Paralophiostoma V.V. Sarma & M. Niranjan gen. nov.
MycoBank number: MB 556725; Index Fungorum number: IF 556725; Facesoffungi number: FoF 06622, 1 morphological species (this study), 1 species with molecular data.
Etymology – In reference to its similarity to Lophiostoma.
Type species – Paralophiostoma hysterioides M. Niranjan & V.V. Sarma.
Saprobic on dead and decaying twigs. Sexual morph: Ascomata perithecoid, scattered, carbonaceous, subglobose, immersed, erumpent with hysterothecoid necks, clypeate, apical long slit-like ostioles, periphysate. Peridium thick-walled with several layers of textura angularis cells. Hamathecium comprising numerous, filamentous, septate, unbranched, trabeculate pseudoparaphyses, anastomosing in a gelatinous matrix. Asci 8-spored, bitunicate, fissitunicate, cylindro-clavate, apically rounded with ocular chamber, long pedicellate. Ascospores overlapping 1-seriate, fusiform, hyaline to pale brown when young, brown to dark brown at maturity, 1-septate with a constriction when young, 3-septate with constrictions at maturity, central septum strongly constricted, uni-guttulate in each cell, obtuse ends with apical caps, each spore having one, supramedian cell, spores often splitting into part spores at maturity. Asexual morph: Undetermined.
Notes – Out of the 24 genera in Lophiostomataceae (Tennakoon et al. 2018b), only Alpestrisphaeria, Biappendiculispora, Guttulispora, Neopaucispora, Parapaucispora, Paucispora and Sigarispora produce 3-septate, brown ascospores but they lack appendages or sheaths. While, Paralophiostoma produces 3-septate, brown ascospores with bipolar appendages and a thin (incipient) sheath. Paralophiostoma is closely related to Guttulispora but differs in having dark- brown ascospores with apical caps, splitting into part spores (Thambugala et al. 2015b). Paralophiostoma has close affinities to Lophiostoma including slit-like ostioles in the ascomata, long pedicellate asci and often phragmosporous, fusiform ascospores. However, the new genus differs from Lophiostoma in having immersed ascomata erumpent with hysterothecoid necks opening with slit-like ostioles, cylindrical asci instead of clavate asci and ascospores splitting into part spores at maturity. Hence based on the morphological and DNA sequence differences, a new genus Paralophiostoma is introduced based on the monotypic species P. hysterioides to be accommodated in Paralophiostomataceae.
Species