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Natural History Museum, University of Oslo, P.O. Box 1172 Blindern, N-0318 Oslo, Norway
Kamran Shalchian-Tabrizi
Håvard Kauserud
Department of Biology, University of Oslo, P.O. Box 1045 Blindern, N-0316 Oslo, Norway
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ABSTRACT |
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 TOP ABSTRACT INTRODUCTIONMATERIAL AND METHODSRESULTSDISCUSSIONLITERATURE CITED |
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The basidiomycete genus Galerina Earle accommodates more than 300 small brown-spored agarics worldwide, predominantly described from the Northern hemisphere. The delimitation of species and infrageneric units hitherto has been based on morphological and, to some extent, ecological characters. In this study we have analyzed nuclear ribosomal LSU and ITS sequences to reveal infrageneric phylogeny and the phylogenetic placement of Galerina among the dark-spored agarics. Sequences from 36 northern hemisphere Galerina species and 19 other dark-spored taxa were analyzed, some of them obtained from EMBL/GenBank. Our results, received from Bayesian and distance methods, strongly suggest that Galerina is a polyphyletic genus. The LSU analysis shows that Galerina is composed of three or four separate monophyletic main groups. In addition, a few species cluster together with other dark-spored agarics. The same groups are recognized in the ITS tree and they correspond roughly to previously recognized subgenera or sections in Galerina. With high support our LSU analysis suggests that Gymnopilus is a monophyletic genus and that Gymnopilus and one of the Galerina lineages ("mycenopsis") are sister groups. The analyses further indicate that the Galerina lineages, as well as the genus Gymnopilus, could be referred to a strongly emendated family Strophariaceae, which corresponds largely to the family as circumscribed by Kühner (1980)
. Our results affirm that morphological characters often are highly homoplastic in the agarics. At the present stage formal taxonomic consequences or nomenclatural changes are not proposed.
Key words: Basidiomycota, Agaricales, brown-spored agarics, Cortinariaceae, Galerina, Gymnopilus, Strophariaceae
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INTRODUCTION |
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TOPABSTRACTINTRODUCTIONMATERIAL AND METHODSRESULTSDISCUSSIONLITERATURE CITED |
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), predominantly described from the Northern hemisphere. Most species have basidiocarps associated with living bryophytes, probably as saprophytes on dead parts, whereas others are confined to woody material or other plant debris. The delimitation of species and infra-generic units hitherto has been based on morphological and, to some extent, ecological characters. The basidiocarps of Galerina are small and mycenoid, although sometimes they are slightly fleshier and occasionally the stipe is provided with a membranous annulus. Important gross-morphological characters separating the species include ecology, fruit body size, veil conditions, surface features of the pileus, insertment of the lamellae, color and lepto-organic characters (flavor and odor). In the majority of the species, the spores are ornamented and have a "plage" (a delimited smooth area on the adaxial side above the apiculus), but in some species they are ornamented also over the plage area or smooth. The spores in species provided with a plage are exceptional by having an inner wall layer, endospore, which inflates after successive exposure to diluted base and acid solutions, and furthermore this endospore is strongly dextrinoid and cyanophilic (the "ammonia-co-acetic treatment," Kühner 1972, 1980). A rich assortment of cystidia of different shapes and locations constitutes, in combination with spore characters, a fundament for recognition of the various Galerina species. In most cases microscopic examination is needed for species recognition and high quality optics often are required, and even then identifications may remain doubtful.
Current circumscription of the genus Galerina largely follows that of Kühner (1935), who excluded groups now placed in Conocybe s. lat. and included G. marginata and related annulate species that previously were referred to Pholiota (TABLE I). This circumscription of Galerina, followed by a later segregation of the G. stagnina group, has been generally accepted. However, Watling and Gregory (1993) included also the genus Kuehneromyces in Galerina. The delimitation of infrageneric units in Galerina and their taxonomic level vary between authors of current classifications (Bon 1992, Gulden and Hallgrímsson 2000, Smith and Singer 1964, Watling and Gregory 1993; TABLE I), but two of the units recognized already by Kühner (1935), Tubariopsis and Naucoriopsis, largely remain as in the original concept, while his third unit, Eugalerina, has been divided in various ways. Several species complexes of Galerina are in need of critical revision (e.g. the G. marginata [cf. Gulden et al 2001] and the G. vittiformis complexes), and numerous species delimitations remain controversial.
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) and to find the phylogenetic placement of its various groups. The genus Gymnopilus is of particular interest because some of its species share salient spore features with Galerina (e.g. plage and inflating endospore) (Kühner 1980). Furthermore many Gymnopilus species have cystidia similar to those of Galerina and the limit between the two genera, especially in southern hemisphere species, has been difficult to draw (Rees et al 1999).
