
==== Front
Mycoscience
Mycoscience
mycosci
Mycoscience
1340-3540
1618-2545
The Mycological Society of Japan Tokyo, JAPAN

mycosci.2024.02.008
10.47371/mycosci.2024.02.008
Short Communication
Cystoderma yongpingense sp. nov. (Squamanitaceae, Agaricales) a new species from southwestern China
Feng Yun-Li a
Sun Da-Feng a * 2942336@qq.com

Fang Yuan b
Hua Rong ab
Liu Shao-Xiong a
Ma Ming a
Guo Xiang a * guoxkm@yeah.net

aKunming Edible Fungi Institute of All China Federation of Supply and Marketing Cooperatives
bYunnan Academy of Edible Fungi Industry Development
* Corresponding author.Kunming Edible Fungi Institute of All China Federation of Supply and Marketing Cooperatives, Kunming 650221,Yunnan, China E-mail address:2942336@qq.com
* Corresponding author.Kunming Edible Fungi Institute of All China Federation of Supply and Marketing Cooperatives, Kunming 650221,Yunnan, China E-mail address:guoxkm@yeah.net
2 5 2024
2024
65 3 151155
24 8 2023
26 2 2024
27 2 2024
2024, by The Mycological Society of Japan
https://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open-access paper distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivative 4.0 international license (CC BY-NC-ND 4.0: https://creativecommons.org/licenses/by-nc-nd/4.0/).
The present study introduces a novel fungus, Cystoderma yongpingense, which was identified in the southwestern region of China. The new species is characterized by a pileus that ranges in color from light orange-red to orange-red; the pileus has a wrinkled surface and is accompanied by a persistent annulus that is membranous and floccose-scaly. Above the annulus, the color transitions from white to yellowish brown. This proposal is substantiated through analyses encompassing both morphological characteristics and phylogenetic relationships. The phylogenetic position of the newly discovered species has been further corroborated through comprehensive maximum likelihood and Bayesian sequence analyses of the ITS + nrLSU DNA regions. Additionally, the technical description of C. yongpingense is enhanced by detailed illustrations and comparative studies with species that are closely related.

phylogeny
taxonomy
Yunnan Province
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pmcThe genus Cystoderma Fayod was established by Fayod in 1889 (Fayod, 1889), and later C. amianthinum (Scop.) Fayod was designated as the type species by Smith and Singer in 1945 (Smith & Singer, 1945). This genus is characterized by distinctive features in its basidiocarps, such as the globose cellular structure in the veil tissues, the weakly to strongly amyloid basidiospores, and a variable annulus on the stipe which can be either evanescent and floccose-scaly or persistent and membranous (Saar, 2012). These basidiocarps are commonly found in habitats like moss, forest litter, or decaying wood beneath coniferous or broadleaved trees (Saar et al., 2016).

The genus Cystoderma, originally classified under the Lepiota section of the Agaricus by Persoon in 1797 (Persoon, 1797), has undergone significant taxonomic revisions over the years. In 1945, Smith and Singer published the first monograph on the genus, categorizing the taxa into two distinct sections: Granulosa and Amianthina (Smith & Singer, 1945). However, in 1962, Singer renamed the Amianthina section to Cystoderma (Singer, 1962). Later, in 2002, after assessing the taxonomic significance of spore amyloidity in the genus Cystoderma, Harmaja (2002) took into account the findings from research on the nuclear DNA content of specific species (Saar & Kullman, 2000) and the phylogenetic analysis of nucLSU data (Moncalvo et al., 2002), further classifying Cystoderma into two genera: Cystoderma, which is placed in the family Squamanitaceae, and Cystodermella, whose phylogenetic position remains unknown for the time being (Liu et al., 2021).

During the course of researching macrofungi in southwestern China, we discovered a Cystoderma species with distinct light orange-red to orange-red coloration. The specimen was collected from a broadleaf forest in Yongping County, Yunnan Province. We have identified it as a new species based on morphological characteristics and molecular analyses.

