Evolutionary innovations through gain and loss of genes in the ectomycorrhizal Boletales.

We aimed to identify genomic traits of transitions to ectomycorrhizal ecology within the Boletales by comparing the genomes of 21 symbiotrophic species with their saprotrophic brown-rot relatives. Gene duplication rate is constant along the backbone of Boletales phylogeny with large loss events in several lineages, while gene family expansion sharply increased in the late Miocene, mostly in the Boletaceae. Ectomycorrhizal Boletales have a reduced set of plant cell-wall-degrading enzymes (PCWDEs) compared with their brown-rot relatives. However, the various lineages retain distinct sets of PCWDEs, suggesting that, over their evolutionary history, symbiotic Boletales have become functionally diverse. A smaller PCWDE repertoire was found in Sclerodermatineae. The gene repertoire of several lignocellulose oxidoreductases (e.g. laccases) is similar in brown-rot and ectomycorrhizal species, suggesting that symbiotic Boletales are capable of mild lignocellulose decomposition. Transposable element (TE) proliferation contributed to the higher evolutionary rate of genes encoding effector-like small secreted proteins, proteases, and lipases. On the other hand, we showed that the loss of secreted CAZymes was not related to TE activity but to DNA decay. This study provides novel insights on our understanding of the mechanisms influencing the evolutionary diversification of symbiotic boletes.

Comparative genomics of Coniophora olivacea reveals different patterns of genome expansion in Boletales.

BACKGROUND: Coniophora olivacea is a basidiomycete fungus belonging to the order Boletales that produces brown-rot decay on dead wood of conifers. The Boletales order comprises a diverse group of species including saprotrophs and ectomycorrhizal fungi that show important differences in genome size. RESULTS: In this study we report the 39.07-megabase (Mb) draft genome assembly and annotation of C. olivacea. A total of 14,928 genes were annotated, including 470 putatively secreted proteins enriched in functions involved in lignocellulose degradation. Using similarity clustering and protein structure prediction we identified a new family of 10 putative lytic polysaccharide monooxygenase genes. This family is conserved in basidiomycota and lacks of previous functional annotation. Further analyses showed that C. olivacea has a low repetitive genome, with 2.91% of repeats and a restrained content of transposable elements (TEs). The annotation of TEs in four related Boletales yielded important differences in repeat content, ranging from 3.94 to 41.17% of the genome size. The distribution of insertion ages of LTR-retrotransposons showed that differential expansions of these repetitive elements have shaped the genome architecture of Boletales over the last 60 million years. CONCLUSIONS: Coniophora olivacea has a small, compact genome that shows macrosynteny with Coniophora puteana. The functional annotation revealed the enzymatic signature of a canonical brown-rot. The annotation and comparative genomics of transposable elements uncovered their particular contraction in the Coniophora genera, highlighting their role in the differential genome expansions found in Boletales species.

Phylogenetic assessment of global Suillus ITS sequences supports morphologically defined species and reveals synonymous and undescribed taxa.

The genus Suillus represents one of the most recognizable groups of mushrooms in conifer forests throughout the Northern Hemisphere. Although for decades the genus has been relatively well defined morphologically, previous molecular phylogenetic assessments have provided important yet preliminary insights into its evolutionary history. We present the first large-scale phylogenetic study of the boundaries of each species in the genus Suillus based on the most current internal transcribed spacer (ITS) barcode sequences available inPUBLIC databases, as well as sequencing of 224 vouchered specimens and cultures, 15 of which were type specimens from North America. We found that species boundaries delimited by morphological data are broadly congruent with those based on ITS sequences. However, some species appear to have been described several times under different names, several species groups cannot be resolved by ITS sequences alone, and undescribed taxa are apparent, especially in Asia. Therefore, we elevated S. tomentosus var. discolor to S. discolor; proposed synonymies of S. neoalbidipes with S. glandulosipes, S. borealis with S. brunnescens, Boletus serotinus and B. solidipes with Suillus elbensis, S. lactifluus with S. granulatus, S. himalayensis with S. americanus; and proposed usage of the names S. clintonianus in the place of the North American S. grevillei, S. weaverae for North American S. granulatus, S. ampliporus in the place of the North American S. cavipes, and S. elbensis in place of the North American S. viscidus. We showed that the majority of Suillus species have strong affinities for particular host genera. Although deep node support was low, geographic differentiation was apparent, with species from North America, Eurasia, and Asia often forming their own clades. Collectively, this comprehensive genus-level phylogenetic integration of currently available Suillus ITS molecular data and metadata will aid future taxonomic and ecological work on an important group of ectomycorrhizal fungi.

