IMAGING-PAM M-Series

Elevating Chlorophyll Fluorescence to the 3D Level

The brand-new integration of a precise 3D scanner into the proven MAXI version of the IMAGING-PAM fluorometer combines saturation pulse analysis with knowledge on size, number, position and angle of leaves. As a result, the effective light intensity per unit of leaf area can be considered when light effects on photosynthesis or photoinhibition are evaluated.

The 3D configuration provides a multitude of additional morphological data for structural phenotyping of plants. Together, morphological parameters and fluorometrically characterized, functional parameters form a new realm in plant phenotyping.

Chlorophyll Fluorescence and PAM Fluorometry

Chlorophyll fluorescence is a very sensitive indicator of photosynthesis. Quantitative information on the quantum yield of photosynthetic energy conversion is obtained by PAM fluorometry and the saturation pulse method (Schreiber U (2004) Pulse-Amplitude-Modulation (PAM) Fluorometry and Saturation Pulse Method: An Overview, pp. 279-319. Kluwer Academic Publishers, Dordrecht, The Netherlands).

A wide range of photosynthetic parameters can be derived from fluorescence measurements, giving insight into the physiological state of all photosynthetically active organisms, including higher plants, mosses and ferns as well as various types of algae, phytoplankton and biofilms.

Chlorophyll Fluorescence Imaging

With the advance of highly sensitive CCD cameras and extremely strong light emitting diodes (LED) development of IMAGING-PAM fluorometers has become possible that not only measure images of chlorophyll fluorescence but are also fully competent in providing all relevant chlorophyll fluorescence parameters using the saturation pulse method. In this way, images of photosynthetic activity and its spatio-temporal variations can be obtained.

All IMAGING-PAM fluorometers provide images for 17 different parameters. The fluorescence parameter Ft is continuously monitored. Fo and Fm are assessed after dark adaptation, serving as reference for fluorescence quenching analysis by the saturation pulse method.

Besides Fv/Fm, the PS II quantum yield after dark acclimation, also the PS II quantum yield during illumination, Y(II), and the quantum yields of regulated and non-regulated energy dissipation, Y(NPQ), Y(NO) as well as the apparent electron transport rate (ETR and PS) can be imaged.

A routine for measuring a PAR-absorptivity image is provided for the MAXI and the MINI version of the IMAGING-PAM (Abs.-image based on images of NIR and red light remission). From this parameter also the apparent rate of photosynthesis is calculated and does not need to use the commonly known PAR-absorptivity mean value of 0.84 (ETR) for all areas anymore.

The parameter PS/50 is displayed in order to depict the apparent photosynthesis with the help of the false color code that is also used for the other photosynthesis parameters.

The new 3D version of IMAGING-PAM is particularly suited for precise measurements of whole above-ground parts of sample plants. It measures the exact leaf height and provides a clear numerical description of single leaves (size, shape, angle, balance point) and entire plants (rosette radius, surface area and number of leaves).

For different applications the MAXI, MINI and MICROSCOPY versions are available in various configurations differing in optical geometries and excitation wavelengths. While blue excitation light is normally used for fluorescence imaging of higher plants and algae, red-orange excitation is recommended for cyanobacteria.

Measuring heads can also be equipped with special LEDs and filter sets for imaging fluorescence from reporter molecules like GFP. The use of power LEDs allows actinic intensities of up to 5000 μmol m-2 s-1 (depending on the M-Series member and configuration).

For the measurement of suspensions additional filter plates are available enhancing the image quality even with reflective surfaces. For PSII measurements under ambient light conditions also the communication with our Universal Light Meter ULM-500 is possible, so that real time light values directly can be taken over to the IMAGING-PAM report file.

For the combination of different measuring techniques like e.g. gas exchange, adapters are available so that PSII imaging can be performed under climate control combined also.