Wood-inhabiting Basidiomycetes in the Caucasus Region : Systematics and Biogeography

The Caucasus region is a hotspot of biodiversity and is one of the few areas in the Northern Hemisphere which harbor Pleistocene glacial refugia. The region encompasses Armenia, Azerbaijan, Georgia, the southernmost European Russia, NE Turkey, and northern Iran. The study on fungal composition of the Caucasus region and its connection and possible contribution to the present mycota of Europe has largely escaped empirical scrutiny. Using taxonomic surveys, phylogenetic reconstruction methods, haplotype analysis, and similarity tests, this study has aimed to, 1) summarize the knowledge on the occurrence of corticioids and polypores in the Caucasus region, 2) resolve the phylogenetic relationships of selected, resupinate wood-inhabiting basidiomycetes for which the Caucasus region is currently the mere, or one of the noteworthy areas of distribution, and, 3) assess the similarity of Caucasian corticioid fungi to those of Europe and important areas in the Northern Hemisphere, and to examine the significance of the Caucasus region as a glacial refugium for these fungi. This study provides the first catalogue of corticioids and polypores (635 species) occurring in the Caucasus region. The phylogeny and systematics of the Caucasian resupinate taxa in focus has been resolved and the usefulness of some morphological characters has been re-evaluated. In this context, four new genera and two new species were described and five new combinations were proposed, two of which were supplemented with modern descriptions. The species composition of corticioids in the Caucasus region is found to be distinctly more similar to Europe and North America than to East Asia and India. The highest molecular diversity and within population pairwise distance for Peniophorella praetermissa has been detected in the Caucasus and East Asia, with the isolates of the latter area being highly divergent from the European ones. This, and the assignment of root haplotype to the Caucasian isolates in a haplotype network for Phlebia tuberucalta and P. livida, call attention to the role of the Caucasus region in shaping the current mycota of Europe.Kaukasia, joka perinteisesti tunnetaan Euroopan ja Aasian kohtauspaikkana, käsittää Georgian, Armenian ja Azerbaidjanin sekä Euroopan puoleisen Venäjän eteläisimmät osat, koillisen Turkin ja Iranin pohjoisosat. Alueen elollinen monimuotoisuus on huomattava ja se on eräs pohjoisen pallonpuoliskon ns. refugioista, eli alueista joilla viimeisen jääkauden aikana säilyi muualta kadonnutta lajistoa. Kaukasian sienilajistoa ja sen roolia Euroopan nykyisen lajiston lähteenä ei ole tarkasti tutkittu. Tietoja alueen puilla kasvavista kantasienistä (käävistä ja orvakoista) ei ole aiemmin koottu yhteen ja tällainen perusselvitys oli tarpeen, jotta lajiston taksonomiaa ja eliömaantiedettä voitaisiin tutkia. Toisaalta sellaisten puilla kasvavien kantasienten, joilla on kasvualustan myötäinen eli resupinaattinen itiöemä, lajit tunnetaan vielä hyvin huonosti ja siksi niiden systematiikan selvittäminen oli tässä työssä etusijalla. Tässä työssä pyrittiin 1) kokoamaan yhteen tiedot Kaukasian käävistä ja orvakoista, 2) selvittämään sellaisten resupinaattisten lajien fylogenia, joiden ainoa tai pääasiallinen levinneisyysalue on Kaukasia, ja 3) tutkimaan Kaukasian merkitystä Euroopassa ja eräillä muilla pohjoisen pallonpuoliskon alueilla esiintyvien puilla kasvavien kantasienten jääkauden aikaisena vetäytymisalueena vertailemalla näiden alueiden ja Kaukasian nykyistä lajistoa. Tutkimuksessa esitetään ensimmäinen yhteenveto alueen käävistä ja orvakoista (noin 626 lajia). Useiden alueen resupinaattisten taksonien asema selvitettiin ja eräiden morfologisten ominaisuuksien käyttökelpoisuus arvioitiin uudelleen. Tieteelle uusina kuvattiin neljä uutta sukua ja kaksi uutta lajia morfologisten, sekä silloin kun tietoa oli saatavilla, myös ekologisten piirteiden ja sekvenssitason aineiston fylogeneettisten analyysien perusteella. Tämän lisäksi työ sisältää viisi nimistöllistä kombinaatiota ja kahteen niistä sisältyvät myös uudet taksonomiset kuvaukset. Kaikkien taksonomisten uutuuksien kuvaus perustuu ulkoisten tuntomerkkien kuvaukseen, sekvenssitason aineiston fylogeneettisiin analyyseihin ja runsaan, tyyppinäytteet sisältävän, materiaalin tutkimukseen. Kaukasian orvakat muistuttavat selvästi enemmän Euroopan kuin Pohjois-Amerikan tai Itä-Aasian ja Intian lajistoa. Peniophorella praetermissan populaatioiden suurin monimuotoisuus löytyy Kaukasiasta ja Itä-Aasiasta mutta nämä kaksi aluetta poikkeavat selvästi toisistaan. Itä-Aasiasta kerätyt kannat, poiketen Kaukasiasta kerätyistä kannoista, erosivat selvästi eurooppalaisista. Kaikki tämä korostaa Kaukasian roolia Euroopan eliöstön muovaajana