The analysis of Moncalvo et al (2002) indicates that the dark-spored agaric families Bolbitiaceae, Cortinariaceae, Coprinaceae, Crepidotaceae and Strophariaceae are polyphyletic as circumscribed in the widely accepted sense of Singer (1986). Singer’s delimitation of these families has been strongly challenged also in morphology based taxonomy, especially by Kühner (1980) who, for example, referred Galerina and Gymnopilus to Strophariaceae while they, according to Singer, belong in Cortinariaceae. In the present study we have included mainly taxa from the dark-spored consortium Cortinariaceae-Strophariaceae and not from the taxonomically more remote families Agaricaceae and Coprinaceae ("P-sathyrellaceae") to investigate the family relationships of Galerina.
This study is a first contribution toward obtaining a new phylogeny of Galerina. Our data also made it possible to investigate family relationships among allied dark-spored agarics.
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MATERIAL AND METHODS |
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TOPABSTRACTINTRODUCTIONMATERIAL AND METHODSRESULTSDISCUSSIONLITERATURE CITED |
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). The origin of collections, the authors of taxa and GenBank accession numbers are presented (TABLE II). Our intention was to include, when possible, at least two samples from each species of Galerina. Species of the G. marginata complex were sampled more extensively to obtain a second dataset to compare with results published by Gulden et al (2001). The G. atkinsoniana/G. vittiformis complex also was sampled extensively. To verify identification and to evaluate selected characters, collections used in the molecular analyses were examined microscopically according to methods described in Gulden and Hallgrímsson (2000).
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): Copelandia (1), Cortinarius (4), Descolea (1), Flammula (1), Flammulaster (1), Gymnopilus (5), Hebeloma (3), Hemipholiota (3), Hypholoma (3), Inocybe (2), Kuehneromyces (2), Melanotus (1), Mythicomyces (1), Naucoria (1), Pachylepyrium (1), Panaeolus (1), Phaeocollybia (3), Phaeogalera (1), Phaeomarasmius (2), Phaeone-matoloma (1), Pholiota (5), Rozites (1), Stagnicola (1) and Tubaria (1).
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with minor modifications: DNA was resuspended in 100 µL dsH2O at the final step of extraction, and DNA templates were diluted 50-fold before PCR amplification. PCR amplification was accomplished with the primers LROR/LR5 and ITS4/ITS5 (White et al 1990) for the nuclear partial LSU region and ITS. PCR was performed in 30 µL reactions containing 17.5 µL 50 x diluted template DNA and 12.5 µL reaction mix (final concentrations: 4 x 250 mM dNTPs, 0.625 mM of each primer, 2 mM MgCl2 and 1 unit DyNAzymeTM II DNA polymerase [Finnzymes Oy, Espoo, Finland]) on a Biometra PCR machine. The nrDNA LSU and ITS amplification program was initiated by a 4 min denaturation step at 94 C, followed by 37 cycles of 30 s at 94 C, 35 s at 54 C and 40 s at 72 C. The program was terminated with a 10 min elongation step at 72 C before storage at 4 C. Automated sequencing was performed on a MegaBACETM 500 DNA Analysis System (Amersham Biosciences, Ohio) with the DYEnamicTM ET Dye Terminator Cycle Sequencing Kit (Amersham Biosciences, Buckinghamshire, England), according to the manufacturers recommendations. PCR products and cycle sequencing products were purified respectively with the ExoSAP-IT and Auto-Seq96TM Dye Terminator Clean-up Kits according to the manufacturer’s recommendations (Amersham Biosciences, Ohio). Both strands of the ITS and LSU amplicons were sequenced with the PCR primers.
Alignments and phylogenetic analyses.— –
Sequence chromatograms were inspected visually and sequences manually aligned with the program BioEdit Sequence Alignment Editor version 5.0.9 (Hall 1999). Regions that could not be aligned reliably were excluded from the analyses. Due to alignment problems only Galerina sequences were included in the ITS alignment, although this represented a polyphyletic dataset (see below).
Phylogenetic trees were constructed from the ITS (85 sequences and 579 characters) and LSU (130 sequences and 733 characters) alignments. Phylogenetic analyses were performed with MrBayes v. 3 (Ronquist and Huelsenbeck 2003) applying a general time reversible (GTR) substitution model, gamma (G) and proportion of invariable site parameters (I) to accommodate variable rates across sites. Other prior settings were set to default values. The Markov chain Monte Carlo (MCMC) chains lasted 2 000 000 generations, and trees were saved each 100 generation, in all counting 20 000 trees. The MCMC analysis implemented four chains (three heated and one cold) starting from random tree topologies. Burn-in was set to 300 000 generations based on the stationarity of the MCMC chains, leaving 17 000 trees for calculation of the consensus tree and posterior probability values. To test the convergence of the MCMC chains, the Bayesian inference was done twice and from different random, starting trees. Comparison of the runs showed almost identical tree topologies, mean likelihood scores and the posterior probability values, and therefore we considered it likely that the MCMC had lasted long enough to converge. Phylogenetic analysis with distance methods were done in PAUP* v. 4.0b10 (Swofford 2000) by inferring trees with maximum likelihood (ML-distance) and LogDet distances. The ML-distance parameters were estimated from a K2P tree generated with NJ, and included these parameters: GTR, G+I and nucleotide frequencies. In the LogDet analysis the I parameter was used by excluding invariable sites in proportion to nucleotide frequency estimated from constant sites only.
