Methods and Technologies at the
Jülich Plant Phenotyping Centre
Hyperspectral Imaging Device for Rhizotrons
High resolution mapping of the shoot and root compartment
The hyperspectral imaging box is a new development of the Forschungszentrum Jülich in cooperation with SPECIM Spectral Imaging Ltd (Finland).
This device will facilitate the structural and functional understanding of shoot and root properties by high resolution imaging spectroscopy. As a first of a kind instrument hyperspectral images will be taken from the root compartment. Plants are grown in flat rhizotrons, which have a transparent screen on one side of the root compartment. The rhizotrons are arranged at a 45° angle with the transparent screen facing down. Roots show a positive geotropic reaction, thus they grow at least in part at the interface between the transparent screen and the soil. The visible portion of the root system at this interface is scanned with the hyperspectral sensors within the imaging box. To also detect fine roots two sensors are used to facilitate a spatial resolution of 100μm over the whole root compartment (Fig. 2).
The light proof housing (Fig. 3) of the imaging station has a size of 2 x 3 x 3,5 m and holds three scanning system in total. Two systems are used to scan the shoot from top view and from the side view. The height of the Shoot-Top-Side scanner is adjustable. So the system is able to grow with the plant to guarantee a fixed sensor to target distance up to a plant height of 50 cm.
The four sensors of the hyperspectral imaging box are CMOS detectors, which measure in the spectral range of 400 -1000 nm with a spectral resolution of 3 nm. Each of the three scanning systems has its own illumination (Fig. 1) and operates independently to guarantee defined illumination and measurement conditions.
This novel Hyperspectral Imaging Box is a new tool for high precision plant phenotyping, which helps to better understand the structural and functional properties of roots. This knowledge will help optimize root traits for breeding and under changing environmental conditions.