DOI: 10.5061/dryad.033ds
title: Data from: Two widespread green Neottia species (Orchidaceae) show mycorrhizal preference for Sebacinales in various habitats and ontogenetic stages

description: Plant dependence on fungal carbon (mycoheterotrophy) evolved repeatedly.
 In orchids, it is connected with a mycorrhizal shift from rhizoctonia to
 ectomycorrhizal fungi and a high natural 13C and 15N abundance. Some green
 relatives of mycoheterotrophic species show identical trends, but most of
 these remain unstudied, blurring our understanding of evolution to
 mycoheterotrophy. We analyzed mycorrhizal associations and 13C and 15N
 biomass content in two green species, Neottia ovata and N. cordata (tribe
 Neottieae), from a genus comprising green and non-green
 (mycoheterotrophic) species. Our study covered 41 European sites,
 including different meadow and forest habitats and orchid developmental
 stages. Fungal ITS barcoding and electron microscopy showed that both
 Neottia species associated mainly with non-ectomycorrhizal Sebacinales
 Clade B, a group of rhizoctonia symbionts of green orchids, regardless of
 the habitat or growth stage. Few additional rhizoctonias from
 Ceratobasidiaceae and Tulasnellaceae, and ectomycorrhizal fungi were
 detected. Isotope abundances did not detect carbon gain from the
 ectomycorrhizal fungi, suggesting a usual nutrition of
 rhizoctonia-associated green orchids. Considering associations of related
 partially or fully mycoheterotrophic species such as Neottia camtschatea
 or N. nidus-avis with ectomycorrhizal Sebacinales Clade A, we propose that
 the genus Neottia displays a mycorrhizal preference for Sebacinales, and
 that the association with non-ectomycorrhizal Sebacinales Clade B is
 likely ancestral. Such a change in preference for mycorrhizal associates
 differing in ecology within the same fungal taxon is rare among orchids.
 Moreover, the existence of rhizoctonia-associated Neottia spp. challenges
 the shift to ectomycorrhizal fungi as an ancestral pre-adaptation to
 mycoheterotrophy in the whole Neottieae.
description: Neottia_18S+ITS+trnL(UAA)intron_alignmentCombined alignment of 18S, ITS, and trnL(UAA) intron of five Neottia species used for infering phylogeny under a partitioned model. This file is in nexus format and contains sequence alignment and MrBayes input data.Neottia_18S+ITS+trnL(UAA)intron.nexNeottia_18S+ITS+trnL(UAA)intron_treeBayesian phylogenetic tree of the Neottia genus based on a concatenation of ITS, 18S, and trnL(UAA) intron, with photosynthetic N. ovata, N. cordata, and N. smallii, putatively photosynthetic and likely partially mycoheterotrophic N. camtschatea, and non-photosynthetic mycoheterotrophic N. nidus-avis in adulthood. The tree is in the newick format.Neottia_18S+ITS+trnL(UAA)intron.treNeottia_18S_alignmentAlignment of 18S of Neottia species produced by MAFFT and used for infering phylogeny. This file is in nexus format and contains sequence alignment and MrBayes input data.Neottia_18S.nexNeottia_18S_treeBayesian majority-rule consensus trees based on 18S of several Neottia species. The tree is in newick format.Neottia_18S.treNeottia_ITS_alignmentAlignment of ITS sequences of several Neottieae species produced by MAFFT and used for infering Neottia phylogeny. This file is in nexus format and contains sequence alignment and MrBayes input data.Neottia_ITS.nexNeottia_ITS_treeBayesian majority-rule consensus tree based on ITS. The tree is in newick format.Neottia_ITS.treNeottia_trnL(UAA)intron_alignmentAlignment of trnL(UAA) intron sequences of several Neottieae species produced by MAFFT and used for infering Neottia phylogeny. This file is in nexus format and contains sequence alignment and MrBayes input data.Neottia_trnL(UAA)intron.nexNeottia_trnL(UAA)intron_treeBayesian majority-rule consensus tree based on trnL(UAA) intron. The tree is in newick format.Neottia_trnL(UAA)intron.treSebacinales_28S_alignmentAlignment of 28S sequences of Sebacinales produced by MAFFT and used for infering Sebacinales phylogeny. This file is in nexus format and contains sequence alignment and MrBayes input data.Sebacinales_28S.nexSebacinales_28S_treeBayesian majority-rule consensus tree of Sebacinales based on part of 28S. The tree is in newick format.Sebacinales_28S.treTulasnellaceae5.8S+28S_alignmentAlignment of 5.8S and short part of 28S sequences of Tulasnellaceae species produced by MAFFT and used for infering phylogeny. This file is in nexus format and contains sequence alignment and MrBayes input data.Tulasnellaceae5.8S+28S.nexTulasnellaceae5.8S+28S_treeBayesian majority-rule consensus tree of Tulasnellaceae based on 5.8S and short part of 28S. The tree is in newick format.Tulasnellaceae_5.8S+28S.treStable_Isotopesδ15N, δ13C, and N concentration values for plants and fungi from four sites.