Papulosaceae Winka & O.E. Erikss., Mycoscience 41 (2):102 (2000)

Index Fungorum number: IF82096; 9 species.

Saprobic on wood in freshwater or marine habitats, and pathogenic on roots in terrestrial habitats. Sexual morph: Ascomata perithecial, solitary, immersed or semi-immersed, black to dark brown, globose to ellipsoidal, coriaceous, ostiolate. Necks cylindrical, periphysate. Peridium composed of cells of textura angularis or brown-walled compressed cells. Paraphyses tapering, simple or branched, septate. Asci 8-spored, unitunicate, cylindrical, short pedicellate, with a J-, or J+, refractive, bipartite or discoid, apical ring. Ascospores uniseriate to biseriate, hyaline or brown, ellipsoidal or fusiform, unicellular to 3-septate, smooth or verruculose, with or without cup-like, bipolar appendages. Asexual morph: Undetermined (adapted from Réblová et al. 2013).

Type genusPapulosa Kohlm. & Volkm.-Kohlm.

Notes – Winka & Eriksson (2000) introduced Papulosaceae and concluded that the exact phylogenetic position of Papulosa could not be established due to the small number of SSU sequences available for unitunicate pyrenomycetes at that time. Papulosa shared similarities with Diaporthales, Ophiostomatales, Phyllachorales and Sordariales based on molecular data, thus the genus was accommodated in the subclass Sordariomycetidae. Maharachchikumbura et al. (2015) placed Papulosaceae as a sister clade to Coniochaetaceae and Cordanaceae. Abdel-Wahab et al. (2011) analyzed LSU sequence data and found that Brunneosporella and Fluminicola clustered with Papulosa amerospora and Cataractispora receptaculorum. A similar relationship was seen in phylogenetic analyses carried out by Réblová et al. (2013) using LSU, SSU, and rpb2 sequence data. Both Brunneosporella and Fluminicola appear in the same clade as that of Papulosa and Pleurophragmium parvisporum and were named as Papulosaceae (Réblová et al. 2013). LSU and SSU sequence analyses of Boonyuen et al. (2012), showed that Brunneosporella (as Ascobrunneispora aquatica) clustered with Papulosa. Maharachchikumbura et al. (2015, 2016b) placed Brunneosporella and Fluminicola in Papulosaceae. Platytrachelon which was introduced by Réblová et al. (2013) has a close phylogenetic relationship with the Papulosaceae. Réblová et al. (2013) included Platytrachelon in Sordariomycetes incertae sedis while Wijayawardene et al. (2018a) listed it under Papulosaceae. However, the phylogenetic placement of Platytrachelon should be verified with more taxon sampling. Khemmuk et al. (2016) introduced a novel genus, Wongia to Papulosaceae based on phylogenetic analyses of combined ITS, LSU, rpb1 and tef1 sequence data. Hence, the family comprises four genera at present.

Ecological and economic significance of Papulosaceae: Most members in this family are found on submerged wood in freshwater or marine habitats as saprobes (Ranghoo et al. 2001).

Figure – Phylogram generated from maximum likelihood analysis based on combined LSU, SSU, ITS and rpb2 sequence data of Diaporthomycetidae. One hundred and ninety-three strains are included in the combined analyses which comprised 3545 characters (859 characters for LSU, 972 characters for SSU, 659 characters for ITS) after alignment. Single gene analyses were carried out and the topology of each tree had clade stability. Tree topology of the maximum likelihood analysis is similar to the Bayesian analysis. The best RaxML tree with a final likelihood value of – 68207.368884 is presented. Estimated base frequencies were as follows: A = 0.248206, C = 0.241993, G = 0.285500, T = 0.224301; substitution rates AC = 1.369088, AG = 2.887040, AT = 1.413053, CG = 1.152137, CT = 6.303994, GT = 1.000000; gamma distribution shape parameter a = 0.315782. Bootstrap support values for ML greater than 75% and Bayesian posterior probabilities greater than 0.95 are given near the nodes. The tree is rooted with Diatrype disciformis (AFTOL-ID 927). Ex-type strains are in bold. The newly generated sequences are indicated in blue.