Fungalpedia – Note 612, Asterotexis
Asterotexis Arx
Citation when using this data: D. S. Marasinghe et al. 2023 (in prep.) – Fungalpedia, Ascomycota.
Index Fungorum, Facesoffungi, MycoBank, GenBank.
Classification: Asterotexaceae, Asterotexales, Dothideomycetidae, Dothideomycetes, Pezizomycotina, Ascomycota, Fungi
Pathogenic on the surface of leaves appearing as blackened circular areas. Superficial mycelium absent. Appressoria- like structures forming underneath the ascomata, solitary or forming small groups, globose, cone-shaped, ovoid to elongate, brown, with a hyaline central penetration peg Sexual morph: Thyriothecia superficial to erumpent on upper surface, clustered, circular or irregular, wall comprising pale brown cells of textura porrecta, branching at the margin,
when viewed in squash mount showing a radial arrangement of cells, with fissure-like ostiole at the centre, with a poorly developed base, basal layer fusing with the host cells. Hamathecium with 2 μm, septate, hyaline, anastomosing pseudoparaphyses, embedded in a gelatinous matrix. Asci 8-spored, bitunicate, fissitunicate, oblong to cylindrical, with short and rounded pedicel or pedicel sometimes absent, with ocular chamber. Ascospores overlapping 2–3-seriate, oblong to fusoid, 1-septum, sometimes 2-septate, upper cell broader than lower cell, hyaline to pale yellow. Asexual morph: Undetermined (Hongsanan et al. 2014a; Guatimosim et al. 2015).
Notes: Arx (1958) established Asterotexis with the type species A. cucurbitacearum which was earlier designated as Dothidella cucurbitacearum. Hongsanan et al. (2014a) re-examined the type species of Asterotexis and accepted it in Asterinaceae. Species of Asterotexis morphologically resemble Trichothyrinula in having a thallus covering the thyriothecia, cylindrical-clavate or clavate asci with 1-septum, hyaline ascospores. Both species are considered pathogenic on leaves (Hongsanan et al. 2014a; Wu et al. 2014). However, the upper wall of Asterotexis is composed of cells textura porrecta and the latter has neatly arranged cells of textura prismatica as in Microthyrium. Guerrero et al. (2011) provided the first molecular data for A. cucurbitacearum and Guatimosim et al. (2015) designated epitype for A. cucurbitacearum with molecular data.
Type species: Asterotexis cucurbitacearum (Rehm) Arx, Fungus, Wageningen 28: 6 (1958).
Other accepted species: Species Fungorum – search Asterotexis.
References
Hongsanan S, Li YM, Liu JK et al 2014a – Revision of genera in Asterinales. Fungal Divers 68:1–68.
Wu HX, Tian Q, Li WJ et al 2014 – A reappraisal of Microthyriaceae. Phytotaxa 176:201–212.
Entry by
Diana Sandamali Marasinghe, Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, 57100, Thailand School of Science, Mae Fah Luang University, Chiang Rai, 57100, Thailand, Mushroom Research Foundation, 128 M.3 Ban Pa Deng T. Pa Pae, A. Mae Taeng, Chiang Mai, 50150, Thailand
Published online 29 August 2023