GEMFOR : Genetics and ecology of forest diseases

Team leader: Cécile Robin

Manager : Léa Peypelut

Background and motivation

We are studying the ecology and dynamics of forest tree pathogen – hosts interactions, under natural evolution and in response to management and anthropogenic disturbance.

The recent period has been characterized by a significant increase in emerging diseases affecting forest trees in Europe (pinewood nematode, ash dieback, chestnut blight, chestnut ink disease, larch canker, but and root rot in pines, …). Drivers of these emerging diseases are multiple: exotic pathogens, climate change, land use change.

Our aim is to develop an integrated approach to biotic risks in forests, based on an understanding of host-pathogen - environment interactions, with a particular focus on the evolutionary dynamics of pathogens in the context of global change. The final aim is to inform public policies and propose silvicultural itineraries that reduce the vulnerability of stands. This integrated multidisciplinary approach with strong interactions with stakeholders involved in management at different levels is convergent with the "One Health" concept. This integrated, "holistic" approach is also developed in the European H2020 HOMED project and in multiple other EU [projects RESIPATH (Biodiversa), SAMFIX (Life), B4EST (H2020 coordinated by INRAE)] or national projects.

We work closely with the Forest Health Department (DSF) of the Ministry of Agriculture and Food (MAA) to develop a range of projects (Diagnosis and understanding of emerging pathologies, Tempos, SPNA, etc.), PhD theses (Pilar Fernandez-Conradi, Marylise Marchand, co-financed by a MAA grant) and epidemiological surveillance studies.

Objectives and scientific strategies

The general objective of our research is to produce knowledge to understand, prevent and manage diseases, and particularly emerging diseases, in forests. We mobilize concepts and tools from phytopathology, epidemiology, evolutionary ecology, population genetics and genomics, and quantitative genetics. We rely on different approaches ranging from observations, sampling and measurements in the field, experiments in greenhouses or in forests and modelling.

More specific objectives are as follows:

1- to identify emerging pathogens, particularly cryptic species complexes, and to detect them as early as possible

2- to determine their life cycle and biological characteristics (growth, reproduction, dispersal, transmission, survival and saprophytic ability, response to temperature)

3- to study pathogen virulence and host adaptation, and host resistance, tolerance and competence

4- to identify the climatic and silvicultural contexts in which pathogens are most damaging (epidemiological risk factors)

5- to understand the natural regulation mechanisms of diseases in forests: tree resistance, at the stand and individual level, and microbial antagonisms exerted on pathogenic fungi

6 - to integrate this knowledge into different types of models, enabling the analysis and management of health risks, taking into account the diversity of ecosystems in which they occur.

Key words

oak powdery mildew (Erysiphe sp.), chestnut blight (Cryphonectria parasitica), but and root rot (Armillaria sp. and Heterobasidion sp.), oak and chestnut ink disease, Botryosphaeriaceae spp. (e.g. Diplodia sapinea), pine wood nematodes (Bursaphelencus sp.)

Staff members