Two widespread green Neottia species (Orchidaceae) show mycorrhizal preference for Sebacinales in various habitats and ontogenetic stages

• DOI: 10.1111/mec.13088
• Publication Date: 2015-01-23T06:31:39Z
• Authors: Tamara Těšitelová; Milan Kotilínek; Jana Jersáková; François‐Xavier Joly; Jiří Košnar; Irina Tatarenko; Marc‐André Selosse
• Keywords: 0301 basic medicine; 570; Carbon Isotopes; Nitrogen Isotopes; Basidiomycota; Molecular Sequence Data; 500; orchid mycorrhiza; 15. Life on land; Sebacinales; Europe; 03 medical and health sciences; Neottieae; germination; mixotrophy; Mycorrhizae; DNA Barcoding, Taxonomic; Orchidaceae; Symbiosis; Ecosystem; Phylogeny

Plant dependence on fungal carbon (mycoheterotrophy) evolved repeatedly. In orchids, it is connected with a mycorrhizal shift from rhizoctonia to ectomycorrhizal fungi and high natural (13)C (15)N abundance. Some green relatives of mycoheterotrophic species show identical trends, but most these remain unstudied, blurring our understanding evolution mycoheterotrophy. We analysed associations biomass content in two species, Neottia ovata N. cordata (tribe Neottieae), genus comprising nongreen (mycoheterotrophic) species. Our study covered 41 European sites, including different meadow forest habitats orchid developmental stages. Fungal ITS barcoding electron microscopy showed that both associated mainly nonectomycorrhizal Sebacinales Clade B, group symbionts regardless the habitat or growth stage. Few additional rhizoctonias Ceratobasidiaceae Tulasnellaceae, were detected. Isotope abundances did not detect gain fungi, suggesting usual nutrition rhizoctonia-associated orchids. Considering related partially fully such as camtschatea nidus-avis A, we propose displays preference for association B likely ancestral. Such change associates differing ecology within same taxon rare among Moreover, existence spp. challenges an ancestral pre-adaptation mycoheterotrophy whole Neottieae.