Content uploaded by Samantha C. Karunarathna
Author content
All content in this area was uploaded by Samantha C. Karunarathna on Sep 12, 2020
Content may be subject to copyright.
Phytotaxa 459 (2): 155–167
https://www.mapress.com/j/pt/
Copyright © 2020 Magnolia Press Article PHYTOTAXA
ISSN 1179-3155 (print edition)
ISSN 1179-3163 (online edition)
Accepted by Sajeewa Maharachchikumbura: 4 Aug. 2020; published: 11 Sept. 2020
https://doi.org/10.11646/phytotaxa.459.2.6
155
Roridomyces phyllostachydis (Agaricales, Mycenaceae), a new bioluminescent
fungus from Northeast India
SAMANTHA C. KARUNARATHNA1,3,4,17†, PETER E. MORTIMER2,13,14,18†, SAOWALUCK TIBPROMMA1,3,4,19,
ARUN KUMAR DUTTA8,20, SOUMITRA PALOI9,21, YUWEI HU1,3,4,5,22, GAUTAM BAURAH7,23, STEPHEN
AXFORD6,24, CATHERINE MARCINIAK6,25, THATSANEE LUANGHARN1,3,4,5,26, SUMEDHA MADAWALA10,27,
CHANG LIN11,28, JUN-ZHU CHEN11,29, KRISHNENDU ACHARYA12,30, NOPPOL KOBMOO9,31, MILAN
C. SAMARAKOON2,5,32, ANURUDDHA KARUNARATHNA5,16,33, SHUYI GAO15,34, JIANCHU XU1,3,4,35 &
SAISAMORN LUMYONG2,13,14,36*
1CAS Key Laboratory for Plant Diversity and Biogeography of East Asia, Kunming Institute of Botany, Chinese Academy of Sciences,
Kunming 650201, Yunnan, P.R. China
2Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
3East and Central Asia Regional Office, World Agroforestry Centre (ICRAF), Kunming 650201, Yunnan, P.R. China
4Centre for Mountain Futures (CMF), Kunming Institute of Botany, Kunming 650201, Yunnan, P.R. China
5Center of Excellence in Fungal Research, Mae Fah Luang University, Chiang Rai 57100, Thailand
6Booyong, New South Wales, Australia
7Balipara Tract & Frontier Foundation, House No. 5, B.P. Baruah Road, 1st Bye Lane, Narikalbari, Guwahati, 781024, Assam, India
8Department of Botany, West Bengal State University, Barasat, North-24-Parganas, West Bengal 700126, India
9National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency, 113
Thailand Science Park, Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand
10Department of Botany, Faculty of Science, University of Peradeniya, Sri Lanka
11College of Biodiversity Conservation, Southwest Forestry University, No. 300, Baiong Road, Panlong District Kunming, Yunnan,
650224, P.R. China
12Molecular and Applied Mycology and Plant Pathology Laboratory, Department of Botany, University of Calcutta, 35, Ballygunge
Circular Road, Kolkata - 700019, West Bengal, India
13Research Center of Microbial Diversity and Sustainable Utilization, Faculty of Science, Chiang Mai University, Chiang Mai 50200,
Thailand
14Academy of Science, The Royal Society of Thailand, Bangkok 10300, Thailand
15College of Humanities and Social Sciences, Yunnan Agriculture University, 650201, P.R. China
16Department of Entomology and Plant Pathology, Faculty of Agriculture, Chiang Mai University, Chiang Mai 50200, Thailand
17
�
samanthakarunarathna@gmail.com; https://orcid.org/0000-0001-7080-0781
18
�
petermortimer@mac.com; https://orcid.org/0000-0003-3188-9327
19
�
saowaluckfai@gmail.com; https://orcid.org/0000-0002-4706-6547
20
�
arun.botany@gmail.com; https://orcid.org/0000-0001-5234-3441
21
�
soumitrabotany@gmail.com; https://orcid.org/0000-0003-3980-9168
22
�
ecoyuweih@163.com; https://orcid.org/0000-0001-7517-7722
23
�
gautam.baruah@baliparafoundation.com; https://orcid.org/0000-0002-4667-6490
24
�
stephen.axford@gmail.com; https://orcid.org/0000-0002-8815-7795
25
�
cathmarciniak@yahoo.com.au; https://orcid.org/0000-0001-7054-1046
26
�
l.thatsanee1990@gmail.com; https://orcid.org/0000-0002-1684-6735
27
�
sumedha.madawala@gmail.com; https://orcid.org/0000-0002-5140-4916
28
�
fungichanglinz@gmail.com; https://orcid.org/0000-0002-8668-1075
29
�
fungichen@163.com; https://orcid.org/0000-0003-2696-4935
30
�
krish_paper@yahoo.com; http://orcid.org/0000-0003-1193-1823
31
�
noppol.kob@biotec.or.th; https://orcid.org/0000-0002-3261-9970
32
�
milan.chameera@yahoo.com; https://orcid.org/0000-0002-4815-125X
33
�
anumandrack@yahoo.com; https://orcid.org/0000-0003-0956-6636
34
�
705763446@qq.com; https://orcid.org/0000-0002-4643-7449
35
�
jxu@mail.kib.ac.cn; https://orcid.org/0000-0002-2485-2254
36
�
scboi009@gmail.com; https://orcid.org/0000-0002-6485-414X
†Authors contributed equally;
Corresponding author: Saisamorn Lumyong (scboi009@gmail.com)
KARUNARATHNA ET AL.
156 • Phytotaxa 459 (2) © 2020 Magnolia Press
Abstract
An interesting bioluminescent fungus growing on dead bamboo stems was collected from bamboo forests in the East Khasi
and West Jayantia Hills Districts of Meghalaya, Northeast India. Both morphological characteristics and phylogenetic analy-
ses of nrITS and nrLSU regions showed that the bioluminescent fungus belongs to the genus Roridomyces and is a new
species to science, as well as the first report of the genus, Roridomyces, in India. Full descriptions, colour photographs,
phylogenetic trees to show the position of the novel bioluminescent taxon, and comparisons with its morphologically and
phylogenetically similar species are provided.
