Waseem M. auteur aut IRD Ducousso M. auteur aut IRD Prin Y. auteur aut IRD Domergue O. auteur aut IRD Hannibal Laure auteur aut IRD Majorel Clarisse auteur aut IRD Jourand Philippe auteur aut IRD Galiana A. auteur aut IRD text journalArticle eng text/pdf born digital access New Caledonian serpentine (ultramafic) soils contain high levels of toxic heavy metals, in particular nickel, (up to 20 g kg−1) and are deficient in essential elements like carbon, nitrogen and phosphorus while having a high magnesium/calcium ratio. Although previous studies showed that ectomycorrhizal symbioses could play an important role in the adaptation of the endemic plants to ultramafic soils (FEMS Microbiol Ecol 72:238–49, 2010), none of them have compared the diversity of microbial communities from ultramafic vs non-ultramafic soils in New Caledonia. We explored the impact of edaphic characteristics on the diversity of ectomycorrhizal (ECM) fungi associated with different endemic species of Tristaniopsis (Myrtaceae) growing under contrasting soil conditions in the natural ecosystems of New Caledonia. ECM root tips were thus sampled from two different ultramafic sites (Koniambo massif and Desmazures forest) vs two volcano-sedimentary ones (Arama and Mont Ninndo). The molecular characterization of the ECM fungi through partial sequencing of the ITS rRNA gene revealed the presence of different dominant fungal genera including, both soil types combined, Cortinarius (36.1%), Pisolithus (18.5%), Russula (13.4%), Heliotales (8.2%) and Boletellus (7.2%). A high diversity of ECM taxa associated with Tristaniopsis species was found in both ultramafic and volcano-sedimentary soils but no significant differences in ECM genera distribution were observed between both soil types. No link could be established between the phylogenetic clustering of ECM taxa and their soil type origin, thus suggesting a possible functional—rather than taxonomical—adaptation of ECM fungal communities to ultramafic soils. specialized NOUVELLE CALEDONIE 084 068 021 27 4 407–413 2017 0940-6360 https://www.documentation.ird.fr/hor/fdi:010069661 10.1007/s00572-017-0761-4 0940-6360 [F B010069661] https://www.documentation.ird.fr/hor/fdi:010069661 https://www.documentation.ird.fr/intranet/publi/depot/2017-05-16/010069661.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2017-05-16 2023-07-11 fdi:010069661 fre