Jeudi 5 octobre 2023 à partir de 11h, dans la salle Millardet, nous aurons le plaisir d'accueillir deux chercheurs australiens, Abebayehu Geffersa et Mohamed Cassim Mohamed Zakeel de l'Agence Nationale Scientifique Australienne CSIRO (https://research.csiro.au/bioticthreats/. Ils vont passer plusieurs jours dans notre unité et vont nous présenter leurs travaux:

 Abebayehu Geffersa : "Economic benefits of breeding major food crops for disease resistance: A conceptual review and Meta-analysis"

A critical challenge for food security is to protect crops from damage caused by microbial pathogens. Breeding crops for disease resistance is a sustainable approach to meeting this challenge. However, pathogen adaptation, leading to the breakdown of resistance, is common and can cause damaging outbreaks of disease. While the importance of genetic, evolutionary and epidemiological factors to managing resistance breakdown are reasonably well understood, there has been little effort to understand the parallel socio-economic dimension. Consequently, incentives for individual decision-makers to invest in managing pathogen evolution are often difficult to articulate or support with solid evidence. We will present research investigating how socio-economic factors influence the management of genetic resistance and pathogen evolution. We first develop a conceptual framework that illustrates the socio-economic challenges to proactively managing resistance ineffectiveness. We extend our conceptual model with a meta-analysis of the agronomic and economic impacts of the adoption of disease-resistant crops worldwide to consolidate empirical evidence. Our assessment highlights that resistance delivers considerable economic and agronomic benefits. However, such benefits will only be fully realized if a significant effort is put into the identification of effective incentives for the adoption and uptake of resistance deployment strategies to increase resistance durability.

Mohamed Cassim Mohamed Zakeel : "Breaking the chain: Modelling the impact of reduced primary inoculum carryover on the spatiotemporal spread  of Ascochyta blight in chickpeas"

Understanding the persistence of plant pathogen inoculum during periods when host plants are absent is crucial for accurately predicting disease epidemics and optimizing control strategies. In this study, we focus on the necrotrophic fungal pathogen Ascochyta rabiei, investigating the persistence and management of primary inoculum in the landscape. Given the challenges posed by this aggressive pathogen, which has shown resistance to genetic controls, reliance on fungicides has increased, emphasizing the urgent need for effective integrated disease management strategies. Field experiments measuring pathogen load on post-harvest crop residues revealed that primary inoculum levels can decay rapidly and are influenced by in-season management choices. To assess potential management interventions at landscape scales and their impact on disease severity, we employed an epidemiological model parameterized with data from field experiments. The model captured various aspects of dispersal and inoculum decay dynamics, offering insights into the efficacy of landscape deployment strategies and management interventions in reducing inoculum persistence between seasons. Leveraging the outcomes of this study, we aim to develop integrated and area-wide disease management strategies to ensure sustainable control of Ascochyta blight in chickpeas