Most cited article - PubMed ID 31998413
The root-symbiotic Rhizoscyphus ericae aggregate and Hyaloscypha (Leotiomycetes) are congeneric: Phylogenetic and experimental evidence
Ericoid mycorrhizal (ErM) fungi (ErMF) are crucial for the establishment of thousands of ericaceous species in heathlands and wetlands by increasing their tolerance to harsh conditions and improving nutrient uptake. However, ErM research has largely focused on a limited number of host species and four ErMF species (especially Hyaloscypha hepaticicola and Oidiodendron maius, to a lesser extent H. bicolor/H. finlandica and H. variabilis). Therefore, the degree to which other ericaceous plants and ErMF form functional associations, and corresponding benefits for plant growth, are not well understood. As such, we lack a clear understanding of how changes in fungal partners may influence plant fitness. To address this gap, we conducted a greenhouse experiment with nine ericaceous plant species and eight ErMF isolates to expand baseline knowledge regarding the effects of the ErM symbiosis on host plant growth. By analyzing ErM root colonization and host plant growth response, we observed that the mycorrhizal growth response (MGR) was variable and depended on plant and fungal identity. Moreover, overall inoculation effects on plant growth were independent from colonization levels. Finally, we found evidence that MGR was influenced by plant phylogeny. These results expand our basic understanding of the ErM symbiosis and provide valuable information for future restoration and conservation efforts.
- Keywords
- Ericaceae, Ericoid mycorrhizal fungi, Heathland, Mycorrhizal growth response, Wetland,
- MeSH
- Ericaceae * microbiology growth & development genetics MeSH
- Phylogeny MeSH
- Plant Roots microbiology growth & development MeSH
- Mycorrhizae * growth & development physiology MeSH
- Symbiosis MeSH
- Publication type
- Journal Article MeSH
Symbioses with fungi are important and ubiquitous on dry land but underexplored in the sea. As yet only one seagrass has been shown to form a specific root-fungus symbiosis that resembles those occurring in terrestrial plants, namely the dominant long-lived Mediterranean species Posidonia oceanica (Alismatales: Posidoniaceae) forming a dark septate (DS) endophytic association with the ascomycete Posidoniomyces atricolor (Pleosporales: Aigialaceae). Using stereomicroscopy, light and scanning electron microscopy, and DNA cloning, here we describe a novel root-fungus symbiosis in the Indo-Pacific seagrass Thalassodendron ciliatum (Alismatales: Cymodoceaceae) from a site in the Gulf of Aqaba in the Red Sea. Similarly to P. oceanica, the mycobiont of T. ciliatum occurs more frequently in thinner roots that engage in nutrient uptake from the seabed and forms extensive hyphal mantles composed of DS hyphae on the root surface. Contrary to P. oceanica, the mycobiont occurs on the roots with root hairs and does not colonize its host intraradically. While the cloning revealed a relatively rich spectrum of fungi, they were mostly parasites or saprobes of uncertain origin and the identity of the mycobiont thus remains unknown. Symbioses of seagrasses with fungi are probably more frequent than previously thought, but their functioning and significance are unknown. Melanin present in DS hyphae slows down their decomposition and so is true for the colonized roots. DS fungi may in this way conserve organic detritus in the seagrasses' rhizosphere, thus contributing to blue carbon sequestration in seagrass meadows.
