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Abstract The terrestrial isopod genusLigidiumincludes 58 species from Europe, Asia, and North America. In Eastern North America four species are recognized:L. floridanumandL. mucronatum, known just from their type localities in Florida and Louisiana respectively,L. blueridgensis, endemic to the southern Appalachians, andL. elrodii, widespread from Georgia to Ontario. The genus shows a marked morphological conservatism, and species are differentiated mostly by small morphological differences; it is not always easy to determine if such variability represents inter‐ or intraspecific variation. Here, we explore the diversity ofLigidiumfrom the southern Appalachian Mountains, exploring the congruence of morphologically defined groups with multilocus phylogenetic reconstructions and molecular species delimitation methods. We have studied a total of 130 specimens from 37 localities, mostly from the southern Appalachians, and analysed mtDNA (Cox1) and nuclear (28S, NaK) sequences. Morphologically, we recognized eight morphotypes, most of them assignable to current concepts ofL.elrodiiandL.blueridgensis. Phylogenetic analyses supported the evolutionary independence of all morphotypes, and suggest the existence of 8–9 species, including limited cryptic diversity. Single‐locus delimitation analyses based on mtDNA data suggest the existence of a much higher number of species than the multilocus analyses. The estimated age of the ancestors of sampled lineages indicates a long presence of the genus in eastern North America and old speciation events through the Miocene. Our results indicate a higher diversity than previously thought among theLigidiumpopulations present in the southern Appalachian Mountains, with several species to be described.
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A phylogenetic and morphological study of the genus Dermoloma (Agaricales, Tricholomataceae) in Europe and North America exposes inefficiency of opportunistic species descriptions
Dermolomais traditionally known as a small genus of agarics classified in the familyTricholomataceae. This study implemented a multilocus phylogeny of six DNA regions to recognize phylogenetic species within the genus. The species concept is reinforced by observations of well-defined morphological characters enhanced by long term sampling effort in Europe and North America. Thirty EuropeanDermolomaspecies are described, including 16 new species from Europe and three from North American. These species are classified into two subgenera morphologically distinguished by spores with positive or negative amyloid reaction. A new genusNeodermolomais introduced for theDermoloma-like speciesN. campestre. Localized or continental-scale species endemicity was confirmed based on studied material, but more inclusive phylogenetic clustering supported a mixture of North American species among the European clades. Of the 22 names validly published from Europe prior to this study, 11 could be assigned to well-definedDermolomaspecies recognized here. Of the remaining 11 names, two were considered representingDermolomaspecies not recorded since their description, and nine were established as later synonyms of other species. Morphological studies ofDermolomaare challenging due to the relatively low number of characters suitable for identification of species. The majority of morphological characters showed continuous variation with high overlap throughout the genus. For this reason, species identification requires an awareness of morphological variability within species, and multiple distinguishing characters need to be combined, and furthermore, often a barcode sequence is needed for a certain identification. Stable isotope analysis inDermolomaof δ13C and δ15N revealed an ecological signature similar to known CHEGD fungi, i.e.ClavariaceaeandHygrocybes.l. This indicates thatDermolomaspecies are biotrophic but neither ectomycorrhizal nor saprotrophic and may form mutualistic root endophytic associations with vascular plants.
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- Award ID(s):
- 2030779
- PAR ID:
- 10623942
- Author(s) / Creator(s):
- ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »
- Publisher / Repository:
- Pensoft
- Date Published:
- Journal Name:
- IMA Fungus
- Volume:
- 16
- ISSN:
- 2210-6340
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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Accepted Manuscript
- Journal Article:
- https://doi.org/10.3897/imafungus.16.157337
