Four new species of Dothideomycetes (Ascomycota) from Para Rubber (Hevea brasiliensis) in Yunnan Province, China
Author
Xu, Rui-Fang
https://orcid.org/0000-0003-1207-8254
Center for Yunnan Plateau Biological Resources Protection and Utilization, College of Biological Resource and Food Engineering, Qujing Normal University, Qujing, Yunnan 655011, China & Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, Thailand
Author
Karunarathna, Samantha C.
https://orcid.org/0000-0001-7080-0781
Center for Yunnan Plateau Biological Resources Protection and Utilization, College of Biological Resource and Food Engineering, Qujing Normal University, Qujing, Yunnan 655011, China & School of Science, Mae Fah Luang University, Chiang Rai, 57100, Thailand
Author
Phukhamsakda, Chayanard
https://orcid.org/0000-0002-1033-937X
Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai, Thailand
Author
Dai, Dong-Qin
https://orcid.org/0000-0001-8935-8807
Center for Yunnan Plateau Biological Resources Protection and Utilization, College of Biological Resource and Food Engineering, Qujing Normal University, Qujing, Yunnan 655011, China
Author
Elgorban, Abdallah M.
https://orcid.org/0000-0003-3664-7853
National Institute of Fundamental Studies (NIFS), Kandy, Sri Lanka
Author
Suwannarach, Nakarin
https://orcid.org/0000-0002-2653-1913
Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
Author
Kumla, Jaturong
https://orcid.org/0000-0002-3673-6541
Department of Botany and Microbiology, College of Science, King Saud University, Riyadh 11451, Saudi Arabia
Author
Wang, Xiao-Yan
https://orcid.org/0009-0009-6430-3637
Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand & Center of Excellence in Microbial Diversity and Sustainable Utilization, Chiang Mai University, Chiang Mai, Thailand
527010142@qq.com
Author
Tibpromma, Saowaluck
https://orcid.org/0000-0002-4706-6547
Center for Yunnan Plateau Biological Resources Protection and Utilization, College of Biological Resource and Food Engineering, Qujing Normal University, Qujing, Yunnan 655011, China
saowaluckfai@gmail.com
text
MycoKeys
2024
2024-03-22
103
71
95
http://dx.doi.org/10.3897/mycokeys.103.117580
journal article
http://dx.doi.org/10.3897/mycokeys.103.117580
1314-4049-103-71
0C28E032647A557A9563F8DDF53D2D47
Nigrograna lincangensis R.F. Xu & Tibpromma
sp. nov.
Fig. 4
Etymology.
The name refers to the location "Lincang, Yunnan, China", where the holotype was collected.
Holotype.
ZHKU 23-0104.
Description.
Saprobic
on a dead branch of
Hevea brasiliensis
.
Sexual morph
: Ascomata 285-360
μm
high, 230-307
μm
diam. (x‾ = 337
x
272
μm
, n = 5), immersed, under the clypeus, sometimes inconspicuous on host surface and small bumps can be seen, solitary, dark brown, globose or ellipsoid, with papilla. Ostioles 117-217
x
68-124
μm
(x‾ = 152
x
99
μm
, n = 10), central, brown, papillate. Peridium 16-45
μm
wide, comprising several layers with dark-brown to dark cells of textura angularis. Hamathecium comprises 1.5-3
μm
wide, unbranched, septate, hyaline, pseudoparaphyses. Asci 45-70
x
9-12
μm
(x‾ = 57
x
10
μm
, n = 10), 8-spored, bitunicate, pedicellate, club shape, cylindrical to clavate, straight or slightly curved, apically rounded, thick-walled. Ascospores 10-15
x
4-6
μm
(x‾ = 13
x
4.8
μm
, n = 30), 1-2-seriate, initially 1-septate, becoming 3-septate at the maturity, fusoid to narrowly ellipsoid, upper part or second cell slightly wider and tapering towards narrow ends, constricted at the septa, hyaline to yellow-brown to brown with age, guttulate, think-walled.
Asexual morph
: Undetermined.
Culture characteristics.
Spores germinated within 12 hours, colonies grow on PDA at 28 °C, circular, floppy, entire edge, raised, grey to taupe, reverse dark brown.
Material examined.
China
,
Yunnan Province
,
Lincang
, on a dead branch of
Hevea brasiliensis
,
28 July 2022
, Rui-Fang Xu, LCR06, (ZHKU 23-0104,
holotype
); ex-type ZHKUCC 23-0798, ZHKUCC 23-0799
.
GenBank numbers.
ZHKUCC 23-0798 = ITS: OR853099, LSU: OR922323, SSU: OR941079,
tef
1-α: OR966282,
rpb
2: OR966280; ZHKUCC 23-0799 = ITS: OR853100, LSU: OR922324, SSU: OR941080,
tef1-α
: OR966283,
rpb
2: OR966281.
Notes.
In the phylogenetic analyses,
Nigrograna lincangensis
(ZHKUCC 23-0798) forms a closely-related clade to
N. asexualis
(ZHKUCC 22-0214),
N. aquilariae
(ZHKUCC 23-0070) and
N. verniciae
with 100% ML and 1.00 PP support (Fig.
