Olivier Raspé

The Faces of Fungi database: fungal names linked with morphology, phylogeny and human impacts

Taxonomic names are key links between various databases that store information on different organisms. Several global fungal nomenclural and taxonomic databases (notably Index Fungorum, Species Fungorum and MycoBank) can be sourced to find taxonomic details about fungi, while DNA sequence data can be sourced from NCBI, EBI and UNITE databases. Although the sequence data may be linked to a name, the quality of the metadata is variable and generally there is no corresponding link to images, descriptions or herbarium material. There is generally no way to establish the accuracy of the names in these genomic databases, other than whether the submission is from a reputable source. To tackle this problem, a new database (FacesofFungi), accessible at www.facesoffungi.org (FoF) has been established. This fungal database allows deposition of taxonomic data, phenotypic details and other useful data, which will enhance our current taxonomic understanding and ultimately enable mycologists to gain better and updated insights into the current fungal classification system. In addition, the database will also allow access to comprehensive metadata including descriptions of voucher and type specimens. This database is user-friendly, providing links and easy access between taxonomic ranks, with the classification system based primarily on molecular data (from the literature and via updated web-based phylogenetic trees), and to a lesser extent on morphological data when molecular data are unavailable. In FoF species are not only linked to the closest phylogenetic representatives, but also relevant data is provided, wherever available, on various applied aspects, such as ecological, industrial, quarantine and chemical uses. The data include the three main fungal groups (Ascomycota, Basidiomycota, Basal fungi) and fungus-like organisms. The FoF webpage is an output funded by the Mushroom Research Foundation which is an NGO with seven directors with mycological expertise. The webpage has 76 curators, and with the help of these specialists, FoF will provide an updated natural classification of the fungi, with illustrated accounts of species linked to molecular data. The present paper introduces the FoF database to the scientific community and briefly reviews some of the problems associated with classification and identification of the main fungal groups. The structure and use of the database is then explained. We would like to invite all mycologists to contribute to these web pages.

Major clades in tropical Agaricus

Agaricus (Basidiomycota) is a genus of saprobic fungi that includes edible cultivated species such as Agaricus bisporus, the button mushroom. There has been considerable ecological, nutritional and medicinal interest in the genus, yet the extent of its diversity remains poorly known, particularly in subtropical and tropical areas. Classification of tropical species has for a large part followed the classification of temperate species. The objective of our study was to examine to what extent this system of classification is appropriate for tropical Agaricus species. Species from temperate sections were therefore compared to the major clades of tropical species using a phylogenetic approach. ITS1 + 2 sequence data from 128 species were used in the phylogenetic analysis. Specimens included four species of genera closely related to Agaricus, 38 temperate species representing the eight classical sections of the genus, and 86 putative species of Agaricus from tropical areas of Africa, Asia and the Americas. Bayesian and maximum likelihood analyses produced relatively congruent trees and almost identical clades. Our data show that (i) only about one-third of tropical species belong to the classical sections based on temperate species; the systematics of the genus therefore needs to be expanded; (ii) among the remaining two-thirds of tropical species, those from the Americas and those from Africa and/or Asia group in distinct clades, suggesting that secondary diversification occurred in these two areas; (iii) in contrast, several clades of classical sections contain American and African + Asian species along with temperate species. In this study, we used approximately 50 distinct species from a small area of northern Thailand, most probably being novel species. This diversity indicates that Agaricus is a species-rich genus in the tropics as well as in temperate regions. The number of species and the hypothetical paleotropical origin of the genus are discussed.

New and Interesting Cantharellus from Tropical Africa

Abstract This paper deals with some of the larger, more or less yellowish or orange Cantharellus species from the tropical African woodlands and rain forests. Four new species with clamp connections are described: Cantharellus guineensis, C. mikemboensis, C. pseudomiomboensis and C. stramineus. The new taxa show moderate to strong resemblance to either Cantharellus rufopunctatus or C. miomboensis. A two-locus phylogeny, based on part of the protein coding genes rpb2 and tef-1, resolved them as a highly supported clade within Cantharellus subgenus Rubrinus, a subgenus still exclusively composed of tropical African species. This monophyletic clade is here described as a new section within subg. Rubrinus. As the subgenus was previously defined as being composed of chanterelles lacking clamp connections, the definition of the subgenus is here amended. Illustrations and new records are also presented for Cantharellus afrocibarius, C. defibulatus, C. miomboensis, C. rufopunctatus and C. sublaevis. This paper provides first sequences for C. defibulatus, C. rufopunctatus and C. sublaevis, all of which are here epitypified, as well as new sequences for more than a dozen other Cantharellus. Cantharellus cibarius var. latifolius is considered a synonym of C. afrocibarius. An identification key to all mainland African Cantharellus is proposed.