Key words: Mycenaceae, new species, Phyllostachys mannii, phylogenetic analyses
Introduction
Bioluminescent organisms are a wonderful creation of the nature. There are several groups of organisms that show their
luminescent properties such as animals, plants, fungi and bacteria (Pandey & Sharon 2017). Bioluminescent organisms
are commonly found in the ocean environments, but they are also found on terrestrial environments (Haddock et al.
2010). The colour of the light emitted by the organism depends on their chemical properties. The bioluminescent
properties are distributed in more or less 17 phyla and over 700 genera of organisms (www.photobiology.info). Among
them, 97 bioluminescent fungi taxa, belonging to four distinct monophyletic lineages of Agaricales are currently
known worldwide (Cortés-Pérez et al. 2019), namely Armillaria (Fr.) Staude, the Mycenaceae Overeem, a third
lineage comprising Omphalotus Fayod and Neonothopanus R.H. Petersen & Krisai, and the Lucentipes lineage
of Mycena (Pers.) Roussel s.l., in the Marasmiineae Aime, Dentinger & Gaya (Desjardin et al. 2008, 2010, 2016;
Vydryakova et al. 2011; Aravindakshan et al. 2012; Chew et al. 2013, 2015; Shih et al. 2014; Mihail 2015; Kaskova
et al. 2017; Cortés-Pérez et al. 2019). All bioluminescent fungi belong to the division Basidiomycota, except for one
species, Xylaria hypoxylon (L.) Grev., which belongs to the division of Ascomycota (Chew et al. 2013; Harvey 1952).
Most of bioluminescent fungi belong to the families Mycenaceae, Pleurotaceae, Omphalotaceae and Physalacriaceae
(Desjardin et al. 2008).
Bioluminescent fungi obtain their luminescence from the enzyme luciferin (Kotlobay et al. 2018). The light
emits from their fruiting bodies or mycelium when luciferins is catalyzed by the enzyme luciferase, in the presence of
oxygen (Pandey & Sharon 2017). During the chemical reaction, several unstable intermediate products are released as
excess energy that makes them visible as light (Airth & Foerster 1962). According to a recent report, bioluminescent
fungi emit green light, which falls in visible light range of 520–530 nm (Vinodkumar & Sarita 2016). Research on
bioluminescent fungi have gained attention due to the application in medical research, agricultural fields, environmental
biosensors, biochemistry, photochemistry, evolution and taxonomic research (Tarr et al. 1997, Chew et al. 2013).
Several hypotheses suggest that the luminescent proprieties of the fungi offer several advantages over other fungi in
regard to the spore dispersal mechanism by attracting insects, and protecting themselves from frugivorous animals
(Bermudes et al. 1992). However, there are still some researchers who believe that bioluminescence is a metabolic
by-product and has no ecological advantage (Lingle 1993).
The genus Roridomyces (Basidiomycota, Mycenaceae) was proposed by Karl-Heinz Rexer in the year 1994
treating Mycena rorida (Fr.) Quél. (= Roridomyces roridus) as the type species (Rexer 1994). Taxa belonging to the
genus Roridomyces were earlier placed in Mycena sect. Roridae having slimy and glutinous nature of stipe surface in
moist conditions (Rexer 1994). However, based on the entirely different hymeniform nature of the pileipellis, Maas
Geesteranus (1989, 1991) erected the type species Mycena rorida (Fr.) Quél. from the genus Mycena. Presently, the
genus includes ten well accepted species based on the Index Fungorum database (accessed on 19/06/2020) viz. R.
appendiculatus Rexer, R. austrororidus (Singer) Rexer, R. irritans (E. Horak) Rexer, R. lamprosporus (Corner) Rexer,
R. mauritianus (Robich & Hauskn.) Hauskn. & Krisai, R. palmensis (Miersch & Dähncke) Miersch & Dähncke, R.
praeclarus (E. Horak) Rexer, R. pruinosoviscidus (Corner) A.L.C. Chew & Desjardin, R. roridus (Fr.) Rexer, and R.
subglobosus (Berk. & M.A. Curtis) Rexer, all of are predominantly distributed in the temperate regions of the world
(Kirk et al. 2008).
India is an extremely biodiversity rich country but, exploration on bioluminescent fungi from this region is very
poor. There are some scattered reports on bioluminescent fungi from India, such as Nothopanus eugrammus (Mont.)
Singer and Omphalotus olearius (DC.) Singer from Western Ghats (Vrinda et al. 1999); Omphalotus olivascens
Bigelow, Miller & Thiers from Kolli Hills, Eastern Ghats (Kumar & Kaviyarasan 2012); and a novel taxon Mycena
RORIDOMYCES PHYLLOSTACHYDIS Phytotaxa 459 (2) © 2020 Magnolia Press • 157
deeptha Aravind. & Manim. from Kerala state (Aravindakshan & Manimohan 2015). To date, there are no reports
on the occurrence of the genus Roridomyces from India and hence, the present study reports the first distributional
record of the genus Roridomyces from India along with the description of a novel bioluminescent taxon based on
morphological and molecular data.