3
). However, we could not compare the morphological characteristics of
N. lincangensis
and
N. asexualis
, because
N. lincangensis
was described only from its sexual morph in nature, while
N. asexualis
was described by its asexual morph in nature from coffee in China. A comparison of the ITS region of
N. lincangensis
and
N. asexualis
revealed 16 base pair differences (3.46%) across 462 nucleotides, 40 base pair differences (4.21%) across 949 nucleotides in
tef
1-α gene, 124 base pair differences (12%) across 1033 nucleotides in
rpb
2 gene.
Nigrograna aquilariae
and
N. verniciae
have very similar morphological characteristics, but they can be differentiated by having wider ascomata (285-360
μm
vs. 180-270
μm
), larger asci (45-70
x
9-12
μm
vs. 49-57
x
7-9
μm
) and larger ascospores (10-15
x
4-6
μm
vs. 10-13
x
3.5-4.5
µm
) in
N. lincangensis
(
Du et al. 2024
); while
N. verniciae
has larger ascomata (340-360
x
350-370
μm
vs. 85-360
μm
x
230-307
μm
) and asci with knob-like to furcate pedicels (
Li et al. 2023
).
Figure 3.
Phylogram generated from Maximum Likelihood analysis based on combined LSU, ITS, SSU,
tef
1-α and
rpb
2 sequence data of 119 taxa, which comprised 4399 base pairs (LSU = 908 bp, ITS = 512 bp, SSU = 1000 bp,
tef
1-α = 925 bp,
rpb
2 = 1054 bp). The best scoring RAxML tree with a final likelihood value of -38918.764563 is presented. The matrix had 2023 distinct alignment patterns, with 39.00% of undetermined characters or gaps. Estimated base frequencies were as follows: A = 0.245191, C = 0.247520, G = 0.268228, T = 0.239061; substitution rates: AC = 1.533778, AG = 3.877174, AT = 1.672983, CG = 1.254032, CT = 8.838860, GT = 1.000000; gamma distribution shape parameter
α
= 0.208600. Bootstrap support values for ML equal to or greater than 60% and Bayesian Inference analysis values equal to or greater than 0.90 PP are labelled at each node. The tree is rooted with
Seriascoma didymospora
(MFLUCC 11-0179) and
S. didymospora
(MFLUCC 11-0194). Related sequences were obtained from
De Silva et al. (2022)
,
Lu et al. (2022)
and
Li et al. (2023)
. The new isolates are indicated in red and the ex-type strains are in bold.
Nigrograna lincangensis
has similar ascomata, asci and ascospore characteristics similar to other
Nigrograna
species (
Jaklitsch and Voglmayr 2016
;
Hyde et al. 2017
;
Tibpromma et al. 2017
;
Dayarathne et al. 2020
;
Mapook et al. 2020
;
Lu et al. 2022
). However,
N. lincangensis
differs from
N. cangshanensis
by having larger ascomata (285-360
x
230-307
μm
vs. 120-135
x
135-155
μm
) (
Tibpromma et al. 2017
).
Nigrograna chromolaenae
can be distinguished from
N. lincangensis
in having smaller ascomata (160-280
x
115-130
μm
vs. 285-360
x
230-307
μm
), smaller asci (40-55
x
7-10
μm
vs. 45-70
x
9-12
μm
), and greyish-brown to dark brown ascospores (
Mapook et al. 2020
).
Nigrograna coffeae
differs from
N. cangshanensis
by having smaller ascomata (90-140
x
140-200
μm
vs. 285-360
x
230-307
μm
), 1-septate ascospores (
Lu et al. 2022
).
Nigrograna novergica
differs from
N. lincangensis
as it occurs on pseudostromata from the host of
Diaporthe
sp. (
Jaklitsch and Voglmayr 2016
).
Nigrograna mycophila
and
N. obliqua
are distinct from
N. lincangensis
by having dark brown ascospores (
Jaklitsch and Voglmayr 2016
).
Nigrograna puerensis
differs from
N. lincangensis
by having acute apical and basal cells and the apical cells are wider than the basal cells (
Lu et al. 2022
).
Nigrograna samueliana
differs from
N. lincangensis
by the absence of ostiole (
Dayarathne et al. 2020
).
Nigrograna thymi
can be easily distinguished from
N. lincangensis
in having 4-5 septate (
Hyde et al. 2017
). Therefore,
N. lincangensis
is described here as a new species, based on phylogeny and morphology.
Figure 4.
Nigrograna lincangensis
(ZHKU 23-0104,
holotype
)
a-c
appearance of ascomata on the host surface
d
vertical section of an ascoma
e
vertical section of ostiole
f
hamathecium and asci
g
section of peridium
h-k
asci
l
ascospores
m
a germinated ascospore
n, o
colonies on PDA (n-front and o-reverse views). Scale bars: 100
µm
(
d
); 50
µm
(
e
); 30
µm
(
f
); 200
µm
(
g
); 10
µm
(
h-k
); 5
µm
(
l
); 20
µm
(
m
).