Molecular and morphological analyses confirm Rhizopogon verii as a widely distributed ectomycorrhizal false truffle in Europe, and its presence in South America.

The genus Rhizopogon includes species with hypogeous or subepigeus habit, forming ectomycorrhizae with naturally occurring or planted pines (Pinaceae). Species of the genus Rhizopogon can be distinguished easily from the other hypogeous basidiomycetes by their lacunose gleba without columella and their smooth elliptical spores; however, the limit between species is not always easy to establish. Rhizopogon luteolus, the type species of the genus, has been considered one of the species that are more abundant in Europe, as well as it has been cited in pine plantation of North and South America, different parts of Africa, Australia, and New Zealand. However, in this study, based on molecular analyses of the ITS nuclear ribosomal DNA (nrDNA) sequences (19 new sequences; 37 sequences from GenBank/UNITE, including those from type specimens), we prove that many GenBank sequences under R. luteolus were misidentified and correspond to Rhizopogon verii, a species described from Tunisia. Also, we confirm that basidiomes and ectomycorrhizae recently collected in Germany under Pinus sylvestris, as well as specimens from South of Brazil under Pinus taeda belong to R. verii. Thanks to the numerous ectomycorrhizal tips collected in Germany, a complete description of R. verii/P. sylvestris ectomycorrhiza is provided. Moreover, since in this paper the presence of R. verii in South America is here reported for the first time, a short description of basidiomes collected in Brazil, compared with collections located in different European herbaria, is included.

Cupreoboletus (Boletaceae, Boletineae), a new monotypic genus segregated from Boletus sect. Luridi to reassign the Mediterranean species B. poikilochromus.

Cupreoboletus is erected as a new monospecific genus of Boletaceae to accommodate the thermophilic southern European species Boletus poikilochromus, characterized by discoloration toward copper-red tints overall, hymenophore forming tiny crystals on drying, a pervasive and long lasting sweet odor and presence of pseudocystidia. Macro- and microscopic descriptions of the species based on re-examination of the type material and recent Italian collections including additional topotypical samples are provided and accompanied by photos and line drawings of the main anatomical structures. In addition, an epitype specimen is selected. Phylogenetic relationships were inferred from multigene molecular analysis based on partial sequences of the nuc rDNA 28S D1/D2 (28S) and internal transcribed spacer (ITS) regions and genes for ribosomal RNA polymerase II subunits 1 (rpb1) and 2 (rpb2) and translation-elongation factor 1-α (tef1α). Ecological context, geographical range and delimitation from closely allied taxa also were elucidated. B. martaluciae is treated as a synonym of C. poikilochromus according to the morphological and molecular comparative study.

Exploring the phylogenetic affiliations and the trophic mode of Sedecula pulvinata (Sedeculaceae).

Sedecula is a monotypic genus of hypogeous fungi that is rare and endemic to dry conifer forests of the western United States. The only known species, Sedecula pulvinata, was described in 1941 and its taxonomic placement and trophic status have remained uncertain ever since. Here we employ isotopic and molecular phylogenetic analyses to determine its nutritional mode and placement on the fungal tree of life. Phylogenetic analysis indicates that S. pulvinata is closely related to the genus Coniophora, in Coniophoraceae (Boletales). Stable isotope comparisons with known ectomycorrhizal and saprotrophic fungi together with phylogenetic evidence also suggest that S. pulvinata is saprotrophic. We conclude that Sedecula likely represents a unique morphological transition between a resupinate basidiocarp morphology (in Coniophora and relatives) and a hypogeous, sequestrate basidiocarp morphology (in Sedecula). Spore dimensions are amended from the original description.

