as they occur.

The Q-Box NF1LP Nitrogen Fixation Package includes:

• Q-S121 Hydrogen Analyzer (0-2000ppm) includes drying column
• Q-S102 O2 Analyzer 9-100% 
• S132 Temperature Sensor
• Q-G267 Pump & Flow Monitor (1L/min)
• Q-G268 Pump & Flow Monitor (2L/min)
• G122 Large Gas Bags (2)
• G132 Plant Growth Pots (4) with lids, fittings and Qubitac
• G161 Nodule Cuvette
• B201 Soybean seeds with Bradyrhizobium japonicum inoculant
• C610 LabQuest mini (2) data interface system
• C901 Logger Pro Software
• C404 Customized Setup Software
• Rugged water-proof case housing all analyzers and sensors
• Q-Box Accessory kit
• Manual
• A248 Battery pack (Optional)

The Nitrogen Fixation Package contains everything required to conduct numerous investigations into the physiology and biochemistry of N2 fixation in an open-flow gas exchange system.  We even supply legume seeds and inoculum! You supply only the computer. Calibration of analyzers is simple, set-up time is minimal and experiments are easy to perform.

Applications:

• Examine the effects of temperature on nitrogenase activity
• Examine the oxygen regulation of N2 fixation
• Measure the nitrogenase electron allocation coefficient
• Examine the relationship between N2 fixation and photosynthate supply
• Determine the effect of N2 fixation inhibition by fertilizers

Data from experiment investigating O2-lability of nitrogenase in an intact soybean plant:

Data showing the effect of temperature on nitrogenase activity:

Z990 FluorPen

The basic standard FluorPen model measures two parameters:

• Ft - continuous fluorescence yield in non-actinic light. Ft is equivalent to Fo if the leaf sample is dark-adapted.
• QY - Photosystem II quantum yield. In a dark-adapted leaf this is equivalent to Fv/Fm. In a light-adapted leaf it is equivalent to Fv‘/Fm‘.

More sophisticated FluorPen models can measure:

• OJIP – Chlorophyll Fluorescence Induction Kinetics
• NPQ – Non-Photochemical Quenching
• Light Curve – Adaptation of Quantum Yield to Several Different Light Levels

Ft and QY data are stored in the FluorPen memory after they are measured. Each value is numbered sequentially and may be recalled for transcription to a computer. Measuring light power is adjustable by flash duration; actinic and saturating flashes are adjustable from 0 to 3,000 µmol photons/m2/s.

Herbicide Application:

• Improvement of the effectiveness of herbicide application
• Testing of new herbicides
• High reduction of herbicide use

Photosynthesis Research:

• Field measurement
• Mutant screening
• Stress detection

Agronomy and Forestry:

• Mapping by fluorescence parameters
• Nutrient – Fertilizer analysis

Software (optional):

• FluorPen 2.0 software (Windows 2000, XP, or higher compatible)
• Bluetooth, USB or serial communication
• Real-time and remote control functions
• Export to Microsoft Excel
• GPS mapping plug-in (extra option)

For fully loaded FluorPen, including a PAR meter please see Z995 FluorPen PAR.

FluorPen data capture screen:

Light Curve data capture screen:

NPQ Protocol Includes Five Measurements in Actinic Light and three measurements during dark relaxation.

• NPQ_Ln = (FM – FM_Ln) / FM_Ln
• NPQ_Lss = (FM – FM_Lss) / FM_Lss
• NPQ_Dn = (FM – FM_Dn) / FM_Dn

NPQ data capture screen:

OJIP measurements capture screen:

Explanation of OJIP Parameters:

• Bckg = background
• F0: = F50µs; fluorescence intensity at 50 µs
• FJ: = fluorescence intensity at j-step (at 2 ms)
• Fi: = fluorescence intensity at i-step (at 60 ms)
• FM: = maximal fluorescence intensity
• FV: = FM – F0 (maximal variable fluorescence)
• VJ = (FJ – F0) / (FM – F0)
• Vi = (Fi – F0) / (FM – F0)
• FM / F0
• FV / F0
• FV/ FM
• M0 or (dV / dt)0 = TR0 / RC – ET0 / RC = 4 (F300 – F0) / (FM – F0)
• Area = area between fluorescence curve and FM (background subtracted)
• Fix Area = total area above the OJIP fluorescence transient – between F40µ and F1s(background subtracted)
• SM = area / FM – F0 (multiple turn-over)
• Ss = the smallest Sm turn-over (single turn-over)
• N = SM . M0 . (1 / VJ) turn-over number QA
• Phi_P0 = 1 – (F0 / FM (or FV / FM)
• Psi_0 = 1 – VJ
• Phi_E0 = (1 – F0 / FM)) . Psi_0
• Phi_D0 = 1 – Phi_P0 – (F0 / FM)
• Phi_Pav = Phi_P0 – (SM / tFM); tFM) = Time to reach FM (in ms)
• ABS / RC = M0 . (1 / VJ) . (1 / Phi_P0)
• TR0 / RC = M0 . (1 / VJ)
• ET0 / RC = M0 . (1 / VJ) . Phi_0)
• DI0 / RC = (ABS / RC) – (TR0 / RC)