Materials and Methods
Sample collection and herbarium specimen preparation
Fresh fruiting bodies of the bioluminescent fungus growing on dead bamboo (Phyllostachys mannii) sticks were
collected from the East Khasi Hills District, Meghalaya, Northeast India. The samples were photographed in situ
and transported to the field station where its fresh macroscopic details were recorded. Photographs recording the
bioluminescence in complete darkness were taken with a Sony A7R3 camera with a Sony FE 90mm F2.8 Macro G
OSS lens. The settings varied a little depending on how bright the particular fungus was, but a typical setting was F14,
ISO 640 (up to 1000 on occasions), 30 Secs exposure (up to 90 Secs on occasions). All photos were focus stacked and
merged using Helicon Focus software. The fruiting bodies were dried at 45 °C on an electric food dryer after recording
the macroscopic details. Once dried, the specimens were sealed in ziplock plastic bags and labeled. The dried specimen
was deposited in the Herbarium of Mae Fah Luang University (MFLU), Chiang Rai, Thailand. The dried mushrooms
samples were brought to mycology laboratory at Kunming Institute of Botany, Chinese Academy of Sciences (KIB) for
micro-morphological and phylogenetic studies under the material transfer agreement signed between Balipara Tract &
Frontier Foundation (BTFF) Assam, India and KIB, Kunming, China.
Morphological study
Macro-morphological characteristics were described following the terminology of Largent et al. (1977), while colours
were recorded following Ridgeway (1912). Description of the microscopic characteristics followed Vellinga (1988).
To observe the microscopic details from the dried fruitbodies, free-handmade sections were taken under a dissecting
microscope (OLYMPUS SZ61) mounting on a glass slide in 3–5% KOH, 1–3% Congo red, and Melzer’s reagent for
highlighting all tissues (Kreisel and Schauer 1987). Microphotography was done with a Nikon ECLIPSE Ni (Nikon,
Tokyo, Japan) compound microscope, with a Canon EOS 600D (Tokyo, Japan) digital camera fitted on the top of the
microscope. Basidia, basidiospores, cystidia, and other microscopic structures were photographed. Measurements were
taken using the Tarosoft® Image Framework program v. 0.9.0.7. The size and shape of basidiospores were followed
[Q = L/W] and calculated considering the mean value of the lengths and widths in side view (Xm). The calculation
was done by using six different basidiocarps from two different collections, 50 spores have been measured (Miettinen
& Larsson 2006). The photographs were edited in Adobe Illustrator CS v. 3. For scanning electron microscopy of the
basidiospores, fragments of lamellae were mounted on aluminum stubs with double sided adhesive tape, coated with
gold palladium alloy, and then observed under a SEM (Hitachi S4800) (Cook et al. 1997).
DNA extraction, PCR amplification, and sequencing
Dried internal tissues of the basidiocarps were used for DNA extraction. Total DNA was extracted using the Biospin
Fungus Genomic DNA Extraction Kit (BioFlux®). The ITS and LSU loci were amplified by Polymerase Chain
Reaction (PCR). The PCR amplifications were performed in a total volume of 25 μL of PCR mixtures containing 9.5
μL ddH2O, 12.5 μL of PCR master mix, 1 μL of DNA template, and 1 μL of each primer (10 μM). PCR amplification
was carried out using primer pairs ITS5/ITS4 for internal transcribed spacer rDNA region (ITS1, 5.8S rDNA and
ITS2), LROR/LR5 for the nuclear ribosomal large subunit 28S rDNA gene (LSU) (Vilgalys & Hester 1990; White et
al. 1990; Liu et al. 1999). The PCR cycling amplification conditions incorporating slight modifications includes a hot
start of 3 min at 94°C, followed by 35 cycles of 95°C for 30 s, 55°C for 1 min, 72°C for 1 min, and a final extension
step at 72°C for 10 min for ITS and LSU regions. The sequencing of purified PCR products was carried out by Sangon
Biotech (Shanghai) Co., Ltd., Shanghai, China.
KARUNARATHNA ET AL.
158 • Phytotaxa 459 (2) © 2020 Magnolia Press
TABLE 1. Strains and GenBank accession numbers used in the phylogenetic analyses (New taxa are indicated black
bold with an asterisk).
Species Culture Culture collection/ Voucher
number
GenBank accession numbers
LSU ITS
Cruentomycena kedrovaya LE212084 - EU517511
Cruentomycena kedrovaya TENN60716 - EU517513
Cruentomycena kedrovaya TENN60729 - EU517512
Cruentomycena kedrovaya TFB11831 EU532597 -
Hemimycena albicolor MICH 11456 - MK169368
Hemimycena gracilis AFTOL-ID 1732 DQ457671 DQ490623
Hemimycena gracilis S2.1 - KY322595
Mycena chlorophos ACL 055 JX975220 -
Mycena chlorophos ACL 259 JX975221 -
Mycena chlorophos ACL271 - KJ206986
Mycena fulgoris ACP1690 - MG926694
Mycena fulgoris ACP1785 - MG926693
Mycena globulispora ACP1704 - MG926697
Mycena globulispora ACP1765 - MG926696
Mycena illuminans ACL 161 - KJ206975
Mycena illuminans ACL 212 - KJ206980
Mycena illuminans ACL175 JX975218 KJ206976
Mycena lumina ACP1679 - MG926687
Mycena lumina ACP1720 - MG926684
Mycena luxfoliicola ACP1684 - MG926686
Mycena luxfoliicola ACP1791 - MG926688
Mycena nebula ACP1353 - MG926690
Mycena nebula ACP1659 - MG926685
Mycena perlae ACP1669 - MG926691
Panellus longinquus WTU-F-043066 - MK169353
Panellus luminescens ACL205 KJ206955 KJ206979
Panellus luxfilamentus ACL274 KJ206959 KJ206988
Panellus stypticus TN6157 - AF289071
Panellus stypticus TN9525 - AF289070
Panellus violaceofulvus CBS 391.50 MH868193 MH856676
Resinomycena rhododendri TENN48598 - EU517510
Resinomycena rhododendri TENN50793 clone 1 EU532599 EU517508
Resinomycena rhododendri TENN50793 clone 2 - EU517509
