Botryosphaeriaceae on palms-a new species of Neodeightonia, N. chamaeropicola, and new records from diseased foliage of ornamental palms in Portugal
Author
Pereira, Diana S.
Author
Phillips, Alan J. L.
text
Phytotaxa
2023
2023-11-29
627
1
1921
1935
https://phytotaxa.mapress.com/pt/article/download/phytotaxa.627.1.1/51323
journal article
280019
10.11646/phytotaxa.627.1.1
2aa5fc45-0415-4a9b-82ed-908e64c1182f
1179-3163
10216659
Sardiniella
Linaldeddu, A. Alves & A.J.L. Phillips,
Mycosphere
7: 900 (2016)
, MycoBank MB817511
Sardiniella
was introduced by
Linaldeddu
et al
. (2016)
with
S. urbana
on a branch canker of
Celtis australis
from
Italy
as the
type
species. It accommodates species that are morphologically similar to, but phylogenetically distinct from
Dothiorella
and
Diplodia
. Species in
Sardiniella
are characterized by hyaline, aseptate conidia that become pigmented and 1-septate with age. While in
Dothiorella
and some
Diplodia
species
, namely those with aseptate brown conidia, the conidia become pigmented while still attached to the conidiogeneous cells, this has not yet been observed in
Sardiniella
. Moreover, the conidial wall is thicker in
Diplodia
than in
Sardiniella
(
Linaldeddu
et al
. 2016
)
. So far,
Sardiniella
species
have been reported as pathogens and saprobes of woody hosts. While
S. urbana
was isolated from diseased ornamental
Celtis australis
trees on the island of
Sardinia
,
Italy
(
Linaldeddu
et al
. 2016
), the remaining species have been isolated from decaying plant material (
Hyde
et al
. 2017
,
Chen
et al
. 2021
,
Dissanayake
et al
. 2021
). Currently
Sardiniella
includes four species based on both morphological and phylogenetic analyses, viz.
S. urbana
(
Linaldeddu
et al
. 2016
)
,
S. celtidis
(
Hyde
et al
. 2017
)
,
S. guizhouensis
(
Chen
et al
. 2021
)
and
S. elliptica
(
Dissanayake
et al
. 2021
)
.
Sardiniella urbana
Linaldeddu, A. Alves & A.J.L. Phillips,
Mycosphere
7: 900 (2016)
, MycoBank MB817512 (
Figure 16
)
Type
:
ITALY
, Sassari, isolated from a branch canker of
Celtis australis
(
Cannabaceae
),
9 Sep 2013
, Benedetto
T
. Linaldeddu (
holotype
LISE
96308, culture ex-type
CBS
141580).
Sexual morph not reported. See
Linaldeddu
et al
. (2016)
for illustrations and descriptions of asexual morph.
FIGURE 16.
Sardiniella urbana
(CDP 1658)
. A–E. Conidiogenous layer. F–K. Conidiogenous cells. L, M. Hyaline, aseptate conidia. N. Pigmented, 1-septate conidium. Scale bars: A, L–M = 10 μm, B–E = 5 μm, F–K = 2.5 μm.
Isolate
CDP
1658.
Sexual morph
: Undetermined.
Asexual morph
:
Conidiomata
on palm leaflets in culture pycnidial, globose to subglobose, non-stromatic, uniloculate, black, solitary, occasionally aggregated in small groups of 2–3, superficial, or immersed in the host becoming erumpent when mature, covered with mycelial hairs, thick-walled.
Conidiophores
reduced to conidiogenous cells.
Conidiogenous cells
lining the pycnidial cavity, hyaline, smooth- and thin-walled, simple, discrete, determinate, cylindrical to broadly lageniform, straight or slightly curved, aseptate, rarely 1-septate, enteroblastic, proliferating at the same level giving rise to periclinal thickenings, or proliferating percurrently giving rise to 1–2 indistinct annelations, 5.69–13.72 × 2.71–5 μm, 95 % confidence limits = 8.12–9.39 × 3.69–4.11 μm (mean ±
SD
= 8.76 ± 1.77 × 3.90 ± 0.60 μm, n = 30).
Conidia
ellipsoid to broadly ellipsoid, few broadly obovoid or slightly reniform, rounded ends, few with subobtuse base, slightly narrower in the middle, thick-walled, hyaline and aseptate, becoming pale brown to brown and 1-septate, rarely 2-septate, with age, eguttulate, 23.71–29.42 × 9.36–11.01 μm, 95 % confidence limits = 25.67–26.63 × 9.84–10.15 μm (mean ±
SD
= 26.15 ± 1.34 × 9.99 ± 0.44 μm), mean ±
SD
conidium length/width ratio = 2.62 ± 0.21 (n = 30).
Culture characteristics
:
Colonies on 1/2
PDA
, reaching
73 mm
diam. after 7 d at 20 ℃ in darkness. Surface flat, with sparse aerial mycelium, with entire, slightly undulate margin, circular shape, whitish to pale, opaque. Reverse pale to yellowish. Turning entirely dark grey to black after about
2 w.
No diffusible pigment
.
Material examined
:
PORTUGAL
,
Lisbon
, Parque das Nações, on foliar lesions of leaflets of
Phoenix reclinata
(
Arecaceae
),
8 May 2021
, Diana
S
. Pereira (specimen
HDP
093,
new host and geographical record
), living culture
CDP
1658 (
ITS
sequence OQ996239,
tef1
sequence
OR
233682).
Hosts
:
Celtis australis
(
Cannabaceae
) (
Linaldeddu
et al
. 2016
) and
Phoenix reclinata
(
Arecaceae
) (present study).
Distribution
:
Italy
(
Linaldeddu
et al
. 2016
) and
Portugal
(present study).
Notes
: Based on the phylogenetic analyses of the combined ITS-
tef1
dataset, strain
CDP
1658 clustered with the ex-type strain and other strains of
Sardiniella urbana
with maximum ML-BS/PP values (
Figure 6
). Sequence comparisons with the ex-type of
S. urbana
(
CBS
141580) for
ITS
and
tef1
showed 100 % and 98.81 %, respectively, sequence similarity and differences are represented by few base pair changes in
tef1
partial sequence. Morphologically,
CDP
1658 isolated in this study is similar to the
holotype
of
S. urbana
from a branch canker of
Celtis australis
in
Italy
(
Linaldeddu
et al
. 2016
). Both produce globose pycnidial conidiomata with ellipsoid, thick-walled, hyaline and aseptate conidia, that become brown and 1–2-septate with age. Nonetheless, conidia of
CDP
1658 are somewhat longer, but narrower than those of the ex-type of
S. urbana
(
CBS
141580) (mean = 26.15 × 9.99 μm
versus
23.5 × 12 μm, respectively) (
Linaldeddu
et al
. 2016
) (
Figure 16
). Thus, based on these morpho-molecular analyses, strain
CDP
1658 was identified as
S. urbana
.
Sardiniella urbana
has only been reported from
Celtis australis
(
Cannabaceae
) in
Italy
(
Linaldeddu
et al
. 2016
). In the present study,
S. urbana
is reported on
Phoenix reclinata
(
Arecaceae
) in
Portugal
, representing a new host and geographical record (
Table 5
). The isolate of
S. urbana
studied was recorded from foliar lesions of
P. reclinata
, but pathogenicity has not been tested.