Morphology and multi-gene phylogeny reveal a novel Torula (Pleosporales, Torulaceae) species from the plateau lakes in Yunnan, China.

Background: During an investigation into lignicolous freshwater fungi from the plateau lakes in Yunnan Province, China, two fresh collections of Torula taxa were collected and examined morpholgically. New information: Torulaluguhuensis is characterised by: conidiophores which are semi-macronematous mononematous, erect, septate, smooth, slightly flexuous and pale brown; conidiogenous cells which are holoblastic, mono- to polyblastic, integrated, terminal, terminal or intercalary in conidial chains, doliiform and pale brown; conidia which are branched chains, acrogenous, straight or slightly curved, dark brown to blackish, pale brown or subhyaline at apex, 1-3 septate, strongly constricted at the septa, verruculose or finely echinulate and rounded at both ends. A new species was introduced, based on morphological and phylogenetic analysis of combined ITS, LSU, RPB2 and TEF sequence data. Detailed descriptions and illustrations are provided, with an updated phylogenetic tree depicting intergeneric relationships within the Torulaceae.

Retiboletus (Boletaceae) in northern Thailand: one novel species and two first records.

Morphological characters and multi-gene phylogenetic analyses were used to identify Retiboletus specimens collected in northern Thailand. Retiboletus brevibasidiatus is described as new to science, whereas R. fuscus and R. nigrogriseus are reported for the first time from Thailand. Retiboletus brevibasidiatus produces medium-sized basidiomes, with a dark blonde to clay pileus and densely reticulate stipe mostly on the upper part with pale yellow to chrome yellow basal mycelium. It is difficult to separate R. brevibasidiatus from other closely related species on the basis of macroscopic characters. However, the new species can be distinguished by microscopic characters, mostly the shorter basidia. The macro- and micro-morphology of the R. fuscus and R. nigrogriseus collections from Thailand fit well with the previous descriptions of materials from China and Japan. Detailed descriptions, molecular phylogeny, and illustrations of the three species are provided.

Mycosphaerangium and Neomelanconium (Cenangiaceae) are closest relatives: phylogenetic relationships, morphology and a new species.

Based on molecular phylogenetic analyses of a multigene matrix of partial nuSSU-ITS-LSU rDNA, RPB1, RPB2 and TEF1 sequences and by morphological evidence, the genus Mycosphaerangium is shown to be the closest relative of Neomelanconium, and confirmed to be a member of the Cenangiaceae (Leotiomycetes). While Mycosphaerangium and Neomelanconium share many traits like similar conidia, conidiogenesis, asci and ascospores, their apothecia differ particularly in excipular features and are therefore recognized as distinct genera. Mycosphaerangium tiliae, described from North America, is excluded from the genus but shown to represent the sexual morph of the European Neomelanconium gelatosporum, and it is therefore synonymized with the latter. Based on morphology, Neomelanconium deightonii is assumed to be congeneric with Neomelanconium gelatosporum, and it is lectotypified. Dermatea tetraspora and Phaeangium magnisporum, the basionyms of Mycosphaerangium tetrasporum and M. magnisporum, respectively, are lectotypified as well, and for M. tetrasporum, the asexual morph is recorded for the first time. Mycosphaerangium quercinum sp. nov. is described as a new species from various Quercus hosts in Europe, where it is shown to be widely distributed. It morphologically and ecologically closely resembles the North American M. tetrasporum, but differs in paraphysis and ascospore morphology and by croziers at its ascus base. The three accepted species of Mycosphaerangium and the two of Neomelanconium are described and illustrated. Mycosphaerangium magnisporum, M. quercinum and M. tetrasporum are recorded to be constantly associated with species of Coryneum, indicating a fungicolous habit, but no evidence for fungal associations has been found in Neomelanconium deightonii and N. gelatosporum.

Mrakia fibulata sp. nov., a psychrotolerant yeast from temperate and cold habitats.

