Claviceps arundinis identification and its role in the die-back syndrome of Phragmites australis populations in central Italy

Abstract

Common reed Phragmites australis (Cav.) Trin. ex Steud. is one of the most widely distributed angiosperms with important ecological functions. In recent decades, it has been affected by a severe decline known as reed die-back syndrome (RDBS), the causal factors of which are still under investigation. Among the biotic factors that influence the dynamic of the reed population, the role of microorganisms is still poorly understood. During surveys carried out on P. australis populations in Central Italy, Claviceps-like sclerotia were detected: is Claviceps infection related to P. australis sexual reproduction and seed production? Could Claviceps infection be involved in the RDBS? These are the questions that we address. We characterized the sclerotia at the morphological, molecular, and chemical level and we demonstrated that they belong to Claviceps arundinis Pažoutová & M. Kolařík. To our knowledge, this is the first report of C. arundinis on P. australis in Italy. Furthermore, the association of C. arundinis with RDBS was evaluated considering a set of macromorphological traits generally related to RDBS, such as P. australis clumping habit, culm height and diameter. No correlation was seen between the occurrence of C. arundinis and the declining status of reed populations.

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Claviceps arundinis identification and its role in
the die-back syndrome of Phragmites australis
populations in central Italy
M. Cerri, L. Reale , C. Moretti , R. Buonaurio, A. Coppi , V. Ferri, B. Foggi , D.
Gigante , L. Lastrucci, M. Quaglia , R. Venanzoni & F. Ferranti
To cite this article: M. Cerri, L. Reale , C. Moretti , R. Buonaurio, A. Coppi , V. Ferri, B. Foggi ,
D. Gigante , L. Lastrucci, M. Quaglia , R. Venanzoni & F. Ferranti (2017): Claviceps arundinis
identification and its role in the die-back syndrome of Phragmites australis populations in central
Italy, Plant Biosystems - An International Journal Dealing with all Aspects of Plant Biology, DOI:
10.1080/11263504.2017.1347111
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PLANT BIOSYSTEMS, 2017
https://doi.org/10.1080/11263504.2017.1347111
Claviceps arundinis identication and its role in the die-back syndrome of Phragmites
australis populations in central Italy
M.Cerria#, L.Realea#, C.Morettia, R.Buonaurioa, A.Coppib, V.Ferria, B.Foggib, D.Gigantec, L.Lastruccib,
M.Quagliaa, R.Venanzonic and F.Ferrantia
aDepartment of Agricultural, Food and Environmental Sciences, University of Perugia, Perugia, Italy; bDepartment of Biology, University of Florence,
Florence, Italy; cDepartment of Chemistry, Biology and Biotechnology, University of Perugia, Perugia, Italy
ABSTRACT
Common reed Phragmites australis (Cav.) Trin. ex Steud. is one of the most widely distributed angiosperms
with important ecological functions. In recent decades, it has been aected by a severe decline known
as reed die-back syndrome (RDBS), the causal factors of which are still under investigation. Among the
biotic factors that inuence the dynamic of the reed population, the role of microorganisms is still poorly
understood. During surveys carried out on P. australis populations in Central Italy, Claviceps-like sclerotia
were detected: is Claviceps infection related to P. australis sexual reproduction and seed production? Could
Claviceps infection be involved in the RDBS? These are the questions that we address. We characterized
the sclerotia at the morphological, molecular, and chemical level and we demonstrated that they belong
to Claviceps arundinis Pažoutová & M. Kolařík. To our knowledge, this is the rst report of C. arundinis on
P. australis in Italy. Furthermore, the association of C. arundinis with RDBS was evaluated considering a set
of macromorphological traits generally related to RDBS, such as P. australis clumping habit, culm height
and diameter. No correlation was seen between the occurrence of C. arundinis and the declining status of
reed populations.
Introduction
Phragmites australis (Cav.) Trin. ex Steud. is one of the most wide-
spread monocotyledonous species (Tucker 1990). It grows in
dierent habitats, such as the shores of lakes, rivers, estuaries,
urban areas (Haslam 1972; Brix 1999). Reed beds are considered
valuable ecosystems and are often protected because of their
important ecological functions (Brix 1999). Since the 1950s, reed
beds have been aected by a severe decline known as reed die-
back syndrome (RDBS). RDBS was initially detected in Northern,
Central, and Eastern Europe (van der Putten 1997) and then in the
Mediterranean area. Recent investigations have also reported
RDBS in Italy (Gigante et al. 2011). RDBS is a complex decline that
aects reed populations, characterized by symptoms such as
smaller size, weaker culms, dead rhizomes and buds, owering
delay, low rhizome starch levels, clumping habit, and an evident
retreat, especially from deep waters (for a general overview, see
van der Putten 1997; Brix 1999). Although widely investigated,
the causes of this decline have not been completely explained
yet. Together with environmental factors, such as water level or
eutrophication, also human activities are reported to be impli-
cated in RDBS; these can involve direct destruction, recreational
use of lake shores, and waste-water dumping (Ostendorp et al.
