SPECIALIZATION AND LOCAL ADAPTATION OF A FUNGAL PARASITE ON TWO HOST PLANT SPECIES AS REVEALED BY TWO FITNESS TRAITS

Authors

  • Delphine Sicard,

    1. Univ Paris-Sud, Laboratoire Ecologie Systématique et Evolution, UMR 8079, Orsay cedex, F-91405; CNRS, Orsay cedex, F-91405, France
    2. Univ Paris-Sud, Laboratoire de Phytopathologie Moléculaire, UMR8618, Orsay cedex, F-91405, France; CNRS, Orsay cedex, F-91405, France
    3. Univ Paris-Sud, UMR de Génétique Végétale du Moulon, INRA/UPS/CNRS/INA-PG, Gif-sur-Yvette, F-91190, CNRS, Gif-sur-Yvette, F-91190; INRA, Gif-sur-Yvette, F-91190; INA-PG, Gif-sur-Yvette, F-91190, France
    4. E-mail: sicard@moulon.inra.fr
    Search for more papers by this author
  • Pleuni S. Pennings,

    1. Univ Paris-Sud, Laboratoire Ecologie Systématique et Evolution, UMR 8079, Orsay cedex, F-91405; CNRS, Orsay cedex, F-91405, France
    2. Evolutionary Biology, Department Biologie II University of Munich (LMU), Luisenstrasse 14, 80333 Munich, Germany
    Search for more papers by this author
  • Catherine Grandclément,

    1. Univ Paris-Sud, Laboratoire de Phytopathologie Moléculaire, UMR8618, Orsay cedex, F-91405, France; CNRS, Orsay cedex, F-91405, France
    Search for more papers by this author
  • Jorge Acosta,

    1. Km 6.5 Carretera Celaya a san Miguel de Allende, Celaya, Gto. CP 38110, Mexico
    Search for more papers by this author
  • Oliver Kaltz,

    1. Laboratoire de Parasitologie Evolutive, CNRS UMR 7103, Université Pierre et Marie Curie, 75252 Paris Cedex 05, France
    Search for more papers by this author
  • Jacqui A. Shykoff

    1. Univ Paris-Sud, Laboratoire Ecologie Systématique et Evolution, UMR 8079, Orsay cedex, F-91405; CNRS, Orsay cedex, F-91405, France
    Search for more papers by this author

Abstract

We investigate the geographic pattern of adaptation of a fungal parasite, Colletotrichum lindemuthianum, on two host species, Phaseolus vulgaris and P. coccineus for two parasite fitness traits: infectivity (ability to attack a host individual) and aggressivity (degree of sporulation and leaf surface damage). Using a cross-inoculation experiment, we show specialization of the fungus on its host species of origin for both traits even when fungi, which originated from hosts growing in sympatry, were tested on sympatric host populations. Within the two host species, we compared infectivity and aggressivity on local versus allopatric plant–fungus combinations. We found evidence for local adaptation for the two traits on P. vulgaris but not on P. coccineus. There was no significant correlation between the degrees of local adaptation for infectivity and aggressivity, indicating that the genetic basis and the effect of selection may differ between these two traits. For the two fitness traits, a positive correlation between the degree of specialization and the degree of local adaptation was found, suggesting that specialization can be reinforced by local adaptation.

Ancillary