- Keywords
- Blue carbon sequestration, Dark septate endophytes, Epiphytism, Marine fungi, Necromass decomposition, Nutrient uptake, Root-fungus symbioses, Seagrasses,
- MeSH
- Alismatales * microbiology physiology MeSH
- Ascomycota physiology MeSH
- Plant Roots * microbiology MeSH
- Symbiosis * MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Indian Ocean MeSH
Novel species of fungi described in this study include those from various countries as follows: Australia, Baobabopsis sabindy in leaves of Eragrostis spartinoides, Cortinarius magentiguttatus among deep leaf litter, Laurobasidium azarandamiae from uredinium of Puccinia alyxiae on Alyxia buxifolia, Marasmius pseudoelegans on well-rotted twigs and litter in mixed wet sclerophyll and subtropical rainforest. Bolivia, Favolaschia luminosa on twigs of Byttneria hirsuta, Lecanora thorstenii on bark, in savannas with shrubs and trees. Brazil, Asterina costamaiae on leaves of Rourea bahiensis, Purimyces orchidacearum (incl. Purimyces gen. nov.) as root endophyte on Cattleya locatellii. Bulgaria, Monosporascus bulgaricus and Monosporascus europaeus isolated from surface-sterilised, asymptomatic roots of Microthlaspi perfoliatum. Finland, Inocybe undatolacera on a lawn, near Betula pendula. France, Inocybe querciphila in humus of mixed forest. Germany, Arrhenia oblongispora on bare soil attached to debris of herbaceous plants and grasses. Greece, Tuber aereum under Quercus coccifera and Acer sempervirens. India, Alfoldia lenyadriensis from the gut of a Platynotus sp. beetle, Fulvifomes subramanianii on living Albizzia amara, Inosperma pavithrum on soil, Phylloporia parvateya on living Lonicera sp., Tropicoporus maritimus on living Peltophorum pterocarpum. Indonesia, Elsinoe atypica on leaf of Eucalyptus pellita. Italy, Apiotrichum vineum from grape wine, Cuphopyllus praecox among grass. Madagascar, Pisolithus madagascariensis on soil under Intsia bijuga. Netherlands, Cytosporella calamagrostidis and Periconia calamagrostidicola on old leaves of Calamagrostis arenaria, Hyaloscypha caricicola on leaves of Carex sp., Neoniesslia phragmiticola (incl. Neoniesslia gen. nov.) on leaf sheaths of standing dead culms of Phragmites australis, Neptunomyces juncicola on culms of Juncus maritimus, Zenophaeosphaeria calamagrostidis (incl. Zenophaeosphaeria gen. nov.) on culms of Calamagrostis arenaria. Norway, Hausneria geniculata (incl. Hausneria gen. nov.) from a gallery of Dryocoetes alni on Alnus incana. Pakistan, Agrocybe auriolus on leaf litter of Eucalyptus camaldulensis, Rhodophana rubrodisca in nutrient-rich loamy soil with Morus alba. Poland, Cladosporium nubilum from hypersaline brine, Entomortierella ferrotolerans from soil at mines and postmining sites, Pseudopezicula epiphylla from sooty mould community on Quercus robur, Quixadomyces sanctacrucensis from resin of Pinus sylvestris, Szafranskia beskidensis (incl. Szafranskia gen. nov.) from resin of Abies alba. Portugal, Ascocoryne laurisilvae on degraded wood of Laurus nobilis, Hygrocybe madeirensis in laurel forests, Hygrocybula terracocta (incl. Hygrocybula gen. nov.) on mossy areas of laurel forests planted with Cryptomeria japonica. Republic of Kenya, Penicillium gorferi from a sterile chicken feather embedded in a soil sample. Slovakia, Cerinomyces tatrensis on bark of Pinus mugo, Metapochonia simonovicovae from soil. South Africa, Acremonium agapanthi on culms of Agapanthus praecox, Alfaria elegiae on culms of Elegia ebracteata, Beaucarneamyces stellenboschensis (incl. Beaucarneamyces gen. nov.) on dead leaves of Beaucarnea stricta, Gardeniomyces kirstenboschensis (incl. Gardeniomyces gen. nov.) rotting fruit of Gardenia thunbergia, Knufia dianellae on dead leaves of Dianella caerulea, Lomaantha quercina on twigs of Quercus suber. Melanina restionis on dead leaves of Restio duthieae, Microdochium