The specimens have been deposited at the Kunming Edible Fungi Institute of All China Federation of Supply and Marketing Cooperatives, Kunming, China (KEF). These specimens were collected in the field following photographic documentation. Microscopic exminations and measurements were carried out using a Leica DM5000B microscope, following procedures described by Li et al. (2022). The dimensions of microscopic features, including spores and basidia, were determined in Melzer's reagent solution based on more than 20 measurements for each feature.

Molecular and phylogenetic analyses

DNA was extracted from dried specimens using a BEIWO Fungal gDNA Isolation Kit (Biomiga, China) according to the manufacturer's instructions with some modifications. The ITS region was amplified using ITS4 and ITS5 primers (White et al., 1990), while the nrLSU region was amplified using LROR (Cubeta et al., 1991) and LR5 primers (Vilgalys & Hester, 1990). PCR products were verified through 1% agarose gel electrophoresis with ethidium bromide. Sequencing of the PCR products was performed at the Beijing Genomics Institute (BGI). The acquired sequences were subsequently deposited in the GenBank database.

Sequence analysis was conducted via the BLAST tool in GenBank (http://www.ncbi.nlm.gov) and the results were downloaded for further analysis (i.e., ITS and nrLSU datasets) (Table 1). The datasets included sequences from the newly identified species as well as those of closely related taxa. Sequence alignment was performed using MAFFT (Katoh & Standley, 2013), employing the ‘--auto’ strategy and normal alignment mode. Gblocks (Talavera & Castresana, 2007) was used to remove ambiguously aligned fragments from the sequence alignment. Phylosuite (Zhang et al., 2020) was used to integrate the ITS and nrLSU sequences. ModelFinder (Kalyaanamoorthy et al., 2017) was used to select the best-fit model using AICc criterion; GTR was identified as the most suitable model. Maximum likelihood phylogenies were inferred using IQ-TREE (Nguyen et al., 2015) under the GTR model; this analysis included 5000 ultrafast bootstraps (Minh et al., 2013), the approximate Bayes test (Anisimova et al., 2011), and the Shimodaira-Hasegawa-like approximate likelihood-ratio test (Guindon et al., 2010).

Table 1. Sequences selected for ITS and nrLSU phylogenetic analyses

Species name	ITS	nrLSU	Voucher	Locality	
Cystoderma amianthinum	AM946480	AM946424	TUF101287	Estonia	
Cystoderma amianthinum	MW242929	-	HMAS291341	China	
Cystoderma andinum	AM946481	AM946425	C57998	Ecuador	
Cystoderma andinum	AM946482	AM946426	C58476	Ecuador	
Cystoderma aureum	MZ424458	MZ413916	HMAS255933	China	
Cystoderma aureum	AM946523	AM946459	C27851	Denmark	
Cystoderma carcharias	UDB015074	-	TUF106011	Estonia	
Cystoderma carcharias	AM946483	AM946428	TAAM172011	Sweden	
Cystoderma carpaticum	LT592276	-	IB19750290	Poland	
Cystoderma carpaticum	LT592274	LT592277	CNF1/7034	Croatia	
Cystoderma chocoanum	-	EU727143	SP393641	Brazil	
Cystoderma chocoanum	-	U85302	NY00775586	Colombia	
Cystoderma clastotrichum	KF727405	KF727342	PDD93758	New Zealand	
Cystoderma clastotrichum	MZ956998	MZ957010	PDD72815	New Zealand	
Cystoderma granosum	MW242933	MW242945	HMAS291346	China	
Cystoderma granosum	MW242932	MW242944	HMAS291348	China	
Cystoderma granosum	MZ424459	MZ413917	HMAS255934	China	
Cystoderma lilaceum	MW242922	MW242948	HMAS291349	China	
Cystoderma lilaceum	MW242923	MW242946	HMAS291350	China	
Cystoderma japonicum	AM946491	AM946435	BR5020079022647	Japan	
Cystoderma japonicum	UDB011137	LT592278	TUF101697	Estonia	
Cystoderma jasonis	UDB015579	-	TUF118180	Estonia	
Cystoderma jasonis	UDB016440	-	TU101948	Canada	
Cystoderma pseudoamianthinum	MZ424460	MZ413918	HMAS255932	China	
Cystoderma pseudoamianthinum	MW242928	MW242940	HMAS291343	China	
Cystoderma pseudoamianthinum	MW242927	MW242939	HMAS291344	China	
Cystoderma simulatum	AM946490	AM946434	PDD83705	New Zealand	
Cystoderma simulatum	AM946489	AM946432	PDD75555	New Zealand	
Cystoderma subvinaceum	AM946501	AM946441	WU19742	Austria	
Cystoderma subvinaceum	AM946502	-	WU10567	Austria	
Cystoderma subvinaceum	MW242924	MW242941	HMAS291342	China	
Cystoderma subglobisporum	MW242934	MW242947	HMAS281432	China	
Cystoderma superbum	AM946503	AM946443	REG (Oct 1976)	Germany	
Cystoderma superbum	AM946504	AM946442	BR22288-75	Belgium	
Cystoderma rugosolateritium	MW242925	MW242937	HMAS291351	China	
Cystoderma tricholomoides	UDB011633	-	BR5020125408845	Germany	
Cystoderma tricholomoides	UDB011634	-	BR De Meyer 597	Netherlands	
Cystoderma tuomikoskii	AM946505	AM946444	H6026179	Finland	
Cystoderma tuomikoskii	AM946507	-	O153775	Norway	
Cystoderma yongpingense	OP935710	OP935734	KEF 11357 [T]	China	
Cystoderma yongpingense	OP935712	OP935736	KEF 11358	China	
Cystoderma yongpingense	OP935739	OP935740	KEF 11359	China	
Floccularia luteovirens	KF114487	KF266879	E6	China	
Floccularia luteovirens	KF114563	KF266878	D17	China	