Roridomyces phyllostachydis ** MFLU19-2825 MT275657 MT274525
Roridomyces phyllostachydis ** MFLU19-2826 MT275658 MT274526
Roridomyces pruinosoviscidus ACL300 KJ206960 -
Roridomyces pruinosoviscidus ACL273 KJ206958 -
Roridomyces roridus DAOM215019 AF261408 -
Roridomyces roridus KA12-0405 - KR673459
Sarcomyxa edulis SPs131 - AB819080
Sarcomyxa edulis SPs49 - AB819086
...continued on the next page
RORIDOMYCES PHYLLOSTACHYDIS Phytotaxa 459 (2) © 2020 Magnolia Press • 159
TABLE 1. (Continued)
Species Culture Culture collection/ Voucher
number
GenBank accession numbers
LSU ITS
Sarcomyxa serotina CBS 438.50 MH868220 MH856703
Sarcomyxa serotina KRCF 1455 - LC389047
Sarcomyxa serotina S24.3 - KY322581
Tricholoma sinoacerbum GDGM44680 KT160221 KT160219
Tricholoma terreum HKAS 53017 EU439369 EU439319
Xeromphalina austroandina TENN-F-055089 - KM011858
Xeromphalina austroandina TENN-F-054975 KM011865 KM011860
Xeromphalina enigmatica LE311992 - MK049914
Xeromphalina enigmatica 13-10-08AV01 - KP835677
Xeromphalina enigmatica 329674 - MN197871
Xeromphalina podocarpi PDD 105558 - KM975433
Xeromphalina setulipes AH 36724 GQ890700 GQ890701
Sequence alignment and phylogenetic analyses
The sequences of the novel fungus were subjected to standard BLAST searches in the GenBank database to determine
the primary identity of the fungus. All the other sequences for conducting the phylogenetic analyses were retrieved
from GenBank. Sequences with high similarity indices were determined from a BLAST search to find the closest
matches, and from recently published data (Cortés-Pérez et al. 2019). Two species of Tricholoma [viz. T. sinoacerbum
(GDGM44680) and T. terreum (HKAS 53017)] were used as the outgroup taxa, based on the earlier studies of Chew
et al. (2013). The sequences and their GenBank numbers are listed in Table 1. Sequences were aligned with MAFFT
online server (Katoh & Standley 2013), and manually adjusted using BioEdit v. 7.2.5 (Hall 1999) and Clustal X
(Thompson et al. 1997). Gaps were treated as missing data.
Clade results from Maximum likelihood (ML) analyses were assessed with 1,000 replicates, and were executed
on the CIPRES web portal (Miller et al. 2011), using RAxML-HPC2 on XSEDE v.8.2.8 (Stamatakis 2014), and
raxmlGUI v.1.3.1 (Silvestro & Michalak, 2011). The best fitting substitution model for each single gene partition were
determined in MrModeltest v.2.3 (Nylander 2004). Bayesian inference posterior probabilities (PP) with GTR+I+G
model was used for each partition. Bayesian Markov Chain Monte Carlo (MCMC) analyses were conducted in
MrBayes v.3.2.2 (Huelsenbeck & Ronquist 2001). The number of generations was set at 3,500,000, with trees being
sampled every 100th generations. Based on the tracer analysis, the first sampled topologies representing 25% trees
were discarded in the burn-in phase. The remaining trees were then used to calculate posterior probabilities (PP) in
the majority rule consensus tree (Larget & Simon 1999). Phylogenetic trees and data files were figured in FigTree
v.1.4.0 (Rambaut 2012) and edited using Microsoft Office PowerPoint 2010 and Adobe Illustrator CS v. 3. Maximum
Likelihood bootstrap values (MLBS ≥50%) and posterior probabilities values for BI (PP ≥0.9) are given above or
below each branch.
Results
Phylogenetic analyses
The phylogenetic analyses were inferred from ML analysis using separately analyzed ITS (Fig. 3) and LSU ribosomal
DNA (Fig. 4) data sets. For the nrDNA ITS region, 47 sequences, distributed over nine genera and two outgroup taxa,
were aligned and their ends trimmed to create a data set of 932 (including gaps) base pairs. The LSU data set had an
alignment length of 899 (including gaps) base pairs representing 19 sequences, belonging to nine genera and two
outgroup taxa. For both the analyses (ITS and LSU), the phylogenetic tree recovered from the Bayesian analysis did
not differ in topology with the tree obtained from ML analyses. Hence, the ML trees generated from the ITS (Fig. 3)
and LSU (Fig. 4) datasets have been shown in the present manuscript.
KARUNARATHNA ET AL.
160 • Phytotaxa 459 (2) © 2020 Magnolia Press
In both ITS and LSU analyses (Figs. 3 and 4), the new species is resolved in the clade comprising of the type
species of the genus Roridomyces (R. roridus) with full support values (100% BS and 1.00 PP) signifying its position
within the genus Roridomyces.
In the ITS analysis, members of the genus Roridomyces comes basal to the cluster comprising of the taxa belonging
to the genus Panellus, Cruentomycena and Resinomycena (Fig. 3). However, this position of the genus Roridomyces
is statistically unsupported. In the clade comprising of the members of Roridomyces, the new species, Roridomyces
phyllostachydis, differ from R. roridus with strong statistical support values (100% BS and 1.00 PP) confirming it as a
distinct taxon. The similar result was also obtained in the LSU analyses where Roridomyces phyllostachydis differed
from Roridomyces pruinosoviscidus and R. roridus with full support values (100% BS and 1.00 PP).
Figure 1. Roridomyces phyllostachydis (MFLU19-2825, holotype). a-e, g-k Different stages of fruiting bodies. b,d,e,g,h Bright luminous
green light emitting stipes in the dark f bioluminescent mycelia on bamboo substrate. Scale bars: 10 mm (a-c) Photos: Stephen Axford.
RORIDOMYCES PHYLLOSTACHYDIS Phytotaxa 459 (2) © 2020 Magnolia Press • 161
Taxonomy
Roridomyces phyllostachydis Karun., Mortimer, Axford sp. nov. Figs 1,2
Index Fungorum number: IF557421
Etymology:—the species epithet “phyllostachydis” refers to the host Phyllostachys from where the fungus was
collected.