buffelskloofinum on seeds of Eragrostis cf. racemosa, Thamnochortomyces kirstenboschensis (incl. Thamnochortomyces gen. nov.) on culms of Thamnochortus fraternus, Tubeufia hagahagana on leaves of Hypoxis angustifolia, Wingfieldomyces cypericola on dead leaves of Cyperus papyrus. Spain, Geastrum federeri in soil under Quercus suber and Q. canariensis, Geastrum nadalii in calcareous soil under Juniperus, Quercus, Cupressus, Pinus and Robinia, Hygrocybe garajonayensis in laurel forests, Inocybe cistophila on acidic soil under Cistus ladanifer, Inocybe sabuligena in a mixed Quercus ilex subsp. ballota/Juniperus thurifera open forest, Mycena calongei on mossy bark base of Juniperus oxycedrus, Rhodophana ulmaria on soil in Ulmus minor forest, Tuber arriacaense in soil under Populus pyramidalis, Volvariella latispora on grassy soils in a Quercus ilex ssp. rotundifolia stand. Sweden, Inocybe iota in alpine heath on calcareous soil. Thailand, Craterellus maerimensis and Craterellus sanbuakwaiensis on laterite and sandy soil, Helicocollum samlanense on scale insects, Leptosporella cassiae on dead twigs of Cassia fistula, Oxydothis coperniciae on dead leaf of Copernicia alba, Russula mukdahanensis on soil, Trechispora sangria on soil, Trechispora sanpatongensis on soil. Türkiye, Amanita corylophila in a plantation of Corylus avellana. Ukraine, Pararthrophiala adonis (incl. Pararthrophiala gen. nov.) on dead stems of Adonis vernalis. USA, Cladorrhinum carnegieae from Carnegiea gigantea, Dematipyriformia americana on swab from basement wall, Dothiora americana from outside air, Dwiroopa aeria from bedroom air, Lithohypha cladosporioides from hospital swab, Macroconia verruculosa on twig of Ilex montana, associated with black destroyed ascomycetous fungus and Biatora sp., Periconia floridana from outside air, Phytophthora fagacearum from necrotic leaves and shoots of Fagus grandifolia, Queenslandipenidiella californica on wood in crawlspace. Morphological and culture characteristics are supported by DNA barcodes. Citation: Crous PW, Jurjević Z, Balashov S, De la Peña-Lastra S, Mateos A, Pinruan U, Rigueiro-Rodríguez A, Osieck ER, Altés A, Czachura P, Esteve-Raventós F, Gunaseelan S, Kaliyaperumal M, Larsson E, Luangsa-ard JJ, Moreno G, Pancorbo F, Piątek M, Sommai S, Somrithipol S, Asif M, Delgado G, Flakus A, Illescas T, Kezo K, Khamsuntorn P, Kubátová A, Labuda R, Lavoise C, Lebel T, Lueangjaroenkit P, Maciá-Vicente JG, Paz A, Saba M, Shivas RG, Tan YP, Wingfield MJ, Aas T, Abramczyk B, Ainsworth AM, Akulov A, Alvarado P, Armada F, Assyov B, Avchar R, Avesani M, Bezerra JL, Bhat JD, Bilański P, Bily DS, Boccardo F, Bozok F, Campos JC, Chaimongkol S, Chellappan N, Costa MM, Dalecká M, Darmostuk V, Daskalopoulos V, Dearnaley J, Dentinger BTM, De Silva NI, Dhotre D, Carlavilla JR, Doungsa-ard C, Dovana F, Erhard A, Ferro LO, Gallegos SC, Giles CE, Gore G, Gorfer M, Guard FE, Hanson S-A, Haridev P, Jankowiak R, Jeffers SN, Kandemir H, Karich A, Kisło K, Kiss L, Krisai-Greilhuber I, Latha KPD, Lorenzini M, Lumyong S, Manimohan P, Manjón JL, Maula F, Mazur E, Mesquita NLS, Młynek K, Mongkolsamrit S, Morán P, Murugadoss R, Nagarajan M, Nalumpang S, Noisripoom W, Nosalj S, Novaes QS, Nowak M, Pawłowska J, Peiger M, Pereira OL, Pinto A, Plaza M, Polemis E, Polhorský A, Ramos DO, Raza M, Rivas-Ferreiro M, Rodriguez-Flakus P, Ruszkiewicz-Michalska M, Sánchez A, Santos A, Schüller A, Scott PA, Şen İ, Shelke D, Śliwa L, Solheim H, Sonawane H, Strašiftáková D, Stryjak-Bogacka M, Sudsanguan M, Suwannarach N, Suz LM, Syme K, Taşkın H, Tennakoon DS, Tomka P, Vaghefi N, Vasan V, Vauras J, Wiktorowicz D, Villarreal M, Vizzini A, Wrzosek M, Yang X, Yingkunchao W, Zapparoli G, Zervakis GI, Groenewald JZ (2024). Fungal Planet description sheets: 1614-1696. Fungal Systematics and Evolution 13: 183-440. doi: 10.3114/fuse.2024.13.11.
