Research Article |
Corresponding author: Bao-Kai Cui ( cuibaokai@yahoo.com ) Corresponding author: Yu-Cheng Dai ( yuchengdai@bjfu.edu.cn ) Academic editor: Dominik Begerow
© 2018 Jia-Hui Xing, Yi-Fei Sun, Yu-Li Han, Bao-Kai Cui, Yu-Cheng Dai.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Xing J-H, Sun Y-F, Han Y-L, Cui B-K, Dai Y-C (2018) Morphological and molecular identification of two new Ganoderma species on Casuarina equisetifolia from China. MycoKeys 34: 93-108. https://doi.org/10.3897/mycokeys.34.22593
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Ganoderma is a cosmopolitan white rot fungal genus, famous for its medicinal properties. In the present study, two new Ganoderma species were collected from south-eastern China and described on the basis of morphological characters and phylogenetic analyses of sequences of the internal transcribed spacer (ITS) region, the translation elongation factor 1-α gene (EF1-α) and the second subunit of RNA polymerase II (RPB2). Specimens of both species were found on living trees of Casuarina equisetifolia. Ganoderma angustisporum sp. nov. is characterised by its sessile basidiomata and almond-shaped, slightly truncate, narrow basidiospores (9–11.3 × 4–5.2 µm). Ganoderma casuarinicola sp. nov. is characterised by its strongly laccate reddish-brown pileal surface, luminous yellow to yellowish-brown cutis and ellipsoid, truncate basidiospores (9–10.2 × 5–6 µm). The two new species are compared with their related taxa. Phylogenetic analyses confirmed that G. angustisporum and G. casuarinicola are distinct species within Ganoderma.
Ganodermataceae , medicinal mushroom, morphology, phylogeny, taxonomy, wood-rotting fungi
Ganoderma P. Karst. is easily recognised by its characteristic appearance, double-walled and truncate basidiospores (
Some Ganoderma species are well known for causing wood decay in a wide range of tree species around the world. For example, G. boninense Pat. is a causal agent of oil palm basal stem rot and is responsible for considerable yield losses in southeast Asian oil palm plantations (
Casuarina equisetifolia Forst. is used as an industrial raw material and wood fuel, as well as for conservation of coastal ecosystems and for agricultural land protection against salinity intrusion (
The examined specimens were deposited in the herbarium of the Institute of Microbiology, Beijing Forestry University (BJFC). Macro-morphological descriptions were based on field notes. Special colour terms followed
The following abbreviations are used: IKI = Melzer’s reagent, IKI– = neither amyloid nor dextrinoid, KOH = 5% potassium hydroxide, CB = Cotton Blue, CB+ = cyanophilous, Q is an average computed by dividing the length by the width of each spore separately, n (a,b) = a spores measured from b specimens.
The CTAB rapid plant genome extraction kit-DN14 (Aidlab Biotechnologies Co. Ltd., Beijing, China) was used to extract total genomic DNA from dried specimens according to the manufacturer’s instructions with some modifications (
Species, specimens, geographic origin and GenBank accession numbers of sequences used in this study.
