Internship OT-23021
Internship M2/ingenieur: Evolution of the Plasmopara viticola oospore reservoir in vineyard soils after implementation of a prophylactic management practice
33140 VILLENAVE-D'ORNON
INRAE presentation
The French National Research Institute for Agriculture, Food, and Environment (INRAE) is a major player in research and innovation. It is a community of 12,000 people with 272 research, experimental research, and support units located in 18 regional centres throughout France. Internationally, INRAE is among the top research organisations in the agricultural and food sciences, plant and animal sciences, as well as in ecology and environmental science. It is the world’s leading research organisation specialising in agriculture, food and the environment. INRAE’s goal is to be a key player in the transitions necessary to address major global challenges. Faced with a growing world population, climate change, resource scarcity, and declining biodiversity, the Institute has a major role to play in building solutions and supporting the necessary acceleration of agricultural, food and environmental transitions.
Work environment, missions and activities
You will be welcomed into the “Sustainable Management of Mildew” team at UMR SAVE, located at the INRAE Bordeaux Nouvelle-Aquitaine center in Villenave d’Ornon (33), under the co-supervision of Paige Breen (doctoral student) , François Delmotte and Charlotte Poeydebat.
Context:
Grapevine downy mildew (GDM), caused by the obligate biotroph oomycete Plasmopara viticola, is one of the most destructive diseases in viticulture.The pathogen originated in eastern North America and was introduced to European vineyards at the end of the 19th century; since then, it has spread all over Europe. P. viticola’s reproductive cycle is comprised of two parts: the asexual phase, which occurs during the grapevine’s growing season and in which the zoospores propagate on green parts of the vine; and the sexual phase, in which the crossing of strains in the leaves towards the end of the grapevine growing season leads to the formation of oospores that overwinter in grapevine leaf debris and the surrounding soil.
Conventional GDM management relies primarily on copper-based fungicide spraying to prevent primary infections and the asexual propagation of the pathogen, and almost entirely neglects the sexual cycle. To meet targets set by the European Commission in its Green Deal, viticulturists must drastically reduce traditional spraying operations. The Chaire “Alexis Millardet,” a research initiative funded by four prestigious Bordeaux châteaux (Ausone, Cheval Blanc, Montrose, and Petrus), aims to improve our understanding of the GDM sexual cycle and to identify, test, and evaluate new methods to fight against GDM by breaking the sexual cycle of the pathogen (i.e., prophylaxy). To further this mission, the Chaire Millardet has developed molecular biology and bioassay methods to evaluate P. viticola quantities and viability in the soil compartment. Part of this project’s work includes a study of post-harvest leaf removal, or defoliation, to reduce the stock of primary inoculum in vineyard soils as a preventative, long-term strategy to manage GDM epidemics. We hypothesize that annual defoliation will significantly reduce the stock of primary inoculum in the long-term, thereby reducing disease pressure. To verify this hypothesis, we have designed an experiment utilizing uprooted vineyards as a proxy for long-term defoliation, in which the time of uprooting corresponds to the implementation of defoliation to prophylactically manage GDM. We have assembled a network of almost 100 vineyards that were uprooted from 1 to 30 years ago and are each matched with a similar control parcel currently in production. We assume that the effect of uprooting grapevines simulates annual post-harvest defoliation, in that it removes the input of new primary inoculum produced on the host plant to vineyard soils.
Mission:
The aim of this internship is to characterize the relationship between the time since vineyard uprooting (a proxy for the start of defoliation) and the quantity and infectious potential of the primary inoculum
reservoir of GDM in the soil. As part of this internship, soil samples will be collected in a network of uprooted and control parcels in January 2025 and will be processed using molecular biology and leaf disk bioassays in the spring of 2025. The intern will also carry out preliminary data analyses of these results. This internship is part of a broader Chaire Millardet PhD thesis in progress. The intern will join the Sustainable Management of GDM team at UMR SAVE, located at the Bordeaux Nouvelle-Aquitaine campus in Villenave D’Ornon (33). The intern will be supervised by Paige Breen (PhD student), François Delmotte and Charlotte Poeydebat.
References:
Caffi, T., Rossi, V., & Lusitani, M. (2011). Long-term survival of Plasmopara viticola oospores. Integrated Protection and Production in Viticulture, 111–114.
Clippinger, J. I., Dobry, E. P., Laffan, I., Zorbas, N., Hed, B., & Campbell, M. A. (2024). Traditional and Emerging Approaches for Disease Management of Plasmopara viticola, Causal Agent of Downy Mildew of Grape. In Agriculture (Switzerland) (Vol. 14, Issue 3). Multidisciplinary Digital Publishing Institute (MDPI). https://doi.org/10.3390/agriculture14030406
Gessler, C., Pertot, I., & Perazzolli, M. (2011). Plasmopara viticola: a review of knowledge on downy mildew of grapevine and effective disease management. Phytopathologia Mediterranea, 50(1), 3–44. https://doi.org/10.2307/26458675
Kennelly, M. M., Gadoury, D. M., Wilcox, W. F., Magarey, P. A., & Seem, R. C. (2005). Seasonal development of ontogenic resistance to downy mildew in grape berries and rachises. Phytopathology, 95(12), 1445–1452. https://doi.org/10.1094/PHYTO-95-1445
Millardet, A. (1883). Address to the Society on oospore infection work. Société Sciences Bordeaux Bulletin 2,24-27.
Poeydebat, C., Courchinoux, E., Demeaux, I., Rodriguez, M., Chataigner, A., Lelièvre M., Goutouly, J.-P., Rossi, J.-P. Raynal, M., Delière, L., & Delmotte, F. (2024). Quantitative assessment and spatial distribution of Plasmopara viticola oospores in vineyard soil.
Training and skills
¡ Recommended education : Master 2 ou 3rd year of agronomy engineering program
¡ Desired knowledge and skills :
- Background in biology, phytopathology, agroecology, agronomy, soil science, and/or viticulture
- Basic understanding of statistics and databases (Excel, R)
- Excellent communication (in English a plus)
- Motivation to conduct experiments
- Flexibility and ability to adapt
- Attention to details
INRAE's life quality
By joining our teams, you benefit from (depending on the type of contract and its duration):
- up to 30 days of annual leave + 15 days "Reduction of Working Time" (for a full time);
- parenting support: CESU childcare, leisure services;
- skills development systems: training, career advise;
- social support: advice and listening, social assistance and loans;
- holiday and leisure services: holiday vouchers, accommodation at preferential rates;
- sports and cultural activities;
- collective catering.
How to apply
I send my CV and my motivation letter
All persons employed by or hosted at INRAE, a public research establishment, are subject to the Civil Service Code, particularly with regard to the obligation of neutrality and respect for the principle of secularism. In carrying out their functions, whether or not they are in contact with the public, they must not express their religious, philosophical or political convictions through their behaviour or by what they wear. > Find out more: fonction publique.gouv.fr website (in French)