Abstract
This report was shared with the winegrowers who made their plots available for my PhD project. It presents the methodology used, the main results, and future research perspectives.The aim of the study was to identify microorganisms capable of protecting grapevines against Plasmopara viticola, the causal agent of downy mildew, in order to reduce reliance on chemical fungicides. Over a two-year period, leaf and soil samples were collected in the spring from 14 vineyard plots in the Bordeaux region. These plots were selected based on long-term records showing contrasting levels of downy mildew incidence and severity. Sampling focused on young leaves and the top few centimeters of soil. Molecular biology analyses (DNA extraction, PCR, and sequencing) were then carried out to characterize the microorganisms (bacteria and fungi) present in these plots. Several hypotheses were explored. The main one, presented in this report, is that plots with low levels of downy mildew symptoms harbor a higher abundance of microorganisms potentially involved in regulating the pathogen.Source : Fournier, P., Pellan, L., Jaswa, A., Cambon, M. C., Chataigner, A., Bonnard, O., Raynal, M., Debord, C., Poeydebat, C., Labarthe, S., Delmotte, F., This, P., & Vacher, C. (2025). Revealing microbial consortia that interfere with grapevine downy mildew through microbiome epidemiology. Environmental Microbiome, 20(1), 37. https://doi.org/10.1186/s40793-025-00691-9