Fungalpedia – Note 1286, Asteroconium

 

Asteroconium. Syd. & P. Syd.

Index Fungorum, Facesoffungi, MycoBank, GenBank, Fig 1

Classification: Incertae sedis, Incertae sedis, Incertae sedis, Incertae sedis, Pezizomycotina, Ascomycota, Fungi

 

Saprobic on Lauraceae, Anacardiaceae and Moraceae. The sexual morph is undetermined. The asexual morph is characterised by conidiomata, which are acervulus to subepidermal, separate or confluent. The ostiole is absent. The conidiomatal wall is comprised of textura angularis with thick-walled, pale brown to hyaline cells. The conidiophores are reduced to conidiogenous cells. Conidiogenous cells are monoblastic, holoblastic or sympodial, indeterminate, cylindrical and flexuous, hyaline with smooth and thick wall. Conidia are hyaline, thin- and smooth-walled with much reduced lumina, rounded or tapered, base truncate or uneven, apex tapered and obtuse, expanding in the upper part and forming 3 stout, short projections at approximately the same level (Sutton 1980, Li et al. 2020).

Notes: Asteroconium was introduced by Sydow (1903) based on A. saccardoi as the type species. Asteroconium is similar to Tribolospora, but differs from the pycnidial conidiomata and holoblastic conidiogenous cells (Li et al. 2020). Chen et al. (1991) reported that A. saccardoi causes white vein disease in Cinnamomum glanduliferum (Lauraceae) in China. Ramakrishnan et al. (1953) reported that A. nothopegiae was discovered on the leaves of Nothopegia dalzellii (Lauraceae). Currently, there are two species listed in Pseudothyrium in Species Fungorum (May, 2024). There is no sequence data available for Pseudothyrium in GenBank (May, 2024). The updated taxonomic treatment of this genus is genera incertae sedis, in Ascomycota (Wijayawardene et al. 2022).

 

Type species: Asteroconium saccardoi Syd. & P. Syd., Annls mycol. 1(1): 36 (1903).

 

 

Figure 1 – Asteroconium saccardoi (redrawn from Sutton 1980; Chen et al. 1991) a Conidia. b Vertical section of conidioma. c Conidiogenous cells and developing conidia Scale bars: a = 20 μm, b = 100 μm, c = 20 μm. (Originally published in Li et al. (2020) and republished with authority).

 

References

Chen XH, Wu JR, Zhang JL. 1991 – White vein disease: a new disease in Cinnamomum glanduliferum. Journal of Southwest Forestry College 11(2), 205–207.

Li WJ, McKenzie EH, Liu JK, Bhat DJ et al. 2020 – Taxonomy and phylogeny of hyaline-spored coelomycetes. Fungal Diversity 100, 279–801.

Ramakrishnan TS, Srinivasan KV, Sundaram NV. 1953 – Additions to fungi of Madras XIV. Proceedings of the Indian Academy of Sciences, Section B 37(3), 83–95.

Sutton BC. 1980 – The Coelomycetes. Fungi imperfecti with pycnidia, acervuli and stromata. Commonwealth Mycological Institute, Kew.

Sydow H, Sydow P. 1903. Asteroconium saccardoi Syd. nov.gen. et spec. Annales Mycologici. 1(1), 35–36.

Wijayawardene NN, Hyde KD, Dai DQ, Sánchez-García ML et al. 2022 – Outline of Fungi and fungus-like taxa–2021. Mycosphere 13(1), 53–453.

Back to Glossary Index Page