PhD position at IRSTEA, Rennes (IRM-Food)

The project aimed at characterisation of water status in plant tissues by MRI. All the necessary details regarding this position are detailed below. Applications close 10 Mai 2017.


MRI-Food (UR OPAALE, IRSTEA) is a multidisciplinary research team focused on the development and applications of Nuclear Magnetic Resonance (NMR) relaxometry and imaging (MRI) methods for the characterisation of structure and processing of bio-products. The research team has an expertise in NMR and MRI applied to horticulture products. 


TITLE: Water status in plant tissues measured by MRI


ABSTRACT:  Spatially  resolved  measurements  of  multi-exponential  transversal  relaxation  time spectra by MRI make it possible to provide quantitative data about water status and distribution in cell compartments in intact fruit tissues. However, the influence of water content on relaxation parameters is  not  completely  explained,  as  relaxation  times  depend  on  water  content  and  also  on  diffusive exchanges  of  water  molecules  between  cell  compartments  through  semi-permeable  membrane. Consequently, to date, there is no quantitative method allowing estimation of the water content and the amount of water in different cell compartments of plant tissues. The objective of this thesis is to study both  the  effects  of  water  content  and  diffusional  exchanges  of  water  molecules  between  cell compartments on the relaxation parameters in order to allow measurements of water content by MRI. Water  content  and  status  of  fruit  tissues  will  be  varied  by  subjecting  fruits  to  different  drying conditions. Multi-exponential relaxation times corresponding to cell compartments and the apparent diffusion coefficient will be measured by MRI on intact fruits. The experimental part of the project will be mainly performed on 1.5 T Siemens MRI system. A 4.7 T Bruker MRI system will potentially also be used.  The candidate should be physicist or engineer. A Master's degree or equivalent is required. 


Thesis supervisors: Maja Musse and François Mariette 


The  application,  consisting  of  the  letter  of  motivation  and  the  CV  can  be  sent  by  e-mail  to