3.2. Taxonomy
Vamsapriyaceae Y.R. Sun, Yong Wang bis & K.D. Hyde, fam. nov.
Index Fungorum number: IF558620; Facesoffungi number: FoF09926
Etymology: Name reflects the type genus
Type genus: Vamsapriya Gawas & Bhat
Saprobic on dead wood. Sexual morph:
Ascomata solitary, scattered, immersed, subglobose, black, ostiolate.
Peridium thin-walled, brown.
Paraphyses hyaline, septate.
Asci 8-spored, unitunicate, cylindrical, short pedicellate, with a J+ apical ring.
Ascospores apiosporous, fusiform to broad fusiform, hyaline. Asexual morph: Hyphomycetous.
Colonies on natural substrate effuse, black, velvety.
Mycelium immersed, septate, branched.
Synnemata present or absent; when present (
Didymobotryum,
Podosporium,
Tretophragmia,
Vamsapriya),
synnemata erect, rigid, dark brown, composed of compact parallel conidiophores.
Conidiophores erect, straight or curved, cylindrical, dark brown, septate.
Conidiogenous cells mono- or polytretic, integrated, terminal, clavate to cylindrical, brown.
Conidia catenate or solitary, acrogenous, simple, pigmented, multi-shaped, septate; when absent (
Diabolocovidia, adapted from Crous et al. [
49]),
conidiophores micronematous, flexuous, mostly reduced to a terminal conidiogenous cell.
Conidiogenous cells monoblastic, subcylindrical to clavate, pale brown, smooth.
Conidia catenate, acrogenous, brown, ellipsoid to obovoid, thin-walled, aseptate.
Notes: A new family,
Vamsapriyaceae, is introduced to accommodate
Diabolocovidia,
Didymobotryum,
Podosporium,
Tretophragmia, and
Vamsapriya. Their phylogenetic position, which is distinct from other families, supports the establishment of the new family within
Xylariales. Although the phylogeny of
Podosporium and
Tretophragmia could not be inferred due to the lack of molecular data, their morphological characters resemble
Didymobotryum and
Vamsapriya in having brown to dark, simple, straight synnemata, monotretic conidiogenous cells and solitary, obclavate, multi-septate, dark brown conidia [
50,
51,
52,
53]. We thus temporarily accept
Podosporium and
Tretophragmia in
Vamsapriyaceae based on morphology. Sequence data are needed to resolve their phylogenetic affinities.
Vamsapriya Gawas & Bhat, Mycotaxon 94: 150 (2006) [2005]
Index Fungorum number: IF29041; Facesoffungi number: FoF00372
Type species: Vamsapriya indica Gawas & Bhat, Mycotaxon 94: 150 (2006) [2005]
Saprobic on dead wood. Sexual morph: Ascomata solitary, scattered, immersed, subglobose, black, ostiolate. Peridium thin-walled, brown. Paraphyses hyaline, septate. Asci 8-spored, unitunicate, cylindrical, straight, short pedicellate, with a J+ apical ring. Ascospores uniseriate or overlapping uniseriate, fusiform to broad fusiform, apiosporous, hyaline, pointed at both ends, surrounded by a mucilaginous sheath. Asexual morph: Hyphomycetous. Colonies on natural substrate effuse, black, velvety. Mycelium immersed, septate, branched. Conidiophores macronematous, synnematous, erect, straight or curved, dark brown, cylindrical, septate. Synnemata erect, rigid, dark brown, composed of compact parallel conidiophores. Conidiogenous cells monotretic, integrated, terminal, clavate to cylindrical. Conidia catenate or solitary, acrogenous, cylindrical, oblong, fusiform or obclavate, brown to dark brown, septate, verruculose.
Notes:
Vamsapriya species are reported from tropical and subtropical regions, and most species are found in terrestrial as saprobes [
26,
27,
28,
29,
30,
31]. Nine species are accepted in the
Vamsapriya, of which six have molecular data.
Vamsapriya is the only holomorphic genus in
Vamsapriyaceae, and
V. bambusicola is the only species with a sexual-asexual connection in
Vamsapriya. Bamboo seems to be the host preference for
Vamsapriya species [
26,
27,
28,
29,
30,
31,
32,
33].
