Introducing Querciphoma styphnolobii sp. nov., the first sexual morph of Querciphoma (Leptosphaeriaceae, Pleosporales)
Author
Gao, Hanxing
0000-0002-1949-2709
Engineering Research Center of Chinese Ministry Education for Edible and Medicinal Fungi, Jilin Agricultural University, Changchun 130018, PR China & College of Plant Protection, Jilin Agricultural University, Changchun 130118, PR China & gaohanxing 168 @ 163. com; https: // orcid. org / 0000 - 0002 - 1949 - 2709
Author
Yin, Jingyan
0000-0001-8448-5698
Engineering Research Center of Chinese Ministry Education for Edible and Medicinal Fungi, Jilin Agricultural University, Changchun 130018, PR China & College of Plant Protection, Jilin Agricultural University, Changchun 130118, PR China & yiyinjingyan @ 163. com; https: // orcid. org / 0000 - 0001 - 8448 - 5698
Author
Li, Yu
0000-0003-4966-701X
Engineering Research Center of Chinese Ministry Education for Edible and Medicinal Fungi, Jilin Agricultural University, Changchun 130018, PR China & yuli 966 @ 126. com; https: // orcid. org / 0000 - 0003 - 4966 - 701 X
Author
Liu, Shuyan
0000-0001-9082-1053
Engineering Research Center of Chinese Ministry Education for Edible and Medicinal Fungi, Jilin Agricultural University, Changchun 130018, PR China & College of Plant Protection, Jilin Agricultural University, Changchun 130118, PR China & liussyan @ 163. com; https: // orcid. org / 0000 - 0001 - 9082 - 1053
Author
Zhu, Zhaoxiang
0000-0002-8330-918X
Engineering Research Center of Chinese Ministry Education for Edible and Medicinal Fungi, Jilin Agricultural University, Changchun 130018, PR China & zhuzx 1985 @ 163. com; https: // orcid. org / 0000 - 0002 - 8330 - 918 X
text
Phytotaxa
2022
2022-07-28
555
4
279
290
http://dx.doi.org/10.11646/phytotaxa.555.4.1
journal article
107626
10.11646/phytotaxa.555.4.1
573fd5ca-4603-452d-8396-93180e7affdf
1179-3163
6919482
Querciphoma styphnolobii
H.X. Gao & Z.X. Zhu
,
sp. nov.
(
Figs. 2–3
)
MycoBank no.: MB 840304.
Etymology:—
The epithet “styphnolobii” refers to the host plant genus
Styphnolobium
.
Type:
—
CHINA
,
Henan Province
,
Xingyang
city,
34°49′N
,
113°21′E
,
130 m
elevation, on the bark of
Styphnolobium japonicum
,
6 Jun 2020
,
Hanxing Gao
1367,
HMJAU 34703
(
holotype
!), HMJAU 35100 (culture collection)
.
Diagnosis:—
Querciphoma styphnolobii
is characterized by eustromatic, pycnidial conidiomata with scleroplectenchymatous cell
type
in the peridium, smooth, hyaline, cylindrical conidia with one middle constricted septum and muriform ascospores.
FIGURE 2.
Teleomorph of
Querciphoma styphnolobii
(HMJAU 34703,
holotype
)
A–C.
Ascomata on the substrate.
D.
Vertical section of ascoma.
E.
Ostiole.
F, G.
Setae.
H–J.
Mature asci and hamathecium.
K, L.
Mature asci.
M, N.
Asci apex.
O–X.
Ascospores (X in Indian ink to show the mucilaginous sheath). Scale bars: A = 1 mm; B, C = 200 μm; D–L = 20 μm; M–X = 10 μm.
Description:—Sexual morph: Ascomata
solitary, gregarious, semi-immersed to erumpent through host tissue, becoming superficial, globose, rough or hairy, dark brown to black, ostiolate, with short papilla, 100–200 × 90–190 µm (av. = 140 × 130 µm, n = 24).