2003). Lastrucci et al. (2016) showed that reed die-back and pro-
longed ooding are related, and highlighted the potential role
of some chemical parameters in the growth of permanently
ooded reeds. However, the role of the microorganisms remains
poorly studied (Wirsel et al. 2002; Nechwatal et al. 2008). In the
natural environment, plants interact with myriads of endophytic
and/or epiphytic microorganisms that may aect host popula-
tion dynamics (Sanchez Marquez et al. 2012; Perez et al. 2013;
Perotto et al. 2013). Given their key role, these interactions need
to be investigated in detail when searching for factors that aect
ecosystem processes. Since 2014, surveys to analyze the health
status of P. australis in Central Italy have been carried out, inves-
tigating a set of morphological traits related to the RDBS. During
the eld activities of August–September 2014 and 2015 (i.e.
the end of the vegetative season), a large number of Claviceps-
like sclerotia were found in the inorescences of P. australis in
Colorito marsh and Lake Trasimeno (Umbria, Central Italy).
Claviceps purpurea (Fr.) Tul. sensu lato is a parasitic ascomycet-
ous fungus that has a wide host-range, which includes the entire
subfamily of Pooideae, many members of the Arundinoideae,
and some species belonging to Panicoideae and Chloridoideae
(Brewer and Loveless 1977). C. purpurea infection results in sub-
stitution of the grains by overwintering sclerotia that contain
various amount of alkaloids, mainly ergosine and ergocristine,
which are toxic to humans and are responsible for the ergotism
(see e.g. Miedaner and Geiger 2015).
ARTICLE HISTORY
Received 10 March 2017
Accepted19 June 2017
KEYWORDS
Alkaloid; Claviceps; common
reed; die-back; sclerotia; seed
© 2017 Società Botanica Italiana
CONTACT M. Cerri cerri.martina@gmail.com
#These authors contributed equally to this work.

2 M. CERRI ET AL.
Mediterranean bioclimate, with annual mean temperature of
13.6°C and mean precipitation of 747mm. The present inves-
tigation was carried out at the end of the growing season of
P. australis (i.e. August–September) in 2014 and 2015.
Plant material
Two permanently ooded (Colorito marsh:CO01, CO03; Lake
Trasimeno: TR01, TR04) and two temporarily ooded (Colorito
marsh: CO09, CO10; Lake Trasimeno: TR09, TR10) plots were cho-
sen from each site. Plots were selected according to a randomly
stratied criterion, on the basis of the ooding duration, which is
an ecological condition that appears to have a prominent role in
the RDBS (Gigante et al. 2014; Lastrucci et al. 2016). These ood-
ing conditions were dened as: (i) permanent ooding, with the
presence of a water column (at least 10cm depth) even in the
driest season of the year (end of summer, for the study area) and
(ii) temporary ooding, with periodic emersion at least in the dri-
est season. For the molecular analysis only, six more plots were
considered in Colorito marsh, where the incidence of infection
appeared higher (CO02, CO04, CO05, CO06, CO07, and CO08).
Morphological characterization of the Claviceps-like
sclerotia
In each plot, 40 Claviceps-like sclerotia were randomly col-
lected from 10 dierent plants, except for the permanently
ooded plots of Lake Trasimeno (TR01, TR04), where no sclero-
tia were detected. The analyzed morphological traits of sclero-
tia were length, color, shape and oating ability, as reported by
Pažoutová et al. (2000). To grow the mycelium, the sclerotia were
surface sterilized for 2min in 1.2% sodium hypochlorite, rinsed
three times for 3min in sterilized distilled water, then placed on
T2 agar plates (Pažoutová et al. 1998), supplemented with ampi-
cillin 100μg ml−1. After 14days of growth at 28°C in the dark,
conidia were obtained; for each plot, 20 conidia were measured,
using the microscope BX 53 (Olympus, Hamburg, Germany).
Extraction of fungal DNA and molecular identication of
the Claviceps-like sclerotia
Genomic fungal DNA was extracted from the sclerotia (ca.
100mg) using Zymo Research Fungal/Bacterial DNA kit (Zymo
Research, Irvine, CA, USA), following the manufacturer instruc-
tions. The amount, purity and integrity of DNA samples were
determined by measuring the absorbance at 260 and 280nm,
and by gel electrophoresis with 1.0% TAE 0.5×agarose gel, for
30min at 100V.
The fungal isolates were identied by sequencing the
Internal Transcribed Spacer (ITS) regions of fungal ribosomal
DNA, using the ITS1 (5′-TCCGTAGGTGAACCTGCGG-3′) and
ITS4 (5′-TCCTCCGCTTATTGATATGC-3′) primers (White et al.