Lentinus giganteus revisited: new collections from Sri Lanka and Thailand

A new collection of Lentinus giganteus from Sri Lanka, where it was originally described, is used to epitypify the species after comparison with the type protologue and drawings held in Peradeniya, Sri Lanka; a full description and illustrations are provided. Additional collections were made at three sites in northern Thailand. Phylogenetic ITS-1-5.8S-ITS2 rDNA sequence analyses using maximum likelihood, maximum parsimony and Bayesian inference all support the transfer of L. giganteus to Pleurotus. Although the collections from Thailand differ slightly morphologically and phylogenetically from P. giganteus sensu stricto, these differences do not yet merit specific status. Instead, P. giganteus is maintained as one widely variable species represented by relatively large fruiting bodies. Saprobic on buried well-rotted wood in forests, P. giganteus is widely consumed in Sri Lanka and might be profitably cultivated in Thailand.

Phylogenetic affinities of the sequestrate genus Rhodactina (Boletaceae), with a new species, R. rostratispora from Thailand

Abstract Rhodactina is a small sequestrate genus in Boletaceae with two described species, R. himalayensis and R. incarnata. Phylogenetic analyses of a three-gene dataset including atp6, tef1 and rpb2 of Rhodactina species along with selected Boletaceae species showed that all Rhodactina species formed a monophyletic clade, sister to the genera Spongiforma and Borofutus in subfamily Leccinoideae with high support. All of the taxa in the clade have a similar chemical reaction in which basidiospores turn purplish, purplish red to violet or violet grey when in contact with potassium hydroxide. The molecular analyses also showed that all Rhodactina specimens collected from Ubon Ratchathani province, northeastern Thailand, belong to a new species. Morphologically, the new species is different from others by having a markedly prominent hilar appendage and a terminal hilum on its basidiospores. Thus, the new species, Rhodactina rostratispora, is introduced with detailed macroscopic and microscopic descriptions and illustrations.

Study of three interesting Amanita species from Thailand: Morphology, multiple-gene phylogeny and toxin analysis.

Amanita ballerina and A. brunneitoxicaria spp. nov. are introduced from Thailand. Amanita fuligineoides is also reported for the first time from Thailand, increasing the known distribution of this taxon. Together, those findings support our view that many taxa are yet to be discovered in the region. While both morphological characters and a multiple-gene phylogeny clearly place A. brunneitoxicaria and A. fuligineoides in sect. Phalloideae (Fr.) Quél., the placement of A. ballerina is problematic. On the one hand, the morphology of A. ballerina shows clear affinities with stirps Limbatula of sect. Lepidella. On the other hand, in a multiple-gene phylogeny including taxa of all sections in subg. Lepidella, A. ballerina and two other species, including A. zangii, form a well-supported clade sister to the Phalloideae sensu Bas 1969, which include the lethal “death caps” and “destroying angels”. Together, the A. ballerina-A. zangii clade and the Phalloideae sensu Bas 1969 also form a well-supported clade. We therefore screened for two of the most notorious toxins by HPLC-MS analysis of methanolic extracts from the basidiomata. Interestingly, neither α-amanitin nor phalloidin was found in A. ballerina, whereas Amanita fuligineoides was confirmed to contain both α-amanitin and phalloidin, and A. brunneitoxicaria contained only α-amanitin. Together with unique morphological characteristics, the position in the phylogeny indicates that A. ballerina is either an important link in the evolution of the deadly Amanita sect. Phalloideae species, or a member of a new section also including A. zangii.