Alessioporus and Pulchroboletus (Boletaceae, Boletineae), two novel genera for Xerocomus ichnusanus and X. roseoalbidus from the European Mediterranean basin: molecular and morphological evidence.

Alessioporus and Pulchroboletus are proposed as new monotypic genera to accommodate the thermo-xerophilic European species Xerocomus ichnusanus and X. roseoalbidus respectively. The present research focused on both morphological features and multigene molecular phylogeny (nrITS, nrLSU, tef-1α datasets) to elucidate the taxonomic status of these two rare Mediterranean boletes and delineate a natural classification within the family Boletaceae. Macro- and microscopic descriptions of the two species based on inclusive taxon sampling are provided and supported by line drawings of the main anatomical features. Phylogenetic relationships, ecology, geographical distribution and delimitation from the most closely allied taxa also are highlighted. In addition, epitype specimens are selected for both species.

A revised phylogeny of Boletaceae using whole genome sequences.

The porcini mushroom family Boletaceae is a diverse, widespread group of ectomycorrhizal (ECM) mushroom-forming fungi that so far has eluded intrafamilial phylogenetic resolution based on morphology and multilocus data sets. In this study, we present a genome-wide molecular data set of 1764 single-copy gene families from a global sampling of 418 Boletaceae specimens. The resulting phylogenetic analysis has strong statistical support for most branches of the tree, including the first statistically robust backbone. The enigmatic Phylloboletellus chloephorus from non-ECM Argentinian subtropical forests was recovered as a new subfamily sister to the core Boletaceae. Time-calibrated branch lengths estimate that the family first arose in the early to mid-Cretaceous and underwent a rapid radiation in the Eocene, possibly when the ECM nutritional mode arose with the emergence and diversification of ECM angiosperms. Biogeographic reconstructions reveal a complex history of vicariance and episodic long-distance dispersal correlated with historical geologic events, including Gondwanan origins and inferred vicariance associated with its disarticulation. Together, this study represents the most comprehensively sampled, data-rich molecular phylogeny of the Boletaceae to date, establishing a foundation for future robust inferences of biogeography in the group.

Three new Melanogaster species (Boletales, Paxillaceae) from southwestern China based on morphological and molecular evidence.

Three newly discovered Melanogaster species, namely M.cyaneus, M.diqingensis, and M.truncatisporus, are introduced and illustrated based on both morphological and molecular data from Sichuan and Yunnan provinces in China. A multigene phylogenetic analysis (nrITS, nrLSU, and rpb2) was performed mainly to verify the placement of the new species in Melanogaster. A second, nrITS-only phylogenetic analysis comprising more Melanogaster species for which only ITS sequences were available, was used to infer the relationship between the new species and as many known Melanogaster species as possible. Specimens of M.cyaneus, M.diqingensis, and M.truncatisporus formed three independent clades in a phylogenetic tree inferred from the ITS data set. The robust support from ITS for these clades and genetic similarity with other species being lower than 93.2% suggest that these three species are indeed distinct from the other Melanogaster species in the phylogeny. Morphologically, M.cyaneus is characterized by its blue or bluish gleba, light brown to yellowish brown peridium, and subglobose to globose basidiospores, 6.2-15 × 4.6-9.0 µm. Melanogasterdiqingensis is distinguished from other Melanogaster species by its pale yellow to brown-yellow peridium and obovate to subglobose basidiospores, 3.0-5.1 × 2.0-4.0 µm. Melanogastertruncatisporus is diagnosed by its subglobose to globose or irregularly elongate-pyriform basidiomata, pale yellow to deeply orange-yellow peridium, and subglobose to globose or pyriform, truncate basidiospores. Additionally, infrageneric classification based on the number of peridium layers, the average thickness of the peridium, and the average length and width of basidiospores was tested with M.cyaneus, M.diqingensis, and M.truncatisporus. Orthogonal partial least squares discriminant (OPLS-DA) analysis placed the three new species within the Melanogaster, Rivulares, and Variegati sections, respectively. However, the morphologically circumscribed sections were not monophyletic in the phylogenetic tree. Therefore, the current infrageneric classification should be abandoned.

