Pseudoechria Y. Marín & Stchigel, gen. nov.
MycoBank number: MB 835511; Index Fungorum number: IF 835511; Facesoffungi number: FoF14651
Etymology – Based on the morphological resemblance with Echria, which also presents tufts of rigid agglutinated long hairs on the neck of the ascomata.
Sexual morph Ascomata ostiolate, immersed or superficial, scattered or aggregated, ovoid, broadly obpyriform or globose, sometimes with flexuous, light brown septate, thick-walled hairs; neck short or long, dark, opaque, with tufts of brown to black, rigid, agglutinated, septate, long, thick-walled hairs. Ascomatal wall membranaceous, translucent, light olive brown to black, or yellowish to light brown with an olivaceous tinge, thin, of textura angularis. Paraphyses absent or present, more or less thread-like, soon evanescent. Asci 8- to 2048-spored, clavate to broadly ellipsoid, or broadly fusiform, short-stipitate, with or without a thick apical ring. Ascospores multiseriate, at first one-celled, hyaline, becoming transversely uniseptate; upper cell olivaceous to dark brown, ellipsoidal, sometimes with subacute ends, with an apical to subapical germ pore; lower cell hyaline, clavate, soon evanescent; gelatinous cauda attached at each end, lash-like. Asexual morph absent.
Type species – Pseudoechria curvicolla (G. Winter) Y. Marín & Stchigel.
Notes – Pseudoechria is introduced to accommodate four species of Podospora, which form a monophyletic clade in the Schizotheciaceae (clade VIII), and were distantly related to Podospora s. str., located in Podosporaceae (clade IV). This genus is characterized by ascomata with tufts of long agglutinated hairs on the neck and (mostly) more than eight-spored per asci. A similar morphology is observed in Schizothecium, which also has ascomata with ornations at the apex and multi-spored asci. In fact, Pse. longicollis was placed in Schizothecium when it was introduced [50]. Both genera differ in the type of ascomata ornamentation, with groups of swollen, agglutinated, short hairs or prominent protruding wall cells in Schizothecium, while in Pseudoechria, the vestiture comprises tufts of rigid, agglutinated, long hairs. Rigid long hairs can also be present in Echria spp. and Arnium hirtum, which are also located in the Schizotheciaceae. Both taxa can be easily distinguished from Pseudoechria by their one-celled ascospores. Moreover, the hairs in A. hirtum are not grouped in tufts as in the other two genera, and this species presents also agglutinated hairs as in Schizothecium, which is not observed in either Echria or Pseudoechria. Pseudoschizothecium, located in Schizotheciaceae, and Rhypophila, located in Naviculisporaceae, also present similar morphology with an ornated ascomata apex and multi-spored asci. Rhypophila differs in having tuberculate projections, whereas Pseudoschizothecium produces warts composed of smaller polygonal cells. Although Triangularia setosa also presents multi-spored asci and ascomata with long and rigid hairs on the neck, as in the genus Pseudoechria, the ascomatal hairs are mostly solitary. However, our phylogenetic analysis confirmed that this species, which was located in the family Podosporaceae (clade IV), is not related to Pseudoechria.
Two strains of Pse. curvicolla included in the phylogenetic study grouped in a monophyletic clade (100% bs/0.99 pp) together with the ex-type strain of Pse. longicollis. However, only ITS and LSU sequences of Pse. curvicolla were available; unfortunately, these two loci display less variability. Consequently, rpb2 and tub2 sequences are necessary to confirm the potential synonymy of both species.
Figure 12. Morphology of Pseudoechria. Ascoma. (A,B) Pseudoechria curvicolla SMH 4381. Tuft of rigid hair of the neck. (C) Pseudoechria curvicolla SMH 4381. Ascomatal wall. (D). Pseudoechria decidua CBS 254.71T. (E). Pseudoechria prolifica CBS 250.71T. Ascus. (F) Pseudoechria curvicolla SMH 4381. Ascospores. (G) Pseudoechria curvicolla SMH 4381. (H) Pseudoechria decidua CBS 254.71T. (I). Pseudoechria prolifica CBS 250.71T. Bars: (A,B) = 100 µm; (C) = 20 µm; (D,E,H,I) = 10 µm; (F) = 50 µm; (G) = 5 µm.
Key to species of Pseudoechria
1. Asci 8-spored | Pse. decidua |
1. Asci more than 8-spored | 2 |
2. Asci 1024-2048-spored, ascospores with upper cell up to 14 μm and lower cell up to 4 μm | Pse. prolifica |
2. Asci 256- or 512-spored, ascospores with upper and lower cell longer than 14 and 4 μm, respectively | 3 |
3. Asci about 256-spored, ascospores with upper cell up to 16 μm long and lower cell up to 9 μm | Pse. curvicolla |
3. Asci about 512-spored, ascospores with upper cell up to 22 μm and lower cell up to 8 μm | Pse. longicollis |
Species