Lancaster University, UK: Lancaster Environment Centre
Whole plant chamber to examine sensitivity of cereal gas exchange to changes in evaporative demand
A plant’s ability to make efficient use of its water supply is key to efficient growth and biomass accumulation. Stomatal pores on the leaves adjust their aperture in response to atmospheric changes in temperature and humidity to optimise the ratio of photosynthesis and transpiration, which is the intrinsic water use efficiency (WUE).
In this study, the rates of transpiration and photosynthesis of various genotypes were measured in a bespoke whole plant gas chamber. Commercial cultivars of wheat were included to understand the range of WUE in this crop, along with various genetic mutants to help understand physiological mechanisms causing this variation.
In order to properly assess the mechanisms at play, the light, temperature, humidity, and gas concentration conditions within the whole plant chamber were controlled, allowing rapid identification of genotypes with higher WUE. An Alicat flow controller was used to strictly regulate the gas flow into the system, in order to maintain a reasonable CO2 concentration across the chamber and maintain stable system pressure. This provided the stable conditions required to accurately assess the water use efficiency of the plants in the study.