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81
Hydropisphaera palmicola (Bionectriaceae), a new species
from Saül (French Guiana)
Christian LECHAT (†)
Jacques FOURNIER
Delphine CHADULI
Anne FAVEL
Ascomycete.org, 14 (2) : 81–84
Mise en ligne le 25/04/2022
10.25664/ART-0349
Abstract: A detailed description of Hydropisphaera palmicola sp. nov. is presented, based on a collection
on dead leaves of Astrocaryum sp. (Arecaceae) in French Guiana. The acremonium-like asexual morph has
been obtained in culture and sequenced. Its placement in the genus Hydropisphaera was confirmed by the
analysis of LSU sequences. Based on morphological and phylogenetic comparison with the known Hydro-
pisphaera species, we propose H. palmicola as a new species. The similarity of our species with H. erubescens
and H. foliicola is discussed.
Keywords: Astrocaryum, Hypocreales, new species, ribosomal DNA, taxonomy, tropical mycology.
Résumé : une description détaillée d’Hydropisphaera palmicola sp. nov. est présentée à partir d’une récolte
sur feuilles mortes d’Astrocaryum sp. (Arecaceae) en Guyane française. La forme asexuée de type acremo-
nium a été obtenue en culture et séquencée. Son placement dans le genre Hydropisphaera a été confirmé
par l’analyse des séquences LSU. Sur la base d’une comparaison morphologique et phylogénétique avec
les espèces d’Hydropisphaera connues, nous proposons H. palmicola comme une nouvelle espèce. La res-
semblance de notre espèce avec H. erubescens et H. foliicola est commentée.
Mots-clés : ADN ribosomal, Astrocaryum, espèce nouvelle, Hypocréales, mycologie tropicale, taxinomie.
Introduction
In the continuity of an inventorial survey of fungi in French Guiana
(GARDIENNET et al., 2019; LECHAT et al., 2019; LECHAT & FOURNIER, 2019a;
2019b; 2019c; 2020a; 2020b; 2020c), an hypocrealean fungus was
collected on dead palm leaves of Astrocaryum sp., which proved to
be different from known species. This fungus was morphologically
characterised, cultured and phylogenetically analysed. Based on its
characteristics, phylogenetic analysis and comparison with other
genera in the Bionectriaceae and with known species of Hydropi-
sphaera Dumort., the specimen described herein is determined to
represent a previously undescribed species of Hydropisphaera.
Materials and methods
Dry specimens were rehydrated and examined using the method
described by ROSSMAN et al. (1999). Microscopical observations and
measurements were made in water and the ascospore ornamenta-
tion was observed in lactic cotton blue not heated. The holotype
specimen was deposited in LIP herbarium (University of Lille). Cul-
tures of the living specimens were made on PDA (Potato Dextrose
Agar) with 5 mg/l of streptomycin in Petri dishes 5 cm diam. incu-
bated at 25°C. DNA extraction, amplification, and sequencing were
performed by ALVALAB (Oviedo, Spain): Total DNA was extracted
from pure culture, blending a portion using a micropestle in 600 µl
CTAB buffer (CTAB 2%, NaCl 1.4 M, EDTA pH 8.0 20 mM, Tris-HCl pH
8.0 100 mM). The resulting mixture was incubated for 15 min. at
65ºC. A similar volume of chloroform: isoamylalcohol (24:1) was
added and carefully mixed with the samples until their emulsion. It
was then centrifuged for 10 min at 13.000 g, and the DNA in the su-
pernatant was precipitated with a volume of isopropanol. After a
new centrifugation of 15 min at the same speed, the pellet was
washed in 70% cold ethanol, centrifuged again for 2 min and dried.
It was finally resuspended in 200 µl ddH2O. PCR amplification was
performed with the primers LR0R and LR5 (VILGALYS & HESTER, 1990)
to amplify the 28S nLSU region. PCR reactions were performed
under a program consisting of a hot start at 95ºC for 5 min, followed
by 35 cycles at 94ºC, 54ºC and 72ºC (45, 30 and 45 s respectively)
and a final 72ºC step 10 min. Chromatograms were checked search-
ing for putative reading errors, and these were corrected.