Can we use environmental DNA as holotypes

The advantages and disadvantages of giving a valid name to a sequence of DNA detected from environmental specimens is presently a hot debate amongst the mycological community. The idea of using intracellular DNA (“mgDNA”) from environmental samples as holotypes seems at face value, to be a good idea, considering the expansion of knowledge among these ‘dark taxa’ or ‘dark matter fungi’ that it could provide (i.e. sequence based taxa without physical specimens and formal nomenclature). However, the limitations of using mgDNA as holotypes needs careful thought, i.e. can we use a short mgDNA fragment, which may contain a small amount of genetic information, to allow discrimination between species? What is the point and are the potential problems of giving valid scientific names to mgDNA? Numerous mycologists and taxonomists, who have many years of experience working on the taxonomy and phylogeny of different groups of fungi, are concerned about the consequences of providing valid names to mgDNA. There has been much debate, through several publications on the considerable problems of using mgDNA as holotypes. The proponents have tried to debate the virtues of using mgDNA as holotypes. Those against have shown that identification to species using mgDNA does not work in many fungal groups, while those for have shown cases where species can be identified with mgDNA. Different disciplines have different reasons and opinions for using mgDNA as holotypes, however even groups of the same disciplines have dissimilar ideas. In this paper we explore the use of mgDNA as holotypes. We provide evidences and opinions as to the use of mgDNA as holotypes from our own experiences. In no way do we attempt to degrade the study of DNA from environmental samples and the expansion of knowledge in to the dark taxa, but relate the issues to fungal taxonomy. In fact we show the value of using sequence data from these approaches, in dealing with the discovery of already named taxa, taxa numbers and ecological roles. We discuss the advantages and the pitfalls of using mgDNA from environmental samples as holotypes. The impacts of expanding the nomenclatural concept to allow using mgDNA from environmental samples as holotypes are also discussed. We provide evidence from case studies on Botryosphaeria, Colletotrichum, Penicillium and Xylaria. The case studies show that we cannot use mgDNA due to their short fragments and the fact that most ITS sequence data presently result from environmental sequencing. We conclude from the evidence that it is highly undesirable to use mgDNA as holotypes in naming fungal species. If this approach adopted, it would result in numerous problems where species identification cannot be confirmed due to limited sequence data available for the holotypes. We also propose an alternative DNA-based system for naming DNA based species which would provide considerably less problems and should be adopted.

A global view of Gyroporus: molecular phylogenetics, diversity patterns, and new species

ABSTRACT Gyroporus (Gyroporaceae, Boletales) is a highly diverse genus of poroid ectomycorrhizal mushrooms with a nearly worldwide distribution. Previous attempts to unravel the diversity within this genus proved difficult due to the presence of semicryptic species and ambiguous results from analysis of ribosomal RNA markers. In this study, we employ a combined morphotaxonomic and phylogenetic approach to delimit species and elucidate geographic and evolutionary patterns in Gyroporus. For phylogenetic analyses, the protein-coding genes atp6 (mitochondrial adenosine triphosphate [ATP] synthase subunit 6) and rpb2 (nuclear second largest subunit of RNA polymerase II) were selected based on their utility in studies of Boletales. We infer several distinct clades, most notably one corresponding to G. castaneus as a speciose Northern Hemisphere group, another unifying G. cyanescens and like entities, and a third group unifying G. longicystidiatus and a New World sister species. Also notable is the recovery of a sister relationship between the cyanescens and longicystidiatus clades. We formally describe five new species of Gyroporus, outline a number of provisional species, and briefly discuss distributional patterns. This study provides an important scaffold for future work on this well-known but poorly understood genus of fungi.

Morphological and phylogenetic characterisation of novel Cytospora species associated with mangroves

Abstract Mangroves are relatively unexplored habitats and have been shown to harbour a number of novel species of fungi. In this study, samples of microfungi were collected from symptomatic branches, stem and leaves of the mangrove species Xylocarpusgranatum, X.moluccensis and Lumnitzeraracemosa and examined morphologically. The phylogeny recovered supports our morphological data to introduce three new species, Cytosporalumnitzericola, C.thailandica and C.xylocarpi. In addition, a combined multi-gene DNA sequence dataset (ITS, LSU, ACT and RPB2) was analysed to investigate phylogenetic relationships of isolates and help in a more reliable species identification.

Morphological and molecular evidence support a new truffle, Tuber lannaense, from Thailand

A new truffle species, Tuber lannaense, is described based on collections from northern Thailand. This species is characterized by yellow-brown to brown ascomata with dark brown gleba and ellipsoid to narrow ellipsoid spores with spiny reticulum. It grows in mycorrhizal association with Betula alnoides and Carpinus poilanei. Tuber lannaense is similar to T. huidongense, but differs in the thinner outer peridium layer. Molecular phylogenetic analysis of the internal transcribed spacers (ITS1 + ITS2) and large subunit of nuclear ribosomal DNA, as well as genetic distance analysis of ITS1 + ITS2, support T. lannaense as being distinct from other Tuber species. Moreover, based on genetic distance analysis, we consider that T. furfuraceum and T. huidongense, which have previously been synonymized, are different species.