Research Article |
Corresponding author: Yue-Hong Yan ( yan.yh@126.com ) Academic editor: Blanca León
© 2021 Zuo-Ying Wei, Zeng-Qiang Xia, Xian-Chun Zhang, Jian-Guo Cao, Yue-Hong Yan.
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:
Wei Z-Y, Xia Z-Q, Zhang X-C, Cao J-G, Yan Y-H (2021) Finding missing diversity from synonyms of Haplopteris (Pteridaceae). PhytoKeys 178: 81-94. https://doi.org/10.3897/phytokeys.178.67622
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Although taxonomists target the remote wild regions to discover new species, taxa lacking a comprehensive and modern systematic treatment may be the new hotspot for biodiversity discovery. The development of molecular systematics integrated with microscopic observation techniques has greatly improved the ability of taxonomists to identify species correctly. Vittaria centrochinensis Ching ex J.F. Cheng, regarded as a synonym of Haplopteris fudzinoi (Makino) E.H.Crane, remained hidden from the eyes of fern taxonomists for more than 20 years. Herein, we collected several population samples of V. centrochinensis by performing molecular phylogenetic analysis of five cpDNA regions (rbcL, atpA, matK, ndhF, and trnL-trnF) and through micromophological observation of specimens which differs from H. fudzinoi by lamina width and exospores. Considering the differences in morphology, geographical range, and genetic distance between these two species, we formally recognized V. centrochinensis as an authentic species and proposed a new combination Haplopteris centrochinensis (Ching ex J.F.Cheng) Y.H.Yan, Z.Y.Wei & X.C.Zhang, comb. nov. Our findings demonstrate that several taxa in synonyms are missing, and nowadays taxonomy should also include re-evaluation of the past taxonomy.
Haplopteris, molecular phylogeny, new combination, nomenclature, Pteridaceae, taxonomy
The question “How many species are there on earth?” is one of the top 125 questions in science, and exploring it is considered equivalent to imagining the number of stars in the sky (
Accurate specimen identification through sequencing of the type specimens or samples from type locality is the key to solving questions regarding taxonomic synonyms. In addition, a clear understanding of the taxonomic status and barcoding database of the species suspected of being independent is required. Haplopteris C.Presl is a genus of vittarioid ferns, long treated as a synonym of Vittaria Sm. (
In this study, we analyzed morphological characteristics and geographic distribution along with the molecular phylogeny to confirm the identity of V. centrochinensis and phylogenetic affinities of this species with H. fudzinoi. We hope that this study can provide a paramount example of re-evaluating of synonyms for new insights into biodiversity discovery.
For morphology, the H. centrochinensis was compared with similar species by analyzing photographs of type specimens and field photos. The features of rhizome scales were obtained using Nikon SMZ-1500 (Japan). The morphology of spores was observed with a Quanta 250 scanning electron microscope (FEI, USA), and spore size was measured using ImageJ software (
The total genomic DNA was extracted from silica-dried leaves by using a plant total genomic DNA kit (Tiangen, Beijing, China), according to the manufacturer’s instructions. The primers used for amplification and sequencing were shown in Table
Regions | Primer name | Primer sequence (5’-3’) | Reference |
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rbcL | AF | ATGTCACCACAAACGGAGACTAAAGC |
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ESRBCL1361R | TCAGGACTCCACTTACTAGCTTCACG |
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atpA | ESATPF412F | GARCARGTTCGACAGCAAGT |
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ESTRNR46F | GTATAGGTTCRARTCCTATTGGACG |
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matK | Vt matK1610F* | GCARTCAARCGTTTAATTRGTA |
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Vt matK rRFQ | TTATTACTGAATTTGGRATCT |
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ndhF | Vt ndhF fAYS | GCTTATTCTACHATGTCTCAGYTRGGATATATGG |
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Vt trnN 2210R | TCGTGARACGAAAATAGCAGTTTATGG |
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trnL-F | F | ATTTGAACTGGTGACACGAG |
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FernL 1Ir1 | GGYAATCCTGAGCCAAATC |
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Species | Location | Voucher | GenBank accession number | ||||
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rbcL | atpA | matK | ndhF | trnL-trnF | |||
Haplopteris centrochinensis comb. nov. | Jiangxi, China | YYH15442-1 | MW810047 | MW810050 | MW810053 | MW810056 | MW810059 |
Haplopteris centrochinensis comb. nov. | Jiangxi, China | YYH15442-2 | MW810048 | MW810051 | MW810054 | MW810057 | MW810060 |
Haplopteris centrochinensis comb. nov. | Jiangxi, China | YYH15442-3 | MW810049 | MW810052 | MW810055 | MW810058 | MW810061 |
Information on species and GenBank accession numbers used in the study. Dash (-) indicates unavailable data.
