This PhD project, jointly proposed by ASTREDHOR and the GDO team at the UMR IRHS (INRAE – Institut Agro – University of Angers), aims to investigate the genetic and biochemical determinants of rose resistance to thrips, a major pest of horticultural crops.

The project combines phenotyping, association genetics (GWAS) and metabolomics approaches, with the aim of identifying new levers for the selection of resistant varieties.

The candidate must have a good knowledge of plant genetics (quantitative genetics) and biochemistry. Knowledge of plant–pest interactions would be an asset. 
The project will require a significant amount of phenotyping work across the various partner organisations. A high degree of rigour will be necessary to manage the various datasets (phenotypic, genotypic, metabolomic and volatilomic).

PhD thesis summary

The aim of this PhD project is to identify natural plant resistance by assessing the intrinsic ability of rose varieties to resist or sustain low level of thrips infestation. The interactions between roses and thrips are poorly documented. However, some plant traits, including flower colour and morphology, plant shape, and volatile organic compounds (VOCs), are known to influence thrips attraction or repellence. Some studies have also highlighted variability in the responses of rose varieties to thrips.
This PhD project therefore aims to characterise rose-thrips interactions in terms of resistance/susceptibility and repellence/attractiveness.
To achieve this objective, the PhD candidate will follow the following methodology: (i) phenotypic characterisation of a large rose collection to assess thrips attraction and repellence; (ii) investigation of the genetic bases of this interaction using a genome-wide association study (GWAS); and (iii) analysis of the floral bud volatilome and metabolome during the interaction.

Keywords: rose, thrips, plant-pest interaction, genetics, metabolomics, volatile organic compounds

Practical information

The PhD research will be carried out mainly in Angers (France), in collaboration with several academic and professional partners.

Application deadline: 13 November 2026
Start date: 1 April 2027

Documents to be provided:
 - CV
 - cover letter
 - two references from academic supervisors

The complete application pack should be sent to Fabrice Foucher, thesis supervisor , Vanessa Soufflet-Freslon and Laurent Ronco, thesis advisors.

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