title: Ploidy-specific symbiotic interactions: divergence of mycorrhizal fungi between cytotypes of the Gymnadenia conopsea group (Orchidaceae).
abstract: Polyploidy is widely recognized as a major mechanism of sympatric speciation in plants, yet little is known about its effects on interactions with other organisms. Mycorrhizal fungi are among the most common plant symbionts and play an important role in plant nutrient supply. It remains to be understood whether mycorrhizal associations of ploidy-variable plants can be ploidy-specific. We examined mycorrhizal associations in three cytotypes (2x, 3x, 4x) of the Gymnadenia conopsea group (Orchidaceae), involving G. conopsea s.s. and G. densiflora, at different spatial scales and during different ontogenetic stages. We analysed: adults from mixed- and single-ploidy populations at a regional scale; closely spaced adults within a mixed-ploidy site; and mycorrhizal seedlings. All Gymnadenia cytotypes associated mainly with saprotrophic Tulasnellaceae (Basidiomycota). Nonetheless, both adults and seedlings of diploids and their autotetraploid derivatives significantly differed in the identity of their mycorrhizal symbionts. Interploidy segregation of mycorrhizal symbionts was most pronounced within a site with closely spaced adults. This study provides the first evidence that polyploidization of a plant species can be associated with a shift in mycorrhizal symbionts. This divergence may contribute to niche partitioning and facilitate establishment and co-existence of different cytotypes.
authors.affiliation: Faculty of Science, University of South Bohemia, Branišovská 31, České Budějovice, 370 05, Czech Republic.
authors.forename: Tamara
authors.initials: T
authors.lastname: Těšitelová
authors.affiliation: Faculty of Science, University of South Bohemia, Branišovská 31, České Budějovice, 370 05, Czech Republic.
authors.forename: Jana
authors.initials: J
authors.lastname: Jersáková
authors.affiliation: Laboratoire Evolution et Diversité Biologique, Université de Toulouse, 3 Paul Sabatier, ENFA, CNRS, UMR 5174, 118 route de Narbonne, Toulouse Cedex, 31062, France.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Roy
authors.affiliation: Faculty of Agriculture, University of South Bohemia, Studentská 13, České Budějovice, 370 05, Czech Republic.
authors.forename: Barbora
authors.initials: B
authors.lastname: Kubátová
authors.affiliation: Faculty of Science, University of South Bohemia, Branišovská 31, České Budějovice, 370 05, Czech Republic.
authors.forename: Jakub
authors.initials: J
authors.lastname: Těšitel
authors.affiliation: Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, Prague, 128 01, Czech Republic.|Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice 1, 252 43, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Urfus
authors.affiliation: Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, Prague, 128 01, Czech Republic.|Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice 1, 252 43, Czech Republic.
authors.forename: Pavel
authors.initials: P
authors.lastname: Trávníček
authors.affiliation: Department of Botany, Faculty of Science, Charles University in Prague, Benátská 2, Prague, 128 01, Czech Republic.|Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice 1, 252 43, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Suda
mesh_terms: D044822:Biodiversity; D018153:Czech Republic; D038821:Mycorrhizae / Q000502:physiology*; D029595:Orchidaceae / Q000254:growth & development / Q000382:microbiology*; D011003:Ploidies; D036226:Seedlings / Q000382:microbiology; D013559:Symbiosis / Q000502:physiology*
keywords: Orchidaceae; Tulasnellaceae; cytotype co-existence; mycorrhiza; niche partitioning; plant-fungus interactions; polyploidy