Three new corticioid species (Basidiomycota) from the Caucasus region

Athelidium caucasicumfrom the Russian Caucasus, Peniophora metuloideafrom NW Iran, and Phlebia parvafrom Georgia and Azerbaijan are described as new to science

Peniophora pseudonuda is a synonym of P. laeta

Peniophora laeta is easily recognized because it is restricted to Carpinus as host in Europe, and the reddish yellow basidioma is provided with prominent teeth or hyphal pegs, disrupting the bark when developing. P. pseudonuda was earlier not even thought of as related to P. laeta, because basidiomata are smooth and developing on the bark. Moreover, basidioma initiation starts with a thin layer of brown-pigmented hyphae on the bark surface. This gives a bluish tint to the mature basidioma, which is in striking contrast to the orange-yellow basidiomata found in P. laeta. Nevertheless, both ITS sequences and crossing tests show that P. pseudonuda is conspecific with P. laeta. This was supported also by similarities in spores, basidia, and cystidia morphology

The Caucasian corticioid fungi: Level of endemism, similarity, and possible contribution to European fungal diversity

We assess the composition of corticioid fungi in the Caucasus region for the first time. The Caucasian corticioids were compared with those of well-documented areas in the Northern Hemisphere using the Tripartite similarity index and cluster analysis. To investigate the significance of the Caucasus region as a possible contributor to the colonization of wood-inhabiting basidiomycetes in Europe, DNA sequences of nuclear ribosomal internal transcribed spacers (ITS1 and ITS2) belonging to the corticioid fungus Peniophorella praetermissa were analysed for comparisons of genetic diversity within and differentiation between geographical regions. Putative species endemism and disjunction of corticioids in the Caucasus region is also discussed. The composition of corticioid fungi in the Caucasus region was found to be distinctly more similar to Europe and North America than to East Asia and India. Similarity tests and molecular Fsts both point to a strong connection between the Caucasus and Europe. The highest molecular diversity in P praetermissa was in the Caucasus and East Asia as compared with other regions studied. The Caucasus and East Asia were significantly differentiated from each other, and unlike Caucasian samples, East Asian sequences were highly divergent from the European ones. This result suggests that the Caucasus might have been a source of colonization for Europe. Endemism is very low, possibly a common feature for wood-inhabiting saprotrophic fungi

Three new species of Aleurodiscus s.l. (Russulales, Basidiomycota) from southern China

Three new species of Aleurodiscus s.l. with corticioid basidiomata are described and illustrated from southern China based on morphological evidence and phylogenetic analyses of ITS and nrLSU sequence data. Aleurodiscus bambusinus was collected from Jiangxi Province on bamboo and is distinct by having a compact texture, simple-septate generative hyphae, abundant acanthophyses, basidia with acanthophysoid appendages and smooth basidiospores. Aleurodiscus isabellinus was collected from Yunnan Province on both angiosperm wood and bamboo and is distinct by having soft basidiomata with yellow to yellowish-brown hymenophore, yellow acanthophyses, simple-septate generative hyphae and smooth basidiospores. Aleurodiscus subroseus was collected from Guangxi Autonomous Region and Guizhou Province on angiosperm wood and is distinct by having pinkish basidiomata when fresh, clamped generative hyphae, clavate acanthophyses and echinulate basidiospores. In the phylogenetic tree, A. bambusinus and A. isabellinus were nested within the A. cerussatus group, whilst A. subroseus was clustered with A. wakefieldiae. An identification key to 26 species of Aleurodiscus s.l. in China is provided