Vamsapriya indica Gawas & Bhat, Mycotaxon 94: 150 (2006) [2005]
Index Fungorum number: IF550801; Facesoffungi number: FoF00374,
Figure 3Saprobic on dead bamboo culms. Sexual morph: Undetermined. Asexual morph: Hyphomycetous. Colonies effuse, dark brown, hairy. Conidiophores macronematous, synnematous, single, erect, cylindrical, straight or slightly flexuous, dark brown, smooth-walled. Synnemata erect, straight or slightly flexuous, dark brown, rigid, with cylindrical to clavate apical fertile part, composed of compactly arranged conidiophores, 1300–1900 um long, 80–150 μm wide at the base, 30–40 μm wide in the middle, 60–140 μm wide at the apical fertile region, with basal portion immersed. Conidiogenous cells monotretic, integrated, terminal, brown, cylindrical to clavate, apically rounded, smooth-walled, 4.5–8.5 × 3–4.5 μm ( = 6.5 × 4 μm, n = 30). Conidia catenate, acrogenous, cylindrical, rounded at the apex, taper and subtruncate at the base, olivaceous brown to brown, 2–8-septate, slightly constricted at the septa, smooth, 20–48 × 4.5–6.5 μm ( = 32 × 5.5 μm, n = 20).
Cultural characters: Conidia germinated on PDA within 12 h, germ tubes produced from both ends. Colonies reached 20 mm diam. within four weeks at 26 °C, cottony, flat, circular, edge entire, white from above, white to yellow from the below.
Material examined: Thailand, Chiang Mai Province, Mae Taeng District, Pa Pae, Mushroom Research Center, on bamboo culms, 10 September 2020, H.W. Shen, M38 (MFLU 21-0088; living culture, MFLUCC 21-0066).
Notes:
Vamsapriya indica is the type species of
Vamsapriya [
26]. Dai et al. [
27] recollected
V. indica from Thailand and provided the culture characters and sequences data. Bao et al. [
32] reported it from a bamboo plant in a freshwater habitat in China. Including our collection, all of these four isolates are recorded from bamboo. Morphological comparison is shown in
Table 3. Our collection has longer synnemata than those of the three isolates.
Vamsapriya chiangmaiensis Y.R. Sun, Yong Wang bis & K.D. Hyde, sp. nov.
Index Fungorum number: IF558618; Facesoffungi number: FoF09927,
Figure 4Etymology: Name reflects the collected site.
Holotype: MFLU 21-0087
Saprobic on dead bamboo culms. Sexual morph: Ascomata 650–1000 × 650–850 μm, solitary scattered, immersed within the host cortex, visible as black, circular dots, in cross section globose to subglobose. Ostiole raised, centric, periphysate ostiolar canal. Peridium composed of hyaline inner layer and dark brown to dark outer layer. Paraphyses long, hyaline, unbranched, septate, 1.5–4 μm wide ( = 2 μm, n = 15). Asci 8-spored, unitunicate, straight or slightly curved, cylindrical, short pedicellate, with apical ring, 140–190 × 6.5–12 μm ( = 160 × 9 μm, n = 15). Ascospores uniseriate, fusiform, 17–26 × 5.5–8 μm ( = 20.5 × 6.5 μm, n = 30), constricted apiosporous with a large cell 12.5–22 μm length, guttulate; basal cell 3.5–6.5 μm length, hyaline, smooth-walled, surround a gelatinous mucilaginous sheath. Asexual morph: Undetermined.
Culture characters: Ascospores germinated on PDA within 12 h, germ tubes produced from one end. Colonies reached 45 mm diam. within four weeks at 26 °C, flat, circular, cottony. White from above; brown to dark brown in the center, white to pale brown around from below.
Material examined: Thailand, Chiang Mai Province, Mae Taeng District, Mushroom Research Center, on bamboo culms, 15 July 2020, Y.R. Sun, M35 (MFLU 21-0087, holotype; ex-type living culture, MFLUCC 21-0065).