Analyses were performed online at phylogeny.lirmm.fr (DEREEPER
et al., 2008). Maximum likelihood phylogenetic analyses were per-
formed with PhyML 3.0 aLRT (ZWICKL, 2006), using the GTR + I + Γ
model of evolution. Branch support was assessed using the non-
parametric version of the approximate likelihood-ratio test, imple-
mented in PhyML SH-aLRT (ANISIMOVA & GASCUEL, 2006).
Nomenclature follows MycoBank (Westerdijk Fungal Biodiversity In-
stitute, Utrecht, The Netherlands).
Taxonomy
Hydropisphaera palmicola Lechat & J. Fourn., sp. nov. Figs. 1–2
– MycoBank: MB843711
Diagnosis: Differs from the most similar species H. erubescens in
having smaller, punctate-striate ascospores, (17–)18–20(–22) × 2.8–
3.2 µm vs. (17–)18–26(–29) × 3.5–4.5 µm.
Holotype: FRENCH GUIANA, Saül, trail head to Roche-Bateau,
3.62056 N, -53.199899 E, ca. 240 m, on dead palm leaves of Astro-
caryum sp. (Arecaceae), 30 Mar. 2021, leg. C. Lechat CLLG21119 (LIP),
ex-type culture no longer viable. GenBank LSU: ON181664.
Etymology: The specific epithet “palmicola” refers to its habitat
on dead palm leaves.
Perithecia solitary, scattered on substratum, superficial, non-stro-
matic, globose, 160–180(–200) µm diam. (Me = 170 µm, n = 10), pale
yellow to pale orange, not collapsing when dry, glabrous, smooth
to slightly roughened, not changing colour in 3% KOH or lactic acid.
Perithecial apex with a minute, acute papilla. Perithecial wall 35–
50 µm thick, composed of two regions: outer region 30–35 µm wide,
of subglobose cells, 8–12(–14) × 5–9 µm, with pale orange walls 1–
1.5 µm thick; inner region 10–12 µm wide, of elongate, flattened
cells, 7–15 × 2–3.5 µm, with hyaline wall. Asci 38–50 × 8–10 µm
(Me = 44 × 9 µm, n=15), short-stipitate, clavate, attenuated at tip;
apex simple, flattened, 8-spored, ascospores multiseriate, filling
each ascus. Paraphyses hyphal, 2–3 µm diam., inserted between
asci. Ascospores (17–)18–20(–22) × 2.8–3.2 µm (Me = 18 × 3 µm,
n=40), fusiform, rounded at ends, (1–)3-septate, hyaline, punctate-
striate, with an inconspicuous ornamentation , best seen in lactic
cotton blue.
Cultural characteristics: After two weeks on PDA at 25°C, colony
15–20 mm diam., producing an acremonium-like asexual morph,
cottony, pale buff in centre, pale greyish brown in middle area, white
at margin, not diffusing colouration in medium, composed of white
to pale brown, septate, smooth hyphae, 2.5–3 µm wide. Conidio-
phores flexuous, rarely branched, 35–48 µm long, 2.5–3.5 µm diam.,
bearing a single phialide, 16–28 long, with a not flared collarette,
82 Ascomycete.org
Fig. 1 – a-d, g, h: Hydropisphaera palmicola (CLLG21119 Holotype); a: Ascomata on the substratum; b: Lateral ascomatal wall in vertical
section; c: Asci and ascospores (b, c in water); d: Ascospores; e: Ascospores of H. erubescens; f: Ascospores of H. foliicola (d-f in lactic
cotton blue); g: Culture at two weeks; h: Conidiophores and conidia from culture, in lactic acid. Scale bars: a = 200 m; b = 20 µm; c, h
= 10 µm; d-f = 5 µm.
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Ascomycete.org
producing conidia in a slimy head. Conidia ellipsoidal, 5–7 × 2–
2.5 µm, smooth, hyaline, attenuated at base, with or without abscis-
sion scar, forming small globose heads at apex of conidiogenous
cells.
