Fungalpedia –Note 42 Cheirosporium
Cheirosporium L. Cai & K.D. Hyde
Citation if using this entry: Noorabadi MT et al. (2023) New genera in 2008-2009. Mycosphere (in prep)
Index Fungorum, Facesoffungi, MycoBank, freshwaterfungi.org, Fig. 1
Cheirosporium was introduced by Cai et al. (2008) based on morphology and phylogenetic analysis, with the type species, Cheirosporium triseriale L. Cai & K.D. Hyde. The taxon was collected as a saprobe on submerged wood in a stream in Yunnan Province, China. Phylogenetic analysis based on LSU and ITS sequences placed the genus within an uncertain position in Pleosporales, Dothideomycetes. Abdel-Aziz (2016) introduced a second new cheirosporous taxon (Pleosporales, Dothideomycetes) from freshwater habitats in Egypt. Phylogenetic analyses of LSU placed Cheirosporium vesiculare Abdel-Aziz in a monophyletic clade with C. triseriale. Both species formed a distal clade in the newly described family, Dictyosporiaceae (Abdel-Aziz 2016). Cheirosporium differs from other genera in Dictyosporiaceae by its branched conidiophores which are semi-macronematous to macronematous and have numerous distinct sterile branches (Cai et al. 2008). Conidiomata are sporodochial, scattered, punctiform, and brown to black. Mycelium is immersed or partially superficial, comprising branched, septate, sub hyaline to pale brown hyphae. Conidiogenous cells are holoblastic, monoblastic, terminal, and determinate. Conidia are acrogenous, cheiroid, olivaceous to brown, solitary, and have smooth walls (Cai et al. 2008).
Type species: Cheirosporium triseriale L. Cai & K.D. Hyde
Fig. 1 – Cheirosporium triseriale (redrawn from Cai et al. 2008) a Sporodochial conidiomata on the host surface. b Individual conidiophores. c Conidia. d Conidiophores bearing conidia. e Squash mount of the conidiophores and conidia. Scale bars: a =200 μm, b-d=20 μm, e=40 μm.
Cheirosporium triseriale has punctiform sporodochia, conidia are complanate and have 1–2 cells per row, without appendages, while C. vesiculare has compact sporodochia and non-complanate conidia with 9–12 cells per row and with 2 to 5 large, globose to sub-globose appendages (Cai et al. 2008; Abdel-Aziz 2016). The sexual morph of this species is undetermined.
References
Abdel-Aziz FA. 2016 – Two new cheirosporous asexual taxa (Dictyosporiaceae, Pleosporales, Dothideomycetes) from freshwater habitats in Egypt. Mycosphere 7,448–457. https://www.mycosphere.org/pdf/Mycosphere_7_4_5.pdf
Cai L, Guo XY, Hyde KD 2008 – Morphological and molecular characterization of a new anamorphic genus Cheirosporium from fresh water in China.
https://doi.org/10.3767/003158508X314732
A
Entry by
Maryam Tavakol Noorabadi, Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, Thailand.
(Edited by Kevin D Hyde)