Chemotaxonomic and phylogenetic studies of Thamnomyces (Xylariaceae)

Abstract

The tropical genus Thamnomyces is characterized by having wiry, black, brittle stromata and early deliquescent asci, lacking an amyloid apical apparatus. Thamnomyces is regarded as a member of the Xylariaceae because the morphology of its ascospores and the anamorphic structures are typical for this family. However, its relationship to other xylariaceous genera remained to be clarified. Cultures of three Thamnomyces species were obtained and studied for morphological characters, and their secondary metabolite profiles as inferred from high performance liquid chromatography coupled with mass spectrometric and diode array detection (HPLC-MS/DAD) were also compared. Cultures of Thamnomyces closely resembled those of the genera Daldinia and Phylacia and even produced several secondary metabolite families that are known to be chemotaxonomic markers for the aforementioned genera. These findings were corroborated by a comparison of their 5.8S/ITS nrDNA sequences. We conclude that Thamnomyces, Daldinia, and Phylacia are derived from the same evolutionary lineage, despite these genera differing drastically in their stromatal morphology and anatomy. Along with Entonaema and Rhopalostoma, these fungi comprise an evolutionarily derived lineage of the hypoxyloid Xylariaceae. A new species of Thamnomyces is erected, and preliminary descriptions of three further, potentially new taxa are also provided.

Ruwenzoria, a new genus of the Xylariaceae from Central Africa

“…Previous molecular phylogenies using different methodologies (cf. discussion in Stadler et al 2009) do not agree with the current one.…”

“…All these compounds are also produced by cultures of Phylacia Lév., Daldinia caldariorum Henn. (Bitzer et al 2008), and Thamnomyces (Stadler et al 2009). Other species of Daldinia so far studied have not been found to produce eutypinols but do contain the naphthol and isosclerones.…”

“…Thamnomyces camerunensis Henn. was recently found again in Cameroon, and cultured and studied for its chemotaxonomic affinities and phylogenetic relationships (Stadler et al 2009). In the course of a chemotaxonomic survey of Hypoxylon with emphasis on taxa occurring in the temperate and subtropical northern hemisphere (Stadler et al 2008b), some African specimens of H. anthochroum Berk.…”

A multiple gene genealogy reveals phylogenetic placement of Rhopalostroma lekae

“…Rhopalostroma species produce BNT (binaphthalene tetrol) as a major metabolite besides certain other undetermined compounds (Stadler et al 2004). Secondary metabolite profiles of Phylacia (Bitzer et al 2008) and Thamnomyces (Stadler et al 2010b) are similar to those obtained from R. angolense (Stadler et al 2010a).…”

“…The other group, including R. africanum, R. angolense, R. dennisii and R. kanyae have isabelline-olivaceous stromatal pigment colors in KOH. The differences of these colors reactions are due to their secondary metabolites, the purplish colors usually results from BNT while greenish brown (olivaceous) group is due to perylene quinone 2 (Stadler et al 2010b). Thus, the KOH extractable pigments of Rhopalostroma species have the potential as an important feature in identification.…”