1990). Furthermore, the identication was conrmed through
sequencing of the β-tubulin gene, which was amplied using
the Bt2a (5′-GGTAACCAAATCGGTGCTGCTTTC-3′) and Bt2b
(5′-ACCCTCAGTGTAGTGACCCTTGGC-3′) primers (Glass and
Donaldson 1995).
Amplications were performed in a MyCyclerThermal cycler
(BioRad, Hercules, CA, USA) following the cycling parameters
Ergotism was a serious problem during the Middle Ages,
although nowadays it persists only in the wildlife and very rarely
among livestock: in Norway, it has been occasionally reported in
moose (Handeland and Vikøren 2005) and in the USA in cattle and
horses (Morrie Craig et al. 2015). The morphological features of
C. purpurea s.l. are relatively variable (Loveless 1971; Pažoutová
et al. 2000). The single-cell conidia are polymorphic, and sclerotia
bear 2–50mm long stromata of variable color, ranging from red
to purple and even to orange, and containing dierent types of
alkaloids. Along with the molecular data obtained from the DNA
sequencing, these morphological and chemical features have
revealed that there are four distinct groups (cryptic species):
G1, which refers to C. purpurea sensu stricto; G2 or C. humidiphila
Pažoutová & M. Kolařík; G2a, which is now ocially recognized
as Claviceps arundinis Pažoutová & M. Kolařík; G3 or C. spartinae
(R.A. Duncan & J.F. White) Pažoutová & M. Kolařík. These four
cryptic species have diverse habitat, host specialization, and
dierent content in alkaloids (Negård et al. 2015). In particular,
C. arundinis is reported to infect only Phragmites and Molinia spe-
cies. Infection by several species belonging to Claviceps genus
has been deeply studied in many food crops, such as Claviceps
africana and Claviceps sorghi in sorghum, C. purpurea in wheat
and Claviceps cypery in yellow nutsedge (van der Putten 1997;
Muthusubramanian et al. 2006; Tooley et al. 2006; van der Linde
and Wehner 2007; Tittlemier et al. 2015). On the other hand, the
interactions of Claviceps spp. with non-domesticated grasses like
P. australis, have been studied much less and are little understood
(Mantle 1969; Haslam 1972; Pažoutová et al. 2002), and to date,
there are no data in the literature concerning the involvement of
Claviceps spp. in RDBS. As Claviceps infects the ovaries, such that
the grains are substituted by sclerotia, a role for C. arundinis in
P. australis sexual reproduction could be supposed. Sexual repro-
duction helps plants to overcome environmental changes, and
aecting this potential might represent an important disadvan-
tage for a plant population. P. australis is believed to spread via
rhizomes, which can produce large patches of genetically identi-
cal plants; however, recent studies have detected many dierent
genotypes within patches (McCormick et al. 2010), which again
suggests a role for sexual reproduction here. On this basis, is
Claviceps infection related to P. australis sexual reproduction and
seed production? Could Claviceps infection be involved in the
RDBS? These are the questions that we are beginning to address.
Therefore, we initially characterized the Claviceps-like sclerotia
collected from the inorescences of P. australis in Colorito marsh
and Lake Trasimeno (Umbria, Central Italy) at the morphological,
molecular and chemical levels and then we explored the possible
role of the fungus in the RDBS and in the sexual reproduction of
P. australis.
Materials and methods
Sampling areas
Two wetlands of Umbria, Central Italy, were sampled here:
Colorito marsh and Lake Trasimeno. Colorito marsh
(43°01′23″N, 12°52′36″E, 752m a.s.l.) is one of the wetlands pro-
tected by the Ramsar Convention. Its annual mean temperature
is 11.5°C and mean precipitation is 1035mm (Frattegiani 2015).
Lake Trasimeno (43°08′05.5″N 12°06′04.6″E, 257m a.s.l.) has a

PLANT BIOSYSTEMS 3
reported by White et al. (1990) for the ITS sequencing and by
Pažoutová et al. (2000) for the β-tubulin gene. The amplica-
tion products were separated by agarose gel electrophoresis
(1.2% in TAE 0.5×), then puried and sequenced by Macrogen
Europe (Amsterdam, the Netherlands). All of the sequences
have been deposited in GenBank under the accession numbers
reported in Table 1. The sequences were compared with those in
GenBank using BlastX, aligned and manually adjusted. For the
phylogenetic analysis, Claviceps grohii (AJ133395.2-FJ711480.1),
Epichloe baconii (L07138.1-AF250733) and Epichloe amarillans
(AF385206.1-AF457467.1) were selected as outgroups to root the
tree. A single dataset constituted by concatenated sequences of
ITS and β-tubulin genes was tted and analyzed. Multiple align-
ments were performed with MAFFT vs. 5 (Katoh et al. 2005), and
then carefully checked for ambiguous positions based on visual
inspection. In order to perform a phylogenetic inference, gaps
were coded as separate characters according to Simmons and
Ochoterena (2000) using FastGap v.1.0.8 (Borchsenius 2007), and
appended at the end of the dataset.