Species name | Voucher no. | Geographic origin | GenBank accession numbers | References | ||
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ITS | EF1-α | RPB2 | ||||
Ganoderma angustisporum | Cui 13817 (holotype) | Fujian, China | MG279170* | MG367563* | MG367507* | this study |
G. angustisporum | Cui 14578 | Guangdong, China | MG279171* | MG367564* | – | this study |
G. angustisporum | Cui 16340 | Guangxi, China | MG279172* | – | – | this study |
G. aridicola | Dai 12588 (holotype) | Durban, South Africa | KU572491 | KU572502 | – |
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G. boninense | WD 2028 | Japan | KJ143905 | KJ143924 | KJ143964 |
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G. boninense | WD 2085 | Japan | KJ143906 | KJ143925 | KJ143965 |
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G. casuarinicola | Dai 16336 (holotype) | Guangdong, China | MG279173* | MG367565* | MG367508* | this study |
G. casuarinicola | Dai 16337 | Guangdong, China | MG279174* | MG367566* | MG367509* | this study |
G. casuarinicola | Dai 16338 | Guangdong, China | MG279175* | MG367567* | MG367510* | this study |
G. casuarinicola | Dai 16339 | Guangdong, China | MG279176* | MG367568* | MG367511* | this study |
G. curtisii | CBS 100131 | NC, USA | JQ781848 | KJ143926 | KJ143966 |
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G. curtisii | CBS 100132 | NC, USA | JQ781849 | KJ143927 | KJ143967 |
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G. destructans | CBS 139793 (type) | Pretoria, South Africa | NR132919 | – | – |
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G. destructans | CMW 43670 | Pretoria, South Africa | KR183856 | – | – |
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G. destructans | Dai 16431 | South Africa | MG279177* | MG367569* | MG367512* | this study |
G. enigmaticum | CBS 139792 (type) | Pretoria, South Africa | NR132918 | – | – |
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G. enigmaticum | Dai 15970 | Africa | KU572486 | KU572496 | MG367513* |
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G. enigmaticum | Dai 15971 | Africa | KU572487 | KU572497 | MG367514* |
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G. heohnelianum | Dai 11995 | Yunnan, China | KU219988 | MG367550* | MG367497* |
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G. heohnelianum | Yuan 6337 | Guangxi, China | MG279160* | MG367551* | MG367498* | this study |
G. heohnelianum | Cui 13982 | Guangxi, China | MG279178* | MG367570* | MG367515* | this study |
G. leucocontextum | GDGM 44489 | Xizang, China | KM396271 | – | – |
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G. leucocontextum | GDGM 44490 | Xizang, China | KM396272 | – | – |
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G. leucocontextum | Dai 15601 | Xizang, China | KU572485 | KU572495 | MG367516* |
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G. lingzhi | Wu 1006-38 (holotype) | Hubei, China | JQ781858 | JX029976 | JX029980 |
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G. lingzhi | Cui 14342 | Sichuan, China | MG279179* | MG367571* | MG367517* | this study |
G. lingzhi | Cui 14375 | Sichuan, China | MG279180* | MG367572* | MG367518* | this study |
G. lobatum | JV 1008/31 | USA | KF605671 | MG367553* | MG367499* | this study |
G. lobatum | JV 1008/32 | USA | KF605670 | MG367554* | MG367500* | this study |
G. lucidum | K 175217 | UK, Europe | KJ143911 | KJ143929 | KJ143971 |
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G. lucidum | Cui 14404 | Sichuan, China | MG279181* | MG367573* | MG367519* | this study |
G. lucidum | Cui 14405 | Sichuan, China | MG279182* | MG367574* | MG367520* | this study |
G. martinicense | LIP SW-Mart08-44 | Martinica | KF963257 | – | – |
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G. martinicense | LIP SW-Mart08-55 (type) | Martinica | KF963256 | – | – |
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G. martinicense | He 2240 | USA | MG279163* | MG367557* | MG367503* | this study |
G. multipileum | CWN 04670 | Taiwan, China | KJ143913 | KJ143931 | KJ143972 |
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G. multipileum | Dai 9447 | Hainan, China | KJ143914 | – | KJ143973 |