Notes:
Vamsapriya chiangmaiensis is the second species that has a sexual morph in
Vamsapriya. It is similar to
V. bambusicola in having solitary, subglobose ascomata, 8-spored, unitunicate, cylindrical asci and fusiform hyaline ascospores. It can be distinguished by the longer asci (140–190 μm vs. 115–140 μm). In addition, polymorphic nucleotides from the
ITS region showed 37 base differences, and the details are given in
Table 4. Therefore, we identified
V. chiangmaiensis as a new species following the suggestions for species delineation [
54].
Vamsapriya uniseptata N.G. Liu & K.D. Hyde , sp. nov.
Index Fungorum number: IF558619; Facesoffungi number: FoF09928,
Figure 5.
Etymology: Name reflects the 1-septate conidia.
Holotype: GZAAS 21-0378
Saprobic on submerged decaying wood in terrestrial habitat. Colonies on natural substrate effuse, black, velvety. Asexual morph: Hyphomycetous. Mycelium mostly immersed, composed of septate, branched, hyaline to brown hyphae. Conidiophores macronematous, synnematous, erect, straight or broadly curved, dark brown, cylindrical, septate. Synnemata erect, rigid, dark brown, composed of compact parallel conidiophores, up to 1300 µm long, 30–50 µm wide in the middle. Conidiogenous cells monotretic, integrated, terminal, clavate, brown to dark brown. Conidia catenate, acrogenous, olivaceous brown, smooth, oblong, rounded at the apex, taper and subtruncate at the base, 1-septate at the middle, septa thickened and darkened, slightly constricted at the septa, with a large globule in each cell, 14–19 × 3.5–4.5 μm ( = 16.5 × 5 µm, n = 30). Sexual morph: Unknown.
Cultural characters: Conidia germinated on PDA within 12 h and germ tubes produced from both ends. Colonies reached 30 mm within four weeks at 26 °C, flat, circular, cottony, white from above, from below brown to dark brown in the center, white to pale brown around.
Material examined: China, Guizhou Province, Xingyi City, Qingshuihe Town, 8 August 2019, N.G. Liu, Q1 (GZAAS 21-0378, holotype; ex-type living culture, GZCC 21-0892).
Notes: Vamsapriya uniseptata is distinguishable by having smaller, 1-septate conidia, while other Vamsapriya species have elongated phragmoconidia. In the BLASTn search, the closest match of the ITS sequence of V. uniseptata is V. khunkonensis (MFLUCC 13-0497, MFLUCC 11-0475 (93.4%)), followed by V. indica (MFLUCC 12-0544 (91.7%)). The LSU sequence of V. uniseptata is V. indica (DLUCC:2062 (99.8%)) and V. khunkonensis (MFLUCC 11-0475 (99.7%)). Vamsapriya uniseptata can be distinguished from V. khunkonensis in the multigene phylogenetic analyses. The ITS region of V. indica (MFLUCC 13-0497) differs by 23 base pairs (527 bp without gaps). Based on distinct morphology and phylogeny, V. uniseptata is introduced as a novel taxon.
3.3. Other Accepted Genera in Vamsapriyaceae
Diabolocovidia Crous, Persoonia 44: 331 (2020)
Index Fungorum number: IF835401; Facesoffungi number: FoF09929.
Parasitic on leaves in terrestrial habitats.
Mycelium composed of septate, branched, hyaline to pale brown hyphae. Asexual morph: Hyphomycetous.
Conidiophores solitary, erect, flexuous, mostly reduced to a terminal conidiogenous cell.
Conidiogenous cells monoblastic, terminal, subcylindrical to clavate, pale brown, smooth.
Conidia catenate, acrogenous, brown, ellipsoid to obovoid, thin-walled, un-septate, verruculose [
49]. Sexual morph: Unknown.
Type species: Diabolocovidia claustri Crous
Notes:
Diabolocovidia is a monotypic genus introduced by Crous et al. [
49] to accommodate
Diabolocovidia claustri, which was isolated from leaves of
Serenoa repens in the U.S.A.