- Keywords
- ITS nrDNA barcodes, LSU, new taxa systematics,
- Publication type
- Journal Article MeSH
In this study, we investigated the morphological and genetic variability of selected species belonging to the genus Chloridium sensu lato, some also referred to as chloridium-like asexual morphs and other undescribed morphologically similar fungi. These species do not conform to the revised generic concept and thus necessitate a re-evaluation in terms of taxonomy and phylogeny. The family Chaetosphaeriaceae (Chaetosphaeriales) encompasses a wide range of asexual morphotypes, and among them, the simplest form is represented by Chloridium sect. Chloridium. The morphological simplicity of the Chloridium morphotype has historically led to the amalgamation of numerous unrelated species, thereby creating a heterogeneous genus. By conducting phylogenetic reconstruction of four DNA loci and examining a set of 71 strains, including all available ex-type and other non-type strains as well as holotypes and other herbarium material, we were able to gain new insights into the relationships between these taxa. Phylogenetic analyses revealed that the studied species are distantly related to Chloridium sensu stricto and can be grouped into two orders in the Sordariomycetes. Within the Chaetosphaeriales, they formed nine well-separated genera in four clades, such as Cacumisporium, Caliciastrum gen. nov., Caligospora gen. nov., Capillisphaeria gen. nov., Curvichaeta, Fusichloridium, Geniculoseta gen. nov., Papillospora gen. nov., and Spicatispora gen. nov. We also established Chloridiopsiella gen. nov. and Chloridiopsis gen. nov. in Vermiculariopsiellales. Four new species and eight new combinations are proposed in these genera. Our study provides a clearer understanding of the genus Chloridium, its relationship to other morphologically similar fungi, and a new taxonomic treatment and molecular phylogeny to facilitate their accurate identification and classification in future research. Taxonomic novelties: New genera: Caliciastrum Réblová, Caligospora Réblová, Capillisphaeria Réblová, Chloridiopsiella Réblová, Chloridiopsis Réblová, Geniculoseta Réblová, Papillospora Réblová, Spicatispora Réblová; New species: Caliciastrum bicolor Réblová, Caligospora pannosa Réblová, Chloridiopsis syzygii Réblová, Gongromerizella silvana Réblová; New combinations: Caligospora dilabens (Réblová & W. Gams) Réblová, Capillisphaeria crustacea (Sacc.) Réblová, Chloridiopsiella preussii (W. Gams & Hol.-Jech.) Réblová, Chloridiopsis constrictospora (Crous et al.) Réblová, Geniculoseta preussii (W. Gams & Hol.-Jech.) Réblová, Papillospora hebetiseta (Réblová & W. Gams) Réblová, Spicatispora carpatica (Hol.-Jech. & Révay) Réblová, Spicatispora fennica (P. Karst.) Réblová; Epitypifications (basionyms): Chaetosphaeria dilabens Réblová & W. Gams, Chloridium cylindrosporum W. Gams & Hol.-Jech. Citation: Réblová M, Nekvindová J (2023). New genera and species with chloridium-like morphotype in the Chaetosphaeriales and Vermiculariopsiellales. Studies in Mycology 106: 199-258. doi: 10.3114/sim.2023.106.04.
