Yu-Ming Ju

Phylogenetic status of Xylaria subgenus Pseudoxylaria among taxa of the subfamily Xylarioideae (Xylariaceae) and phylogeny of the taxa involved in the subfamily.

To infer the phylogenetic relationships of Xylaria species associated with termite nests within the genus Xylaria and among genera of the subfamily Xylarioideae, beta-tubulin, RPB2, and alpha-actin sequences of 131 cultures of 114 species from Xylaria and 11 other genera of the subfamily were analyzed. These 11 genera included Astrocystis, Amphirosellinia, Discoxylaria, Entoleuca, Euepixylon, Kretzschmaria, Nemania, Podosordaria, Poronia, Rosellinia, and Stilbohypoxylon. We showed that Xylaria species were distributed among three major clades, TE, HY, and PO, with clade TE-an equivalent of the subgenus Pseudoxylaria-encompassing exclusively those species associated with termite nests and the other two clades containing those associated with substrates other than termite nests. Xylaria appears to be a paraphyletic genus, with most of the 11 genera submerged within it. Podosordaria and Poronia, which formed a distinct clade, apparently diverged from Xylaria and the other genera early. Species of Entoleuca, Euepixylon, Nemania, and Rosellinia constituted clade NR, a major clade sister to clade PO, while those of Kretzschmaria were inserted within clade HY and those of Astrocystis, Amphirosellinia, Discoxylaria, and Stilbohypoxylon were within clade PO.

Chemotaxonomy of Entonaema, Rhopalostroma and other Xylariaceae*

Entonaema, Pulveria, Phylacia, Rhopalostroma, Sarcoxylon and Thamnomyces are relatively small and poorly studied genera of Xylariaceae. Their affinities to the mainstream of the family largely remain to be evaluated. Secondary metabolite profiles of type materials, recently collected specimens, and cultures, were generated to address this problem from a chemotaxonomic point of view. Micro-scale extraction and subsequent analytical HPLC with uv/visual (diode array) and ms detection in the positive and negative Electrospray mode were carried out, employing spectral libraries and standardised gradients that had been optimised to detect characteristic pure compounds in species of allied genera. Surprisingly, the characteristic metabolites had frequently remained stable even in specimens collected up to 190 years ago. Hence, this methodology not only proved valuable to establish the conspecificity of type materials with recent records, but also revealed some interesting correlations: (1) Stromatal pigments of Entonaema cinnabarina, E. globosum and E. liquescens are mitorubrins and other characteristic compounds also prevailing in particular species of Hypoxylon; (2) Rhopalostroma, Phylacia, Pulveria and Thamnomyces contain binapththalenes and other compounds typical of Daldinia and Hypoxylon; (3) Sarcoxylon, as well as E. dengii, E. moluccanum and E. pallida, contained none of these pigments, but characteristic yet unknown lipophilic metabolites were detected in their stromatal extracts; (4) Cultures of E. cinnabarina and Rhopalostroma indicum, obtained for the first time, produced essentially the same secondary metabolites that are also typical of Daldinia, but absent in Biscogniauxia, Hypoxylon and other xylariaceous genera. Hence, chemotaxonomic characters reflected the adaptive radiation of this family. Correlations between the evolution of morphological/anatomical characters are discussed.

Molecular chemotaxonomy of Daldinia and other Xylariaceae

In a polyphasic classification approach, stromata and cultures of Daldinia and allied Xylariaceae from around the world were studied for: (1) morphology of teleomorphs and anamorphs; (2) metabolite patterns in stromata and cultures, employing analytical HPLC-UV-visible (diode array) detection and mass spectrometric detection; (3) amplified 18S rDNA restriction patterns (ARDRA); and (4) PCR amplified minisatellite regions. Comparison of type material, herbarium specimens, cultures, and freshly collected material revealed new evidence on their geographic distribution. Several Daldinia spp. were identified in Europe and other locations for the first time. The results point towards the existence of further undescribed species. Stromata of a given species never contained the same major metabolites as corresponding cultures. Most cultures of Daldinia spp. produced naphthalene and chromane derivatives, differing from allied genera by the absence of mellein. Stromata of Daldinia spp. did not produce mitorubrin, but generally contained binaphthyls. Metabolite profiles were correlated with colours of KOH-extractable stromatal pigments. The yellow azaphilones and benzophenones found in D. childiae were lacking in species with purple stromatal pigments. Cytochalasins were found in stromata of D. eschscholzii. Genetic fingerprints helped to distinguish morphologically closely related taxa. ARDRA gave specific results for species whose 18S rDNA contained insertions, while minisatellite PCR provided specific genetic fingerprints. A combination of both PCR based techniques provided a fair resolution of genetic subtypes, reflecting the intrageneric variance in Daldinia as established from morphological data and secondary metabolite profiles.