The dataset was analyzed using Bayesian inference with
MrBayes 3.1.2 (Ronquist and Huelsenbeck 2003). Based on jMod-
eltest (Posada 2008), the best tting models of nucleotide sub-
stitution resulted GTR +I + Γ. Analyses were performed using
incrementally heated Markov chains simultaneously started from
random trees, and run for one million cycles sampling one tree
every 1000 generations. The stationary phase was reached when
the average standard deviation of split frequencies reached 0.01.
Trees that preceded the stabilization of the likelihood value (the
burn-in) were discarded, and the remaining trees were used to cal-
culate a majority-rule consensus phylogram. The trees were viewed
and edited with TreeView (Page 1996), with indication of Bayesian
Posterior Probabilities (PP) values for the internal tree nodes.
Determination of the alkaloid content
Sclerotia were ground and homogenized for 24h with com-
mercial wheat our, certied alkaloids free, and after clean up
with MycoSep columns, they were analyzed by the Romer Labs
Diagnostic (Tulln, Austria) using HPLC uorescence detection.
The same commercial wheat our was used as negative control.
Plant macromorphological traits
The chosen macromorphological traits were height (cm) and
diameter (mm) of culms, and presence of clumping habit (an
abnormal growth of the reeds caused by the loss of apical dom-
inance and the development of dormant lateral buds), based on
the methodology adopted by Gigante et al. (2011, 2013). These
traits have been proved to be frequently associated to a condi-
tion of RDBS (Gigante et al. 2014; Lastrucci et al. 2016). The per-
centage of sclerotia on 50 spikelets and the percentage of viable
seeds per plot were also estimated. Seed viability was dened
using the 2,3,5-triphenyltetrazolium chloride (TTC) assay (Reale
et al. 2011), whereby 30 individual seeds per plot were incu-
bated for 48h in 1% TTC solutions in the dark at 24°C. Due to
the reduction of triphenyl tetrazolium chloride by respiratory
activity in the cells, viable seed turned red.
Statistical analysis
Normality and homoscedasticity of our dataset were checked
for each of the analyzed parameter, using Shapiro–Wilk and
Bartlett test, respectively. For data with normal distribution, we
used paired t-test or ANOVA; if normality was not respected,
Mann–Whitney U-test was performed. A level of p < 0.05 was
considered to be a statistically signicant dierence.
Results
Fungal characterization
During the eld surveys carried out in Colorito marsh and Lake
Trasimeno, Claviceps-like sclerotia were observed in the inores-
cences of P. australis. They were banana-shaped, between 5 and
11.7mm long (mean length, 6.8 mm±0.26mm) black or dark
brown (Figure 1), able to oat in water even for 24h. After 8days
of incubation on T2 agar plates at 28°C, sclerotia developed an
aerial whitish mycelium that subsequently became partially
pink. These mycelia had a growth rate of 0.5–0.7mmday−1. The
single-cell conidia were hyaline, from rounded to elongated,
with lengths from 6 to 8.84μm (mean length, 8.13±0.30μm).
The morphological traits of all fungal isolates t with those
reported for C. arundinis (Pažoutová et al. 2015).
All of the isolates were identied as Claviceps spp. through
comparison of their ITS sequences (600bp) with those in GenBank.
Furthermore, the sequencing of ITS region and β-tubulin gene
were carried out for the phylogenetic analysis on amplicons of
approximately 600 and 400bp, respectively. The Bayesian phy-
logram that resulted from their concatenation is reported in
Figure 2. The topology of the phylogram is largely consistent
with the one obtained by Negård et al. (2015). All the isolates
from Colorito marsh and Lake Trasimeno clustered together with
G2a group isolates of the recently described species C. arund-
inis (Figure 2; Bayesian posterior probability, 0.75) (Pažoutová
et al. 2015). Moreover, G1 and G3 form highly supported clades
(Bayesian posterior probability, 1.00 and 0.86, respectively),
Table 1.GenBank accession numbers for DNA sequences used in this study.
Note: CO, Colfiorito marsh; TR, Lake Trasimeno; ITS, internal transcribed spacer.