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G. multipileum | Cui 14373 | Sichuan, China | MG279184* | MG367575* | MG367521* | this study |
G. multiplicatum | SPC9 | Brazil | KU569553 | – | – |
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G. multiplicatum | 60119011 | Brazil | MG279185* | – | – | this study |
G. multiplicatum | URM 83346 | Brazil | JX310823 | – | – |
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G. orbiforme | Cui 13918 | Hainan, China | MG279186* | MG367576* | MG367522* | this study |
G. orbiforme | Cui 13880 | Hainan, China | MG279187* | MG367577* | MG367523* | this study |
G. philippii | Cui 14443 | Hainan, China | MG279188* | MG367578* | MG367524* | this study |
G. philippii | Cui 14444 | Hainan, China | MG279189* | MG367579* | MG367525* | this study |
G. resinaceum | Rivoire 4150 | France, Europe | KJ143915 | – | – |
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G. resinaceum | CBS 194.76 | Netherlands, Europe | KJ143916 | KJ143934 | – |
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G. ryvardenii | HKAS 58053 (type) | Cameroon, Africa | HM138671 | – | – |
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G. ryvardenii | HKAS 58054 | Cameroon, Africa | HM138672 | – | – |
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G. ryvardenii | HKAS 58055 | Cameroon, Africa | HM138670 | – | – |
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G. shandongense | Dai 15785 | Shandong, China | MG279190* | MG367580* | MG367526* | this study |
G. shandongense | Dai 15787 | Shandong, China | MG279191* | MG367581* | MG367527* | this study |
G. shandongense | Dai 15791 | Shandong, China | MG279192* | MG367582* | MG367528* | this study |
G. sinense | Wei 5327 | Hainan, China | KF494998 | KF494976 | MG367529* | this study |
G. sinense | Cui 13835 | Hainan, China | MG279193* | MG367583* | MG367530* | this study |
G. tropicum | He 1232 | Guangxi, China | KF495000 | MG367584* | MG367531* | this study |
G. tropicum | Yuan 3490 | Yunnan, China | JQ781880 | KJ143938 | – |
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G. tropicum | Dai 16434 | Hainan, China | MG279194* | MG367585* | MG367532* | this study |
G. tsugae | Dai 12751b | CT, USA | KJ143919 | KJ143939 | KJ143977 |
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G. tsugae | Cui 14110 | Jilin, China | MG279195* | MG367586* | MG367533* | this study |
G. tsugae | Cui 14112 | Jilin, China | MG279196* | MG367587* | MG367534* | this study |
G. weberianum | CBS 219.36 | Philippines | JQ520219 | – | – |
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G. williamsianum | Wei 5032 | Hainan, China | KU219994 | – | – |
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G. williamsianum | Dai 16809 | Thailand | MG279183* | MG367588* | MG367535* | this study |
G. zonatum | FL-02 | FL, USA | KJ143921 | KJ143941 | KJ143979 |
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G. zonatum | FL-03 | FL, USA | KJ143922 | KJ143942 | KJ143980 |
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Outgroup | ||||||
Amauroderma rugosum | Cui 9011 | Guangdong, China | KJ531664 | KU572504 | MG367506* |
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Tomophagus colossus | TC-02 | Vietnam | KJ143923 | KJ143943 | – |
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Besides the sequences generated from this study, other reference sequences were selected from GenBank for phylogenetic analyses. Sequences were aligned in MAFFT 6 (
Phylogenetic analyses in this study followed the approach of
The combined ITS, EF1-α and RPB2 dataset included sequences from 66 fungal samples representing 27 taxa. The selected models were K80 for 5.8S, K80 + G for ITS1, HKY + G for ITS2, GTR + I + G for ITS1+ ITS2 + 5.8S. The best model selected and applied in the BI analysis for the combined ITS, EF1-α and RPB2 partition was a GTR+I+G model. BI analysis and ML analysis resulted in the same topology with an average standard deviation of split frequencies = 0.006025 (BI).
Ganoderma angustisporum is characterised by its sessile basidiomata, white pore surface, almond-shaped, slightly truncate and narrow basidiospores.
CHINA. Fujian Prov., Pingtan County, on living tree of Casuarina equisetifolia, 18 August 2016, Cui 13817 (BJFC!).
angustisporum (Lat.): referring to the narrow basidiospores.
