Diaporthales genera incertae sedis » Diaporthales genera incertae sedis » Alascospora

Alascospora evergladensis

Alascospora evergladensis Raja, Violi & Shearer

Index Fungorum number: IF 514032; Facesoffungi number: FoF 06209

Holotype: ILL40789

Etymology: Referring to the type locality, the Everglades

 

Sexual morph: Ascomata 125–232 × 135–236 µm, superficial to partly immersed, scattered, globose, subglobose or hemispherical and flattened at the base, membranaceous, ostiolate, light brown, translucent when young, darkening with age. Peridium ca. 5–10 µm wide, composed of hyaline to brown pseudoparenchymatic cells, with dark brown amorphous material deposited irregularly on the peridial surface, especially dense around the ostiole. Pseudoparaphyses sparse, hyaline, septate, filamentous, sometimes irregular, constricted or not at the septa, 20–40 × 2–4 µm. Asci 32–74 × 34–58 µm, (mean and SD = 60 ± 7 × 43 ± 6 µm, n = 25), bitunicate, thickwalled, globose to subglobose, short, pedicellate, containing eight irregularly arranged ascospores. Ascospores 30–40 × 12–16 µm (mean and SD = 36 ± 2.3 × 14 ± 1.3 µm, n = 45), ellipsoidal, 1-septate, septum thin and hyaline at first becoming thicker and darker in older ascospores, upper cell longer and wider than lower cell, hyaline when young, younger ascospores with minute hyaline, apical papillae, multiguttulate, becoming dark brown with age, surrounded by a translucent gelatinous sheath that appears as lateral wings in outline; each side of the sheath ca. 40–45 × 9–10 µm; in older ascospores sheath condensing and darkening to form a dark, appressed, verruculose ascospore wall covering. Asexual morph: undetermined. (Description from Raja et al. 2010)

 

Material examined: USA. Florida, Everglades Water Management District, Water Conservation Area 2A, phosphorus unenriched site U3, 26°17′15.07″N, 80°24′41.08″W, water temperature 19 C, pH 7, on submerged Nymphaea odorata petiole, 17 Nov 2008, Huzefa A. Raja and Helen Violi, SFWMD 1-1. (HOLOTYPE, ILL40789).

 

Notes: We establish Alascospora as a new genus in the Pleosporales incertae sedis pending molecular work on this genus. Thus far attempts to isolate this fungus in pure culture have not been successful due to failure of ascospores to germinate. In our current study we have examined more than 75 dead, decaying rhizomes and petioles of N. odorata but have found A. evergladensis only three times. This suggests that A. evergladensis might be a rare species or that the range of environmental conditions within which it reproduces might be quite narrow. (Notes from Raja et al. 2010)

 

Freshwater distribution: USA (Raja et al. 2010)

 

Fig 1 Alascospora evergladensis (ILL40789, holotype). a Herbarium specimen. b Section of ascoma (redrawn from Raja et al. 2010). c Squash amount of ascomata. d Mycelium. e, f Young, globose, thick-walled ascus. g Globose to subglobose ascus with mature ascospores. h Young, multiguttulate, septate, ascospore with wing-shaped gelatinous sheath (arrows indicate wing-shape gelatinous sheath which swells in water when freshly collected). i Mature ascospores showing verruculose sheath (arrows indicate appressed sheath). j–k Spore surface showing appressed sheath that appears verruculose due to condensed sheath (j: arrow indicate apical papillae, k: arrow shows septum). Scale bars: b = 50 μm, c = 100 μm, d–g = 20 μm, i–k = 5 μm. (Pem et al. 2019)

 

References

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

Pem D (2019) Mycosphere notes 275-324: A morpho-taxonomic revision and typification of obscure Dothideomycetes genera (incertae sedis). Mycosphere 10:1115–1246. https://doi.org/10.5943/mycosphere/10/1/22

 

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