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Doctorant en génétique/biochimie des céréales

L'unité BIA propose un sujet de thèse sur "Modelling wheat starch degradability for estimating the relations between genetic, structure and function"

Mis à jour le 07/02/2018
Publié le 06/02/2018
Mots-clés :

Laboratories and researchers

INRA BIA, Nantes, France (https://www6.angers-nantes.inra.fr/bia), Kamal Kansou, Luc Saulnier CSIRO Cereal Quality Group, Canberra, Australia, Jean-Philippe Ral


Wheat starches can vary greatly in composition, structure and processing quality amongst cultivars, with different impacts on the many uses of starch and flour in the agri-food industry. Being able to fully exploit this genetic diversity is critical for wheat breeders and users. For this reason, relating wheat genetic to starch structure and functional properties is a major challenge for the research. A part of the difficulty arises from the need to get sufficient data to cope with incomplete knowledge. Because enzymatic degradation of starch provides information on both structural and functional aspects, it can be used as a cornerstone to investigate the triplet genetic-structure-function, with less characterisation measurements.

The main objective of this thesis is to develop an approach to estimate the relations between genetic information, structural properties and the degradability of wheat starch by α-amylase. The originality of the approach is to screen starches from a large 4/8-way population of wheat lines owned by the CSIRO, on basic structural/compositional attributes and starch degradability kinetics. To handle expected gaps of knowledge and data, a modelling approach combining conceptual and data-driven analysis will be applied to identify and estimate the putative causal relations governing the starch degradability. In-depth structural analysis on selected starches will be performed to assess these relations and to lead towards a better understanding of starch degradability. The project also aims at fuelling innovation in wheat breeding.


The project is a joint proposition between the Cereal Quality group of CSIRO and INRA BIA that will exploit the potential of the wheat MAGIC population of CSIRO, using experimental and modelling approaches developed by INRA. The proposal was developed under a linkage action INRA-CSIRO signed on 5 November 2015.

The research group at BIA Nantes has developed a multivariate model to characterise relations between the structural properties of starches from maize mutants and their hydrolysis kinetics. This model would allow prediction of starch degradability by commercial alpha-amylases1. However it was developed from a limited number of corn starches. We propose to enhance this model on the MAGIC pilot sub-population combining BIA’s expertise on starch degradation and using the genetic diversity and analytical power of CSIRO’s wheat MAGIC population (4 and 8 ways, thousands of samples available for characterisation). This collaboration would help implement modelling approaches integrating background knowledge and data that will be used for estimating the causal relations governing the starch degradability behaviour. This will provide an innovative opportunity to highlight new QTLs (Quantitative Trait Loci) within the Wheat Quality space. Finally this would provide valuable information on new ways to tailor starch for industrial purposes, for baking but also malting, biofermentation and biofuel production.

Main objectives and proposed methodology

The main objectives of the project are 1) establish whether genetic information, chemical and structural information can interplay with the enzymatic degradability of starch and 2) build a predictive model of starch degradability that implements these interactions. The main methodology steps are:
1. Adjusting methods for rapid determination of hydrolysis kinetics over a representative set of starches from MAGIC population and over starches generated from transgenic wheat lines
2. Using medium to high-throughput methods for screening starches from large number of wheat lines for degradability, basic structural/compositional properties including crystallinity and differential scanning calorimetry (DSC) measurements
3. Applying statistical analysis to identify correlation pathways between wheat line genetics, starch structural factors and degradability behaviour. Pathways will be formalized as causal models complemented with knowledge inputs from domain experts and literature.
4. Model outputs analysis will guide specific analysis on small number of selected starches, for example to identify QTL for structural traits.


crop genetics, starch, enzymatic hydrolysis, statistical analysis, causal modelling, wheat

Scientific environment

The thesis takes place in the framework of an international collaboration between two important laboratories working on crop quality and polysaccharide science. The student will benefit from the innovative technologies developed at CSIRO and INRA in the carbohydrate modelling and engineering of grain. The student will have opportunity to visit and collaborate with world leading experts in carbohydrate metabolism, and starch degradation. Our research groups have a strong publication record, regular presence in major international conferences, rigorous intellectual property management and benchmark commercialization achievements, which together will ensure all results obtained by the fellow will be scientifically recognized and promoted.


This problem implies the use of experimental and modelling techniques to investigate the triplet genetic- structure-function in wheat starch. We are looking for candidate with a Master or Engineering degree in crop genetics, bio-chemistry or physico-chemistry with interest for modelling. Candidate should be proficient in English.

Net monthly income: 1400€ according to French regulations for PhD + extra-funding from CISRO for general expenditure during the stay in Canberra

Project specifics: PhD thesis will be supervised jointly by INRA and CISRO. The PhD student will spend an equal amount of time in the two research centres in Canberra (Australia) and in Nantes (France).

Selection process

Funding agencies, INRA and Région Pays de Loire, require completion of the selection process to confirm the doctoral scholarship by September 2018. For this reason:
- The starting date for the scholarship is October 2018.
- The application must be sent before the 30th March 2018 in English or in French with the following:

  • CV
  • Cover letter
  • Master thesis summary
  • Two contact persons (professor or master supervisor)

Selection process will proceed with interviews of selected candidates, and final decision will be given by May 2018.


Kamal Kansou Kamal.Kansou@inra.fr

Jean-Philippe Ral Jean.Ral@csiro.au

Luc Saulnier luc.saulnier@inra.fr

1 Kansou K., Buleon, A., Gerard, C., & Rolland-Sabate, A. (2015). Multivariate model to characterise relations between maize mutant starches and hydrolysis kinetics. Carbohydrate Polymers, 133, 497-506.