Holotype:—MFLU19-2825
Diagnosis:—Comparatively larger basidia (29‒33 × 10‒12 μm) and basidiospores (9‒10 × 5‒6 μm) combined with
distinct luminescent glutinous stipe suitably distinguish the newly discovered taxon from all other known Roridomyces
species.
Pileus 3‒15 mm diam., initially convex to obtusely conical with a shallow central depression, expanding to
broadly conical, subumbilicate to umbilicate with a prominent central depression; margin translucent-striate; surface
dry, pruinose to glabrous, striations light pink, center covers with light brown scales, elsewhere beige or pale pink,
hygrophanous, colour changes to brownish yellow on drying; context thin (< 0.3 mm) at the margin, comparatively
thicker towards the center (upto 0.6 mm), yellowish white. Lamellae 2–4 mm broad, subdecurrent to decurrent,
occasionally deeply decurrent, distant (12‒16 reaching the stipe) with 1‒3 series of lamellulae, beige to yellowish
white; edge even, discolorous, pale white. Stipe 10‒28 × 0.5‒2 mm, central, cylindrical, slightly tapering at the pileus,
with a slightly swollen base, hollow; surface glutinous, slimy, moist, white at the extreme apex with reddish brown
base, elsewhere pale brown, hygrophanous, glows bright, luminous green, in the dark, glabrous to pruinose except at
the base, white, strigose basal mycelium. Odor not recorded. Bioluminescent only in the stipe surface, emitting bright
even luminous green light.
Basidiospores 9‒10 × 5‒6 μm [Xm = 9.63 ± 0.26 × 5.28 ± 0.16 μm, Q =1.65‒1.92, Qm = 1.83 ± 0.08, n =50],
elongate, hyaline, thin-walled, amyloid. Basidia 29‒33 × 10‒12 μm, clavate, hyaline, thin-walled, 4-spored; sterigmata
1‒3 μm long, cylindrical. Pleurocystidia absent. Lamellae edge sterile with well-developed cystidia. Cheilocystidia
27–37.5 × 8–11.5 μm, clavate, hyaline, thin-walled. Lamellae trama composed of loosely arranged circular cells,
hyaline, inamyloid, nongelatinous. Pileipellis hymeniform consisting of more or less globose to spheropedunculate
cells, 18.5–29 × 17.5–29 μm diam., hyaline, thin-walled. Stipitipellis hyphae 8‒10 μm diam., cylindrical, hyaline,
inamyloid; cortical hyphae 6‒9 μm diam., cylindrical, hyaline, dextrinoid, nongelatinous, thin-walled; medullary
hyphae 5‒24 μm diam, net like, hyaline, thick-walled, dextrinoid. Caulocystidia 3.0‒10 μm in diam., cylindrical,
to subcylindrical, sometimes subclavate with obtuse apex, sometime less pointed, hyaline, thin walled, oil granule
presents with KOH. Clamp-connections present in all tissues.
Ecology and distribution:—Gregarious or scattered, growing on dead bamboo sticks, Northeast India (Mawlynnong
and Krang Shuri), June to September.
Material examined:—INDIA. Meghalaya, East Khasi Hills District, Mawlynnong, 25°12ʹ31″N, 91°54ʹ38″E,
elev. 560 m, on dead bamboo sticks, 21 August 2019, Gautam Baura (MFLU19-2825, holotype). Additional specimen
examined: INDIA. Meghalaya, West Jayantia Hills district, Krang Shuri, 25°17ʹ14″N, 92°07ʹ21″E, elev. 1021 m, on
dead bamboo sticks, 23 August 2019, Gautam Baura (MFLU19-2826, paratype).
Discussion
The characteristic features of Roridomyces phyllostachydis includes a small sized, subumbilicate to umbilicate,
centrally depressed pileus coloured beige or pale pink with light brown center and light pink striations; subdecurrent
to decurrent, distant lamellae; a central stipe that is slightly bulbous at base with entirely glutinous and slimy surface
colored pale brown with white apex and reddish brown base that emit bright luminous green light evenly at dark;
broadly ellipsoid, amyloid basidiospores (9‒10 × 5‒6 μm); absence of pleurocystidia; clavate cheilocystidia measuring
27–37.5 × 8–11.5 μm; hymeniform pileipellis consisting of more or less globose to spheropedunculate cells measuring
18.5–29 × 17.5–29 μm; and habitat specific to bamboo plant.
With regard to similar sized, brownish to pale yellow-brown, umbilicate to subumbilicate pileus having minute
brownish squamules at the center, the present specimen appears close to Roridomyces austrororidus (Singer) Rexer.
However, R. austrororidus, originally described from Chile, differs from R. phyllostachydis by its larger sized (9–12 ×
6–8 µm), ovate to broadly elliptic basidiospores, longer cheilocystidia (40–80 × 3–9 µm), and larger sized cells in the
pileipellis (20–90 × 10–30 µm; Horak 1978).
KARUNARATHNA ET AL.
162 • Phytotaxa 459 (2) © 2020 Magnolia Press
FIGURE 2. Roridomyces phyllostachydis (MFLU19-2825, holotype). a-g Basidiospores e-g Basidia h, i Subhymenium cells. j Stipitipellis
hyphae. k, l Stipe cortex cells. m, n Pileipellis cells. o Cheilocystidia. p Young basidiospores with sterigmata. q-t Mature basidiospores.
Scales bar: 2 µm (a-d, m-o, q), 4 µm (e-g), 10 µm (h, i, l), 20 µm (j, k), 1 µm (p).
RORIDOMYCES PHYLLOSTACHYDIS Phytotaxa 459 (2) © 2020 Magnolia Press • 163
FIGURE 3. Maximum Likelihood tree generated using RAxML based on the ITS dataset. MLBS Bootstrap support values for maximum
likelihood (≥50%) and posterior probabilities values (PP) for BI (≥0.9 PP) are given above or below each branch. The new species is
indicated in red bold font. The tree is rooted to Tricholoma sinoacerbum (GDGM44680) and T. terreum (HKAS 53017).