The ITS and nrLSU datasets used for the phylogenetic analyses included 44 samples representing 20 species, with Floccularia luteovirens (Alb. & Schwein.) Pouzar being used as an outgroup species (Table 1). This study contributed six new sequences, including three ITS and three nrLSU sequences, from the new species. After removal of segments with ambiguous alignment and subsequent concatenation, a total of 1568 base pairs (bp) including 653 bp of ITS and 915 bp of nrLSU were used for the final analysis. The resultant Maximum Likelihood (ML) tree is presented in Fig. 1, with bootstrap values annotated on the branches.

Fig. 1. Maximum likelihood (ML) tree of Cystoderma yongpingense based on ITS + nrLSU sequences. The tree is rooted with Floccularia luteovirens. Maximum likelihood support values / Bayesian posterior probabilities / Shimodaira-Hasegawa-like approximate likelihood-ratio (> 60 / 0.6) are shown on the nodes. The new species is shown in bold.

Our phylogenetic analysis clearly showed that Cystoderma yongpingense was a new species (ML bootstrap = 99.9); it was also observed to cluster with C. tricholomoides Heinem. & Thoen, albeit with lower supporting evidence.

Taxonomy

Cystoderma yongpingense Y. L. Feng, X. Guo & Y. Fang, sp. nov.　Fig.2, 3

Fig. 2. Cystoderma yongpingense (holotype, KEF 11357) Fresh basidiomes in situ. Bars: 1 cm.

Fig. 3. Microscopic structures of Cystoderma yongpingense (holotype, KEF 11357). A: basidiospores; B: basidia; C: sphaerocysts from pileus; D: elements of annulus; Bars: A, B 5 μm; C, D 10 μm.

Fungal Names No.: FN571242

Diagnosis: The new species is characterized by a pileus that ranges in color from light orange-red to orange-red; the pileus has a wrinkled surface and is accompanied by a persistent annulus that is membranous and floccose-scaly. Above the annulus, the color transitions from white to yellowish brown. The basidiospores of this species are ellipsoid to narrowly ovoid, smooth, hyaline, and inamyloid, and lack a germ pore.

Type: China, Yunnan Province, Yongping County, Baotai Temple, 25°11′30″N 99°31′52″E, alt. 2368 m, gregarious in a broadleaf forest litter dominated by Fagaceae, 17 Aug 2022, KEF 11357 (holotype, GenBank accession No.: ITS = OP935710, nrLSU = OP935734).

