Rhizosphere Traits

We will use experimental as well as modelling approaches at the rhizosphere (sub-mm) and whole plant scale (dm). High-throughput phenotyping will enable us to screen drought responses and rhizosphere trait expressions (e.g. rhizosheath, which is the soil that adheres to the roots after extracting it from the soil and considered to be a proxy for rhizosphere processes such as mucilage exudation and root hair growth) of 48 maize and 32 wheat varieties. Large scale field experiments at two sites differing in environmental conditions, such as soil and climate, will help us to connect plant scale observations to agronomic performance on the field scale. At the plant scale, we will use an automated root pressure chamber that allows for simultaneous monitoring of transpiration, soil and leaf water potential. A numerical model will be developed to effectively include rhizosphere traits into a radial model of root water uptake which includes as parameters the root length density and the effective root radius, that is including rhizosphere processes. Our approach is to use an effective radial model of water flow toward the root surface, rather than an architecture model, which would require a large number of root hydraulic properties that cannot be easily measured. The radial model will be coupled with water flow into the plant tissues, including xylem cavitation, and across the stomata.

Project number: 031B0908