- Keywords
- Chaetosphaeria, conidiogenesis, lignicolous fungi, multi-locus, new taxa, phialide,
- Publication type
- Journal Article MeSH
Core Ericaceae produce delicate hair roots with inflated rhizodermal cells that host plethora of fungal symbionts. These poorly known mycobionts include various endophytes, parasites, saprobes, and the ericoid mycorrhizal (ErM) fungi (ErMF) that form the ErM symbiosis crucial for the fitness of their hosts. Using microscopy and high-throughput sequencing, we investigated their structural and molecular diversity in 14 different host × site combinations in Northern Bohemia (Central Europe) and Argentine Patagonia (South America). While we found typical ericoid mycorrhiza in all combinations, we did not detect ectomycorrhiza and arbuscular mycorrhiza. Superficial mantles of various thickness formed by non-clamped hyphae were observed in all combinations except Calluna vulgaris from N. Bohemia. Some samples contained frequent intercellular hyphae while others possessed previously unreported intracellular haustoria-like structures linked with intracellular hyphal coils. The 711 detected fungal OTU were dominated by Ascomycota (563) and Basidiomycota (119), followed by four other phyla. Ascomycetes comprised Helotiales (255), Pleosporales (53), Chaetothyriales (42), and other 19 orders, while basidiomycetes Sebacinales (42), Agaricales (28), Auriculariales (7), and other 14 orders. While many dominant OTU from both hemispheres lacked close relatives in reference databases, many were very similar to identical to unnamed sequences from around the world. On the other hand, several significant ericaceous mycobionts were absent in our dataset, incl. Cairneyella, Gamarada, Kurtia, Lachnum, and Leohumicola. Most of the detected OTU could not be reliably linked to a particular trophic mode, and only two could be reliably assigned to the archetypal ErMF Hyaloscypha hepaticicola. Probable ErMF comprised Hyaloscypha variabilis and Oidiodendron maius, both detected only in N. Bohemia. Possible ErMF comprised sebacinoid fungi and several unnamed members of Hyaloscypha s. str. While H. hepaticicola was dominant only in C. vulgaris, this model ErM host lacked O. maius and sebacinoid mycobionts. Hyaloscypha hepaticicola was absent in two and very rare in six combinations from Patagonia. Nine OTU represented dark septate endophytes from the Phialocephala fortinii s. lat.-Acephala applanata species complex, including the most abundant OTU (the only detected in all combinations). Statistical analyses revealed marked differences between N. Bohemia and Patagonia, but also within Patagonia, due to the unique community detected in a Valdivian temperate rainforest. Our results show that the ericaceous hair roots may host diverse mycobionts with mostly unknown functions and indicate that many novel ErMF lineages await discovery. Transhemispheric differences (thousands of km) in their communities may be evenly matched by local differences (scales of km, m, and less).
- Keywords
- Central Europe, Ericoid mycorrhizal fungi, Fungal root endophytes, Helotiales, Hyaloscypha sp., Oidiodendron maius, Root-associated fungi, Sebacinales, South America,
- MeSH
- Ascomycota MeSH
- Basidiomycota * MeSH
- Endophytes genetics MeSH
- Ericaceae * microbiology MeSH
- Plant Roots microbiology MeSH
- Mycorrhizae * genetics MeSH
- Symbiosis MeSH
- Publication type
- Journal Article MeSH
Most of our knowledge on the ericoid mycorrhizal (ErM) symbiosis comes from temperate heathlands characterized by acidic peaty soils and many experiments with a few ascomycetous fungi. However, ericaceous plants thrive in many other ecosystems and in temperate coniferous forests, their seedlings often prosper on decomposing wood. While wood is typically exploited by basidiomycetous ectomycorrhizal (EcM) and saprobic fungi, the role of ErM fungi (ErMF) is much less clear. We explored the cultivable mycobiota of surface sterilized hair roots of Vaccinium spp. growing on decomposing wood in two coniferous forests in Mid-Norway (Scandinavia) and Northern Bohemia (Central Europe). Obtained isolates were identified using molecular tools and their symbiotic potential was tested in vitro. While the detected community lacked the archetypal ErMF Hyaloscypha hepaticicola and the incidence of dark septate endophytes and EcM fungi was negligible, it comprised other frequent asexual ascomycetous ErMF, namely H. variabilis and Oidiodendron maius, together with several isolates displaying affinities to sexual saprobic H. daedaleae and H. fuckelii. Ascomycete-suppressing media revealed representatives of the saprobic basidiomycetous genera Coprinellus, Gymnopilus, Mycena (Agaricales), and Hypochnicium (Polyporales). In the resyntheses, the tested basidiomycetes occasionally penetrated the rhizodermal cells of their hosts but never formed ericoid mycorrhizae and in many cases overgrew and killed the inoculated seedlings. In contrast, a representative of the H. daedaleae/H. fuckelii-related isolates repeatedly formed what morphologically appears as the ErM symbiosis and supported host's growth. In conclusion, while basidiomycetous saprobic fungi have a potential to colonize healthy-looking ericaceous hair roots, the mode(-s) of their functioning remain obscure. For the first time, a lineage in Hyaloscypha s. str. (corresponding to the former Hymenoscyphus ericae aggregate) where sexual saprobes are intermingled with root symbionts has been revealed, shedding new light on the ecology and evolution of these prominent ascomycetous ErMF.