Etymology: The species epithet “yongpingense” refers to the place where the type species was collected.

Pileus 25-45 mm, convex at the early stage, gradually flattening at the later stage, light orange-red to orange-red, finely covered granulose scales, slightly wrinkled, with remnants of partial veil at margin. Lamellae adnate, white to pale cream, crowded, with 1-2 lamellulae of different lengths, less than 2 mm broad. Stipe 35-60 × 3-6 mm, light yellow to light orange-red, cylindrical, hollow, uneven, with a persistent membranous floccose-scaly annulus, white to yellowish brown and silky striate above the annulus, light yellow to light orange-red below the annulus, densely covered with granular furfuraceous squamules.

Basidiospores ellipsoid to narrow ovoid, smooth, hyaline, no germ pore, inamyloid, (3.5-)4.0-5.6(-6.0) × 3.2-4(-4.5) μm, L = 4.78 µm, W = 3.56 µm, Q = 1.32-1.44. Basidia barrel-shaped to clavate, smooth, hyaline, 4-spored, clavate, smooth, hyaline, 4-spored, (11-)13.0-20.5 × 3.8-4.8 μm; Pleurocystidia and cheilocystidia absent. Pileipellis composed of chains of numerous yellowish brown sphaerocysts, globose to ellipsoid, sometimes flask-shaped, brownish orange in H2O, darkening in KOH, 13.5-35 × 12.4-31.2 μm. Annulus composed of attached cylindrical, oblong to ellipsoid sphaerocysts, hyaline hyphae, branched and interwoven.

Additional specimens examined: China, Yunnan Province, Yongping County, Baotai Temple, 25°11′30″N 99°31′52″E, alt. 2368 m, gregarious in a broadleaf forest litter dominated by Fagaceae, 17 Aug 2022, KEF 11358 (GenBank accession No.: ITS = OP935712, nrLSU = OP935736); China, Yunnan Province, Yongping County, Baotai Temple, gregarious in a broadleaf forest litter in the forests dominated by Fagaceae, 17 Aug 2022, KEF 11359 (GenBank accession No.: ITS = OP935739, nrLSU = OP935740).

Comments: Cystoderma yongpingense exhibits distinct characteristics, including a light orange-red to orange-red pileus and a light yellow to light orange-red stipe that is densely covered with granular furfuraceous squamules. It also possesses a persistent membranous floccose-scaly annulus, with the area above the annulus appearing white to yellowish brown. The spores of C. yongpingense measure 4-5.6 × 3.2-4 μm and are inamyloid. This species is typically found growing in a broadleaf forest litter dominated by Fagaceae. Phylogenetic analyses have indicated a close relationship between C. yongpingense, C. tricholomoides, and C. japonicum Thoen & Hongo. However, in terms of morphology, the latter two species exhibit differences from the newly discovered species. Cystoderma tricholomoides is characterized by a yellow-ochre to light brown pileus, with a light ochre persistent membranous volviform veil and inamyloid basidiospores, measuring 4.6-6 × 2.9-3.4 μm (Murakami, 2010). Cystoderma japonicum is different from C. yongpingense, for its yellow-ochre to orange-yellow pileus and inamyloid ellipsoid basidiospores measuring 4-5 × 2.5-3.5 μm (Saar et al., 2009). In China, C. japonicum has been documented in Sichuan and Gansu Provinces, where it is commonly found in coniferous and broad-leaved forests (Li et al., 2022).

The results of phylogenetic and morphological analyses support Cystoderma yongpingense as a new species.

Disclosure

The authors declare no conflicts of interest for this study. All the experiments undertaken in this study comply with the current laws of the People's Republic of China.

Acknowledgments

The research was supported by Yunnan Province integration project (202402AN360003), the National Key R & D Program of China project (2022YFD1200602) and Yunnan Province Science and Technology Department project (202305AC160067). The authors thank Zhu-Liang Yang (Kunming Institute of Botany, Chinese Academy of Sciences, China) for helpful comments on the manuscript.
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