Diabolocovidia claustri is characterized by mononematous, micronematous conidiophores in
Xylariaceae. In their phylogenetic analyses,
Diabolocovidia is basal to
Vamsapriya [
49].
Diabolocovidia is the only genus without synnemata in
Vamsapriyaceae.
Didymobotryum Sacc., Syll. fung. (Abellini) 4: 626 (1886)
Index Fungorum number: IF8009; Facesoffungi number: FoF09930.
Saprobic on decaying plants materials in terrestrial habitats. Colonies on natural substrate effuse, olivaceous to dark brown, velvety. Mycelium mostly immersed, composed of septate, branched, thick-walled, subhyaline hyphae. Asexual morph: Hyphomycetous. Conidiophores macronematous, synnematous, erect, straight or broadly curved, dark brown, cylindrical, septate. Synnemata erect, rigid, dark brown, composed of compact parallel conidiophores. Conidiogenous cells monotretic, integrated, integrated or discrete, cylindrical to clavate, olivaceous brown to dark brown. Conidia catenate, dry, acrogenous, cylindrical, verrucose, 1-septate, slightly constricted at the septa, olivaceous brown to brown. Sexual morph: Unknown.
Type species: Didymobotryum rigidum (Berk. & Broome) Sacc.
Notes:
Didymobotryum was introduced by Saccardo [
55] typified by
D. rigidum.
Didymobotryum species have a worldwide distribution [
56,
57,
58,
59]. Six species are accepted in the Index Fungorum [
37] but only
D. rigidum has molecular data (
ITS: LC228650,
LSU: LC228707).
Podosporium Schwein., Trans. Am. phil. Soc., New Series 4(2): 278 (1832) [1834]
Index Fungorum number: IF9487; Facesoffungi number: FoF09931.
Saprobic on decaying plants materials in terrestrial habitats. Colonies on natural substrate effuse, brown, velvety. Mycelium mostly immersed, composed of septate, flexuous branched hyphae. Asexual morph: Hyphomycetous. Conidiophores arranged in synnemata, brown, septate, sometimes branched at the apex. Synnemata erect, rigid, brown to dark. Conidiogenous cells mono- or polytretic, integrated or discrete, subulate or cylindrical, darkly pigmented. Conidia solitary, obclavate or bacilliform, multi-septate, brown to dark brown. Sexual morph: Unknown.
Type species: Podosporium rigidum Schwein.
Notes:
Podosporium was introduced by Schweinitz [
60] with
P. rigidum as the type species. Since then, many
Podosporium species have been discovered worldwide [
60,
61,
62,
63]. Most of them are saprobes in terrestrial habitats [
60,
61,
62,
63]. There are 67 species listed in the Index Fungorum [
37] but no sequence data are available.
Tretophragmia Subram. & Natarajan, Proc. Natl. Inst. Sci. India, B, Biol. Sci. 39: 550 (1974) [1973]
Index Fungorum number: IF10265; Facesoffungi number: FoF09932.
Saprobic on plants materials in terrestrial habitats. Colonies on natural substrate effuse, dark, velvety. Asexual morph: Hyphomycetous. Conidiophores macronematous, synnematous, brown, septate, erect, straight or broadly curved. Synnemata rigid, brown to dark, simple, erect, straight, consisting of a stalk and a capitate, broadened, fertile head. Conidiogenous cells monotretic, subulate or cylindrical, darkly pigmented. Conidia solitary, obclavate to fusiform or irregular in shape, straight, curved or bent, multi-septate, dark brown. Sexual morph: Unknown.
Type species: Tretophragmia nilgirensis (Subram.) Subram. & Natarajan
Notes:
Tretophragmia was introduced in 1974. The asexual morph of
Tretophragmia is similar to
Didymobotryum,
Podosporium and
Vamsapriya, while no sexual morph is reported. Seifert et al. [
53] treated
Tretophragmia as a synonym of
Podosporium. However,
Tretophragmia is accepted in the Index Fungorum [
37] and the MycoBank [
64] as a separate genus. So far, only two species of
Tretophragmia have been described [
37] and no sequence data are available. Thus, based on morphology and until DNA sequences data are available, we regard this as a separate genus.