Sample name Gene name Accession number
CO_01 β-tubulin KX690628
CO_02 β-tubulin KX690629
CO_03 β-tubulin KX690630
CO_04 β-tubulin KX690631
CO_05 β-tubulin KX690632
CO_06 β-tubulin KX690633
CO_07 β-tubulin KX690634
CO_08 β-tubulin KX690635
CO_09 β-tubulin KX690636
CO_10 β-tubulin KX690637
Tr10 β-tubulin KX690638
CO_01 ITS KX690640
CO_02 ITS KX690641
CO_03 ITS KX690642
CO_04 ITS KX690643
CO_05 ITS KX690644
CO_06 ITS KX690645
CO_07 ITS KX690646
CO_08 ITS KX690647
CO_09 ITS KX690648
CO_10 ITS KX690649
Tr10 ITS KX690650

4 M. CERRI ET AL.
are shown in Figure 4; no signicant dierences were observed
between the two locations. On the contrary, the traits showed
signicant dierences with respect to the ooding situation. In
the permanently ooded plots, there was a signicant higher
percentage of clumping (p=3.11E-09; df= 22), and signicant
lower culm height (p=1.10E-07; df=35) and diameter (p=0.29
E-03; df = 34) (Figure 4(D–F)). No signicant dierences were
observed in macromorphological traits (clumping, culm height
and diameter) between permanently ooded plots of Colorito
while G2 and G2a species are closer (Figure 2). Morphological
and molecular analyses showed that all our isolates belong to
the same cryptic species. Consequently, sclerotia from dierent
plants belonging to the same plots considered for morphological
investigation were pooled together for the HPLC uorescence
detection analysis.
The chromatograms (Figure 3) showed that ergosine, ergosi-
nine, ergocrystine and ergocrystinine, were present in the sclero-
tia collected in Colorito marsh and Lake Trasimeno. Consistently
with Negård et al. (2015), this conrms the inclusion of the isolates
in the G2a group.
Plant macromorphological traits
The three chosen macromorphological traits were analyzed
(i.e. clumping, and culm height and diameter), and these data
Figure 1.(A) Phragmites australis ear with C. arundinis sclerotia bar = 1 cm;
(B) sclerotia of C. arundinis, bar=5mm.
Figure 2.Bayesian tree based on partial ITS gene sequence and β-tubulin gene.
Numbers at the nodes represent the Bayesian Posterior Probabilities (PP). Strains
from this study are indicated with black arrows.
Figure 3. Histograms showing the quantification of ergot alkaloids with HPLC
fluorescence detection. Bars indicate measure uncertainty. Limit of detection=10.

PLANT BIOSYSTEMS 5
5(A–C)). Finally, for sexual reproduction, although dierences in
the percentages of vital seeds were seen between the location
and the ooding condition, these did not reach statistical sig-
nicance (Figure 5(D,E)). When we considered separately sites
(Lake Trasimeno and Colorito marsh) and ooding condition
marsh (where Claviceps sclerotia were detected) and perma-
nently ooded plots of Lake Trasimeno (where Claviceps sclero-
tia were not detected) (Figure 4(G–I)).
Fungus abundance (%sclerotia/spikelets) did not show any
dierence between location and ooding condition (Figure
Figure 4.Histograms showing the three chosen morphological traits of P. australis (i.e. clumping, and culm height and diameter). Each parameter was determined
considering all of the plots for each site (A, B, and C), for the flooding condition (D, E, and F), or separating flooding condition and lake (G, H, and I). Bars indicate
standard errors. Different symbols for each trait indicate significant differences according to Student’s t-tests (p<0.05) (A–F) or ANOVA (p<0.05) (G–I). TR PF=Trasimeno
permanently flooded; TR TF=Trasimeno temporarily flooded; CO PF=Colfiorito permanently flooded; CO TF=Colfiorito temporarily flooded.
Figure 5.Histograms showing the sclerotia abundance (A, B, and C) and percentage of vital seeds (D, E, and F). Each parameter was determined considering all of the plots
for each site (A, D) or for the flooding condition (B, E) or separating flooding condition and lake (C, F). Bars indicate standard errors. Different symbols for each trait indicate
significant differences according to Mann-Whitney U-tests (A, B), Student’s t-tests (D, E) (p<0.05) or ANOVA (p<0.05) (C, F). TR PF=Trasimeno permanently flooded; TR
TF=Trasimeno temporarily flooded; CO PF=Colfiorito permanently flooded; CO TF=Colfiorito temporarily flooded.

6 M. CERRI ET AL.
one strategy to the other in response to environmental changes.
Stress can induce sexual reproduction that would translate in an
increase of diversity within populations; otherwise, the asexual
propagation through rhizomes is prevailing (Clevering and Lissner
1995). As Claviceps infects the ovaries, and the grains are substi-
tuted by the Claviceps sclerotia, there might well be relationship
between caryopsis dierentiation, and presence of sclerotia. In
Lake Trasimeno, these data showed higher rates of viable seeds
in the declining reed stands (i.e. the permanently ooded plots),
which would potentially be to increase genetic variability, as pre-
viously observed by Reale et al. (2011). In Colorito marsh, no
dierences were observed between the two ooding situations.
