2024 Volume 65 Issue 3 Pages 151-155
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.
The 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.
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).
| 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.
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.
Cystoderma yongpingense Y. L. Feng, X. Guo & Y. Fang, sp. nov. Fig.2, 3
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.
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.
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.