- Keywords
- Agaricales, Ericoid mycorrhiza, Hyaloscypha, Mycena, Root-associated fungi, Saprobic fungi,
- MeSH
- Agaricales * MeSH
- Basidiomycota * MeSH
- Wood MeSH
- Ecosystem MeSH
- Ericaceae * microbiology MeSH
- Plant Roots microbiology MeSH
- Mycorrhizae * MeSH
- Symbiosis MeSH
- Vaccinium * microbiology MeSH
- Publication type
- Journal Article MeSH
Chloridium is a little-studied group of soil- and wood-inhabiting dematiaceous hyphomycetes that share a rare mode of phialidic conidiogenesis on multiple loci. The genus has historically been divided into three morphological sections, i.e. Chloridium, Gongromeriza, and Psilobotrys. Sexual morphs have been placed in the widely perceived genus Chaetosphaeria, but unlike their asexual counterparts, they show little or no morphological variation. Recent molecular studies have expanded the generic concept to include species defined by a new set of morphological characters, such as the collar-like hyphae, setae, discrete phialides, and penicillately branched conidiophores. The study is based on the consilience of molecular species delimitation methods, phylogenetic analyses, ancestral state reconstruction, morphological hypotheses, and global biogeographic analyses. The multilocus phylogeny demonstrated that the classic concept of Chloridium is polyphyletic, and the original sections are not congeneric. Therefore, we abolish the existing classification and propose to restore the generic status of Gongromeriza and Psilobotrys. We present a new generic concept and define Chloridium as a monophyletic, polythetic genus comprising 37 species distributed in eight sections. In addition, of the taxa earlier referred to Gongromeriza, two have been redisposed to the new genus Gongromerizella. Analysis of published metabarcoding data showed that Chloridium is a common soil fungus representing a significant (0.3 %) proportion of sequence reads in environmental samples deposited in the GlobalFungi database. The analysis also showed that they are typically associated with forest habitats, and their distribution is strongly influenced by climate, which is confirmed by our data on their ability to grow at different temperatures. We demonstrated that Chloridium forms species-specific ranges of distribution, which is rarely documented for microscopic soil fungi. Our study shows the feasibility of using the GlobalFungi database to study the biogeography and ecology of fungi. Taxonomic novelties: New genus: Gongromerizella Réblová; New sections: Chloridium section Cryptogonytrichum Réblová, Hern.-Restr., M. Kolařík & F. Sklenar, Chloridium section Gonytrichopsis Réblová, Hern.-Restr., M. Kolařík & F. Sklenar, Chloridium section Metachloridium Réblová, Hern.-Restr., M. Kolařík & F. Sklenar, Chloridium section Volubilia Réblová, Hern.-Restr., M. Kolařík & F. Sklenar; New species: Chloridium bellum Réblová & Hern.-Restr., Chloridium biforme Réblová & Hern.-Restr., Chloridium detriticola Réblová & Hern.-Restr., Chloridium gamsii Réblová & Hern.-Restr., Chloridium guttiferum Réblová & Hern.-Restr., Chloridium moratum Réblová & Hern.-Restr., Chloridium peruense Réblová & Hern.-Restr., Chloridium novae-zelandiae Réblová & Hern.-Restr., Chloridium elongatum Réblová & Hern.-Restr., Chloridium volubile Réblová & Hern.-Restr.; New varieties: Chloridium bellum var. luteum Réblová & Hern.-Restr., Chloridium detriticola var. effusum Réblová & Hern.-Restr., Chloridium chloridioides var. convolutum Réblová & Hern.-Restr.; New combinations: Chloridium section Gonytrichum (Nees & T. Nees) Réblová, Hern.-Restr., M. Kolařík & F. Sklenar, Chloridium section Mesobotrys (Sacc.) Réblová, Hern.-Restr., M. Kolařík & F. Sklenar, Chloridium section Pseudophialocephala (M.S. Calabon et al.) Réblová, Hern.