In preliminary LSU analyses, where we tested different potential outgroup taxa distantly related to the ingroup, Inocybe clustered basically and was chosen as outgroup in the LSU analysis. The Galerina group "tubariopsis," appearing as clearly defined and monophyletic in the LSU analysis, was chosen as outgroup in the ITS analysis.
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RESULTS |
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TOPABSTRACTINTRODUCTIONMATERIAL AND METHODSRESULTSDISCUSSIONLITERATURE CITED |
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To evaluate the potential polyphyletic status of Galerina and the relationships to other dark-spored taxa, we established another dataset, with the first part of the LSU nrDNA gene. Fifty-eight LSU sequences from 28 Galerina species were generated together with 20 sequences from 19 other dark-spored species. In addition 51 sequences representing 50 species were retrieved from GenBank from various dark-spored taxa and included in the alignment. A Bayesian analysis of the LSU alignment was performed (as stated above). GenBank sequences from Inocybe agardhii and Inocybe curvipes (AY380366
[GenBank]
and AY239022
[GenBank]
) were used as outgroup sequences in the analyses of LSU. The resulting consensus phylogram is shown (FIG. 1
). Although low support was obtained for basal branches in the tree, the topology indicates that Galerina is a highly polyphyletic genus, clustering into four more or less independent lineages referred to provisional names as "mycenopsis," "naucoriopsis," "galerina" and "tubariopsis" (shown in different colors in FIG. 1). The "galerina" group obtained low support in the LSU analysis. These four groups largely reflect already recognized morphology-based subgenera or sections within Galerina (TABLE I). However some Galerina species were not included in these four main groups (cf. species in red in FIG. 1). Of note, the genus Gymnopilus was found to be monophyletic and Gymnopilus and "mycenopsis" occurred together as a highly supported group (FIG. 1). Phylogenetic inferences of the LSU data with distance methods by inferring trees with maximum likelihood (ML-distance) and LogDet-distance methods, resulted in highly congruent topologies (results not shown).
Although being a polyphyletic dataset, a Bayesian analysis of the Galerina ITS dataset also was performed (as described above) to infer phylogenetic relationships between Galerina taxa, independently of other dark-spored agarics. The "tubariopsis" group was used as outgroup in this analysis. Most Galerina species grouped into the same four groups as in the LSU tree (FIG. 2) and largely the same species had intermediate positions in the ITS tree (cf. taxa in red in FIG. 2). The "mycenopsis" group obtained low support in the ITS analysis. Of note, the 36 species included in the ITS alignment grouped into monophyletic groups except for Galerina marginata and Galerina atkinsoniana (cf. FIG. 2). Phylogenetic analysis of the ITS dataset with distance methods by inferring trees with maximum likelihood (ML-distance) and LogDet-distances gave largely the same topology (results not shown).
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DISCUSSION |
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TOPABSTRACTINTRODUCTIONMATERIAL AND METHODSRESULTSDISCUSSIONLITERATURE CITED |
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), as earlier suggested by Moncalvo et al (2002). The LSU tree shows that Galerina has 3–4 separate main groups and some odd species interspersed between other dark-spored genera. Roughly the same groups are recognized in the ITS tree (FIG. 2). However the ITS data constitute otherwise a highly polyphyletic dataset by not including other brown-spored taxa. Bearing in mind its "artificial" status, the ITS dataset nevertheless can be used to investigate species relationships within the four main groups of Galerina. The resolved lineages correspond more or less to previously recognized subgenera or sections in Galerina, and we accordingly have named them "mycenopsis," "naucoriopsis," "galerina" and "tubariopsis." These groups are discussed separately below as are the isolated species. The LSU tree also indicates that the genera Phaeogalera (represented by P. stagnina) and Kuehneromyces (represented by K. mutabilis [Schaeff.] Singer & A.H. Sm. and Pholiota lignicola [Peck] Jacobsson [= K. lignicola {Peck} Redhead]) are correctly kept separate from Galerina as currently done (TABLE I). These two genera occur at the basis of a /psilocybe clade in the analysis of Moncalvo et al (2002).
Family concepts and affinities of the different Galerina lineages.— –
The surrounding agaric consortium of our LSU analysis was chosen, through initial phylogenetic analyses, from the ochre- to black-spored range of agarics generally referred to the families Bolbitiaceae, Coprinaceae, Cortinariaceae, Crepidotaceae and Strophariaceae in the sense of Singer (1986). The sample corresponds to the old groups Dermini (with ochre to rusty brown spores), Pratelli (with brown to purplish-black spores) and a small part of the black-spored Coprinarii of Fries (1836–1838). These black-spored agarics of the Coprinarii (the Panaeolus/Copelandia group [= subfamily Panaeoloidae of Coprinaceae]) differ from the other members of Coprinaceae by having spore pigments that do not discolor in H2SO4 (Kühner 1980). In the widely accepted family scheme of Singer (1986), Galerina belongs in the family Cortinariacae. Galerina belongs in Strophariaceae, according to Kühner (1980), who drastically changed Singer’s circumscription of the dark-spored families in the Dermini-Pratelli-Coprinarii range. Strophariaceae in the sense of Kühner includes only saprophytic species with a spore color range from brown to black, and it further assembles all species containing styryl-pyroles and psilocybin/psilocin, as well as all species with the special kind of cystidia termed chrysocystidia. Cortinariaceae sensu Kühner contains only ectomycorrhizal genera and only those with ochre to rusty brown spores.