Basidiomes annual, sessile and broadly attached, applanate, shell-shaped, projecting up to 13.5 cm, 10 cm wide and 1.1 cm thick at base, corky when fresh, becoming hard corky to woody hard upon drying. Pileal surface strongly laccate, reddish-brown to dark brown, with a thin crust, concentrically zonate or azonate; margin distinct, slightly obtuse. Pore surface white when fresh, turning light buff when dry; pores round to angular, 3–5 per mm; dissepiments slightly thick to thick, entire. Context corky, homogeneous, greyish-brown, bearing distinct concentric growth zones, black melanoid band present, up to 0.4 cm thick. Tubes woody hard, greyish-brown, up to 0.7 cm long. Hyphal system trimitic; generative hyphae bearing clamp connections; all the hyphae IKI–, CB+; tissues darkening in KOH. Pellis: pellis cells regularly arranged into a palisade; terminal cells clavate, yellowish to pale brown, thin-walled, occasionally with blunt outgrowth and protuberance in the apical or lateral parts, bearing a simple septum at base, moderately amyloid at maturity, 15–33 × 4–10 μm. Context generative hyphae colourless, thin-walled, bearing clamp connections, unbranched, 2–4.5 µm in diam; skeletal hyphae dominant, pale yellowish-brown, thick-walled to subsolid, frequently branched, interwoven, 3–6 µm in diam; binding hyphae abundant, pale yellowish-brown, thick-walled with a narrow lumen to subsolid, frequently branched, tortuous, interwoven, 1–2.5 µm in diam. Tubes generative hyphae colourless, thin-walled, bearing clamp connections, unbranched, slightly swollen at the distal end, 2–2.8 μm in diam; skeletal hyphae dominant, pale brown to distinctly brown, thick-walled with a medium or narrow lumen to subsolid, frequently branched, strongly interwoven, 3–4.5 μm in diam; binding hyphae brownish-yellow, thick-walled to almost solid, frequently branched, interwoven, 1–1.8 μm in diam. Basidia barrel-shaped, yellowish to pale brown, with a clamp connection and four sterigmata, 11–16 × 6.5–9 µm; basidioles pear-shaped to fusiform, 8–15 × 5–8 µm. Basidiospores mostly almond-shaped at maturity, slightly truncate, yellowish to pale brown, IKI–, CB+, double-walled, exospore smooth, endospore with coarse echinulate, (8–)9–10.5(–11) × (3.5–)4–5 µm, L = 8.89 μm, W = 4.27 μm, Q = 2.01–2.24 (n = 60/2, with the turgid vesicular appendix excluded); (8–)9–11.3(–12) × (3.8–)4–5.2 µm, L = 10.26 μm, W = 4.31 μm, Q = 2.36–2.4 (n = 60/2, with the turgid vesicular appendix included).
A white rot.
CHINA. Guangdong Prov., Maoming, Dianbai, on living trees of Casuarina equisetifolia, 20 June 2017, Cui 14578, Cui 16494 and Cui 16495 (BJFC!).
Ganoderma casuarinicola is characterised by its strongly laccate reddish-brown pileal surface, white pore surface, luminous yellow to yellowish-brown cutis.
CHINA. Guangdong Prov. Zhanjiang, Dianbai, on living tree of Casuarina equisetifolia, 4 October 2015, Dai 16336 (BJFC!).
casuarinicola (Lat.): referring to the host tree genus Casuarina.
Basidiomes annual, stipitate to substipitate, pileus sectorial to shell-shaped, projecting up to 10 cm, 7 cm wide and 2 cm thick at base, corky, without odour when fresh, becoming hard corky to woody hard when dry. Pileal surface strongly laccate, reddish-brown, with a thin crust; margin obtuse, cream to reddish-brown. Stipe flattened or subcylindrical, lateral, reddish-brown, up to 6 cm long and 1.7 cm in diam. Pore surface white when fresh, turning cream when dry; pores round to angular, 4–6 per mm; dissepiments thin to slightly thick, entire. Context corky, heterogeneous, the upper layer generally light yellow up to 0.1 cm thick and the lower layer generally dark brown close to the tubes up to 1 cm thick, showing distinct concentric growth zones, black melanoid band absent. Tubes woody hard, greyish-brown, up to 0.9 cm long. Hyphal system trimitic; generative hyphae bearing clamp connections, occasionally with simple septa; all the hyphae IKI–, CB+; tissues darkening in KOH. Pellis: Pellis