These results suggest that the relation between health status of
plants and viable seeds production is also aected by other envi-
ronmental factors. Considering that there were no dierences
in the presence of sclerotia between sites and ooding situa-
tions, the present hypothesis is for no correlations between the
presence of sclerotia and viable seeds. This hypothesis was also
tested by a Spearman rank correlation (data not shown), which
conrmed the absence of any relation between these two traits.
Continuous advances in microbial ecology have revealed
unknown aspects of fungal roles in ecosystems and have highlighted
their importance as possible driving forces inuencing plants
growth and tness (Ernst et al. 2003; Wäli et al. 2013). The present
study outlines for the rst time the presence of C. arundinis
in Italy and represents just the rst step in the monitoring of
P. australis – C. arundinis interaction. Data collected supplied new
useful information about the possible role of this microorganism
in the conservation status of P. australis, but our hypothesis should
be tested in other areas and ecological conditions.
Acknowledgment
The authors would like to thank Bianca Rita Eleuteri, Laura Picchiarelli,
Maddalena Chiappini and Mario Muzzatti for the assistance during eld
work. Lastly, we want to thank “Oasi La Valle” and “Parco di Colorito” for pro-
viding their facilities for the eld surveys, and Christopher Berrie for scientic
editing of the manuscript.
Disclosure statement
No potential conict of interest was reported by the authors.
Funding
This work was supported by the University of Perugia and by the Italian
Ministry of University and Scientic Research, call for research “Futuro in
Ricerca 2013” [grant number RBFR13P7PR].
ORCID
L. Reale http://orcid.org/0000-0001-7570-3972
C. Moretti http://orcid.org/0000-0003-1500-7320
A. Coppi http://orcid.org/0000-0003-4760-8403
B. Foggi http://orcid.org/0000-0001-6451-4025
D. Gigante http://orcid.org/0000-0003-1787-5164
M. Quaglia http://orcid.org/0000-0002-1137-2585
R. Venanzoni http://orcid.org/0000-0002-7768-0468
F. Ferranti http://orcid.org/0000-0002-2548-3868
(permanent or temporary), only in the temporarily ooded plots
of Lake Trasimeno the percentage of viable seeds is signicantly
dierent and higher with respect to the others (Figure 5(F)).
Discussion
The rst aim of this study was to characterize the Claviceps-like
sclerotia that were collected in two dierent wet ecosystems
in Italy. The circumscription of the species C. purpurea was
recently rened in a study conducted by Pažoutová et al. (2015),
in which C. humidiphila, C. arundinis and C. spartinae were
described. Negård et al. (2015) supported these new insights
into taxonomic, chemotypic, and ecotypic relationships of the
C. purpurea complex. The morphological, molecular, and chem-
ical features of the isolates obtained in the present study from
sclerotia collected both in Colorito marsh and Lake Trasimeno,
t with those previously reported for C. arundinis (Negård et al.
2015; Pažoutová et al. 2015). To the best of our knowledge, the
present study is the rst report of C. arundinis in Italy. Pažoutová
et al. (2015) also demonstrated that the new established cryp-
tic species has a relatively narrow host range, as C. arundinis
infects only Phragmites and Molinia species; thus, it appears to
exclude the cross infection with other Poaceae cultivated in the
surroundings. This is important, above all, in Colorito marsh,
where niche cereals are cultivated near the marsh and consti-
tute a crucial element for the economy of the area.
The present study goes a step forward in the investigation of
the role of C. arundinis infection in RDBS. Signicant dierences
in the three parameters associated to RDBS (i.e. clumping, culm
height and diameter) were observed between the dierent ood-
ing situations (i.e. temporary or permanent), but not between
the collection sites. Permanently ooded plots showed higher
clumping, lower culm diameter and lower culm height, suggest-
ing a general declining condition. These data are consistent with
the observations of Lastrucci et al. (2016), who associated per-
manent vs. temporary ooded condition to declining vs. healthy
status of the reeds, respectively. However, the present data for
the sclerotia abundance suggest that C. arundinis infection and
RDBS are two unrelated events, as the presence of C. arundinis
co-occurs across traits of good conservation status and does not
show any dierential presence between permanently and tem-
porarily ooded plots. Therefore, C. arundinis does not appear to
contribute to RDBS, while also RDBS does not appear to aect
the presence of C. arundinis. Indeed, considering that Claviceps
species have biotrophic life style (Tudzynski and Scheer 2004),
the good host’s health status is imperative for fungal survival.
