Symbiotic germination capability of four Epipactis species (Orchidaceae) is broader than expected from adult ecology1

0377423 - ÚVGZ 2013 RIV US eng J - Článek v odborném periodiku
Těšitelová, Tamara - Těšitel, J. - Jersáková, Jana - Říhová, G. - Selosse,, M.-A.
Symbiotic germination capability of four Epipactis species (Orchidaceae) is broader than expected from adult ecology1.
American Journal of Botany. Roč. 99, č. 6 (2012), s. 1020-1032. ISSN 0002-9122. E-ISSN 1537-2197
Grant CEP: GA AV ČR IAA600870802; GA MŠMT LC06073
Výzkumný záměr: CEZ:AV0Z60870520
Klíčová slova: ecological niche * ectomycorrhizal ascomycete * Epipactis * habitat preferences * mixotrophy * mycoheterotrophy * orchid mycorrhiza * Orchidaceae * Pezizales * seed germination
Kód oboru RIV: EH - Ekologie - společenstva
Impakt faktor: 2.586, rok: 2012

Premise of the study: Both abiotic and biotic factors shape species distributions. Orchids produce minute seeds with few nutrient reserves, thus requiring mycorrhizal fungi for germination. Therefore, both environmental conditions and mycorrhizal fungi distribution affect their germination success, but these ecological requirements and their congruence with habitat preferences of adults remain poorly understood. We investigated the importance of these factors during germination in four forest orchid species of the genus Epipactis. Methods: We sowed seeds of three habitat specialists and one generalist in different forest types at sites harboring adults of at least one of these ecologically diverging species. We analyzed germination pattern and identified mycorrhizal fungi of both seedlings and adults. Key results: Habitat conditions had little influence on germination pattern as seedlings grew in more habitats than expected from the adults’ ecology. Ectomycorrhizal fungi availability did not limit germination. Suitable mycorrhizal fungi, mostly pezizalean ascomycetes, were recruited in various forest types, though the fungal communities differed according to habitat type. Finally, orchids with divergent ecological preferences shared similar mycorrhizal fungi. Conclusions: Limited adult distribution contrasted with successful seed germination at diverse sites and indicates existence of niche differentiation between adults and seedlings. Ecological specialization may thus be determined by factors other than mycorrhizal fungi that act later in the ontogeny, perhaps during the transition to above-ground development.
Trvalý link: http://hdl.handle.net/11104/0209582