Cryptic species of Curvularia in the culture collection of the Queensland Plant Pathology Herbarium
Author
Tan, Yu Pei
Author
Crous, Pedro W.
Author
Shivas, Roger G.
text
MycoKeys
2018
35
1
25
http://dx.doi.org/10.3897/mycokeys.35.25665
journal article
http://dx.doi.org/10.3897/mycokeys.35.25665
1314-4049-35-1
Curvularia sporobolicola Y.P. Tan & R.G. Shivas
sp. nov.
Fig. 5
C-E
Type.
Australia, Queensland, Musselbrook Reserve, leaf of
Sporobolus australasicus
, 2 May 1995, J.L. Alcorn (holotype BRIP 23040b, includes ex-type culture).
Description.
Colonies
on PDA approx. 6 cm diam. after 7 d at 25 °C, surface funiculose, margin fimbriate, olivaceous black, velutinous.
Hyphae
subhyaline, smooth, branched, septate, 3
µm
wide.
Conidiophores
erect, straight to flexuous, geniculate, pale yellowish-brown, septate, up to 55
µm
long, 4−5
µm
wide, basal cell swollen, 6−10
µm
diam.
Conidiogenous cells
cylindrical, slightly flared at the apex, integrated, sympodial, pale brown, smooth, with darkened and thickened scars.
Conidia
hemi-ellipsoidal, curved, 4-distoseptate with a faint narrow median septum, (34-) 37-41 (-45)
x
(14-) 17-20 (-23)
µm
, brown to dark brown, end cells rounded and paler, hila non-protuberant, sometimes darkened.
Etymology.
Named after
Sporobolus
, the grass genus from which it was isolated.
Notes.
Based on multilocus phylogenetic analyses,
C. sporobolicola
clustered sister to
C. papendorfii
, which are both sister to
C. eragrosticola
(Fig. 1).
Curvularia sporobolicola
is distinguished in three loci from the ex-type cultures of
C. papendorfii
(99% in ITS, 96% in gapdh and 98% in tef1α) and
C. eragrosticola
(98% in ITS, 92% in gapdh and 98% in tef1α). These three species are similar in having dark brown, hemi-ellipsoidal, curved, conidia, which makes identification by morphology difficult. The conidia of
C. sporobolicola
tend to be wider than those of C.
eragrosticola
(25-35
x
9-19
µm
, this study) and
C. papendorfii
(30-50
x
9-19
µm
,
Sivanesan 1987
).
Curvularia sporobolicola
is only known from the type specimen on
S. australasicus
, which is a native Australian grass with a broad distribution in the tropics and subtropics (
Simon and Alfonso 2011
). Other
Curvularia
species associated with
Sporobolus
include
C. australis
,
C. crustacea
,
C. eragrostidis
,
C. geniculata
,
C. lunata
,
C. ovariicola
,
C. pallescens
,
C. ravenelii
and
C. ryleyi
(
Sivanesan 1987
,
Farr and Rossman 2018
), although this is the first
Curvularia
species associated with
S. australasicus
.