Moreover, the ergot alkaloids have probably evolved to provide
advantages to the fungus itself, but they bring about protection
to the host as a side-eect (Agrawal 2000; Wäli et al. 2013). We
also investigated the inuence of the presence of Claviceps on
P. australis reproduction. Plants that produce seeds have several
colonization advantages over species that undergo asexual repro-
duction, including the ability to disperse over longer distances, to
produce genetically diverse populations capable of overcoming
adverse environmental conditions, and to remain dormant over
long periods of time. P. australis shows both vegetative and sex-
ual reproduction and its energy allocation can be shifted from

PLANT BIOSYSTEMS 7
Negård M, Uhlig S, Kauserud H, Andersen T, Høiland K, Vrålstad T. 2015. Links
between genetic groups, indole alkaloid proles and ecology within the
grass-parasitic Claviceps purpurea species complex. Toxins 7: 1431–1456.
Ostendorp W, Dienst M, Schmieder K. 2003. Disturbance and rehabilitation of
lakeside Phragmites reeds following an extreme ood in Lake Constance
(Germany). Hydrobiologia 506–509: 687–695.
Page RD. 1996. TreeView: an application to display phylogenetic trees on
personal computers. Comput Appl Biosci 12: 357–358.
Pažoutová S, Fučíkovský L, Leyva-Mir SG, Flieger M. 1998. Claviceps citrina
sp. nov., a parasite of the halophytic grass Distichlis spicata from Mexico.
Mycol Res 102: 850–854.
Pažoutová S, Kolinska R, Honzatko A. 2002. Host specialization of dierent
populations of ergot fungus (Claviceps purpurea). Czech J 2002: 75–81.
Pažoutová S, Olšovská J, Linka M, Kolínská R, Flieger M. 2000. Chemoraces
and habitat specialization of Claviceps purpurea populations. Appl
Environ Microbiol 66: 5419–5425.
Pažoutová S, Pešicová K, Chudíčková M, Šrůtka P, Kolařík M. 2015. Delimitation
of cryptic species inside Claviceps purpurea. Fungal Biol 119: 7–26.
Perez L, Gundel PE, Ghersa CM, Omacini M. 2013. Family issues: fungal
endophyte protects host grass from the closely related pathogen
Claviceps purpurea. Fungal Ecol 6: 379–386.
Perotto S, Angelini P, Bianciotto V, Bonfante P, Girlanda M, Kull T, Mello A,
Pecoraro T, Perini C, Persiani AM, et al. 2013. Interactions of fungi with
other organisms. Plant Biosyst 147: 208–218. DOI:10.1080/11263504.20
12.753136.
Posada D. 2008. jModelTest: phylogenetic model averaging. Mol Biol Evol 25:
1253–1256.
Reale L, Gigante D, Landucci F, Venanzoni R, Ferranti F. 2011. Correlation
between sexual reproduction in Phragmites australis and die-back
syndrome. Int J Plant Reprod Biol 3: 133–140.
Ronquist F, Huelsenbeck JP. 2003. MrBayes 3: Bayesian phylogenetic
inference under mixed models. Bioinformatics 19: 1572–1574.
Sanchez Marquez S, Bills GF, Herrero N, Zabalgogeazcoa I. 2012. Non-
systemic fungal endophytes of grasses. Fungal Ecol 5: 289–297.
Simmons MP, Ochoterena H. 2000. Gaps as characters in sequence-based
phylogenetic analyses. Syst biol 49: 369–381.
Tittlemier SA, Drul D, Roscoe M, McKendry T. 2015. Occurrence of ergot and
ergot alkaloids in western Canadian wheat and other cereals. J Agric Food
Chem 63: 6644–6650.
Tooley PW, Bandyopadhyay R, Carras MM, Pažoutová S. 2006. Analysis of
Claviceps africana and C. sorghi from India using AFLPs, EF-1α gene intron
4, and β-tubulin gene intron 3. Mycol Res 110: 441–451.
Tucker GC. 1990. The genera of Arundinoideae (Gramineae) in the
southeastern United States. J. Arnold Arboretum 71: 145–177.
Tudzynski P, Scheer J. 2004. Claviceps purpurea: molecular aspects of a
unique pathogenic lifestyle. Mol Plant Pathol 5: 377–388.
van der Linde EL, Wehner FC. 2007. Symptomatology and morphology of
Claviceps cyperi on yellow nut sedge in South Africa. Mycologia 99: 586–591.
van der Putten WH. 1997. Die-back of Phragmites australis in European
wetlands: an overview of the European Research Programme on reed die-
back and progression (1993–1994). Aquat Bot 59: 263–275.
Wäli P, Wäli PR, Saikkonen K, Tuomi J. 2013. Is the pathogenic ergot fungus
a conditional defensive mutualist for its host grass? PLoS One 8: e69249.
DOI:10.1371/journal.pone.0069249.
White TJ, Bruns T, Lee S, Taylor J. 1990. Amplication and direct sequencing
of fungal ribosomal RNA genes for phylogenetics. In: Innis MA, Gelfand
DH, Sninsky JJ, White TJ, editors. PCR Protocols: a guide to methods and
applications. San Diego, CA: Academic Press. pp. 315–322.
