Di Mattia, J. | Search bioRxiv

bioRxiv2026

Towards operational epidemiology of Pyricularia oryzae in sports turf: contribution of a multi-matrix molecular monitoring strategy at stadium scale

Gray leaf spot can cause severe turfgrass damage, particularly in intensively managed sports fields, while disease management remains challenging due to the rapid development of symptoms under favorable environmental conditions. Early detection of Pyricularia oryzae could therefore provide valuable information for anticipating disease development and supporting management decisions. This study aimed to develop a digital PCR (dPCR) molecular tool to support the monitoring and management of gray leaf spot disease in stadium turfgrass. The assay showed high sensitivity, consistently detecting P. oryzae when infected tissue represented only 0.05% of a mixture with healthy turfgrass, and enabled pathogen detection before symptom appearance under both controlled and field conditions. Different matrices were also investigated across 15 stadiums to identify the most relevant material for disease monitoring. Roots showed the highest prevalence of P. oryzae detection, including during asymptomatic periods, highlighting their potential as a relevant matrix for pathogen surveillance. In a stadium monitored several months after a gray leaf spot outbreak, P. oryzae DNA was still detected in roots from 27 of the 32 sampled zones despite the absence of visible symptoms. Overall, these results demonstrate the potential of dPCR for the early detection and monitoring of P. oryzae in stadium turfgrass, particularly through root sampling during periods when environmental conditions are not favorable for gray leaf spot development, and a spatio-temporal surveillance at stadium scale.

plant biology↗

bioRxiv2024

First application of digital-PCR in oenology for the specific detection of intact cells of Brettanomyces bruxellensis in the winemaking process

Wine is a complex matrix resulting from a fermentation process carried out by specific microbial communities. These communities can be in competition and the development of some microorganisms, as the yeast Brettanomyces bruxellensis, can impact the fermentation process and lead to organoleptic alterations of wine. To manage this risk, microbiological diagnostic methods as microscopic observations, qPCR or flow cytometry are already used in oenology, but remain either not specific enough, or tedious. In this context, IAGE (Ingenierie et Analyses en Genetique Environnementale) has developed the first digital-PCR system enabling the detection and quantification of B. bruxellensis during the whole winemaking process. Furthermore, wine DNA extraction was optimized to enable a representative and sensitive analysis of B. bruxellensis intact cells, as well as an easy-to-implement protocol to cope with the increasing number of samples to analyze. The IAGE workflow for B. bruxellensis quantification has been proven to be successful when analyzing naturally-contaminated samples during the different steps of the winemaking process and offers a robust method to oenologists for appropriate treatments and risk management in wine cellars. HighlightsO_LIDevelopment of a dPCR method led to a highly-specific analysis of B. bruxellensis intact cells in different steps of the winemaking process. C_LIO_LIDNA extraction method has been optimized to be robust across various types of wine with varying concentrations of inhibitors, as well as throughout different stages of the wine making process. C_LIO_LIThe complete process was proven successful in analyzing a large number of naturally-contaminated samples, giving results in less than 48 hours. C_LI

microbiology↗