Astrosphaeriella
Astrosphaeriella Syd. & P. Syd., Annls mycol. 11(3): 260 (1913)
Saprobic or parasitic on bamboo, palm or stout grasses in freshwater or terrestrial habitats. Sexual morph: Ascostromata solitary to gregarious, erumpent to superficial, conical or mammiform, at maturity with stellate appearance from above, dark opaque, uniloculate, glabrous, brittle, carbonaceous, ostiolate. Peridium relatively thick, poorly developed at the base, composed of thick, opaque and melanized cells, arranged in a textura angularis with palisade-like cells at the rim. Pseudoparaphyses dense, trabeculate, filiform, hyaline, anastomosing, embedded in a hyaline gelatinous matrix. Asci 8-spored, bitunicate, fissitunicate, cylindrical to cylindric-clavate, subsessile to short-pedicellate, apically rounded with ocular chamber. Ascospores overlapping uni- to bi-seriate, hyaline to brown, fusiform with rounded to acute ends, septate, smooth, with or without appendages or mucilaginous sheaths (Phookamsak et al. 2015). Asexual morph: Coelomycetous. Conidiomata pycnidial, scattered or solitary, immersed to superficial, conical or hemisphaerical to globose. Pycnidial walls composed of several layers of dark brown to black, textura angularis to textura intricata of cells. Conidiophores reduced to conidiogenous cells. Conidiogenous cells holoblastic or phialidic, integrated, cylindrical or cylindric-clavate or ampulliform, septate or aseptate, hyaline, smooth. Conidia globose to subglobose, or oblong, aseptate, hyaline, smooth (Phookamsak et al. 2015).
Type species: Astrosphaeriella fusispora Syd. & P. Syd.
Notes: Astrosphaeriella is characterized by carbonaceous, conical to mammiform ascostromata with ruptured, reflexed, stellate, host remnants and hyaline to brown, fusiform ascospores (Liu et al. 2011; Phookamsak et al. 2015). Astrosphaeriella aquatica K.D. Hyde, A. seychellensis K.D. Hyde & Goh and A. thailandensis J. Ren et al. were only found from freshwater habitats (Hyde 1994; Hyde and Frohlich 1998; Hyde and Goh 1998; Ren et al. 2013). Other freshwater Astrosphaeriella species were found from both freshwater and terrestrial habitats (see list below). Astrosphaeriella aquatica resembles A. seychellensis and A. thailandensis in having hyaline, fusiform ascospores, but differs in having a wide spreading mucilaginous sheath which is drawn out at the poles.
Phookamsak et al. (2015) transferred Astrosphaeriella sensu lato, which have coriaceous ascomata with short to long neck and striate ascospores, to a newly established family Pseudoastrosphaeriellaceae. Astrosphaeriella papuana Aptroot has striate ascospores which are typical characters of Pseudoastrosphaeriellaceae (Aptroot 1995; Hyde and Frohlich 1998; Phookamsak et al. 2015). However, molecular data for A. papuana is unavailable, thus this species is retained in Astrosphaeriellaceae. Astrosphaeriella papuana might be transferred to Pseudoastrosphaeriellaceae when the type specimen is recollected and recircumscribed.
Astrosphaeriella stellata (Pat.) Sacc. was treated as an earlier name of A. fusispora and followed by some studies (Hyde and Frohlich 1998; Hyde et al. 2000; Tanaka et al. 2009; Liu et al. 2011). Liu et al. (2011) named one collection MFLUCC 10–0555 as A. stellata, which was later considered as a reference specimen of A. fusispora (Phookamsak et al. 2015). Therefore, A. stellata isolated from freshwater habitats is probably a collection of A. fusispora.
The asexual morph was developed in the culture of Astrosphaeriella bambusae Phookamsak& K.D. Hyde (Phookamsak et al. 2015).
List of freshwater Astrosphaeriella species
Astrosphaeriella aquatica K.D. Hyde, Mycol. Res. 98(7): 719 (1994)
Freshwater distribution: Papua New Guinea (Hyde 1994), Ecuador (Hyde and Frohlich 1998)
Astrosphaeriella exorrhiza Boise, Sydowia 38: 117 (1986) [1985]
Freshwater distribution: Ecuador (Hyde and Frohlich 1998)
Astrosphaeriella maquilingiana (Rehm) K.D. Hyde & J. Fröhl., Sydowia 50(1): 103 (1998)
Basionym: Trematosphaeria maquilingiana Rehm, Leafl. of Philipp. Bot. 8: 2952 (1916)
Synonymy: Trematosphaeria maquilingiana var. schizostachyi Rehm, Leafl. of Philipp. Bot. 8: 2952 (1916)
Trematosphaeria maquilingiana Rehm, Leafl. of Philipp. Bot. 8: 2952 (1916) var. maquilingiana
Freshwater distribution: Australia (Vijaykrishna and Hyde 2006)
Astrosphaeriella papuana Aptroot, Nova Hedwigia 60(3–4): 333 (1995)
Freshwater distribution: Papua New Guinea (Hyde and Frohlich 1998), Philippines (Cai et al. 2003)
Astrosphaeriella seychellensis K.D. Hyde & Goh, S. Afr. J. Bot. 64: 332 (1998)
Freshwater distribution: Seychelles (Hyde and Goh 1998)