The LSU tree (FIG. 1) includes a large unsupported clade that embraces all the Galerina species of our analysis. This clade corresponds largely to the family Strophariaceae sensu Kühner (1980) (indicated by arrow in FIG. 1), except for the fact that only a fragment of the family Bolbitiaceae occurs here (the genus Agrocybe), while Kühner included the whole family Bolbitiaceae in his Strophariaceae (the other genera of Bolbitiaceae, Bolbitius, Conocybe and Descolea occur in the upper part of the tree). In addition the two ectomycorrhizal genera Hebeloma and Phaeocollybia are irregular in the essentially saprophytic Strophariaceae of Kühner. None of our Galerina lineages appear close to genera of the Cortinariaceae, neither do the isolated Galerina species, and we conclude that Galerina species belong in the family Strophariaceae, not in the Cortinariaceae.
Gymnopilus and "mycenopsis" constitute one monophyletic group.— –
With high support our LSU analysis suggests that Gymnopilus is a monophyletic genus, as previously suggested by Rees et al (2002) and Guzmán-Dávalos et al (2003) inferred from ITS analyses, and that Gymnopilus and our "mycenopsis" constitute a highly supported group. A close relationship between Galerina and Gymnopilus as suggested by the LSU topology is highly interesting because relationships and delimitation of these genera have been much disputed (Kühner 1980, Singer 1986, Rees et al 1999, Rees et al 2002). "Presence or the absence of styrylpyrones bis-noryangonin and hispidin provides the only clear-cut means of differentiation between the two genera," according to Rees et al (1999). Rees et al (2002) however state that some species of Gymnopilus has been found lately without these pigments. A close relationship between the two genera is not evident from comparison of fruit body aspects of northern hemisphere Galerina and Gymnopilus species. The relatively fleshy, often caespitose and lignicolous, bitter-tasting Gymnopilus species are quite different from the typically small and bryophilous Galerina species. Galerina pruinatipes, also described as Gymnopilus laricicola J. Favre, may serve as an odd example of fruit body similarity. However, in the southern hemisphere, a group of small, mostly eccentrically stipitate species of Galerina are difficult to distinguish from small-statured Gymnopilus species in the field and even after microscopic examination (Rees et al 1999). Typical of these Gymnopilus species apart from their small fruit bodies are more or less tibiiform cystidia and dextrinoid spores with a more or less distinct plage. Interestingly, our "mycenopsis" group that forms the sister group of Gymnopilus does not include the Galerina species with tibiiform cystidia.
More than anything, spore features seem to unite Galerina and Gymnopilus. Typical of both genera are ochre to rusty brown, amygdaloid-ellipsoid and ornamented spores often provided with a plage. An inflating, dextrinoid/cyanophilic endospore appears to be unique to species of these genera (Kühner 1972, 1980). This kind of endospore is found in the "mycenopsis" group (in fact in all the groups except that of "tubariopsis") and it has been demonstrated in these Gymnopilus species: G. junonius, G. penetrans, G. liquiritiae, G. bellulus, G. flavus and G. fulgens (Kühner 1980).
"mycenopsis".— –
Most species included in the "mycenopsis" lineage in our ITS and LSU analyses have a typical "Galerina" appearance; that is a mycenoid fruit body, presence of a more or less fugacious veil, and yellow to dark red-brown color. They are bryophilous, and some are strictly sphagnophilous. Galerina paludosa is a parasite on Sphagnum (Redhead 1981). In current classifications the species of this group are referred to subgenus/section Mycenopsis (or subsection Mycenopsidae) and to section Calyptrospora (TABLE I). They are characterized microscopically by faintly ornamented to practically smooth spores that in some species are more or less calyptrate (i.e. with an outer wall layer that tends to separate and form smaller or larger blisters, particularly in the area around the apiculus) and by cystidia that are lageniform to ventricose-capitate and restricted to the lamellae edge (cheilocystidia).
The separate position of G. paludosa, as a sister group of Gymnopilus in the LSU tree, corresponds to the findings of Moncalvo et al (2002) where G. paludosa is included in the /gymnopiloid clade as a sister group of a monophyletic gymnopilus clade. Galerina pumila, which currently is referred to section Mycenopsis or its equivalents and which also occurs in the "mycenopsis" clade in the ITS tree, is found in two separate positions outside the clade in the LSU tree. The species differs from the other species of the "mycenopsis" clade by having truly smooth spores and elongate, narrow cystidia. It has been interpreted as the Agaricus mycenopsis of Fries and is the type species of section Mycenopsis A.H. Sm. & Singer (subgenus Mycenopsis Bon 1992). When a splitting of the genus Galerina is implemented in forthcoming studies, the position of G. pumila becomes important for nomenclatural reasons.
