The 6400-17 Whole Plant Arabidopsis Chamber is the newest addition to the family of chamber accessories for the LI-6400/ 6400XT Portable Photosynthesis System. The large diameter (2.75 in., 7 cm) of the 6400-17 allows for measurements of entire Arabidopsis rosettes, rather than just the leaves. Measuring whole rosettes allows for repeatable measurements for growth studies that were previously difficult to achieve without the use of custom chamber configurations.

The 6400-17 is easily integrated with the LI-6400/6400XT sensor head by mounting to the lower leaf chamber manifold. Because the 6400-17 mounts directly to the lower manifold, excellent air mixing is achieved without the need for additional fans within the chamber.

Interchangeable chamber bottom plates are provided for use with readily available 2.5 in. (65 mm) pots or 1.5 in. (38 mm) Cone-tainers. Chamber air temperature is measured by a thermocouple in the air return path, preventing radiant effects from the light source. This thermocouple plugs into the existing thermocouple block on the LI-6400/ 6400XT sensor head. The leaf temperature is computed in software using an energy balance approximation. An o-ring sealed top plate with a Propafilm covering is placed over the chamber when making measurements. The o-ring provides a tight seal that eliminates the need for traditional foam gaskets.

Because soils or artificial media are present within the chamber volume, CO2 fluxes from the soil can be introduced into the whole plant measurement. A standard peat media mix capped with a heavy clay layer on top suppresses soil respiration. An exhaust tube fitting is also provided that can be used to apply a slight over-pressure within the chamber, which also suppresses CO2 fluxes from the soil.