The curse of the uncultured fungus

The international DNA sequence databases abound in fungal sequences not annotated beyond the kingdom level, typically bearing names such as “uncultured fungus”. These sequences beget low-resolution mycological results and invite further deposition of similarly poorly annotated entries. What do these sequences represent? This study uses a 767,918-sequence corpus of public full-length fungal ITS sequences to estimate what proportion of the 95,055 “uncultured fungus” sequences that represent truly unidentifiable fungal taxa – and what proportion of them that would have been straightforward to annotate to some more meaningful taxonomic level at the time of sequence deposition. Our results suggest that more than 70% of these sequences would have been trivial to identify to at least the order/family level at the time of sequence deposition, hinting that factors other than poor availability of relevant reference sequences explain the low-resolution names. We speculate that researchers’ perceived lack of time and lack of insight into the ramifications of this problem are the main explanations for the low-resolution names. We were surprised to find that more than a fifth of these sequences seem to have been deposited by mycologists rather than researchers unfamiliar with the consequences of poorly annotated fungal sequences in molecular repositories. The proportion of these needlessly poorly annotated sequences does not decline over time, suggesting that this problem must not be left unchecked

Fungal diversity notes 253–366: taxonomic and phylogenetic contributions to fungal taxa

Notes on 113 fungal taxa are compiled in this paper, including 11 new genera, 89 new species, one new subspecies, three new combinations and seven reference specimens. A wide geographic and taxonomic range of fungal taxa are detailed. In the Ascomycota the new genera Angustospora (Testudinaceae), Camporesia (Xylariaceae), Clematidis, Crassiparies (Pleosporales genera incertae sedis), Farasanispora, Longiostiolum (Pleosporales genera incertae sedis), Multilocularia (Parabambusicolaceae), Neophaeocryptopus (Dothideaceae), Parameliola (Pleosporales genera incertae sedis), and Towyspora (Lentitheciaceae) are introduced. Newly introduced species are Angustospora nilensis, Aniptodera aquibella, Annulohypoxylon albidiscum, Astrocystis thailandica, Camporesia sambuci, Clematidis italica, Colletotrichum menispermi, C. quinquefoliae, Comoclathris pimpinellae, Crassiparies quadrisporus, Cytospora salicicola, Diatrype thailandica, Dothiorella rhamni, Durotheca macrostroma, Farasanispora avicenniae, Halorosellinia rhizophorae, Humicola koreana, Hypoxylon lilloi, Kirschsteiniothelia tectonae, Lindgomyces okinawaensis, Longiostiolum tectonae, Lophiostoma pseudoarmatisporum, Moelleriella phukhiaoensis, M. pongdueatensis, Mucoharknessia anthoxanthi, Multilocularia bambusae, Multiseptospora thysanolaenae, Neophaeocryptopus cytisi, Ocellularia arachchigei, O. ratnapurensis, Ochronectria thailandica, Ophiocordyceps karstii, Parameliola acaciae, P. dimocarpi, Parastagonospora cumpignensis, Pseudodidymosphaeria phlei, Polyplosphaeria thailandica, Pseudolachnella brevifusiformis, Psiloglonium macrosporum, Rhabdodiscus albodenticulatus, Rosellinia chiangmaiensis, Saccothecium rubi, Seimatosporium pseudocornii, S. pseudorosae, Sigarispora ononidis and Towyspora aestuari. New combinations are provided for Eutiarosporella dactylidis (sexual morph described and illustrated) and Pseudocamarosporium pini. Descriptions, illustrations and / or reference specimens are designated for Aposphaeria corallinolutea, Cryptovalsa ampelina, Dothiorella vidmadera, Ophiocordyceps formosana, Petrakia echinata, Phragmoporthe conformis and Pseudocamarosporium pini. The new species of Basidiomycota are Agaricus coccyginus, A. luteofibrillosus, Amanita atrobrunnea, A. digitosa, A. gleocystidiosa, A. pyriformis, A. strobilipes, Bondarzewia tibetica, Cortinarius albosericeus, C. badioflavidus, C. dentigratus, C. duboisensis, C. fragrantissimus, C. roseobasilis, C. vinaceobrunneus, C. vinaceogrisescens, C. wahkiacus, Cyanoboletus hymenoglutinosus, Fomitiporia atlantica, F. subtilissima, Ganoderma wuzhishanensis, Inonotus shoreicola, Lactifluus armeniacus, L. ramipilosus, Leccinum indoaurantiacum, Musumecia alpina, M. sardoa, Russula amethystina subp. tengii and R. wangii are introduced. Descriptions, illustrations, notes and / or reference specimens are designated for Clarkeinda trachodes, Dentocorticium ussuricum, Galzinia longibasidia, Lentinus stuppeus and Leptocorticium tenellum. The other new genera, species new combinations are Anaeromyces robustus, Neocallimastix californiae and Piromyces finnis from Neocallimastigomycota, Phytophthora estuarina, P. rhizophorae, Salispina, S. intermedia, S. lobata and S. spinosa from Oomycota, and Absidia stercoraria, Gongronella orasabula, Mortierella calciphila, Mucor caatinguensis, M. koreanus, M. merdicola and Rhizopus koreanus in Zygomycota