*Astrosphaeriella stellata (Pat.) Sacc., Syll. fung. (Abellini) 24(2): 938 (1928)
Basionym: Amphisphaeria stellata Pat., Bull. Soc. mycol. Fr. 29: 223 (1913)
Synonymy: Astrosphaeriella stellata var. palmicola F. San Martín & P. Lavín, Lavin & Lavín, Acta Bot. Mexicana 46: 22 (1999)
Astrosphaeriella bambusella Höhn., Sber. Akad. Wiss. Wien, Math.-naturw. Kl., Abt. 1 129: 168 (1920)
Astrosphaeriella fuscomaculans W. Yamam., Sci. Rep.Hyogo Univ. Agric., Ser. 2, Agr. Biol. 1: 63 (1954)
Microthelia fuscomaculans (W. Yamam.) E. Müll., Beitr. Kryptfl. Schweiz 11(no. 2): 286 (1962)
Freshwater distribution: China (Tsui et al. 2001; Wong and Hyde 2001; Luo et al. 2004; Hu et al. 2013), Philippines (Cai et al. 2003)
Astrosphaeriella thailandensis J. Ren, C.Y. Jie, Y.L. Jiang, K.D. Hyde & Yong Wang bis, Sydowia 65(1): 33–43 (2013)
Freshwater distribution: Thailand (Ren et al. 2013)
Key to freshwater Astrosphaeriella species
1. Ascospores surrounded by sheath or with append- age…......................... 2
1. Ascospores without sheath or appendage................................................ 6
2. Ascospores sometimes slightly verrucose........................ A. maquilingiana
2. Ascospores smooth-walled...................................................................... 3
3. Ascospores with minute appendages at both ends................. A. exorrhiza
3. Ascospores surrounded by a mucilaginous sheath......................... 4
4. Ascospores pigmented.............................................................. A. stellata
4. Ascospores hyaline................................................................................. 5
5. Ascospores 30–42 × 7–8 μm, sheath drawn out at the poles...... A. aquatica
5. Ascospores 16–22 × 4–4.5 μm, sheath appears as remnants in dried material A. seychellensis
6. Ascospores with striate ornamentation...................................... A. papuana
6. Ascospores smooth-walled............................................... A. thailandensis
References
Dong W, Wang B, Hyde KD, McKenzie EHC, Raja HA, Tanaka K, Abdel-Wahab MA, Abdel-Aziz FA, Doilom M, Phookamsak R, Hongsanan S, Wanasinghe DN, Yu X-D, Wang G-N, Yang H, Yang J, Thambugala KM, Tian Q, Luo Z-L, Yang J-B, Miller AN, Fournier J, Boonmee S, Hu D-M, Nalumpang S, Zhang H (2020) Freshwater Dothideomycetes. Fungal Divers 105:319–575
Hu DM, Liu F, Cai L (2013) Biodiversity of aquatic fungi in China. Mycology 4:125–168
Hyde KD (1994) Aquatic fungi on rachides of Livistona in the Western Province of Papua New Guinea. Mycol Res 98:719–725
Hyde KD, Aptroot A, Fröhlich J, Taylor JE (2000) Fungi from palms. XLIII. Lophiostoma and Astrosphaeriella species with slit-like ostioles. Nova Hedwigia 70:143–160
Hyde KD, Frohlich J (1998) Fungi from palms XXXVII. the genus Astrosphaeriella, including ten new species. Sydowia 50:81–132
Hyde KD, Goh TK (1998) Fungi on submerged wood in the Riviere St Marie-Louis, The Seychelles. S Afr J Bot 64:330–336
Liu JK, Phookamsak R, Jones EBG, Zhang Y, Ko-Ko TW, Hu HL, Boonmee S, Doilom M, Chukeatirote E, Bahkali AH, Wang Y, Hyde KD (2011) Astrosphaeriella is polyphyletic, with species in Fissuroma gen. nov., and Neoastrosphaeriella gen. nov. Fungal Divers 51:135–154
Luo J, Yin J, Cai L, Zhang KQ, Hyde KD (2004) Freshwater fungi in Lake Dianchi, a heavily polluted lake in Yunnan, China. Fungal Divers 16:93–112
Phookamsak R, Norphanphoun C, Tanaka K, Dai DQ, Luo ZL, Liu JK, Su HY, Bhat DJ, Bahkali AH, Mortimer PE (2015) Towards a natural classification of Astrosphaeriella-like species; introducing Astrosphaeriellaceae and Pseudoastrosphaeriellaceae fam. nov. and Astrosphaeriellopsis, gen. nov. Fungal Divers 74:143–197
Ren J, Zeng C, Jie CY, Jiang YL, Hyde KD, Wang Y (2013) A new Thai species of Astrosphaeriella (Dothideomycetes, Ascomycota) from submerged wood in freshwater. Sydowia 65:33–43
Tanaka K, Hirayama K, Yonezawa H, Hatakeyama S, Harada Y, Sano T, Shirouzu T, Hosoya T (2009) Molecular taxonomy of bambusicolous fungi: Tetraplosphaeriaceae, a new pleosporalean family with Tetraploa-like anamorphs. Stud Mycol 64:175–209
Tsui CKM, Hyde KD, Hodgkiss IJ (2001) Paraniesslia tuberculata gen. et sp. nov., and new records or species of Clypeosphaeria, Leptosphaeria and Astrosphaeriella in Hong Kong freshwater habitats. Mycologia 93:1002–1009
Vijaykrishna D, Hyde KD (2006) Inter- and intra-stream variation of lignicolous freshwater fungi in tropical Australia. Fungal Divers 21:203–224
Wong MKM, Hyde KD (2001) Diversity of fungi on six species of Gramineae and one species of Cyperaceae in Hong Kong. Mycol Res 105:1485–1491
Recent Genus
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