Ostiole
central, smooth, with ostiolar canal filled with hyaline cells, 40–50 µm long, 20–30 µm diam. (av. = 45 × 25 µm, n = 10).
Setae
septate, brown, 42–60 µm (av. = 56 µm, n = 20).
Peridium
20–60 µm (av. = 40 µm, n = 20) wide at the base, 18–50 µm (av. = 35 µm, n = 20) wide at the sides, comprising 3–6 layers, with outer layer heavily pigmented, blackish to dark brown, thick-walled, scleroplectenchymatous cells of textura angularis, cells towards the inside lighter, with inner layer composed 3–4 layers, hyaline, flattened, thin-walled cells of textura angularis, (6.5–)9.0–34(–38) × (5.0–)6.0–15 μm (av. = 18 × 9.0 μm, n = 35).
Hamathecium
composed of numerous, dense, cylindrical to filiform, long, cellular pseudoparaphyses, embedded in mucilage, rarely branched, septate, 1–2.5 μm wide.
Asci
8-spored, bitunicate, fissitunicate, fusiform, short-pedicellate, rounded at apex with a minute ocular chamber, 86–138 × 18–21 µm (av. = 115 × 19 µm, n = 22).
Ascospores
biseriate, mostly ellipsoidal, muriform, 3−6 transversely eusepta, with one vertical septum, constricted at the middle septum, conical and narrow at the ends, surrounded by a mucilaginous sheath, initially hyaline, becoming light brown at maturity, 18–24 × 8–11 µm (av. = 22 × 9 µm, n = 50).
FIGURE 3.
Anamorph of
Querciphoma styphnolobii
(HMJAU 35100, holotype)
A–C.
Cultures after 16 days at 25°C (A: PDA. B: CMD. C: OA).
D.
Conidiomata on OA.
E, F.
Conidioma.
G, H.
Conidiogenous cells.
I, J.
Conidia. Scale bars: A–C = 1cm; D = 200 μm; E, F = 20 μm; G–J = 10 μm.
Asexual morph
:
Coelomycetous
structures produced in culture.
Conidiomata
pycnidial, eustromatic, solitary, sometimes aggregated, globose to subglobose, light brown, uni- to multi-locular, with 1–3 papillate ostioles, superficial or immersed in the agar, 110–260 µm (av. = 170 µm, n = 32) wide.
Conidiomata wall
scleroplectenchyma, comprising of 3–4 layers of textura angularis, outermost layer brown, inner layer hyaline, 4.0–9.0 × 2.5–6.5 µm (av. = 6.0 × 5.0 µm, n = 53).
Setae
brown, septate, 25–87 µm (av. = 64 µm, n=20).
Conidiophore
cylindrical to phialide-like, hyaline, arising from the inner layers of conidioma.
Conidiogenous cells
holoblastic, discrete, or integrated with septate, hyaline.
Conidia
cylindrical, hyaline, 1(–3) septates, the septa in the middle constricted, with 2 large guttules or several tiny guttules, 12–19 × 4.0–7.0 µm (av. = 16 × 6.0 µm, n = 77).
Culture characteristics
:
Colony
slow-growing, optimum growth at 25°C, not growing at 35°C on all media, reaching
40 mm
on PDA,
55 mm
on CMD,
58 mm
on OA after 2 weeks at 25°C. Colonies circular, dense, slightly raised to convex, or dome-shaped, dull, surface slightly rough with small turfs, velvety to floccose; colony dark-green at the margin, grey-greenish at the center on CMD and OA, almost dark on PDA. Conidiomata only formed on OA.
Distribution and Habitat:—
China
, on
Styphnolobium japonicum
.
Discussion:—
Querciphoma styphnolobii
is compatible with the generic concept of
Querciphoma
in having eustromatic, uni- to multi-locular, pycnidial conidiomata with septate setae and a thick-walled peridium of brown to dark brown or reddish-brown, scleroplectenchymatous cells. Morphologically, the
type
species,
Querciphoma minuta
has smaller (
Q. minuta
: (3.5–)4–5(–6) × 3(–3.5) µm
vs.