cells regularly arranged into a palisade; terminal cells clavate, luminous yellow to yellowish-brown, thick-walled, occasionally expanded at the apex, moderately amyloid at maturity, 40–70 × 5–13 μm. Context generative hyphae colourless, thin-walled, with clamp connections, occasionally branched, 2–4 µm in diam; skeletal hyphae dominant, pale yellowish-brown, thick-walled to subsolid, frequently branched, interwoven, 3–5.5 µm in diam; binding hyphae abundant, pale yellowish-brown, thick-walled with a narrow lumen to subsolid, frequently branched, tortuous, interwoven, 1–3 µm in diam. Tubes generative hyphae colourless, thin-walled, mostly bearing clamp connections, occasionally with simple septa, occasionally branched, slightly swollen at the distal end, 1.5–3 μm in diam; skeletal hyphae dominant, pale brown to distinctly brown, thick-walled with a medium or narrow lumen to subsolid, frequently branched, strongly interwoven, 2–4.5 μm in diam; binding hyphae brownish-yellow, thick-walled to almost solid, frequently branched, interwoven, 1.5–2.5 μm in diam. Basidia barrel-shaped, yellowish to pale brown, with a clamp connection and four sterigmata, 12–18 × 9.5–13 µm; basidioles pear-shaped, 9–16 × 8–12 µm. Basidiospores mostly ellipsoid at maturity, truncate, yellowish to pale brown, IKI–, CB+, double-walled, exospore smooth, endospore with coarse echinulate, (8–)8.5–9 (–10) × (4.2–)5.5–6.5(–7) µm, L = 8.82 μm, W = 5.65 μm, Q = 1.52–1.60 (n = 60/2, with the turgid vesicular appendix excluded); (8.3–)9–10.2(–11.5) × (4.5–)5–6(–7) µm, L = 9.85 μm, W = 5.77 μm, Q = 1.68–1.72 (n = 60/2, with the turgid vesicular appendix included).
a white rot.
CHINA. Guangdong Prov., Zhanjiang, Dianbai, on living trees of Casuarina equisetifolia, 4 October 2015, Dai 16337, Dai 16338, Dai 16339, Dai 17892, Cui 16370, Cui 16376 and Cui 16377 (BJFC!).
The two new Ganoderma species were found on living trees of Casuarina equisetifolia from the southeast coast of China. However, they are quite different from each other in morphology. Their main morphological differences are presented in Table
Morphological differences between the two new Ganoderma species collected on Casuarina from China.
Species | Pileal surface | Context | Cuticle cells | Shape of basidiospores | Size of basidiospores |
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G. angustisporum | reddish brown to dark brown | homogeneous, black melanoid band present | thin-walled, septate | almond-shaped | (8–)9–10.5(–11) × (3.5–)4–5 µm (with the turgid vesicular appendix excluded) (8–)9–11.3(–12) × (3.8–)4–5.2 µm (with the turgid vesicular appendix included) |
G. casuarinicola | reddish brown | not fully homogeneous, black melanoid band absent | thick-walled to subsolid, non-septate | ellipsoid | (8–)8.5–9 (–10) × (4.2–)5.5–6.5(–7) µm (with the turgid vesicular appendix excluded)(8.3–)9–10.2(–11.5) × (4.5–)5–6(–7) µm (with the turgid vesicular appendix included) |
In the phylogenetic tree inferred from ITS, EF1-α and RPB2 sequences, G. angustisporum clustered together with G. boninense, G. ryvardenii Tonjock & Mih and G. zonatum Murrill, these four species forming a strong support (BS = 100%, BPP =1.00; Fig.
In the phylogenetic tree, we obtained G. casuarinicola as sister to G. enigmaticum M.P.A. Coetzee, Marinc. & M.J. Wingf., a species described from South Africa, but morphologically, G. enigmaticum can be easily distinguished from G. casuarinicola by its golden yellow pileal surface without furrows and narrower basidiospores (8–11 × 3.5–6 μm,
In conclusion, both morphology and phylogeny inferred from the combined ITS, EF1-α and RPB2 sequences support that the specimens, collected on living trees of Casuarina equisetifolia from the southeast coast of China, are two new species within the Ganoderma genus.
The research was financed by the National Natural Science Foundation of China (Project No. 31670016) and the Fundamental Research Funds for the Central Universities (Project No. 2016ZCQ04).