title: Adaptation to resistant hosts increases fitness on susceptible hosts in the plant parasitic nematode Globodera pallida.
abstract: Trade-offs between virulence (defined as the ability to infect a resistant host) and life-history traits are of particular interest in plant pathogens for durable management of plant resistances. Adaptation to plant resistances (i.e., virulence acquisition) is indeed expected to be associated with a fitness cost on susceptible hosts. Here, we investigated whether life-history traits involved in the fitness of the potato cyst nematode Globodera pallida are affected in a virulent lineage compared to an avirulent one. Both lineages were obtained from the same natural population through experimental evolution on resistant and susceptible hosts, respectively. Unexpectedly, we found that virulent lineages were more fit than avirulent lineages on susceptible hosts: they produced bigger cysts, containing more larvae and hatching faster. We thus discuss possible reasons explaining why virulence did not spread into natural G. pallida populations.
authors.affiliation: INRA UMR1349 IGEPP (Institute for Genetics, Environment and Plant Protection) F-35653 Le Rheu France.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Fournet
authors.affiliation: INRA UMR1349 IGEPP (Institute for Genetics, Environment and Plant Protection) F-35653 Le Rheu France.
authors.forename: Delphine
authors.initials: D
authors.lastname: Eoche-Bosy
authors.affiliation: INRA UMR1349 IGEPP (Institute for Genetics, Environment and Plant Protection) F-35653 Le Rheu France.
authors.forename: Lionel
authors.initials: L
authors.lastname: Renault
authors.affiliation: INRA UMR1349 IGEPP (Institute for Genetics, Environment and Plant Protection) F-35653 Le Rheu France.
authors.forename: Frédéric M
authors.initials: FM
authors.lastname: Hamelin
authors.affiliation: INRA UMR1349 IGEPP (Institute for Genetics, Environment and Plant Protection) F-35653 Le Rheu France.
authors.forename: Josselin
authors.initials: J
authors.lastname: Montarry
keywords: Experimental evolution; fitness benefit; life‐history traits; selection; trade‐off; unnecessary virulence