-Restr., M. Kolařík & F. Sklenar, Chloridium simile (W. Gams & Hol.-Jech.) Réblová & Hern.-Restr., Chloridium chloridioides (W. Gams & Hol.-Jech.) Réblová & Hern.-Restr., Chloridium subglobosum (W. Gams & Hol.-Jech.) Réblová & Hern.-Restr., Chloridium fuscum (Corda) Réblová & Hern.-Restr., Chloridium ypsilosporum (Hol.-Jech.) Réblová & Hern.-Restr., Chloridium costaricense (G. Weber et al.) Réblová & Hern.-Restr., Chloridium cuneatum (N.G. Liu et al.) Réblová & Hern.-Restr., Fusichloridium cylindrosporum (W. Gams & Hol.-Jech.) Réblová, Gongromeriza myriocarpa (Fr.) Réblová, Gongromeriza pygmaea (P. Karst.) Réblová, Gongromerizella lignicola (F. Mangenot) Réblová, Gongromerizella pachytrachela (W. Gams & Hol.-Jech) Réblová, Gongromerizella pini (Crous & Akulov) Réblová; New name: Chloridium pellucidum Réblová & Hern.-Restr.; Epitypifications (basionyms): Chaetopsis fusca Corda, Gonytrichum caesium var. subglobosum W. Gams & Hol.-Jech.; Lectotypification (basionym): Gonytrichum caesium Nees & T. Nees. Citation: Réblová M, Hernández-Restrepo M, Sklenář F, Nekvindová J, Réblová K, Kolařík M (2022). Consolidation of Chloridium: new classification into eight sections with 37 species and reinstatement of the genera Gongromeriza and Psilobotrys. Studies in Mycology 103: 87-212. doi: 10.3114/sim.2022.103.04.
- Keywords
- 35 new taxa, Chaetosphaeriaceae, molecular systematics, phialidic conidiogenesis, soil fungi, species delimitation methods, wood-inhabiting fungi,
- Publication type
- Journal Article MeSH
Historically, Hyaloscypha s. lat. (Hyaloscyphaceae, Helotiales) included various saprobes with small apothecia formed on decaying plant matter, usually wood, that were defined by chemical and (ultra)structural aspects. However, recent molecular phylogenetic and resynthesis studies have narrowed the concept of the genus and shown that it contains several widely distributed species with unknown sexual morphs that form ectomycorrhizae, ericoid mycorrhizae, and mycothalli and also grow endophytically in plant roots and hypogeous ectomycorrhizal (EcM) fruitbodies (i.e., the historical Hymenoscyphus ericae aggregate). Hence, some of the sexually reproducing saprobic Hyaloscypha s. lat. and the symbionts belong to the monophyletic Hyaloscypha s. str. Here, we introduce two new root-symbiotic Hyaloscypha s. str. species, i.e., H. gabretae and H. gryndleri spp. nov. While the former was isolated only from ericaceous hosts (Vaccinium myrtillus from Southern Bohemia, Czechia and Calluna vulgaris from England, UK), the latter was obtained from a basidiomycetous EcM root tip of Picea abies (Pinaceae), roots of Pseudorchis albida (Orchidaceae), and hair roots of V. myrtillus from Southern Bohemia and C. vulgaris from England. Hyaloscypha gryndleri comprises two closely related lineages, suggesting ongoing speciation, possibly connected with the root-symbiotic life-style. Fungal isolates from ericaceous roots with sequences similar to H. gabretae and H. gryndleri have been obtained in Japan and in Canada and Norway, respectively, suggesting a wide and scattered distribution across the Northern Hemisphere. In a series of in vitro experiments, both new species failed to form orchid mycorrhizal structures in roots of P. albida and H. gryndleri repeatedly formed what morphologically corresponds to the ericoid mycorrhizal (ErM) symbiosis in hair roots of V. myrtillus, whereas the ErM potential of H. gabretae remained unresolved. Our results highlight the symbiotic plasticity of root-associated hyaloscyphoid mycobionts as well as our limited knowledge of their diversity and distribution, warranting further ecophysiological and taxonomic research of these important and widespread fungi.