The section Calyptrospora, according to its authors, is based on a single character (Smith and Singer 1964) and its taxonomic value is questionable also because the spores in a single species vary with regard to degree of calyptration (i.e. percentage of spores affected and size of the blisters). The distinctly calyptrate G. calyptrata and G. sphagnicola appear together in both trees; G. fallax, which is variable with regard to calyptration, takes different positions within the clade in both trees, while G. hypnorum, present only in the ITS analysis, takes a position among the noncalyptrate species of the clade. This species has been variously interpreted and, according to Smith and Singer (1964), has noncalyptrate spores and cystidia with acute to obtuse necks. The analyzed material collected by Smith (MICH 46292, 46302), however, has many spores with small blisters and mostly ventricose-capitate cystidia and corresponds in these respects to the included Norwegian collection (O 154362). Apparently the taxonomic importance of calyptration should be tuned down and the section Calyptrospora abandoned. The collection identified as a form of G. hypnorum (O 73206) has aberrant, voluminous cystidia (Gulden in press). It occurs with the other G. hypnorum collections in the ITS tree, but has a strange position in the LSU tree together with species of the "galerina" lineage.
An annulate thickening is seen near the spore apex in G. allospora and has been considered unique for this species. However we found the same character in the holotype material of G. fibrillosa when this was studied microscopically. Galerina fibrillosa is a rare species that, according to its author, reminds one of a Phaeomarasmius and differs from the typical galerinas by being dark (Verona brown, snuff brown, dark, dull, vinaceous cinnamon, etc.) with a convex-umbonate and coarsely matted-fibrillose pileus (Smith and Singer 1964). It was made the type species of the small section Inoderma A.H. Sm. & Singer; its name refers to the fibrillose pileus. An inclusion here of G. fibrillosa in the ‘mycenopsis’ clade as indicated in the ITS tree does not seem unnatural in view of the spore apex thickening shared with G. allospora, but also because other species in the group has a more or less scurfy-subscaly pileus deviating from the normal smooth pattern in Galerina. Galerina harrisonii, for example, originally was described as Phaeomarasmius harrisonii and shares a more convex, less conic-campanulate pileus with G. fibrillosa.
"naucoriopsis".— – The core group of the "naucoriopsis" lineage includes the more fleshy Galerina species, in particular by having an incurved pileus margin and an annulus or annulate zone on the stipe. The "naucoriopsis" species vary considerably with regard to habitat-substrate preferences and often form fruit bodies on woody and herbal debris or grow in mossy or grassy sites, and some of the species seem little specific in this regard being able to switch from a lignicolous to a terricolous habit. In the "naucoriopsis" lineage the spores are more or less distinctly ornamented, and large ventricose-fusoid cystidia occurring on the edge as well as on the sides of the lamellae (pleurocystidia) are characteristic.
Our "naucoriopsis" lineage includes the toxic species G. marginata, which according to morphological and molecular studies, was considered identical with inter alia G. venenata and G. autumnalis (Gulden et al 2001). Material identified as G. marginata, G. autumnalis and G. venenata have been shown to contain amatoxins and have caused intoxications (Enjalbert et al 2004, Tyler and Smith 1963, Tyler et al 1963). G. marginata in the broad sense contains amanitins (
, ß and 
) in different concentrations related to substrate conditions and sometimes even in higher amounts than in fruit bodies of Amanita phalloides, according to Enjalbert et al (2004). Also G. badipes, with an aberrant position in the LSU analysis (FIG. 1), contains amatoxin (-amanitin) (Besl et al 1984) and fits in our "naucoriopsis" lineage in this respect. In fact all reported amanitin-containing Galerina species belong in section Naucoriopsis (Enjalbert et al 2004).
The phylogenetic relationship between the two central species of "naucoriopsis," G. marginata and G. pseudomycenopsis, was studied by Gulden et al (2001) with ITS sequences. Ecologically and morphologically there are clear differences between these species (Horak and Miller 1992, Gulden and Vesterholt 1999). It was concluded, however, that the applied molecular methods could not distinguish the two species. The two species did not separate well in our present analyses. A status of G. pseudomycenopsis as a distinct species may be inferred from a limited mating experiment conducted at the lab of Ronald Petersen, Knoxville, Tennessee, in 2002, where single-spore isolates of G. pseudomycenopsis from Greenland were crossed with single-spore isolates of G. autumnalis from North America (Washington) and of G. marginata from Europe (Norway and Austria). All crosses of G. pseudomycenopsis with G. marginata/G. autumnalis were incompatible, while all crosses between G. marginata and G. autumnalis were compatible (Peterson personal communication). Galerina pseudomycenopsis has not been analyzed with respect to amanitin-content.
