title: Population structure and temporal maintenance of the multihost fungal pathogen Botrytis cinerea: causes and implications for disease management.
abstract: Understanding the causes of population subdivision is of fundamental importance, as studying barriers to gene flow between populations may reveal key aspects of the process of adaptive divergence and, for pathogens, may help forecasting disease emergence and implementing sound management strategies. Here, we investigated population subdivision in the multihost fungus Botrytis cinerea based on comprehensive multiyear sampling on different hosts in three French regions. Analyses revealed a weak association between population structure and geography, but a clear differentiation according to the host plant of origin. This was consistent with adaptation to hosts, but the distribution of inferred genetic clusters and the frequency of admixed individuals indicated a lack of strict host specificity. Differentiation between individuals collected in the greenhouse (on Solanum) and outdoor (on Vitis and Rubus) was stronger than that observed between individuals from the two outdoor hosts, probably reflecting an additional isolating effect associated with the cropping system. Three genetic clusters coexisted on Vitis but did not persist over time. Linkage disequilibrium analysis indicated that outdoor populations were regularly recombining, whereas clonality was predominant in the greenhouse. Our findings open up new perspectives for disease control by managing plant debris in outdoor conditions and reinforcing prophylactic measures indoor.
authors.affiliation: INRA, UR 1290 BIOGER-CPP, Avenue Lucien Brétignières, Thiverval-Grignon, F-78850, France.
authors.forename: Anne-Sophie
authors.initials: AS
authors.lastname: Walker
authors.forename: Pierre
authors.initials: P
authors.lastname: Gladieux
authors.forename: Véronique
authors.initials: V
authors.lastname: Decognet
authors.forename: Marc
authors.initials: M
authors.lastname: Fermaud
authors.forename: Johann
authors.initials: J
authors.lastname: Confais
authors.forename: Jean
authors.initials: J
authors.lastname: Roudet
authors.forename: Marc
authors.initials: M
authors.lastname: Bardin
authors.forename: Alexandre
authors.initials: A
authors.lastname: Bout
authors.forename: Philippe C
authors.initials: PC
authors.lastname: Nicot
authors.forename: Christine
authors.initials: C
authors.lastname: Poncet
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Fournier
mesh_terms: D020171:Botrytis / Q000235:genetics* / Q000472:pathogenicity; D005602:France; D051456:Gene Flow; D014644:Genetic Variation; D005843:Geography; D058507:Host Specificity; D018895:Microsatellite Repeats / Q000235:genetics; D010935:Plant Diseases / Q000382:microbiology*; D065856:Rubus / Q000382:microbiology*; D032322:Solanum / Q000382:microbiology*; D027843:Vitis / Q000382:microbiology*