Keqinzhangia aquatica gen. et sp. nov. and Pseudocoronospora hainanense gen. et sp. nov., isolated from freshwater in southern China

Abstract

During the investigation of the diversity of aquatic hyphomycetes from southern China, two interesting isolates were collected. Then, the two isolates were cultured and sequenced, and a BLAST search of its LSU sequences against data in GenBank revealed that the closest related taxa in the genus Microthyrium. Phylogenetic analyses, based on the combined sequence data from the small and large nuclear subunit ribosomal DNA (SSU and LSU), revealed that our isolates belong to the Microthyriaceae. Combined morphological characters, we nally described our isolates as two new genera and species in Microthyriaceae, named as: Keqinzhangia aquatica and Pseudocoronospora hainanense. The full descriptions, illustrations and a phylogenetic tree showing the position of the two new genera were provided in this paper.

Novelties in Microthyriaceae (Microthyriales): Two New Asexual Genera with Three New Species from Freshwater Habitats in Guizhou Province, China

“…In our phylogenetic analysis, Paramirandina is sister to Keqinzhangia aquatica ( Figure 1 ). Paramirandina has cymbiform, fusiform or narrowly lunate conidia, while Keqinzhangia has cylindrical, obclavate, bacilliform, fusiform, sub-oblecythiform or cuneiform conidia [ 14 ]. Comparison of the LSU sequences of Pa. aquatica and K. aquatica showed 93.29% (793/850 bp) identity, while Pa. cymbiformis and K. aquatica showed 92.88% (743/800 bp) identity.…”

“…Notes: Paramirandina aquatica is similar to Heliocephala variabilis [ 41 ] in conidiophores; similar to Mirandina inaequalis [ 44 ] and Keqinzhangia aquatica [ 14 ] in conidial shape; and similar to Pa. cymbiformis (HKAS 112619). However, Pa. aquatica differs from H. variabilis by cymbiform or narrowly lunate, fusiform conidia, and polyblastic conidiogenous cells.…”

“…Two new Triscelophorus species were introduced by Qiao et al [ 13 ], and the systematic placement of Triscelophorus was confirmed within Microthyriaceae. Recently, four asexual genera were introduced to the family [ 13 , 14 ]. So far, Microthyriaceae contains 16 genera, including eight asexual genera, Antidactylaria , Hamatispora , Isthmomyces , Keqinzhangia , Neoanungitea , Pseudocoronospora , Pseudopenidiella , and Triscelophorus [ 12 , 13 , 14 , 15 ].…”

“…Recently, four asexual genera were introduced to the family [ 13 , 14 ]. So far, Microthyriaceae contains 16 genera, including eight asexual genera, Antidactylaria , Hamatispora , Isthmomyces , Keqinzhangia , Neoanungitea , Pseudocoronospora , Pseudopenidiella , and Triscelophorus [ 12 , 13 , 14 , 15 ]. Asexual morphs in Microthyriaceae are characterized by micronematous to macronematous, mononematous, unbranched or branched, hyaline or brown conidiophores, some reduced to conidiogenous cells, integrated, terminal, determinate or sympodial, mono- to polyblastic conidiogenous cells, and subcylindrical to ellipsoid, obclavate, pale brown, verruculose, aseptate to multi-septate conidia, solitary or in branched chains, sometimes radial on compact heads; ramoconidia when present, subcylindrical to fusoid-ellipsoid, pale brown, verruculose, aseptate [ 12 ].…”

“…Asexual morphs in Microthyriaceae are characterized by micronematous to macronematous, mononematous, unbranched or branched, hyaline or brown conidiophores, some reduced to conidiogenous cells, integrated, terminal, determinate or sympodial, mono- to polyblastic conidiogenous cells, and subcylindrical to ellipsoid, obclavate, pale brown, verruculose, aseptate to multi-septate conidia, solitary or in branched chains, sometimes radial on compact heads; ramoconidia when present, subcylindrical to fusoid-ellipsoid, pale brown, verruculose, aseptate [ 12 ]. Sexual morphs in the family have circular, flattened, dark brown thyriothecia with radiating cells and a central ostiole, cylindrical to obpyriform, 8-spored asci and fusiform to ellipsoidal, hyaline or brown, 1-septate ascospores, often with ciliate appendages [ 4 , 8 , 12 , 13 , 14 , 15 , 16 ].…”