Myrothecium-like new species from turfgrasses and associated rhizosphere
Author
Liang, Junmin
Author
Li, Guangshuo
Author
Zhou, Shiyue
Author
Zhao, Meiqi
Author
Cai, Lei
text
MycoKeys
2019
51
29
53
http://dx.doi.org/10.3897/mycokeys.51.31957
journal article
http://dx.doi.org/10.3897/mycokeys.51.31957
1314-4049-51-29
Paramyrothecium sinense J.M. Liang, G.S. Li & L. Cai
sp. nov.
Fig. 6
Type.
China, Beijing, Olympic Park, from rhizosphere soil of
Poa
sp., 13 Dec 2017, S.Y. Zhou, holotype HMAS 247956, ex-holotype culture CGMCC3.19212 = LC12136.
Description.
Colonies on PDA, CMA and OA approx. 5-6 cm diam. after 7 d at 25 °C. Hyphae white, hyaline, smooth, branched, 1-2
μm
wide, reverse on PDA pale luteous. Conidiomata sporodochial, stromatic, cupulate, superficial, scattered or gregarious, oval or irregular in outline, 80-600
μm
diam., 50-150
μm
deep, with a white setose fringe surrounding an olivaceous green to black agglutinated slimy mass of conidia. Stroma poorly developed, hyaline, of textura angularis. Setae arising from stroma, thin-walled, hyaline, 1-3-septate, straight to flexuous, 45-90
μm
long, 1-3
μm
wide, tapering to an acutely rounded apex. Conidiophores arising from the basal stroma, consisting of a stipe and a penicillately branched conidiogenous apparatus; stipes unbranched, hyaline, septate, smooth, 20-30
x
2-3
μm
; primary branches aseptate, unbranched, smooth, 13-40
x
2-3
μm
; secondary branches aseptate, unbranched, smooth, 8-15
x
2-3
μm
; terminating in a whorl of 3-6 conidiogenous cells; conidiogenous cell phialidic, cylindrical to subcylindrical, hyaline, smooth, straight to slightly curved, 7-16
x
1-3
μm
, with conspicuous collarettes and periclinal thickenings. Conidia aseptate, hyaline, smooth, cylindrical, 6-7
x
2-3
μm
(av. 7
+/-
0.3
x
2
+/-
0.2
μm
, n = 40), rounded at both ends.
Figure 6.
Paramyrothecium sinense
(from ex-type CGMCC3.19212)
a-c
colony on PDA, CMA, OAd conidiomata on SNAe sporodochial conidioma f setae g conidia h conidiogenous cells. Scale bars: 20
μm
(e, f); 10
μm
(g); 5
μm
(h).
Distribution.
China.
Etymology.
Named after the country of collection, China.
Additional isolate examined.
China, Beijing, Olympic Park, from rhizosphere soils of
Poa
sp., 13 Dec 2017, S.Y. Zhou, LC12137, LC12138, LC12139.
Notes.
Lombard et al. (2016)
introduced a new genus,
Paramyrothecium
, based on an epitype of
Myrothecium roridum
Tode, 1790.
Gams (2016)
pointed out that
Myrotheciella catenuligera
, the type species of
Myrotheciella
was listed as a synonym of
P. roridum
by
Lombard et al. (2016)
, thus
Paramyrothecium
is illegitimate and
Myrotheciella
should be the correct name for
Paramyrothecium
. However, the original description of
Myrotheciella catenuligera
suggested that it lacks seta (
Spegazzini 1911
), thus is clearly different from the morphological circumscription of
P. roridum
. Therefore, we do not agree with the treatment of
Lombard et al. (2016)
of listing
Myrotheciella catenuligera
as a synonym of
P. roridum
.
Paramyrothecium sinense
formed a highly supported distinct clade closely related to
P. humicola
. The setae of this species are terminated with obtuse apices, dissimilar to the acute apices in
P. humicola
. In addition, the conidiophore stipes (20-30
μm
long) and primary branches (13-40
μm
long) of
P. sinense
are much longer than those of
P. humicola
(stipe, 12-22
μm
long; primary branches, 7-17
μm
long) (
Lombard et al. 2016
). Among old un-sequenced taxa in
Myrothecium
, only
M. biforme
and
M. dimorphum
show seta with obtuse apices, but both taxa produce two types of conidia (
Jiang et al. 2014
;
Watanabe et al. 2003
).