Considering beige coloured pileus with brownish center, subdecurrent to decurrent lamellae, and intense
luminescent stipe emitting greenish light, the Malaysian taxon Mycena gombakensis appears similar to the present
taxon. Micromorphologically, M. gombakensis has much smaller basidiospores (6.4–7.2 × 4.0–4.8 μm), fertile lamellar
edge, cylindrical to irregular shaped diverticulate cheilocystidia, diverticulate hyphae in the pileipellis, and absence of
caulocystidia (Chew et al. 2014).
KARUNARATHNA ET AL.
164 • Phytotaxa 459 (2) © 2020 Magnolia Press
Among other morphologically and phylogenetically close taxa (Figs 3-4): Roridomyces pruinosoviscidus differs
from the present taxon by its differently coloured pileus with curved margin, orangish stipe apex, much smaller sized
basidiospores (5–6.5 × 3–3.7 μm), and yellowish green light emission throughout the entire parts of basidiocarp (Corner
1954; Chew et al. 2015). Roridomyces roridus has bell shaped to almost applanate pileus colored pale brown to tan
that fades to white or yellowish white; entirely white lamellae; equal shaped stipe entirely white colored; elliptical and
somewhat differently sized basidiospores (8–12 × 4–6 μm) and habitat predominantly under conifers (Arora 1986).
For identification of most fungi populations are delimited into species based on a number of different and subtle
morphological features. The comparatively larger sized basidia and basidiospores combined with distinct luminescence
region of stipe are enough to distinguish the newly discovered taxon from all other known Roridomyces species.
Furthermore, in addition to morphological differences, phylogenetic analyses based on the ITS and LSU datasets
supports the recognition of the presently described taxon as a distinct new species in Roridomyces (Figs 3-4).
Fungal luminescence mostly occurs during the dark hours of night. The mechanism of light emission was illustrated
by Kaskova et al. (2017). However, the ecological effects of fungal bioluminescence have been less studied and the
hypotheses relating whether fungal bioluminescence facilitate the dispersal of basidiospores (Bechara 2015) and helps
in reproduction or as a means of reducing predation by fungivores are still worthy for further study.
FIGURE 4. Maximum Likelihood tree generated using RAxML based on LSU sequence. MLBS Bootstrap support values for maximum
likelihood (≥50%) and posterior probabilities values (PP) for BI (≥0.9 PP) are given above or below each branch. The new species is in
red bold. The tree is rooted to Tricholoma sinoacerbum (GDGM44680) and T. terreum (HKAS 53017).
Acknowledgments
Peter Mortimer thanks Chiang Mai University for partially funding this research. Samantha C. Karunarathna would
like to thank the CAS President’s International Fellowship Initiative (PIFI) young staff under the grant number:
2020FYC0002 and the National Science Foundation of China (NSFC) under the project code 31851110759 for funding
this work. Arun Kumar Dutta acknowledges support from the Department of Science & Technology (DST), New
Delhi, India, in the form of DST-Inspire Faculty Fellowship (DST/INSPIRE/04/2018/001906, dated 24 July, 2018) and
DST-FIST (Project No. SR/FST/LSI-630/2015) facility in the Department of Botany, West Bengal State University.
Saowaluck Tibpromma would like to thank the International Postdoctoral Exchange Fellowship Program (number
Y9180822S1), CAS President’s International Fellowship Initiative (PIFI) (number 2020PC0009), China Postdoctoral
RORIDOMYCES PHYLLOSTACHYDIS Phytotaxa 459 (2) © 2020 Magnolia Press • 165
Science Foundation and the Yunnan Human Resources, and Social Security Department Foundation for funding her
postdoctoral research. Balipara Foundation is thanked for funding and field support and Globally Managed Services is
thanked for partially funding this work. Kunming Institute of Botany, Chinese Academy of Science (KIB) is thanked
for providing laboratory facilities for morphology and phylogeny work, and Mr Gu Zhi-Jia in KIB is thanked for
the assistance in taking the scanning electron microscopy photographs. Dr. Shaun Pennycook is thanked for help in
naming the new fungal species.
References
Airth, R.L. & Foerster, G.E. (1962) The isolation of catalytic components required for cell-free fungal bioluminescence. Archives of
Biochemistry and Biophysics 97: 567–573.
https://doi.org/10.1016/0003-9861(62)90124-8
Aravindakshan, D.M., Kumar, T.K.A. & Manimohan, P. (2012) A new bioluminescent species of Mycena sect. Exornatae from Kerala
State, India. Mycosphere 3 (5): 556–561.
https://doi.org/10.5943/mycosphere/3/5/4
Aravindakshan, D.M. & Manimohan, P. (2014) Three new species of Mycena sect. Longisetae. Mycosphere 5 (2):290–297.
https://doi.org/10.5943/mycosphere/5/2/3
Aronsen, A. & Læssøe, T. (2016) The genus Mycena s.l. Fungi of northern Europe vol. 5. Narayana press, Gylling.
Arora, D. (1986) Mushrooms Demystified. Ten Speed Press, 1056.
Bechara, E.J.H. (2015) Bioluminescence: A Fungal Nightlight with an Internal Timer. Current Biology 25 (7): 283–285.
https://doi.org/10.1016/j.cub.2015.01.004
Bermudes, D., Peterson, R.H. & Neason, K.N. (1992) Low level bioluminescence detected in Mycena haematopus basidiocarps. Mycologia
84: 799–802.
https://doi.org/10.1080/00275514.1992.12026208
Chew, A.L.C., Tan, Y.S., Desjardin, D.E., Musa, M.Y. & Sabaratnam, V. (2013) Taxonomic and phylogenetic re-evaluation of Mycena
illuminans. Mycologia 105 (5): 1325–1335.
https://doi.org/10.3852/13-009
Chew, A.L.C., Desjardin, D.E., Tan, Y.S., Musa, M.Y. & Sabaratnam, V. (2015) Bioluminescent fungi from Peninsular Malaysia - a
taxonomic and phylogenetic overview. Fungal Diversity 70: 149–187.
https://doi.org/10.1007/s13225-014-0302-9
Cook, R., Inman, A. & Billings, C. (1997) Identification and classification of powdery mildew anamorphs using light and scanning
electron microscopy and host range data. Mycological Research 101: 975–573.
