A new Arthrinium-like genus of Amphisphaeriales in China

Abstract

Species of Arthrinium s. l. are usually known as endophytes, pathogens or saprobes occurring on various hosts and substrates and are characterised by globose to subglobose, sometimes irregular, dark brown and smooth-walled or finely verruculose conidia, always with a truncate basal scar. Currently, Arthrinium s. l. contains two phylogenetically distinct clades, namely, Apiospora and Arthrinium s. s. However, Arthriniumtrachycarpi and Ar.urticae have still not been properly classified. With new isolates from diseased leaves of Lithocarpusglaber collected in China, we propose the new Arthrinium-like genus Neoarthrinium in Amphisphaeriales. Based on the morphology and phylogeny of multiple loci, the new genus is established with the type species, N.lithocarpicola and three new combinations, N.moseri (syn. Wardomycesmoseri), N.trachycarpi (syn. Ar.trachycarpi) and N.urticae (syn. Ar.urticae) are added to this genus.

Keywords: Apiospora; Arthrinium; Neoarthrinium; phylogeny; taxonomy.

Figure 1.

Phylogram of Amphisphaeriales resulting from a Maximum Likelihood analysis, based on a combined matrix of ITS, LSU, tef1 and tub2. Numbers above the branches indicate ML bootstraps (left, ML BS ≥ 50%) and Bayesian Posterior Probabilities (right, BPP ≥ 0.90). The tree is rooted with Clypeosphaeriamamillana (CBS 140735) and Pseudosporidesmiumknawiae (CBS 123529). New species and combinations proposed in the present study are marked in blue.

Figure 2.

NeoarthriniumlithocarpicolaA colony on PDAB conidiomata formed in culture C–F conidiogenous cells giving rise to conidia G–I conidia. Scale bars: 500 μm (B), 10 μm (C–I).