Discussion
HYDROPISPHA ERA PALMICOLA is placed in the genus Hydropisphaera
based on the morphological characteristics of its sexual and asexual
morphs, as well as the phylogenetic analysis of its LSU sequence.
This fungus is morphologically characterised by its glabrous asco-
mata not changing colour in 3% KOH or lactic acid and fusiform, 3-
sepate ascospores. Several glabrous species of Hydropisphaera
exhibit these characteristics, including H. erubescens (Roberge ex
Desm.) Rossman & Samuels and H. foliicola Lechat & J. Fourn., which
are morphologically separable only by size, ornamentation and as-
cospore septation, like all glabrous species of Hydropisphaera (LECHAT
& FOURNIER, 2017). Our fungus was cultured, and the culture resulted
in an acremonium-like asexual morph, which fits well with Hydropi-
sphaera, as species in this genus are known to have an acremonium
or gliomastix-like asexual morph (ROSSMAN et al., 1999; SUMMERBELL et
al., 2011; LECHAT et al., 2010; LECHAT & FOURNIER, 2016). Our phyloge-
netic analysis based on LSU sequences (Fig. 2) shows that H. palmi-
cola is nested within the Hydropisphaera clade. Phylogenetically, the
closest species to H. palmicola is H. saulensis Lechat & J. Fourn., which
differs mainly in its dark brownish orange to blackish brown asco-
mata and ellipsoidal, verrucose ascospores (LECHAT & FOURNIER,
2020b). The new species is morphologically similar to H. erubescens
(Roberge ex Desm.) Rossman & Samuels, but differs from it in having
significantly smaller ascospores (17–)18–20(–22) × 2.8–3.2 µm vs.
(17–)18–26(–29) × 3.5–4.5 µm (Fig. 1). Moreover, the ascospores of
H. erubescens are spinulose as defined by LECHAT & FOURNIER (2017),
while those of H. palmicola have a punctate-striate ornamentation.
Hydropisphaera foliicola also resembles our fungus, but differs from
it by having smaller, ellipsoidal, verrucose ascospores (14–)15–17
(–18) × 4–4.7(–5) m vs. (17–)18–20(–22) × 2.8–3.2 µm (LECHAT &
FOURNIER, 2017). Based on differences in microscopical characters and
phylogenetic analysis, H. palmicola Lechat & J. Fourn. is therefore
proposed as a new species.
Acknowledgements
The authors gratefully acknowledge Dr Amy Rossman (Oregon
State University, Corvallis, U.S.A.) for her advice and scientific assis-
tance and for her presubmission review of a preliminary draft. We
express our appreciation to the Parc Amazonien de Guyane (PAG)
for having organised the field trips to Saül in the context of the ABC
inventorial project.
Authors’ contribution
Christian Lechat was responsible for the conception of the study,
morphological studies, phylogenetic analyses, design of figures and
plates and writing a first draft. Jacques Fournier critically reviewed
the first draft and proposed an improved version, and took care of
the registration at MycoBank. Delphine Chaduli and Anne Favel
managed the culture collection in which the culture was to be de-
posited and took care of the registration at GenBank. All authors ex-
cept CL read and approved the final manuscript.
Fig. 2 – Maximum likelihood phylogeny (-lnL = 3116.64105) of Hydropisphaera spp. inferred by Phyml 3.0, model hky85 from a 800 bp
matrix of 28s rDNA sequence, rooted with Dialonectria diatrypicola.
84 Ascomycete.org
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2: J. Fournier – Las Muros, 09420 Rimont, France – jfournzeroneuf@gmail.com
1: C. Lechat (†)
3: D. Chaduli – CIRM-CF, INRAE, Aix Marseille Univ, UMR1163 BBF (Biodiversité et Biotechnologie Fongiques), 13288 Marseille Cedex 09, France – delphine.chaduli@univ-amu.fr
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2 4
4: A. Favel – CIRM-CF, INRAE, Aix Marseille Univ, UMR1163 BBF (Biodiversité et Biotechnologie Fongiques), 13288 Marseille Cedex 09, France – anne.favel@univ-amu.fr