Tree fluxes are sugar-rich, sometimes ephemeral, substrates occurring on sites where tree sap (xylem or phloem) is leaking through damages of tree bark. Tree sap infested with microorganisms has been the source of isolation of many species, including the biotechnologically relevant carotenoid yeast Phaffia rhodozyma. Tree fluxes recently sampled in Germany yielded 19 species, including several psychrophilic yeasts of the genus Mrakia. Four strains from tree fluxes represented a potential novel Mrakia species previously known from two isolates from superficial glacial melting water of Calderone Glacier (Italy). The Italian isolates, originally identified as Mrakia aquatica, and two strains from Germany did not show any sexual structures. But another culture collected in Germany produced clamped hyphae with teliospores. A detailed examination of the five isolates (three from Germany and two from Italy) proved them to be a novel yeast species, which is described in this manuscript as Mrakia fibulata sp. nov. (MB 830398), holotype DSM 103931 and isotype DBVPG 8059. In contrast to other sexually reproducing Mrakia species, M. fibulata produces true hyphae with clamp connections. Also, this is the first psychrotolerant Mrakia species which grows above 20 °C. Spring tree fluxes are widespread and can be recognized and sampled by amateurs in a Citizen Science project. This substrate is a prominent source of yeasts, and may harbor unknown species, as demonstrated in the present work. The description of Mrakia fibulata is dedicated to our volunteer helpers and amateurs, like Anna Yurkova (9-years-old daughter of Andrey Yurkov), who collected the sample which yielded the type strain of this species.

Coryneumheveanum sp. nov. (Coryneaceae, Diaporthales) on twigs of Para rubber in Thailand.

During studies of microfungi on para rubber in Thailand, we collected a new Coryneum species on twigs which we introduce herein as C.heveanum with support from phylogenetic analyses of LSU, ITS and TEF1 sequence data and morphological characters. Coryneumheveanum is distinct from other known taxa by its conidial measurements, number of pseudosepta and lack of a hyaline tip to the apical cell.

Liberomycespistaciae sp. nov., the causal agent of pistachio cankers and decline in Italy.

A new canker and decline disease of pistachio (Pistaciavera) is described from Sicily (Italy). Observations of the disease and sampling of the causal agent started in spring 2010, in the area where this crop is typically cultivated, Bronte and Adrano (Catania province) and later extended to the Agrigento and Caltanissetta provinces. Isolations from the margins of twig, branch and stem cankers of declining plants resulted in fungal colonies with the same morphology. Pathogenicity tests on 5-year-old potted plants of Pistaciavera grafted on P.terebinthus reproduced similar symptoms to those observed in nature and the pathogen was confirmed to be a coloniser of woody plant tissue. Comparison of our isolates with the type of the apparently similar Asteromellapistaciarum showed that our isolates are morphologically and ecologically different from A.pistaciarum, the latter being a typical member of Mycosphaerellaceae. Asteromellapistaciarum is lectotypified, described and illustrated and it is considered to represent a spermatial morph of Septoriapistaciarum. Multi-locus phylogenies based on two (ITS and LSU rDNA) and three (ITS, rpb2 and tub2) genomic loci revealed isolates of the canker pathogen to represent a new species of Liberomyces within the Delonicicolaceae (Xylariales), which is here described as Liberomycespistaciae sp. nov. (Delonicicolaceae, Xylariales). The presence of this fungus in asymptomatic plants with apparently healthy woody tissues indicates that it also has a latent growth phase. This study improves the understanding of pistachio decline, but further studies are needed for planning effective disease management strategies and ensuring that the pathogen is not introduced into new areas with apparently healthy, but infected plants.

Beta-tubulin and Actin gene phylogeny supports Phaeoacremoniumovale as a new species from freshwater habitats in China.

A new species of Phaeoacremonium, P.ovale (Togniniaceae), was isolated during a diversity study of freshwater fungi from Yunnan Province in China. Morphological and cultural studies of the fungus were carried out and its sexual and asexual morphs (holomorph) are introduced herein. This species is characterised by peculiar long-necked, semi-immersed ascomata with oval to ellipsoid ascospores and ellipsoid to ovoid conidia. Phylogenetic analyses of a combined TUB and ACT gene dataset revealed that strains of P.ovale constitute a strongly supported independent lineage and are related to P.griseo-olivaceum and P.africanum. The number of nucleotide differences, across the genes analysed, also supports establishment of P.ovale as a new species.