title: Temporal patterns of orchid mycorrhizal fungi in meadows and forests as revealed by 454 pyrosequencing.
abstract: Orchid mycorrhizal (OrM) symbionts play a key role in the growth of orchids, but the temporal variation and habitat partitioning of these fungi in roots and soil remain unclear. Temporal changes in root and rhizosphere fungal communities of Cypripedium calceolus, Neottia ovata and Orchis militaris were studied in meadow and forest habitats over the vegetation period by using 454 pyrosequencing of the full internal transcribed spacer (ITS) region. The community of typical OrM symbionts differed by plant species and habitats. The root fungal community of N. ovata changed significantly in time, but this was not observed in C. calceolus and O. militaris. The rhizosphere community included a low proportion of OrM symbionts that exhibited a slight temporal turnover in meadow habitats but not in forests. Habitat differences in OrM and all fungal associates are largely attributable to the greater proportion of ectomycorrhizal fungi in forests. Temporal changes in OrM fungal communities in roots of certain species indicate selection of suitable fungal species by plants. It remains to be elucidated whether these shifts depend on functional differences inside roots, seasonality, climate or succession.
authors.affiliation: Institute of Ecology and Earth Sciences, University of Tartu, 14A Ravila, 50411, Tartu, Estonia.
authors.forename: Jane
authors.initials: J
authors.lastname: Oja
authors.affiliation: Institute of Ecology and Earth Sciences, University of Tartu, 14A Ravila, 50411, Tartu, Estonia.|Institute of Botany, Academy of Sciences of the Czech Republic, CZ-252 43, Průhonice, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Kohout
authors.affiliation: Institute of Ecology and Earth Sciences, University of Tartu, 14A Ravila, 50411, Tartu, Estonia.
authors.forename: Leho
authors.initials: L
authors.lastname: Tedersoo
authors.affiliation: Institute of Agricultural and Environmental Sciences, Estonian University of Life Sciences, 5 Kreutzwaldi, 51014, Tartu, Estonia.
authors.forename: Tiiu
authors.initials: T
authors.lastname: Kull
authors.affiliation: Institute of Ecology and Earth Sciences, University of Tartu, 14A Ravila, 50411, Tartu, Estonia.
authors.forename: Urmas
authors.initials: U
authors.lastname: Kõljalg
mesh_terms: D001487:Basidiomycota / Q000502:physiology*; D060026:Endophytes / Q000502:physiology; D004957:Estonia; D065928:Forests; D065948:Grassland; D008969:Molecular Sequence Data; D038821:Mycorrhizae / Q000502:physiology*; D029595:Orchidaceae / Q000382:microbiology*; D017422:Sequence Analysis, DNA / Q000379:methods*; D013997:Time Factors
keywords: Ceratobasidiaceae; Orchidaceae; Sebacinales; Tulasnellaceae; fungal community composition; next-generation sequencing; primer specificity; temporal dynamics