Corner, E.J.H. (1954) Further descriptions of luminous agarics. Transactions of the British Mycological Society 37 (3): 256–271.
https://doi.org/10.1016/S0007-1536(54)80009-X
Cortés-Pérez, A., Desjardin, D.E., Perry, B.A., Ramírez-Cruz, V., Ramírez-Guillén, F., Villalobos-Arámbula, A.R. & Rockefeller, A.
(2019) New species and records of bioluminescent Mycena from Mexico. Mycologia 111 (2): 319–573.
https://doi.org/10.1080/00275514.2018.1554172
Desjardin, D.E., Oliveira, A.G. & Stevani, C.V. (2008) Fungi bioluminescence revisited. Photochemical & Photobiological Sciences 7
(2): 170–182.
https://doi.org/10.1039/b713328f
Desjardin, D.E., Perry, B.A., Lodge, D.J., Stevani, C.V. & Nagasawa, E. (2010) Luminescent Mycena: new and noteworthy species.
Mycologia 102 (2): 459–477.
https://doi.org/10.3852/09-197
Desjardin, D.E., Perry, B.A. & Stevani, C.V. (2016) New luminescent mycenoid fungi (Basidiomycota, Agaricales) from São Paulo State,
Brazil. Mycologia 108 (6):1165–1174.
Haddock, S.H.D., Moline, M.A. & Case, J.F. (2010) Bioluminescence in the Sea. Annual Review of Marine Science 2: 443–493.
https://doi.org/10.1146/annurev-marine-120308-081028
Hall, T.A. (1999) BioEdit: a user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucleic
Acids Symposium Series 41: 95–98.
Harvey, E.N. (1952) Bioluminescence. Academic Press, New York, NY.
Horak, E. (1978) Mycena rorida (Fr.) Quel. and related Species from the Southern Hemisphere. Berichte der Schweizerischen Botanischen
Gesellschaft 88 (1/2): 20–29.
KARUNARATHNA ET AL.
166 • Phytotaxa 459 (2) © 2020 Magnolia Press
Huelsenbeck, J.P. & Ronquist, F. (2001) MRBAYES: Bayesian inference of phylogenetic trees. Bioinformatics 17 (8):754–755.
https://doi.org/10.1093/bioinformatics/17.8.754
Larget, B. & Simon, D.L. (1999) Markov chain Monte Carlo algorithms for the Bayesian analysis of phylogenetic trees. Molecular biology
and evolution 16 (6):750–759.
https://doi.org/10.1093/oxfordjournals.molbev.a026160
Kaskova, Z.M., Dörr, F.A., Petushko, V.N., Purtov, K.V., Tsarkova, A.S., Rodionova, N.S., Mineev, K.S., Guglya, E.B., Kotlobay, A.,
Baleeva, N.S., Baranov, M.S., Arseniev, A.S., Gitelson, J.I., Lukyanov, S., Suzuki, Y., Kanie, S., Pinto, E., Mascio, P.D., Waldenmaier,
H.E., Pereira, T.A., Carvalho, R.P., Oliveira, A.G., Oba, Y., Bastos, E.L., Stevani, C.V. & Yampolsky, I.V. (2017) Mechanism and
color modulation of fungal bioluminescence. Science advances 3 (4): e1602847.
https://doi.org/10.1126/sciadv.1602847
Katoh, K. & Standley, D.M. (2013) MAFFT multiple sequence alignment software version 7: improvements in performance and usability.
Molecular biology and evolution 30 (4):772–780.
https://doi.org/10.1093/molbev/mst010
Kirk, P.M., Cannon, P.F., Minter, D.W. & Stalpers, J.A. (2008) Dictionary of the Fungi (10th ed.). Wallingford: CAB International, 606
pp.
Kotlobay, A.A., Sarkisyan, K.S., Mokrushina, Y.A., Marcet-Houben, M., Serebrovskaya, E.O., Markina, N.M., Somermeyer, L.G.,
Gorokhovatsky, A.Y., Vvedensky, A., Purtov, K.V., Petushkov, V.N., Rodionova, N.S., Chepurnyh, T.V., Fakhranurova, L.I., Guglya,
E.B., Ziganshin, R., Tsarkova, A.S., Kaskova, Z.M., Shender, V., Abakumov, M., Abakumova, T.O., Povolotskaya, I.S., Eroshkin,
F.M., Zaraisky, A.G., Mishin, A.S., Dolgov, S.V., Mitiouchkina, T.Y., Kopantzev, E.P., Waldenmaier, H.E., Oliveira, A.G., Oba,
Y., Barsova, E., Bogdanova, E.A., Gabaldón, T., Stevani, C.V., Lukyanov, S., Smirnov, I.V., Gitelson, J.I., Kondrashov, F.A. &
Yampolsky, I.V. (2018) Genetically encodable bioluminescent system from fungi. Proceedings of the National Academy of Sciences
115 (50): 12728–12732.
https://doi.org/10.1073/pnas.1803615115
Kreisel, H. & Schauer, F. (1987) Methoden des mykologischen Laboratoriums. Lubrecht & Cramer, Limited.
Kumar, M. & Kaviyarasan, V. (2012) Few common poisonous mushrooms of Kolli Hills, South India. Journal of Academia and Industrial
Research 1 (1): 19–22.
Largent, D., Johnson, D. & Watling, R. (1977) How to identify mushrooms to genus III: Microscopic features. Mad River Press, Eureka,
CA, USA, 148 pp.