In both analyses the aberrant G. jaapii forms a sister group of the core group. The strictly bryophilous G. jaapii is a slender species of a more Galerina-like look than the other species of the group, but it generally has a well developed annulus. In contrast to the core species it has cystidia of the "mycenopsis" type, present only as cheilocystidia, and almost smooth spores with an apical pore borne on 2-spored basidia. The spore characters are shared with G. badipes that occurs close to G. jaapii in the ITS tree. Galerina jaapii generally has been considered a species of section Mycenopsis, while G. badipes, which has typical "naucoriopsis" cheilo- and pleurocystidia, in all classifications has been included in section/subgenus Naucoriopsis. A monophyletic "naucoriopsis" clade includes also G. salicicola, according to the ITS tree. Galerina salicicola, which gross-morphologically fits well in "naucoriopsis," was placed in section Physocystis together with G. pruinatipes and a few more species (Smith and Singer 1964) on account of somewhat special (utriform-broadly lageniform) but rather polymorph cystidia (cheilo-and pleurocystidia). Orton (1960), who originally described the species, mentioned G. badipes and G. nana as probably the nearest relatives. A more thorough phylogenetic analysis with multiple genetic markers is necessary to draw further taxonomic conclusions in this important group of Galerina species.
"galerina".— – The "galerina" lineage includes bryophilous species with typical Galerina habit and yellow, amber to red brown color. They generally are referred to section Galerina. The species of this lineage have the same type of cystidia as the species of "naucoriopsis," but these occur also as caulocystidia, covering more or less the entire stipe, and on the pileus (pileocystidia) in some taxa. The spores are ornamented distinctly and often borne on 2-spored basidia, as also frequently seen in the "naucoriopsis" lineage. The "galerina" and the "naucoriopsis" lineages appear closer related to each other than to any other of the Galerina lineages as inferred from the LSU analyses, but apart from the cystidia and the tendency to develop 2-spored forms they do not appear to have characters in common that also are not shared with species of the other Galerina groups. The "galerina" group includes the type species of the genus Galerina Earle, Agaricus vittaeformis Fr.
Within the "galerina" group, the studied material was separated on three species as follows: Specimens with pileocystidia were identified as G. atkinsoniana; the atkinsoniana-collections had either predominantly 2-spored or 4-spored basidia and were referred to two distinct forms. Material without pileocystidia was identified either as G. minima or G. vittiformis. Specimens with a well developed veil, forming a whitish brim on the pileus or persisting as fibrils on the stipe were identified as G. minima (= G. terrestris V.L. Wells & Kempton [Gulden in press]). All collections of this species had 4-spored basidia. Typical features of G. minima are also a farinaceous flavor and occurrence in pioneer vegetation in cold climates. The material of G. vittiformis had no veil, the odor/flavor was not always documented, and the collections had either 2- or 4-spored forms corresponding to the situation in G. atkinsoniana. Neither of our analyses renders support or any clear clue to the differentiation of the taxa in this lineage, and apparently the 2-and 4- spored states are not stable conditions.
"tubariopsis".— – The "tubariopsis" lineage includes bryophilous species with a typical Galerina appearance but aberrant microscopic features. Clamp connections, otherwise present at all septa in all Galerina species, occur inconsistently in this group, and important spore characters vary as well. All species of the lineage have tibiiform cystidia that occur in most parts of the fruit bodies but never as pleurocystidia. The lineage corresponds to the morphologically defined subgenus Tubariopsis, but includes in addition a few species that generally are placed in subgenus Galerina, in section Tibiicystidiae or its equivalents. These are G. pseudocerina, included in the LSU analysis, and G. tibiicystis and G. hybrida, in the ITS analysis.
Core species of the lineage, G. clavata, G. laevis, G. arctica and G. semilanceata, are characterized by a total lack of clamp connections and furthermore by spores that differ from the Galerina spores in general by lacking the plage as well as the inflating/dextrinoid/cyanophilic endospore. These species currently are placed in section Tubariopsis of the subgenus, while G. stordalii (= G. dimorphocystis ss. Kühner 1972) belongs in a section of its own, Hemitubariopsis, characterized by sporadic clamp connections (found only at the base of basidia and at some hyphal septa). Galerina stordalii occurs well separated from the core species in both trees. The spores of G. stordalii lack a plage as is common in the subgenus but differ fundamentally from the typical pattern of the subgenus by having the inflating/dextrinoid/cyanophilic endospore and an apical pore. This latter feature led Smith and Singer (1964) to place the species in section Porospora (subgenus Galerina).
The last three species of the lineage (viz. G. pseudocerina, G. tibiicystis and G. hybrida) have clamp connections at all septa and dextrinoid spores with a more or less delimited plage just like species of the other subgenera of Galerina. Of these G. pseudocerina differs from all others of the lineage by having a somewhat more hemispheric and fleshy pileus and by its coarsely ornamented spores. Galerina tibiicystis and G. hybrida, which are similar species, share an exclusively sphagnophilous habit with G. stordalii, while some of the other species of the lineage occasionally may occur on Sphagnum.
