Fungalpedia – Note 441, Xenoteratosphaeria

 

Xenoteratosphaeria Quaedvl. & Crous

Citation when using this data: Tibpromma et al. 2024 (in prep.) – Fungalpedia, Fungal pathogens.

Index Fungorum, Facesoffungi, MycoBank, GenBank, Fig. 1 

Classification: Teratosphaeriaceae, Mycosphaerellales, Dothideomycetidae, Dothideomycetes, Pezizomycotina, Ascomycota, Fungi

Based on phylogenies of ITS, LSU, RPB2, TEF-1α and Btub sequences, Quaedvlieg et al. (2014) introduced Xenoteratosphaeria as monotypic genus within Teratosphaeriaceae, Mycosphaerellales in Dothideomycetes with the type species Xenoteratosphaeria jonkershoekensis. The type species of this genus had initially been described as Mycosphaerella jonkershoekensis by Wyk et al. (1975) (≡ Teratosphaeria jonkershoekensis, Crous et al. (2007)). Xenoteratosphaeria members can be found as foliicolous or plant pathogenic and characterized by immersed ascomata, substomatal, black, singular, gregarious, immersed, becoming erumpent through the stomatal pore, pyriform or globose with a papillate periphysate ostiole; obclavate asci, straight, subsessile or with a small pedicel, narrowing slightly to a rounded apex with a distinctive ocular chamber, 8-spored, bitunicate with fissitunicate dehiscence; fusiform ascospores, bi- to multiseriate, tapering gradually to the rounded ends, widest in the middle of the upper cell, with the lower cell slightly narrower and longer, straight, hyaline, becoming pale brown with age, medianly septate (Quaedvlieg et al. 2014). In morphologically (including ascospores becoming brown and verruculose in asci), Xenoteratosphaeria is similar to Teratosphaeria but can be distinct in culture hyphae terminate in brown, multicellular chlamydospore-like structures, not observed in Teratosphaeria s.str. (Quaedvlieg et al. 2014). No further species have been introduced to this genus, which remains monotypic.

Type species: Xenoteratosphaeria jonkershoekensis (P.S. van Wyk, Marasas & Knox-Dav.) Quaedvl. & Crous

Other accepted species: This genus is monotypic.

Figure 1 – Xenoteratosphaeria jonkershoekensis (CBS H-20102, holotype). a Ascus. b Ascospores. c Germinating ascospore. Scale bars = 10 µm. Redrawn from Crous et al. (2008).

 

References

Crous PW, Braun U, Groenewald JZ. 2007 – Mycosphaerella is polyphyletic. Studies in Mycology 58(1), 1–32.

Crous PW, Summerell BA, Mostert L, Groenewald JZ. 2008 – Host specificity and speciation of Mycosphaerella and Teratosphaeria species associated with leaf spots of Proteaceae. Persoonia-Molecular Phylogeny and Evolution of Fungi 20(1), 59–86.

Quaedvlieg W, Binder M, Groenewald JZ, Summerell BA et al. 2014 – Introducing the Consolidated Species Concept to resolve species in the Teratosphaeriaceae. Persoonia-Molecular Phylogeny and Evolution of Fungi 33(1), 1–40. 

Wyk PV, Marasas WF, Knox-Davies PS. 1975 – Teratosphaeria proteae-arboreae and Mycosphaerella jonkershoekensis, two new Ascomycetes on Protea in South Africa. Journal of South African botany. 41, 231–238.

 

Entry by

Zhang GQ, Center for Yunnan Plateau Biological Resources Protection and Utilization, College of Biological Resource and Food Engineering, Qujing Normal University, Qujing, Yunnan 655011, P.R. China.

 

(Edited by Saowaluck Tibpromma, Samaneh Chaharmiri-Dokhaharani, & Achala R. Rathnayaka)

 

Published online 2 December 2024

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