Morphological and phylogenetic analyses reveal three new species of Diaporthe from Yunnan, China
Author
Huang, Shengting
College of Life Sciences, Yangtze University, Jingzhou 434025, Hubei, China
Author
Xia, Jiwen
https://orcid.org/0000-0002-7436-7249
College of Life Sciences, Yangtze University, Jingzhou 434025, Hubei, China
Author
Zhang, Xiuguo
Shandong Provincial Key Laboratory for Biology of Vegetable Diseases and Insect Pests, College of Plant Protection, Shandong Agricultural University, Taian, Shandong, 271018, China
Author
Sun, Wenxiu
College of Life Sciences, Yangtze University, Jingzhou 434025, Hubei, China
text
MycoKeys
2021
2021-02-19
78
49
77
http://dx.doi.org/10.3897/mycokeys.78.60878
journal article
http://dx.doi.org/10.3897/mycokeys.78.60878
1314-4049-78-49
5BCC2C78F2F856C3B93134F805790F02
Diaporthe machili S.T. Huang, J.W. Xia, W.X. Sun, & X.G. Zhang
sp. nov.
Figure 5
Etymology.
Named after the host genus on which it was collected,
Machilus pingii
.
Diagnosis.
Diaporthe machili
differs from
D. caryae
and
D. sackstonii
in the types of conidia (
D. machili
only produces beta conidia, while
D. caryae
produces alpha conidia and beta conidia, and
D. sackstonii
only produces alpha conidia), and from
D. caryae
in longer beta conidia (29.0-39.0
x
1.3-1.5 vs. 15.5-34.0
x
1.1-1.4
μm
).
Type.
China, Yunnan Province: Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, on diseased leaves of
Machilus pingii
(
Lauraceae
). 19 April 2019, S.T. Huang, HSAUP194.111 holotype, ex-holotype living culture SAUCC194.111.
Figure 5.
Diaporthe machili
(SAUCC194.111)
a
infected leaf of
Machilus pingii
b, c
surface and reverse of colony after 15 days on PDA
d, e
conidiomata
f-h
conidiophores and conidiogenous cells
i-k
beta conidia. Scale bars: 10
μm
(
f-k
).
Description.
Asexual morph: Conidiomata pycnidial, aggregated, black, erumpent, subglobose to globose, exuding creamy conidial droplets from central ostioles after 30 days in light at 25 °C. Conidiophores 7.0-11.4
x
1.8-2.8
μm
, hyaline, unbranched, densely aggregated, mostly ampulliform, cylindrical, guttulate, septate, straight or slightly curved, swelling at base, tapering towards apex. Beta conidia 29.0-39.0
x
1.3-1.5
μm
(mean = 32.5
x
1.4
μm
, n = 20), filiform, hyaline, aseptate, mostly curved, J-shaped, swelling in middle, tapering towards both ends. Alpha and gamma conidia not observed. Sexual morph not observed.
Culture characteristics.
Cultures incubated on PDA at 25 °C in darkness, growth rate 16.3-17.5 mm diam/day, aerial mycelium abundant, white on surface, reverse white to pale yellow, with an obvious concentric zonation, pycnidia forming after 15 days.
Additional specimen examined.
China, Yunnan Province: Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, on diseased leaves of
Pometia pinnata
(
Sapindaceae
). 19 April 2019, S.T. Huang, HSAUP194. 69 paratype; living culture SAUCC194. 69.
Notes.
In the phylogenetic tree,
Diaporthe machili
forms an independent clade and is phylogenetically distinct from
D. caryae
and
D. sackstonii
(Fig.
1
).
Diaporthe machili
can be distinguished from
D. caryae
in ITS, TUB, TEF, CAL and HIS loci by 67 nucleotide differences in concatenated alignment (5/459 in ITS, 10/416 in TUB, 15/334 in TEF, 7/454 in CAL and 30/455 in HIS), and from
D. sackstonii
in ITS, TUB and TEF loci by 58 nucleotide differences (12/559 in ITS, 23/486 in TUB and 23/348 in TEF). Moreover,
Diaporthe machili
differs from
D. caryae
in having longer beta conidia (29.0-39.0
x
1.3-1.5 vs. 15.5-34.0
x
1.1-1.4
μm
).
Diaporthe machili
only produces beta conidia, while
D. caryae
produces alpha conidia and beta conidia, and
D. sackstonii
only produces alpha conidia (
Thompson et al. 2015
;
Yang et al. 2018b
).