- Keywords
- Core Ericaceae, Ericoid mycorrhizal fungi, Hyaloscypha hepaticicola, Hymenoscyphus ericae, Meliniomyces, Pezoloma ericae, Rhizoscyphus ericae, Root symbiotic fungi,
- MeSH
- Ascomycota * MeSH
- Tracheophyta * MeSH
- Phylogeny MeSH
- Plant Roots MeSH
- Mycorrhizae * genetics MeSH
- Publication type
- Journal Article MeSH
Despite decades of intensive research (especially from 1970s to 1990s), the ericoid mycorrhizal (ErM) hair root is still largely terra incognita and this simplified guide is intended to revive and promote the study of its mycobiota. Basic theoretical knowledge on the ErM symbiosis is summarized, followed by practical advices on Ericaceae root sample collection and handling, microscopic observations and photo-documentation of root fungal colonization, mycobiont isolation, maintenance and identification and resynthesis experiments with ericoid plants. The necessity of a proper selection of the root material and its surface sterilization prior to mycobiont isolation is stressed, together with the need of including suitable control treatments in inoculation experiments. The culture-dependent approach employing plating of single short (~ 2 mm) hair root segments on nutrient media is substantiated as a useful tool for characterization of Ericaceae root-associated fungal communities; it targets living mycelium and provides metabolically active cultures that can be used in physiological experiments and taxonomic studies, thus providing essential reference material for culture-independent approaches. On the other hand, it is stressed that not every mycobiont isolated from an ericoid hair root necessarily represent an ErM fungus. Likewise, not every intracellular hyphal coil formed in the Ericaceae rhizodermis necessarily represents the ErM symbiosis. Taxonomy of the most important ericoid mycobionts is updated, mutualism in the ErM symbiosis is briefly discussed from the mycobiont perspective, and some interesting lines of possible future research are highlighted.
- Keywords
- Culture-dependent approach, Ericaceae, Ericoid mycorrhizal fungal diversity, In vitro resynthesis, Isolate identification, Microscopy, Mycobiont isolation, Plating of surface-sterilized root segments,
- MeSH
- Ericaceae * MeSH
- Plant Roots MeSH
- Mycorrhizae * MeSH
- Plants MeSH
- Symbiosis MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
A high number of fungal strains were isolated from roots of Brassicaceae species collected across western and southern Europe, resulting in an unexpectedly rich collection of Cadophora species. These isolates enable us to present a new and comprehensive view of the ecological, morphological, and phylogenetic traits of root-inhabiting members of this helotialean genus. We provide phylogenetic placement of all of our isolates based on a four-gene dataset, analyze their phenotypic traits in relation to their phylogenetic relationships, and infer the potential distribution ranges of the species by sequence comparisons with available databases. We consider seven well supported phylogenetic lineages as species new to science. Six further lineages probably also represent new species but remain undescribed due to the lack of diagnostic morphological characters. Our results show that Cadophora, as currently circumscribed, is paraphyletic and encompasses a broad spectrum of morphologies and lifestyles. Among the new species, only two (C. ferruginea and C. constrictospora) form phialides and conidia typical of Cadophora, three species (C. echinata, C. gamsii and C. variabilis) produce chains of swollen hyphal segments that may function as holoblastic conidia, and one species (C. fascicularis) produces chains of holoblastic ramoconidia and conidia. Ancestral state reconstruction analysis suggests that phialidic conidiogenesis evolved several times in Cadophora s. lat. from a putatively holoblastic common ancestor. Most Cadophora lineages are rare as estimated from the availability of sequence data, in spite of having relatively wide distribution ranges, whereas five lineages may represent endemic relationships given their restricted distributions. Our dataset, probably the most comprehensive available for Cadophora, nevertheless shows knowledge gaps concerning the phylogenetic relationships within this genus and highlights a need for further investigation.
- Keywords
- 7 new species, Biogeography, Cadophora, Dark septate endophytes, Ploettnerulaceae, Symbiosis,
- Publication type
- Journal Article MeSH