Rostrupomyces, a new genus to accommodate Xerocomussisongkhramensis, and a new Hemileccinum species (Xerocomoideae, Boletaceae) from Thailand.

A new genus, Rostrupomyces is established to accommodate Xerocomussisongkhramensis based on multiple protein-coding genes (atp6, cox3, tef1, and rpb2) analyses of a wide taxon sampling of Boletaceae. In our phylogeny, the new genus was sister to Rubinosporus in subfamily Xerocomoideae, phylogenetically distant from Xerocomus, which was highly supported as sister to Phylloporus in the same subfamily Xerocomoideae. Rostrupomyces is different from other genera in Boletaceae by the following combination of characters: rugulose to subrugulose pileus surface, white pores when young becoming pale yellow in age, subscabrous stipe surface scattered with granulose squamules, white basal mycelium, unchanging color in any parts, yellowish brown spore print, and broadly ellipsoid to ellipsoid, smooth basidiospores. In addition, Hemileccinuminferius, also from subfamily Xerocomoideae, is newly described. Detailed descriptions and illustrations of the new genus and new species are presented.

Australasian sequestrate fungi 18: Solioccasus polychromus gen. & sp. nov., a richly colored, tropical to subtropical, hypogeous fungus.

Solioccasus polychromus gen. & sp. nov., the most brightly colored hypogeous fungus known, is described from Papua New Guinea and tropical northern Australia south into subtropical forests along the Queensland coast and coastal mountains to near Brisbane. Phylogenetic analysis of molecular data places it as a sister genus to Bothia in the Boletineae, a clade of predominantly ectomycorrhizal boletes. Ectomycorrhizal trees, such as members of the Myrtaceae (Eucalyptus, Corymbia, Lophostemon, Melaleuca spp.) and Allocasuarina littoralis, were present usually in mixture or in some cases dominant, so we infer some or all of them to be among the ectomycorrhizal hosts of S. polychromus.

Four Novel Species and Two New Records of Boletes from India.

Repeated macrofungal explorations, followed by thorough examination of species through morphology and molecular phylogeny, have made it clear that European and American names of wild mushrooms were inadvertently misapplied quite often to Asian lookalikes by mycologists/taxonomists in the past. Therefore, in order to reveal this mushroom treasure, in recent years, taxonomical research on wild mushrooms has been intensified in Asian countries, including India, by undertaking a combined approach of morpho-taxonomy and multigene molecular phylogeny. Boletoid mushrooms (Boletaceae) are no exception. While working on boletoid mushrooms of the Indian Himalayas, authors recently came across six interesting species of boletoid mushrooms. In the present communication, four novel species, namely Leccinellum binderi, Cyanoboletus paurianus, Xerocomus uttarakhandae, and Xerocomellus himalayanus, are established based on morphology and molecular phylogenetic estimations. Moreover, Cyanoboletus macroporus and Xerocomus fraternus are also reported here for the first time in India.

Phylogenetic and Morphological Evidence Reveal Five New Species of Boletes from Southern China.

Fungi of the order Boletales are extremely important in both ecology and economy, since most of them are ectomycorrhizal fungi, which play vital roles in maintaining forest ecosystems, water and soil protection, vegetation restoration and so on. Although previous studies have shown that this order has a very high species diversity in China, there are few reports on the species diversity of boletes in Jiangxi Province, China. Based on morphological (macroscopic and microscopic morphological characteristics) and phylogenetic analyses (ITS, LSU, and TEF1-α sequences), in this study, the wild boletes in Jiangxi Province were investigated, and five new species are described: Austroboletus albus, Xanthoconium violaceipes, Xanthoconium violaceofuscum, Xerocomus rutilans and Xerocomus subsplendidus. Descriptions and hand drawings of the new species are presented.

Villoboletus persicinus, gen. et sp. nov. (Boletaceae), a bolete with flocculent-covered stipe from northern China.

