Fungalpedia – Note 622, Meliola
Meliola. Fr., Syst.
Citation when using this data: D. S. Marasinghe et al. 2023 (in prep.) – Fungalpedia, Ascomycota.
Index Fungorum, Facesoffungi, MycoBank, GenBank., Fig 1
Classification: Meliolaceae, Meliolales, Meliolomycetidae, Sordariomycetes, Pezizomycotina, Ascomycota, Fungi
Epiphytic on leaves, stems or branches or hyperparasitic on fungi appearing as blackened colonies. Superficial hyphae branched, septate, darker at the septa, brown, with hyphopodia, hyphal setae present. Hyphopodia capitate, 2-celled, brown, alternate or opposite. Hyphal setae brown to dark brown, branched, septate or aseptate, forming around the base of the ascomata, straight or curly, rounded or acute at the apex, smooth-walled. Sexual morph: Ascomata superficial, solitary to gregarious, globose to subglobose, verrucous, thick-walled, ostiolate, with ascomatal setae present. Peridium comprises hyaline inner cell and dark brown outer wall with textura angularis. Hamathecium with evanescent paraphyses. Asci 2–4-spored, unitunicate, broadly clavate to oblong, evanescent. Ascospores 2–4-seriate, initially hyaline and verrucose becoming smooth and brown at maturity, oblong to broadly cylindrical, 3–4-septate, constricted and darker at the septa, rounded ends. Asexual morph: Phialides ampulliform, alternate or opposite on hyphae, sometimes curved, pale brown to brown. Conidia hyaline (Adapted from Hongsanan et al. 2015a; Hyde et al. 2020b).
Notes: Fries (1825) introduced Meliola and is the largest genus in Meliolales. Species of Meliola are characterized by having setose globose to subglobose ascomata, evanescent paraphyses, 2–4-spored unitunicate asci with 3–4-septate, brown, oblong to broadly cylindrical ascospores Hongsanan et al. (2015a) examined the type species of Meliola nidulans and some characters were not observed due to the poor condition of the herbarium material. It is morphologically similar to Amazonia, Asteridiella but Irenopsis, differs from these genera in having hyphal setae on the mycelium and lacking vermiform appendages and setae on the perithecial surface (Hansford 1961). Cannon and Paul (2007) reported the asexual morph of Meliola as phialidic (Hongsanan et al. 2015a). Meliola species are biotrophic and recorded on a wide range of host plants in tropical and sub-tropical regions (Zeng et al. 2017). It is the most species-rich genus in Meliolales which develop on leaves, petioles, twigs and sometimes fruits of vascular plants (Piepenbring et al. 2011; Hongsanan et al. 2015a; Zeng et al. 2017). Species delineation of this genus is usually based on the recorded host, however, the host-specificity of Meliola has not yet been established. According to the updated phylogeny, Meliola is a polyphyletic genus as it comprises two separate clades in Meliolales (Zeng et al. 2020).
Type species: Meliola nidulans (Schwein.) Cooke, Grevil- lea 11(no. 57): 37 (1882)
Other accepted species: Species Fungorum – search Meliola.
Figure 1 – Meliola chandrasekharanii. a Apical portion of the mycelial setae. b Hypophodiate iate mycelium. c Phialides. d Ascospores. Scalebars: a–d = 7 µm. Redrawn from Hosagoudar and Riju (2013)
References
Fries E 1825 – Systema orbis. Vegetabilis 2:1–373.
Hansford CG 1961 – The Meliolaceae a monograph. Sydowia Beih 2:1–806.
Hongsanan S, Tian Q, Peršoh D, Zeng XY et al 2015a – Meliolales. Fungal Divers 74(1):91–141.
Hosagoudar VB 2013 – Meliolales of India. J Threatened Taxa 5:3701–3788 3:3993–4068.
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