Sclerotinia sclerotiorumis a fungus that causes white rot on several hundred plant species, some of which are of agronomic and economic interest. The control, more or less complete, of the disease consists essentially of preventive chemical interventions.

The aim of the Scleroleg project was to provide producers (fruits, vegetables and rapeseed) alternative protection techniques for better management of white rot while achieving quality production and respecting the environment.

 

Over more than 3 years, several crops have been studied (carrots, rapeseed, beans, endives, melons) in order to acquire knowledge about the pathogen and the epidemiological processes. The project included:

• evaluation of the genetic and phenotypic diversity of S. sclerotiorum from different host plants and different French regions,
• the study of sources of inoculum (air and soil) and the development of epidemics in the field,
• the evaluation and / or validation of existing risk prediction tools and the development of new tools to assist experimentation to better target and seek action levers,
• the development and evaluation of the combination of different complementary protection techniques to provide producers with innovative and sustainable production systems.

Our work focused on several hundred strains and showed:

• high genetic diversity and lack of genetic structuring by the host plant,
• diversity in aggressiviy and lack of host specialization,
• the almost continuous presence of viable inoculum in the air,
• potential exchanges of airborne inoculum between regions hundreds of kilometers apart,
• the presence of the species S. subarctica for the first time south of the 52nd parallel.

SUGGESTED READINGS

Leyronas, C., Bardin, M., Berthier, K., Duffaud, M., Troulet, C., Torres, M., Villeneuve, F., Nicot, P. C. (2018). Assessing the phenotypic and genotypic diversity of Sclerotinia sclerotiorum in France. European Journal of Plant Pathology, 152, 933-944. https://hal.inrae.fr/hal-02623334v1 Leyronas, C., Benigni, M., Leignez, Duffaud, M., Villeneuve, F., Nicot, P. C. (2019). Characterization of Sclerotinia sclerotiorum airborne inoculum, the widespread agent of white mould disease. Aerobiologia, 35, 243-252. https://hal.inrae.fr/hal-02623206v1 Leyronas, C., Morris, C. E., Choufany, M., Soubeyrand, S. (2018). Assessing the aerial interconnectivity of distant reservoirs of Sclerotinia sclerotiorum. Frontiers in Microbiology, 9 : 2257.http://prodinra.inra.fr/record/443523 Leyronas, C., Troulet, C., Duffaud, M., Villeneuve, F., Benigni, M., Leignez, Nicot, P. C. (2018). First report of Sclerotinia subarctica in France detected with a rapid PCR-based test. Canadian Journal of Plant Pathology, 48, 248-253. https://hal.inrae.fr/hal-02621012v1 Villeneuve, F., Leyronas, C., Nicot, P. C., Bardin, M., Faloya, V. (2019). Projet Sclerotinia sclerotiorum : meilleure connaissance du champignon pathogène, évaluation du risque et évaluation de méthodes de protection. Innovations Agronomiques, 71, 401-413. https://hal.inrae.fr/hal-02627650v1