Wirsel SGR, Runge-Froböse C, Ahrén DG, Kemen E, Oliver RP, Mendgen
KW. 2002. Four or more species of cladosporium sympatrically colonize
Phragmites australis. Fungal Genet Biol 35: 99–113.
References
Agrawal AA. 2000. Overcompensation of plants in response to herbivory and
the by-product benets of mutualism. Trends Plant Sci 5: 309–313.
Borchsenius F. 2007. FastGap 1.0.8. Software distributed by the author.
Available from: https://192.38.46.42/aubot/fb/FastGap_home.htm.
Brewer J, Loveless AR. 1977. Ergot of Pennisetum macrourum in South Africa.
Kirkia 10: 589–600.
Brix H. 1999. The European research project on reed die-back and progression
(EUREED). Limnol Ecol Manag Inl Waters 29: 5–10.
Clevering OA, Lissner J. 1995. Taxonomy, chromosome numbers, clonal
diversity and population dynamics of Phragmites australis. Aquat Bot 64:
185–208.
Ernst M, Mendgen KW, Wirsel SGR. 2003. Endophytic fungal mutualists: seed-
borne Stagonospora spp. enhance reed biomass production in axenic
microcosms. Mol Plant Microbe Interact 16: 580–587.
Frattegiani M. 2015. Servizio Sistemi naturalistici e zootecnia Sezione Aree
protette e progettazione integrata. https://www.regione.umbria.it/
documents/18/2512711/Colorito_vegetazione_ott_15.pdf/e973c55c-
12ad-4c0f-b8b8-813962d0996
Gigante D, Angiolini C, Landucci F, Maneli F, Nisi B, Vaselli O, Venanzoni R,
Lastrucci L. 2014. New occurrence of reed bed decline in southern
Europe: do permanent flooding and chemical parameters play a role?
C R Biol 337: 487–498.
Gigante D, Landucci F, Venanzoni R. 2013. The reed die-back syndrome
and its implications for oristic and vegetational traits of Phragmitetum
australis. Plant Sociol 50: 3–16.
Gigante D, Venanzoni R, Zuccarello V. 2011. Reed die-back in southern
Europe? A case study from Central Italy. C R Biol 334: 327–336.
Glass NL, Donaldson GC. 1995. Development of primer sets designed for use
with the PCR to amplify conserved genes from lamentous ascomycetes.
Appl Environ Microbiol 61: 1323–1330.
Handeland K, Vikøren T. 2005. Presumptive gangrenous ergotism in free-
living moose and a roe deer. J Wildl Dis 41: 636–642.
Haslam SM. 1972. Phragmites communis Trin. (Arundo Phragmites L.,?
Phragmites australis (Cav.) Trin. ex Steudel). J Ecol 60: 585–610.
Katoh K, Kuma K, Toh H, Miyata T. 2005. MAFFT version 5: improvement in
accuracy of multiple sequence alignment. Nucl Acid Res 33: 511–518.
Lastrucci L, Gigante D, Vaselli O, Nisi B, Viciani D, Reale L, Coppi A., Fazzi V.,
Bonari G, Angiolini C. 2016. Sediment chemistry and ooding exposure:
a fatal cocktail for Phragmites australis in the Mediterranean basin? Int J
Liminol 52: 365–377.
Loveless AR. 1971. Conidial evidence for host restriction in Claviceps
purpurea. Trans Br Mycol Soc 56: 419–434.
Mantle PG. 1969. Studies on Claviceps purpurea (Fr.) Tul parasitic on
Phragmites communis Trin. Ann Appl Biol 63: 425–434.
McCormick MK, Kettenring KM, Baron HM, Whigham DF. 2010. Spread
of invasive Phragmites australis in estuaries with diering degrees of
development: genetic patterns, Allee eects and interpretation. J Ecol 98:
1369–1378.
Miedaner T, Geiger HH. 2015. Biology, genetics, and management of ergot
(Claviceps spp.) in rye, sorghum, and pearl millet. Toxins 7: 659–678.
Morrie Craig A, Klotz JL, Duringer JM. 2015. Cases of ergotism in livestock
and associated ergot alkaloid concentrations in feed. Front Chem 3:
1–6.
Muthusubramanian V, Bandyopadhyay R, Reddy DR, Tooley PW. 2006.
Cultural characteristics, morphology, and variation within Claviceps
africana and C. sorghi from India. Mycol Res 110: 452–464.
Nechwatal J, Wielgoss A, Mendgen K. 2008. Diversity, host, and habitat
specicity of oomycete communities in declining reed stands (Phragmites
australis) of a large freshwater lake. Mycol Res 112: 689–696.