Q. styphnolobii
: 12.3–19 × 4.4–7.0 µm), broadly ellipsoidal, aseptate, and brown conidia (
Crous & Groenewald 2017
).
Q. styphnolobii
is easily distinguished by its smooth, hyaline, cylindrical conidia with mostly one middle constricted septum.
Querciphoma styphnolobii
differs from
Alloleptosphaeria
,
Pseudoleptosphaeria
and
Subplenodomus
in the structure of the conidiomata wall (scleroplectenchyma
vs.
pseudoparenchymatous) (
Ariyawansa
et al.
2015
,
Hongsanan
et al.
2020
).
Querciphoma styphnolobii
shares similar pycnidial characters with
Leptosphaeria
sensu stricto
,
Plenodomus
, and
Paraleptosphaeria
in the scleroplectenchymatous cell
type
in the peridium (
de Gruyter
et al.
2013
,
Ariyawansa
et al.
2015
,
Wanasinghe
et al.
2016
,
Aiello et al. 2020
,
Phukhamsakda
et al.
2020
). However,
Q. styphnolobii
has mostly 1-septate conidia rather than aseptate conidia (
Ariyawansa
et al.
2015
,
Hongsanan
et al.
2020
).
Based on morphology,
Querciphoma styphnolobii
is most similar to
Chaetoplea
with similar black perithecial ascomata with scleroplectenchymatous cells, pycnidial conidiomata with oblong to ellipsoidal, smooth-walled conidia. However,
Chaetoplea
produced brown conidia and fusiform to ellipsoidal ascospores with only transverse septa (
Phookamsak
et al.
2014
), while
Q. styphnolobii
can be easily distinguished by hyaline conidia with one middle constricted septum and muriform ascospores.
Querciphoma styphnolobii
also closely related to
Sclerenchymomyces
that was introduced by
Phukhamsakda
et al.
(2020)
which includes two species.
Sclerenchymomyces jonesii
(Wanasinghe, Camporesi & K.D. Hyde) Phukhams. & K.D. Hyde (2020: 43)
shares similarities with
Q. styphnolobii
in having globose, rough or hairy ascomata, cylindrical, short-pedicellate asci, and overlapping uniseriate, ellipsoidal, muriform ascospores with conical and narrow at the ends, but the former has different aseptate and smaller conidia (3–4 × 2–2.5 μm versus 12–19 × 4.0–7.0 µm) (
Wanasinghe
et al.
2016
,
Phukhamsakda
et al.
2020
). In addition,
Sclerenchymomyces clematidis
Phukhams. & K.D. Hyde (2020: 41)
obviously differs from
Q. styphnolobii
in broad cylindrical to oblong, and yellowish conidia with 3 septa (
Phukhamsakda
et al.
2020
).
Thirteen genera of
Leptosphaeriaceae
were included in our phylogenetic tree (
Figure. 1
) except
Chaetoplea
whose sequences are unavailable.
Querciphoma styphnolobii
is closely related to
Q. minuta
, and formed an independent lineage with high statistical support (MPBP/MLBP/BIPP = 100/100/1). In a BLASTn search of GenBank, the ITS sequence of
Q. styphnolobii
was 95.8% (100% query coverage) similar to
Q. minuta
(LG1401-MS6E) with 24 nucleotide differences from 572 base pairs (4.2%), while the LSU and SSU sequences showed 99.54% (with 96% query coverage) and 100% (with 100% query coverage) similarity to
Q. minuta
(CBS 105.91), respectively. Sequence analyses also confirmed our identification. Combined morphological and phylogenetic analyses confirmed our new species
Q. styphnolobii
as a distinct member of the genus
Querciphoma
. With the discovery of new species, the sexual morph of
Querciphoma
were supplemented. This paper also contributes to a more comprehensive update and improved identification of
Querciphoma
based on our collection.