Résumé
In order to better control current diseases of plants and prevent future epidemics, it is crucial to develop an improved understanding of the factors underlying pathogen emergence, adaptation and spread. Recent methodological developments in molecular epidemiology now allow tackling such question through fine reconstruction of disease dynamics in space and time. To date, essentially all studies on plant pathogens have focused on "contemporary" individu ais sampled over a fairly limited period of time (a round 30 years at a maximum) but recent developments in DNA sequencing technology now make possible reconstructing historical genomes dating back to previous centuries. We intended to apply such development to the case of historical crop pathogenic bacterial genomes retrieved from herbarium collection material. In this talk I will expose our first results and discuss future research directions. (Résumé d'auteur)