Species | Location | Voucher | GenBank accession number | ||||
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rbcL | atpA | matK | ndhF | trnL-trnF | |||
Haplopteris taeniophylla (Copel.) E.H. Crane | Luzon, Philippines | FWL974 | – | – | KC812901 | KC812935 | KC812969 |
Nantou, Taiwan, China | Chen1493 | – | – | KC812874 | KC812908 | KC812942 | |
Haplopteris doniana (Mett. ex Hieron.) E.H. Crane | Yunnan, China | Kuo1418 | – | – | KC812880 | KC812914 | KC812948 |
Tamdao, Vietnam | Kuo1801 | – | – | KC812905 | KC812939 | KC812973 | |
Haplopteris fudzinoi (Makino) E.H. Crane | Sichuan, China | Kuo2225 | KX165003 | KX165201 | KC812895 | KC812929 | KC812963 |
Haplopteris linearifolia (Ching) X.C. Zhang | Yunnan, China | Liu9457 | KX165012 | KX165209 | KC812899 | KC812933 | KC812967 |
Haplopteris mediosora (Hayata) X.C. Zhang | Nantou, Taiwan | Chen1492 | KX165015 | KX165211 | KC812875 | KC812909 | KC812943 |
Haplopteris amboinensis (Fée) X.C. Zhang | Hainan, China | Kuo1715 | – | – | KC82879 | KC812913 | KC812947 |
Haplopteris flexuosa (Fée) E. H. Crane | Yunnan, China | Kuo1142 | – | – | KC812881 | KC812915 | KC812949 |
Antrophyum parvulum Blume | Nantou, Taiwan, China | Chen1495 | – | – | KC812877 | KC812911 | KC812945 |
Antrophyum sessilifolium (Cav.) Spreng | Taitung, Taiwan, China | Chen1502 | KX164974 | KX165181 | KC812876 | KC812910 | KC812944 |
The morphological and micromorphological characters of H. centrochinensis and H. fudzinoi are presented in Figure
Features | H. centrochinensis | H. fudzinoi |
Lamina width | 10–15 mm | 8–10 mm |
Lamina margin | Flat | Reflexed |
Adaxial costa | Slightly raised | Greatly raised |
Abaxial costa | Carinated | Sharp carinate |
Rhizome scale | Long, margin toothed | Short, lower margin subentire, upper part minutely denticulate |
Exospores | Scabrate | Psilate |
Sorus position | Between the frond costa and margin | Close to the lamina edge |
Morphological observations in H. centrochinensis YYH15442 (A, C, F, G, I) and H. fudzinoi SG1654 (B, D, H, J) A habitat C sorus position and flat lamina F type specimen (provided by National Plant Specimen Resource Center, http://www.cvh.ac.cn); and G, I spore and ornamentation in H. centrochinensis YYH15442 B habitat (taken by Hong-Jin Wei) D sorus position and flat lamina (taken by Hong-Jin Wei) H, J spore and ornamentation in H. fudzinoi SG1654 E rhizome scale, left: H. fudzinoi, right: H. centrochinensis.
The two phylogenetic analyses (BI, ML) recovered congruent topologies, with Antrophyum parvulum and Antrophyum sessilifolium as outgroups (Fig.
1 | 2 | 3 | 4 | 5 | 6 | 7 | |
2 | 0.073* | ||||||
3 | 0.120* | 0.001 | |||||
4 | 0.120* | 0 | 0 | ||||
5 | 0.120* | 0.001 | 0.001 | 0.001 | |||
6 | 0.120* | 0.001 | 0.001 | 0.001 | 0 | ||
7 | 0.120* | 0 | 0 | 0 | 0.001 | 0.001 | |
8 | 0.073* | 0 | 0 | 0.000 | 0.001 | 0.001 | 0 |
Geographic distribution of H. centrochinensis and H. fudzinoi in China. The dataset is provided by the National Specimen Information Infrastructure (http://www.nsii.org.cn).