Formulas Derived From:

R.J. Strasser, A. Srivastava and M. Tsimilli-Michael (2000): The fluorescence transient as a tool to characterize and screen photosynthetic samples. In: Probing Photosynthesis: Mechanism, Regulation and Adaptation (M. Yunus, U. Pathre and P. Mohanty, eds.), Taylor and Francis, UK, Chapter 25, pp 445-483.

Specifications:

• Measured Parameters: Fo, Ft, Fm, Fm’ (standard), Kautsky induction (OJIP), Fast kinetics (optional)
• Actinic and Saturating Light: Adjustable from 0-3000 uE
• Measuring Light: Adjustable by duration
• Detector Wavelength: Range PIN photodiode with 697nm – 750nm bandpass filters
• FluorPen Software: Windows 2000, XP, or higher
• Sample Holder: Mechanical leaf clip
• Bios Upgradeable firmware
• Communication:  Bluetooth 1.1 or USB/serial port (optional)
• Memory Capacity: Up to 4Mb
• Internal Data: Logging Up to 100,000 data points
• Display: 2 x 8 characters LC display
• Keypad: Sealed, 2-key tactile response
• Keypad Escape Time: Turns off after 5 minutes of no use
• Power Save Mode: Autosleep
• Power Supply: 4 AAA alkaline or rechargeable batteries
• Battery Lif:e 70 hours typical with full operation
• Low Battery Detection: Low battery indication displayed
• Size: 57 x 30 x 120 mm
• Weight: 180 g
• Operating Conditions: Temperature: 0 to +55ºC; 32 to +130ºF Relative humidity: 0 to 95% (non-condensing)
• Storage Conditions: Temperature: -10 to +60ºC; 14 to +140ºF Relative humidity: 0 to 95% (non-condensing)
• Warranty: 1 year parts and labor

References:

• Fernandez-Marin B. Becerril JM, Garcia-Plazaola JI.  Unravelling the roles of desiccation-induced xanthophyll cycle activity in darkness: a case study in Lobaria pulmonary: Planta 231:1335–1342 (2010)
• Ruiz-Sanchez. M. et al. The arbuscular mycorrhizal symbiosis enhances the photosynthetic efficiency and the antioxidative response of rice plants subjected to drought stress: Journal of Plant Physiology 167(11):862-869 (2010)
• Frolec J,  Rebıcek J, Lazar D, Naus J, Impact of two different types of heat stress on chloroplast movement and fluorescence signal of tobacco leaves.  Plant Cell Rep 29:705–714 (2010)
• Harding SA et al. A comparative analysis of phenylpropanoid metabolism, N utilization, and carbon partitioning in fast- and slow-growing Populus hybrid clones.  Journal of Experimental Botany 60: 3443-3452 (2009)
• Zhang M. et al. : Ecology and Environmemtal Sciences 18 (6): 2272-2277 (2009).
• Kuvykin I.V. et al. Computer simulation study of pH-dependent regulation of electron transport in chloroplasts: Cell Biophysics 54(4):455-464 (2009)
• Chitu E, Ionita AD, Cirjaliu-Murgea M, Chitu V, Filipescu L.  Evaluation of Foliar Nutritive Fluids Effect on Apple Photosystem II Efficiency using Chlorophyll Fluorescence Bulletin UASVM Horticulture, 66(1)/(2009) Print ISSN 1843-5254; Electronic ISSN 1843-5394
• Macek P, Mackova J, de Bello F. Morphological and ecophysiological traits shaping altitudinal distribution of three Polylepis treeline species in the dry tropical Andes. Acta Oecologica 35 778–785 (2009) 
• Rosescu MR,Andrei M. The study of photosystem II efficiency on selected synanthropic plant species.  Annals, Food Science and technology V10, pg 115-119 (2009)
• Woo N.S. Badger MR, Pogson BJ.  A rapid, non-invasive procedure for quantitative assessment of drought survival using chlorophyll fluorescence: Plant Methods 4(27) (2008)