Biphasic taxonomic approaches for generic relatedness and phylogenetic relationships of Teichosporaceae

Abstract

The placement of the dothideomycetous family Teichosporaceae has been controversial. Recent phylogenetic investigations have used a taxonomic lumping approach with the Floricolaceae and its genera have been synonymized under the earlier family name, Teichosporaceae. Intergeneric relationships were therefore obscure and proper generic delimitation was needed in upcoming studies. We here taxonomically revised the family Teichosporaceae based on both morphological and phylogenetic evidence. Teichosporaceae species have immersed or semi-immersed, erumpent to superficial, ostiolate ascomata, cellular or trabeculate pseudoparaphyses, cylindrical to oblong or sub-clavate asci and ellipsoid to oblong or fusiform, cylindric-fusiform or oblong to elliptical, ovoid to clavate, symmetric or asymmetric, initially hyaline or pale brown to dark brown or yellowish brown, 1–3-septate or muriform ascospores. Asexual morphs are coelomycetous. Type or representative specimens of Teichosporaceae were loaned and fresh specimens were collected from China and Thailand. Maximum likelihood and Bayesian analyses of a combined ITS, LSU, SSU, tef1-α and rpb2 dataset were performed to clarify the phylogenetic affinities of taxa and examine monophyly of newly proposed genera. One new species (Floricola festucae), one new host record (Ramusculicola thailandica) and four new combinations (Aurantiascoma nephelii, A. quercus, Magnibotryascoma acaciae, M. melanommoides) are introduced. The broad genus concept of Teichospora is dismissed based on morphological dissimilarities and the monophyletic status of the proposed genera. We accept Asymmetrispora, Aurantiascoma, Floricola, Magnibotryascoma, Misturatosphaeria, Pseudoaurantiascoma, Pseudomisturatosphaeria, Ramusculicola and Teichospora as distinct genera in the Teichosporaceae. All recognized genera are phenotypically characterized and phylogenetically well-supported. The phylogenetic placements of three genera (Chaetomastia, Loculohypoxylon and Sinodidymella), which do not have molecular data cannot be conclusively clarified at present, but are still placed in Teichosporaceae for future studies.