Fungalpedia – Note 7 Alascospora
Alascospora Raja, Violi & Shearer
Citation if using this entry: Fahalli et al. (2023) New genera in 2010-2011. Mycosphere (in press)
Based on unique morphological characteristics Alascospora, a freshwater ascomycete, was introduced in Pleosporales incertae sedis (Pleosporomycetidae, Dothideomycetes), by Raja et al. (2010). The sole species of the genus Alascospora evergladensis was isolated from submerged dead petioles of Nymphaea odorata, during an investigation of aquatic fungi along a phosphorus gradient in the Florida Everglades. The fungus produces light brown, translucent, and membranous ostiolate perithecia. Dark and amorphous material is irregularly deposited on the peridium, especially around the ostiole. Asci are globose, fissitunicate, and thick-walled. Ascospores are 1-septate and hyaline when young, and enclosed by a hyaline gelatinous sheath that resembles two wings (Raja et al. 2010).
Fig 1 – Microscopic morphologies of Alascospora evergladensis (Photo credits by Raja et al. 2010). a Ascoma. b Young and thick-walled ascus. c Globose to subglobose ascus with mature ascospores. d Fissitunicate ascus. e, f Young, multiguttulate ascospores with wing-shape gelatinous sheath. g, h Mature ascospores. i, j Verruculose ascospores. Scale bars: a=50 μm, b-j=10 μm.
Young ascospores’ sheaths stretch in water and are translucent, the sheath seems condensed and darkens with age. These exclusive morphological characteristics suggested a new genus and species in Pleosporales (Raja et al. 2010).
Type species: Alascospora evergladensis Raja, Violi & Shearer
Raja HA, Violi HA, Shearer CA. 2010- Freshwater ascomycetes: Alascospora evergladensis, a new genus, and species from the Florida Everglades. Mycologia 102, 33-38. https://doi.org/10.3852/09-096
Maryam Fallahi, Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, Thailand.
(Edited by Kevin D Hyde)