Galerina species without clear affinities.— –
Galerina nana, G. pruinatipes, G. pseudocamerina and G. triscopa occur in various positions close to the "naucoriopsis" lineage in the LSU tree. In the ITS tree they also take positions close to "naucoriopsis" together with G. chionophila (only present in the ITS analysis). All these species have typical Galerina spores (i.e. amygdaliform, ornamented with plage, dextrinoid and cyanophilic). They are born on two-spored basidia in G. nana, G. pseudocamerina and G. pruinatipes just like in G. jaapii and G. badipes of the "naucoriopsis" lineage. All but the bryophilous or terricolous G. chionophila also share the lignicolous habit with the typical species of this lineage. In current classifications these four species are referred to widely different infrageneric taxa: G. nana is the type species of section Inocyboides Singer (= subgenus Inocybula [Singer] Bon) that is particular by presence of thick-walled cheilo- and pleurocystidia (reminding of those found in the genus Inocybe). Except for these cystidia, G. nana is similar to the G. marginata group. The species occurs linked to the /panaeoloideae clade in the analysis of Moncalvo et al (2002). Galerina pruinatipes was placed in section Physocystis by Smith and Singer (1964) on account of its large, broad-headed cystidia that are present as cheilo-, pleuro-, caulo- and pileocystidia, and in section Galerina by Bon (1992). The species also has been placed in the genus Gymnopilus (as G. laricicola J. Favre). Galerina pseudocamerina and G. triscopa are most often placed in section Tibiicystidiae on account of their cystidia. Our LSU tree indicates that these four species together with the two groups "galerina" and "naucoriopsis" may constitute a single monophyletic genus (Galerina Earle emnd.). However this unit will have to encompass a fairly broad variation in cystidial shape and topology. More data are necessary to draw conclusion on this topic.
Galerina pseudobadipes and G. stylifera are morphologically similar species that occur at a distance from the other Galerina species in both trees. Their spores differ clearly from the typical Galerina spore by being smooth, blunt-ellipsoid and only faintly dextrinoid. These species have tibiiform cystidia and form fruit bodies on woody substrate. They traditionally have been referred to section Tibiicystidiae or to a new section Styliferae of subgenus Naucoriopsis Kühner (1972). In the LSU phylogeny G. pseudobadipes occurs in the vicinity of the "tubariopsis" lineage where the other Galerina species with tibiiform cystidia are found, but separated from the others by a group of Panaeolus/Copelandia species. More species and genetic markers need to be included before a phylo-genetically statistical supported position of G. stylifera and G. pseudobadipes can be reached.
Concluding remarks and further perspectives.— –
This study represents a first attempt to investigate the phylogeny of Galerina and its allied genera. Our investigation demonstrates clearly that Galerina is a poly-phylethic genus, that Gymnopilus is monophyletic, and that a part of Galerina (the "mycenopsis" lineage) is closely related to Gymnopilus. It also affirms isolated positions for Phaeogalera and Kuehneromyces in relation to Galerina. On the family level it demonstrates that the family Strophariaceae in the sense of Kühner agrees fairly well with the molecular phylogenies and that all the different lineages of Galerina species fall within the frame of Strophariaceae sensu Kühner. A high correspondence between the resolved lineages and previously defined subgenera/sections indicates that traditional morpho-taxonomy in Galerina operates fairly well at lower taxonomic levels. However our analyses affirm previous findings by e.g. Larsson et al (2004) that many morphological characters (e.g. fruit body morphology, cystidial shape) are highly homoplastic. On the specific level our analyses yield little additional information for solving taxonomically intricate complexes.
Judging from the present selection of Galerina taxa, where southern hemisphere species are not included, this study demonstrates that the old genus Galerina collapses and must be segregated in at least three different monophyletic genera. It further indicates that some morphologically based infrageneric units should be abandoned (e.g. the sections Calyptrospora A.H. Sm. & Singer, Inoderma A.H. Sm. & Singer and Physocystis A.H. Sm. & Singer). At the present stage, due to limited amount of data we are not ready to proclaim formal taxonomic consequences or nomenclatural changes. Several studies have shown that multiple unlinked loci should be analyzed before formal taxonomic conclusions are drawn (e.g. Rokas et al 2003). This also is indicated in our results by some incongruent topological patterns in the ITS and LSU trees (e.g. the placements of G. badipes and G. pumila). Our preliminary results will be pursued by more collaborated analyses of multiple loci and a broader taxonomic sample.
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ACKNOWLEDGMENTS |
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FOOTNOTES |
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1 Corresponding author. E-mail: gro.gulden{at}nhm.uio.no
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LITERATURE CITED |
|---|
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TOPABSTRACTINTRODUCTIONMATERIAL AND METHODSRESULTSDISCUSSIONLITERATURE CITED |
|---|
Besl H, Mack P, Schmied-Heckel I. 1984. Giftpilze in den Gattungen Galerina und Lepiota. Zeitschrift für Mykologie 50:183–189.
Enjalbert F, Cassanas G, Rapior S, Renault C, Chaumont J-P. 2004. Amatoxins in wood-rotting Galerina marginata. Mycologia 96:720–729.
Fries EM. 1836–1838. Epicrisis Systematis Mycologici seu Synopsis Hymenomycetum. Upsaliae, 610 p.