Some collections from northern China are proposed as the new genus and species Villoboletus persicinus based on morphological assessments and molecular phylogenetic evidence. It is circumscribed by the pink pileus, white context turning pale blue to bule when exposed, yellow hymenophore surface turning blue when bruised, stipe covered with plenty of flocculent hairs, ellipsoid-fusiform to subfusiform smooth basidiospores, and the presence of hymenial cystidia. Phylogenetic analyses inferred from four gene fragments (28S, tef1, rpb1, and rpb2) revealed a distinct position of this new genus in Boletaceae, but no place to accommodate it at subfamily rank.

Exploring the Relationships between Four New Species of Boletoid Fungi from Northern China and Their Related Species.

The family Boletaceae primarily represents ectomycorrhizal fungi, which play an essential ecological role in forest ecosystems. Although the Boletaceae family has been subject to a relatively global and comprehensive history of work, novel species and genera are continually described. During this investigation in northern China, many specimens of boletoid fungi were collected. Based on the study of their morphology and phylogeny, four new species, Butyriboletus pseudoroseoflavus, Butyriboletus subregius, Tengioboletus subglutinosus, and Suillellus lacrymibasidiatus, are introduced. Morphological evidence and phylogenetic analyses of the single or combined dataset (ITS or 28S, rpb1, rpb2, and tef1) confirmed these to be four new species. The evidence and analyses indicated the new species' relationships with other species within their genera. Detailed descriptions, color photographs, and line drawings are provided. The species of Butyriboletus in China were compared in detail and the worldwide keys of Tengioboletus and Suillellus were given.

Boletaceae in China: Taxonomy and phylogeny reveal a new genus, two new species, and a new record.

Boletaceae, the largest family in Boletales, has been attracted by mycologists in the world due to its diverse morphology and complex history of evolution. Although considerable work has been done in the past decades, novel taxa are continually described. The current study aimed to introduce three new taxa and one new record of Boletaceae from China. The morphological descriptions, color photographs, phylogenetic trees to show the positions of the taxa, and comparisons with allied taxa are provided. The new genus Hemilanmaoa is unique in the Pulveroboletus group, and Hemilanmaoa retistipitatus was introduced as the type species. It can be distinguished by its bluing basidioma when injured, a decurrent hymenophore, a stipe covered with distinct reticulations, and a fertile stipitipellis. Porphyrellus pseudocyaneotinctus is characterized by its pileipellis consisting of broadly concatenated cells and thin-walled caulocystidia in Porphyrellus. In Phylloporus, Phylloporus biyangensis can be distinguished by its hymenophores that change to blue when injured and yellow basal mycelium. Lanmaoa angustispora, as a new record, is first reported in Northern China. Internal transcribed spacer (ITS), 28S rDNA (28S), translation elongation factor 1-alpha (tef1-α), RNA polymerase II subunit 1 (rpb1), and RNA polymerase II subunit 2 (rpb2) were employed to execute phylogenetic analyses.

Reappraisal of the Genus Exsudoporus (Boletaceae) Worldwide Based on Multi-Gene Phylogeny, Morphology and Biogeography, and Insights on Amoenoboletus.

The boletoid genera Butyriboletus and Exsudoporus have recently been suggested by some researchers to constitute a single genus, and Exsudoporus was merged into Butyriboletus as a later synonym. However, no convincing arguments have yet provided significant evidence for this congeneric placement. In this study, we analyze material from Exsudoporus species and closely related taxa to assess taxonomic and phylogenetic boundaries between these genera and to clarify species delimitation within Exsudoporus. Outcomes from a multilocus phylogenetic analysis (ITS, nrLSU, tef1-α and rpb2) clearly resolve Exsudoporus as a monophyletic, homogenous and independent genus that is sister to Butyriboletus. An accurate morphological description, comprehensive sampling, type studies, line drawings and a historical overview on the nomenclatural issues of the type species E. permagnificus are provided. Furthermore, this species is documented for the first time from Israel in association with Quercus calliprinos. The previously described North American species Exsudoporus frostii and E. floridanus are molecularly confirmed as representatives of Exsudoporus, and E. floridanus is epitypified. The eastern Asian species Leccinum rubrum is assigned here to Exsudoporus based on molecular evidence, and a new combination is proposed. Sequence data from the original material of the Japanese Boletus kermesinus were generated, and its conspecificity with L. rubrum is inferred as formerly presumed based on morphology. Four additional cryptic species from North and Central America previously misdetermined as either B. frostii or B. floridanus are phylogenetically placed but remain undescribed due to the paucity of available material. Boletus weberi (syn. B. pseudofrostii) and Xerocomus cf. mcrobbii cluster outside of Exsudoporus and are herein assigned to the recently described genus Amoenoboletus. Biogeographic distribution patterns are elucidated, and a dichotomous key to all known species of Exsudoporus worldwide is presented.