Lee, J. (2015) Basic bioluminescence. Available from: http://photobiology.info/LeeBasicBiolum.html#targetText=Some%2017%20phyla
%20and%20at,but%20a%20few%20marine%20species (accessed 11 March 2020)
Lingle, W.L. (1993) Bioluminescence and ligninolysis during secondary metabolism in the fungus Panellus. Journal of Bioluminescence
and chemiluminescence 8: 100.
Liu, Y.J., Whelen, S. & Hall, B.D. (1999) Phylogenetic relationships among ascomycetes: evidence from an RNA polymerse II subunit.
Molecular biology and evolution 16 (12):1799–808.
https://doi.org/10.1093/oxfordjournals.molbev.a026092
Maas-Geesteranls, R.A. (1989) Conspectus of the Mycenas of the Northern Hemisphere - 12. Sections Fuliginellae, Insignes, lngratae,
Euspeireae, and Caespitosae. Proceedings of the Koninklijke Nederlandse Akademie van Wetenschappen 92: 363–397.
Maas-Geesteranls, R.A. (1991) Studies in Mycenas. Additions and Corrections, Part 2. Proceedings of the Koninklijke Nederlandse
Akademie van Wetenschappen 94: 545–571.
Miettinen, O. & Larsson, K.H. (2006) Trechispora elongata species nova from North Europe. Mycotaxon 96:193–198.
Mihail, J.D. (2015) Bioluminescence patterns among North American Armillaria species. Fungal Biology 119:528–537.
https://doi.org/10.1016/j.funbio.2015.02.004
Miller, M.A., Pfeiffer, W. & Schwartz, T. (2011) The CIPRES science gateway: a community resource for phylogenetic analyses. In:
Proceedings of the 2011 TeraGrid Conference: extreme digital discovery. pp. 1–8.
https://doi.org/10.1145/2016741.2016785
Nylander, J.A. (2004) MrModeltest v2 (Program distributed by the author.) Evolutionary Biology Centre, Uppsala University, Sweden.
[http://www.ebc.uu.se/systzoo/staff/nylander]
Pandey, A.D & Sharon, M. (2017) Bioluminescent Organisms. BAOJ Chemistry 3 (2): 029.
Rambaut, A. (2012) FigTree v1. 4. Molecular evolution, phylogenetics and epidemiology. Edinburgh, UK: Available from: http://tree.bio.
ed.ac.uk/software/ (accessed 11 September 2020)
Rexer, K.H. (1994) Die Gattung Mycena s.l., Studien zu Ihrer Anatomie, Morphologie und Systematik (Ph.D. thesis). Tübingen, Germany:
Eberhard-Karls-Universität Tübingen. [in German]
Ridgeway, R. (1912) Color standards and color nomenclature. Washington, DC, 43 pp., 53 col. pi.
https://doi.org/10.5962/bhl.title.62375
RORIDOMYCES PHYLLOSTACHYDIS Phytotaxa 459 (2) © 2020 Magnolia Press • 167
Shih, Y.S., Chen, C.Y., Lin, W.W. & Kao, H.W. (2014) Mycena kentingensis, a new species of luminous mushroom in Taiwan, with
reference to its culture method. Mycological Progress 13: 429–435.
https://doi.org/10.1007/s11557-013-0939-x
Silvestro, D. & Michalak, I. (2012) raxmlGUI: a graphical front-end for RAxML. Organisms Diversity & Evolution 12 (4): 335–337.
https://doi.org/10.1007/s13127-011-0056-0
Stamatakis, A. (2014) RAxML version 8: a tool for phylogenetic analysis and post-analysis of large phylogenies. Bioinformatics 30 (9):
1312–1313.
https://doi.org/10.1093/bioinformatics/btu033
Tarr, C.L., Patel, J.S., Puhr, N.D., Sowers, E.G. & Bopp, C.A. (1997) Strockbine NA 83: 727–736.
Thoen, E., Harder, C.B., Kauserud, H., Botnen, S., Vik, U., Taylor, A.F.S., Menkis, A. & Skrede, I. (2020) The ubiquitous mycenas - purely
saprotrophs or potential plant root symbionts? [unpublished]
Vellinga, E.C. (1988) Glossary 54–64. In: Flora Agaricina Neerlandica 1.
Thompson, J.D., Gibson, T.J., Plewniak, F., Jeanmougin, F. & Higgins, D.G. (1997) The CLUSTAL_X windows interface: flexible
strategies for multiple sequence alignment aided by quality analysis tools. Nucleic acids research 25 (24): 4876–4882.
https://doi.org/10.1093/nar/25.24.4876
Vilgalys, R. & Hester, M. (1990) Rapid genetic identification and mapping of enzymatically amplified ribosomal DNA from several
Cryptococcus species. Journal of bacteriology 172 (8): 4238–4246.
https://doi.org/10.1128/JB.172.8.4238-4246.1990
Vinodkumar, K. & Sarita, H. (2016) A Review on Bioluminescent fungi: A Torch of Curiosity. International Journal of Life Sciences
(Special Issue) A7: 107–110.
Vrinda, K.B., Pradeep, C.K. & Abraham, T.K. (1999) Bioluminescent agarics from Western Ghats. Mushroom Research 8 (2): 31–33.
Vydryakova, G.A., Gusev, A.A. & Medvedeva, S.E. (2011) Effect of organic and inorganic toxic compounds on luminescence of luminous
fungi. Applied Biochemistry and Microbiology 47: 293–297.
https://doi.org/10.1134/S0003683811010194
White, T.J., Bruns, T.D., Lee, S. & Taylor, J. (1990) Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics.
In: Innis, M.A., Gelfand, D.H., Sninsky, J.J. & White, T.J. (Eds.) PCR Protocols: a guide to methods and applications. Academic
Press, San Diego, pp. 315–322.
https://doi.org/10.1016/B978-0-12-372180-8.50042-1