Gulden G. The agaric genera Galerina Earle and Phaeogalera Kühner in Greenland. Biosystematics. (In press).
———, Hallgrímsson H. 2000. The genera Galerina and Phaeogalera (Basidiomycetes, Agaricales). Acta Botanica Islandica 13:3–54.
———, Vesterholt J. 1999. The genera Galerina and Phaeogalera (Basidiomycetes, Agaricales) on the Faroe Islands. Nordic J Bot. 19:685–706.[CrossRef]
———, Dunham S, Stockman J. 2001. DNA studies in the Galerina marginata complex. Mycol Res 105:432–440.[CrossRef]
Guzmán-Dávalos L, Mueller GM, Cifuentes J, Miller AN, Santerre A. 2003. Traditional infrageneric classification of Gymnopilus is not supported by ribosomal DNA sequence data. Mycologia 95:1204–1214.
Hall TA. 1999. BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucl Acids Symp Ser 41:95–98.
Hansen L, Knudsen H. 1992. Nordic Macromycetes. Vol. 2. Copenhagen: Nordsvamp. 474 p.
Horak E. 1994. Addenda ad Galerinam. 1. Galerina robertii sp. n., eine neue Art aus den französischen Alpen. Zeitschr Mykologie 60:85–90.
———, Miller OK jr. 1992. Phaeogalera and Galerina in arctic-subarctic Alaska (USA) and the Yukon Territory (Canada). Can J Bot 70:414–433.
Kühner R. 1935. Le genre Galerina (Fries) Quélet. Encyclo-pédie Mycologique VII. Paris: Paul Lechavalier. 1–240.
———. 1972. Agaricales de la zone alpine. Genres Galera Earle et Phaeogalera gen. nov. Bull Trimest Soc Mycol Fr 88:41–153.
———. 1980. Les Hyménomycètes agaricoïdes (Agaricales, Tricholomatales, Pluteales, Russulales). Etude générale et classification. Bull Soc Linn Lyon 49 Numéro special 1027 p.
Larsson KH, Larsson E, Kõljalg U. 2004. High phylogenetic diversity among corticioid homobasidiomycetes. Mycol Res 108:983–1002.[CrossRef][Medline]
Moncalvo J-M, Vilgalys R, Redhead SA, Johnson JE, James TY, Aime MC, Hofstetter V, Verduin SJW, Larsson E, Baroni TJ, Thorn RG, Jacobsson S, Clémençon H, Miller Jr OK. 2002. One hundred and seventeen clades of euagarics. Mol Phyl Evol 23:357–400.[CrossRef][Medline]
Murray MG, Thompson WF. 1980. Rapid isolation of high molecular weight plant DNA. Nucl Acid Res 8:4321–4325.
Orton PD. 1960. New check list of British agarics and boleti. Part III. Notes on genera and species in the list. Trans Brit Mycol Soc 42:159–439.
Redhead SA. 1981. Parasitism of bryophytes by agarics. Can J Bot 59:63–67.
Rees BJ, Orlovich DA, Marks PBD. 1999. Treading the fine line between small-statured Gymnopilus and excentrically stipitate Galerina species in Australia. Mycol Res 103:427–442.[CrossRef]
———, Zuccarello GC, Orlovich DA. 2002. Relationships between Australian and northern hemisphere Gymnopilus species II. A preliminary phylogeny of species of Gymnopilus and related genera based on internal transcribed spacer (ITS) region of ribosomal DNA. Mycotaxon 84:93–110.
Rokas A, Williams BL, King N, Carroll SB. 2003. Genome-scale approaches to resolving incongruence in molecular phylogenies. Nature 425:798–804.[CrossRef][Medline]
Ronquist F, Huelsenbeck JP. 2003. MrBayes 3: Bayesian phylogenetic inference under mixed models. Bioinformatics 19:1572–1574.
Singer R. 1986. The Agaricales in modern taxonomy. Koenigstein: Koeltz Scientific Books. 981 p. plus illustrations.
Smith AH, Singer R. 1964. A monograph on the genus Galerina Earle. New York: Hafner Publishing Co. 384 p.
Swofford DL. 2000. PAUP*. Phylogenetic Analyses Using Parsimony (*and other methods). Version 4. Sunderland: Sinauer Associates.
Tyler VE, Smith AH. 1963. Chromatographic detection of Amanita toxins in Galerina venenata. Mycologia 55: 358–359.[CrossRef]
———, Brady LR, Benedict RG, Khanna JM, Malone MH. 1963. Chromatographic and pharmacologic evaluation of some toxic Galerina species. Lloydia 26:154–157.
Watling R, Gregory NM. 1993. Cortinariaceae p.p. In: Henderson DM, Orton PD, Watling R, eds. British fungus flora Agarics and Boleti 7. Edinburgh: Royal Botanical Garden. 131 p.
White TJ, Bruns T, Lee S, Taylor J. 1990. Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: Innis MA, Gelfand DH, Sninsky JJ, White TJ. eds. PCR protocols, a guide to methods and applications. San Diego: Academic Press. p 315–322.
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