New genera, species, and combinations of Boletaceae from Brazil and Guyana.

Brasilioporus olivaceoflavidus, gen. et sp. nov., Brasilioporus simoniarum, sp. nov., Neotropicomus australis, gen. et sp. nov., and Nevesoporus nigrostipitatus, gen. et sp. nov. (Boletaceae, Boletales, Basidiomycota), are described from the endangered Atlantic Forest biome of eastern Brazil. New combinations into these new genera are proposed for the Guyanese taxa Xerocomus parvogracilis, Tylopilus rufonigricans, and Tylopilus exiguus. Boletaceae subfamily Chalciporoideae was recircumscribed to include the new genus Nevesoporus. Molecular phylogenetic analyses using a multilocus data set (ITS+28S+TEF1+RPB1+RPB2) from a large taxon set across the Boletaceae justify recognition of the new genera. Morphological, ecological, and DNA sequence data are provided for the new species. A key to known native and introduced bolete species from the Brazilian Atlantic Forest is provided.

Diversity and Host Relationships of the Mycoparasite Sepedonium (Hypocreales, Ascomycota) in Temperate Central Chile.

We present the first major survey of regional diversity, distribution and host-association of Sepedonium. Whereas the rather scarce worldwide records of this mycoparasitic fungus suggested no specific distribution pattern of most species before, we provide new evidence of endemic and specific host-parasite guilds of Sepedonium in Southern South America, including the description of a new species. The corresponding inventory was performed in temperate central Chile. The regional landscape, a mosaic of exotic timber plantations and remnants of native Nothofagus forests, facilitates a unique combination of endemic and adventitious Boletales hosts. During a two-year survey, 35 Sepedonium strains were isolated and cultured from infected basidiomata of allochthonous Chalciporus piperatus, Paxillus involutus, Rhizopogon spp. and Suillus spp., as well as from the native Boletus loyita, B. loyo, B. putidus and Gastroboletus valdivianus. Taxonomic diagnosis included morphology of conidia and conidiophores, sequences of ITS, RPB2 and EF1 molecular markers and characteristics of in vitro cultures. Phylogenetic reconstructions were performed using Bayesian methods. Four Sepedonium species could be identified and characterized, viz.: S. ampullosporum, S. chrysospermum, S. laevigatum and the newly described species S. loyorum. The most frequent species on introduced Boletales was S. ampullosporum, followed by S. chrysospermum and S. laevigatum. S. loyorum sp. nov. was found exclusively on native boletacean hosts, separated from its closest relative S. chalcipori by micromorphological and molecular attributes. Species descriptions and identification keys are provided. Ecological and biogeographical aspects of endemic and allochthonous symbiotic units consisting of mycoparasite, ectomycorrhizal fungal host and respective mycorrhizal tree are discussed.

The first complete mitochondrial genome of edible and medicinal fungus Chroogomphus rutilus (Gomphidiaceae, Boletales) and insights into its phylogeny.

In the present study, we assembled and annotated the complete mitochondrial genome of Chroogomphus rutilus. The complete mitochondrial genome of C. rutilus was composed of circular DNA molecules, with a size of 37,508 bp. The GC content of the C. rutilus mitogenome was 22.82%. A total of 18 protein-coding genes (PCGs), 2 ribosomal RNA (rRNA) genes, and 24 transfer RNA (tRNA) genes were detected in the C. rutilus mitogenome. Phylogenetic analysis based on combined mitochondrial gene dataset indicated that the C. rutilus exhibited a close relationship with species from the genus Rhizopogon. This study served as the first report on the complete mitochondrial genome from the family Gomphidiaceae, which will promote the understanding of phylogeny, evolution, and taxonomy of this important fungal species.