Synonym is the first concern in the estimation of the total number of species in one taxon, and only after its resolution can one ask the next question regarding how many additional species there are in the taxon (
Various taxa, especially widely distributed ones, still require a comprehensive systematic treatment that also involves evaluating their nomenclature. Then, if cryptic taxa or misunderstood species have to be segregated, naming these taxa needs first to be evaluated against synonymy as potential sources of the needed name, otherwise a new name needs to be proposed. However, the number of taxonomists has significantly declined (
The reason for numerous synonyms existing only in books may be the lack of sufficient morphological judgments made in the past. In the present study, the phylogeny (Fig.
Here, we proposed a new combination H. centrochinensis (Ching ex J.F.Cheng) Y.H.Yan, Z.Y.Wei & X.C.Zhang, comb. nov. The taxonomic treatment of H. centrochinensis is as follows.
Vittaria centrochinensis Ching ex J.F.Cheng: Fl. Jiangxi 1: 365. 1993. Basionym.
Vittaria taeniophylla sensu F.Zhang, non Copel.: Fl. Zhejiang 1: 111. 1993. p.p.
Vittaria fudzinoi sensu X.C.Zhang, non Makino: Fl. Rep. Poup. Sin. 3(2):20.1999. p.p.
Haplopteris fudzinoi sensu Zhang & Gilbert, non (Makino) E. H. Crane: Fl. China 2(3): 254.2013. p.p.
China. Hubei Province, Enshi Tujia and Miao Autonomous Prefecture, Hefeng District, elev. 1200 m, October 1958, Hong-Jun Li, 8394 (holotype, PE!; isotypes, IBSC!, NAS!).
Guangxi Province: Damiaoshan District, 26 July 1958, Shao-Qing Chen, 15853 (IBSC); Quanzhou District, April 27, 2013, Quanzhou census team, 450324130427042LY (GXMG). Guizhou Province: Kaili City, census team, 3592 (CNBG); Xingren District, 9 August 1960, census team, 7872 (CNBG); Yinjiang, December 26, 1930, Y. Tsiang, 7867 (CNBG). Hunan Province: Shaoyang City, Dongkou District, 24 May 1983, Ze-Yong Yang, 166 (IBSC); Xinning District, September 9, 1984, Anonymous, 394 (PE). Jiangxi Province: Shangrao City, Yanshan District, Wuyi Mountain National Nature Reserve, 1729 m, October 7, 2019, Yue-Hong Yan, Zuo-Ying. Wei, Quan Yuan, YYH15442 (NOCC); Shangrao City, Yushan District, Sanqingshan, July 27, 1991, Sheng-Xiu Xu, 91018 (JXU); Jinggangshan City, Jinggangshan, April 13, 1983, Sheng-Xiu Xu, 83422 (JXU); Jinggangshan City, Jinggangshan, February 1982, 8210118 (JXU); Jinggangshan City, Jinggangshan, November 4, 1982, 8220349 (JXU); Jinggangshan City, Jinggangshan, July 2, 1973, Jing -Fu Cheng, 730433 (JXU); Shangrao City, Yushan District, Huaiyushan, July 1970, 0028466 (PEY); Pingxiang City, Luxi District, March 24, 2014, Gong-Xi, Chen and Dai-Gui Zhang, LXP-06-1246, LXP-06-1251, LXP-06-1201 (SYS). Zhejiang Province: Quzhou City, Kaihua District, September 1, 2019, She-Lang Jin, Hong-Yu Wei, Jiao Zhang, JSL5850 (
Vittaria centrochinensis Ching ex J.F.Cheng was initially published in “Flora of Jiangxi” as a new species found in two distributed provinces (i.e., Jiangxi and Hubei). The type locality is situated in the Hefeng District from which a single specimen was cited. Additional specimens were cited from Jiangxi Province.
We thank NSII and Shanghai Chenshan Herbarium (