Hypomiltin, a novel azaphilone from Hypoxylon hypomiltum, and chemotypes in Hypoxylon sect. Hypoxylon as inferred from analytical HPLC profiling

A novel azaphilone named hypomiltin was isolated by preparative reversed phase HPLC from the stromatal extract of the xylariaceous ascomycete Hypoxylon hypomiltum. Its chemical structure was determined by mass spectrometry and 2D nuclear magnetic resonance spectroscopy. Analytical HPLC profiling of stromatal crude extracts, using UV/visual (diode array) and mass spectrometric detection based on electrospray ionisation, revealed the presence of hypomiltin also in Hypoxylon intermedium, H. perforatum, H. trugodes, and Pulveria porrecta. In contrast, this compound was found neither in type material of H. hypomiltum var. lavandulocinereum nor in several further Hypoxylon species. Despite being chemically related to mitorubrin, hypomiltin never co-occurred with the latter compound and its derivatives. Characteristic secondary metabolite profiles of several further Hypoxylon species are correlated with the colours of their taxonomically significant KOH-extractable pigments. These species are divided into chemotypes, based on analytical HPLC data. The results point toward an extraordinary diversity of secondary metabolites in Hypoxylon.

New Hypoxylon species and notes on some names associated with or related to Hypoxylon

These new species of Hypoxylon are described: H. elevatidiscus, H. squamulosum, H. subalbum and H. vinosopulvinatum. A referenced list of all Hypoxylon species known to us described since 1996 is given and a key presented. Names associated with Hypoxylon that were not given in the Ju and Rogers monograph are annotated and diagnostic corrections of taxa discussed in that monograph are given.

New and interesting Biscogniauxia taxa, with a key to the world species

Six new taxa of Biscogniauxia are described from Taiwan, including four new species: B. ambiens, B. cylindrispora, B. formosana , and B. latirima ; and two new varieties: B. albosticta var. orientalis and B. formosana var. kentingensis. Their cultural and anamorphic data are also provided. A description is provided for B. doidgeae based on its type. Cultural and anamorphic data are given for B. philippinensis var. microspora. A key to the 57 known species of Biscogniauxia in the world is also given.

Amphirosellinia gen. nov. and a new species of Entoleuca

The new genus Amphirosellinia is erected to include five xylariaceous fungi with erumpent or immersed perithecioid stromata. Amphirosellinia fushanensis, A. nigrospora and A. tennesseensis are newly described, whereas A. evansii and A. quercina are new combinations. Synnematous, geniculosporium-like anamorphs are known for A. fushanensis, A. nigrospora, A. tennesseensis and A. evansii; the anamorph of the latter species was produced on natural substratum, whereas those of the former three species were produced in culture. Dichotomous keys are presented for the Amphirosellinia species and for some genera that might be confused with Amphirosellinia. Entoleuca ellisii also is described as new. It readily can be separated from the known species in the genus by its smaller ascospore size range and short ascospore germ slit.

Ophiodiaporthe cyatheae gen. et sp. nov., a diaporthalean pathogen causing a devastating wilt disease of Cyathea lepifera in Taiwan.

The scaly tree fern, Cyathea lepifera, in Taiwan has been devastated by an ascomycetous pathogen in recent years. This fungus resembles species of Diaporthe, but unlike anamorphs of Diaporthe that produce two types of conidia, its anamorph produces one conidium type. It is described herein as Ophiodiaporthe cyatheae gen. et sp. nov. Through pathogenicity tests, O. cyatheae was demonstrated to be the causal agent of the C. lepifera wilt disease. Of interest, sporulating structures of O. cyatheae have not been found on C. lepifera plants but in culture thus far. The mating system is homothallic. Phylogenetic analyses based on combined sequences of nSSU-rDNA, nLSU-rDNA, EF1-α-1 and RPB2 placed O. cyatheae in Diaporthaceae. Combined sequences of EF1-α-2 and TUB indicated that O. cyatheae had its origin within Diaporthe.

Xylaria cranioides and Poronia pileiformis and their anamorphs in culture, and implications for the status of Penzigia

Cultures of Penzigia cranioides and Poronia pileiformis obtained from material collected in Taiwan produced anamorphs in Xylocoremium and Lindquistia, respectively. The former is reminiscent of those produced by undoubted Xylaria species. Penzigia cranioides, the type species of the genus, is therefore accepted as X. cranioides. Penzigia thus becomes a taxonomic synonym of Xylaria. The position of P. pileiformis in Poronia is considered justified primarily on its anamorph; an epitype is designated.

Paramphisphaeria costaricensis gen. et sp. nov. and Pachytrype rimosa sp. nov. from Costa Rica

Paramphisphaeria is described as a new genus on the basis of the single species, P. costaricensis. It differs from Amphisphaeria spp. primarily in having bicellular ascospores with a germ slit and in having an ascus apical ring that does not become blue in iodine. It resembles Amphisphaeria in its brown color and lack of constriction at the septum of the ascospore. An anamorph is unknown. It tentatively is placed in the Xylariaceae for reasons discussed. Pachytrype rimosa is described as a new species.