Proliferophorum G.N. Wang, H. Zhang, K.D. Hyde & Senan., gen. nov.; Index Fungorum number: IF555401
Etymology: The generic epithet ‘‘Proliferophorum’’ refers to the proliferation of conidiophores.
Saprobic on decaying, submerged wood in freshwater habitat. Sexual morph: Undetermined. Asexual morph: Hyphomycetous. Colonies irregular, hairy, black, gregarious. Mycelium mostly immersed in substratum, consisting of branched, septate, subhyaline to pale brown, smooth hyphae. Conidiophores macronematous, mononematous, caespitose, cylindrical, unbranched, erect, straight and curved at the upper part, dark brown, light brown at the apex, 8–10-septate, not constricted at the septa, smooth, sometimes percurrently proliferating 1–2 times at broken ends, with few upper cells, guttulate. Conidiogenous cells holoblastic, polyblastic, terminal, sympodial, pale brown or subhyaline, with minute, truncate conidiogenous loci. Conidia fusiform to cylindrical, aseptate when young, 2–3-septate when mature, rarely up to 4-septate, slightly constricted at the septa, dark brown at central cells, pale brown
at end cells, guttulate at some stage, dry, smooth.
Type species: Proliferophorum thailandicum G.N. Wang, H. Zhang, K.D. Hyde & Senan.
Notes: Proliferophorum is introduced as a monotypic genus in the subclass Diaporthomycetidae to accommodate a hyphomycetous species forming mononematous, caespitose conidiophores, sometimes percurrently proliferating 1–2 times at broken ends of conidiogenous cells and fusiform to cylindrical conidia. The genus was found on wood, similar to the genus Minimelanolocus R.F. Castan˜eda & Heredia, which has conidiophores that are generally conspicuous, mononematous, solitary or fasciculate, septate, erect, straight or flexuous, smooth or verrucose, and brown to dark brown with a melanised base (Castan˜eda-Ruiz et al. 2003). The conidia of Minimelanolocus are generally, cylindrical, naviculate, clavate, obclavate and pale brown to dark brown (Liu et al. 2015b). However, Proliferophorum differs from Minimelanolocus in its conidiophores that have a few upper guttulate cells and conidia having obvious droplets. In addition, LSU sequence data analysis shows the genus does not group with species in Chaetothyriales. Phylogenetic analyses of taxa within Diaporthomycetidae indicate that Proliferophorum forms a single lineage, between Phomatosporales Senan. et al. and Amplistromatales M.J. D’souza et al. The sporothrix-like asexual morph of Phomatosporales was reported from culture by Rappaz (1992). Amplistromatales comprises the families Amplistromataceae Huhndorf et al. and Catabotrydaceae Petr. ex M.E. Barr and their asexual morphs have been reported as acrodontium-like for Amplistroma Huhndorf et al. (Maharachchikumbura et al. 2015). Proliferophorum and acrodontium-like asexual morphs are distinct.
Fig. Phylogram inferred from maximum likelihood analysis of a combined LSU, SSU and ITS sequence dataset using a GTRGAMMA model of evolution. Maximum likelihood bootstrap support greater than 80% and Bayesian posterior probability greater than 0.80 BYPP are indicated at the nodes. Newly introduced strain is in blue bold and type strains are in bold. The tree is rooted to Leotia lubrica (AFTOLID 1 = OSC 100001). The combined LSU, SSU and ITS sequence dataset comprised 67 strains (including the new strain and outgroup taxon) and manually adjusted dataset totally comprised 2228 characters including gaps. The best scoring RAxML tree was selected to represent the relationships among taxa, in which a final likelihood value of – 22073.200898.
- Proliferophorum thailandicum