Research Article |
Corresponding author: Ming Yue ( yueming@nwu.edu.cn ) Academic editor: Clifford Morden
© 2024 Pei-Liang Liu, Qian-Xi Guo, Jian-Qi Zhang, Lu-Lu Xun, Yuan Lu, Ming Yue.
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:
Liu P-L, Guo Q-X, Zhang J-Q, Xun L-L, Lu Y, Yue M (2024) Hedysarum qilianshanense sp. nov. (Fabaceae, Hedysareae), a new species from the Qilianshan Mountains in Gansu, China. PhytoKeys 237: 103-116. https://doi.org/10.3897/phytokeys.237.116236
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Hedysarum qilianshanense sp. nov. (Fabaceae, Hedysareae) is described and illustrated from the Qilianshan Mountains in Gansu, China. This new species is similar to H. przewalskii, but can be distinguished by its corolla being light purple to purple, standard 15–19 mm long, wings 14–16 mm long, keels 16–19 mm long, and the ovary and legume being glabrous. The new species can be easily distinguished from H. neglectum Ledeb. by its bract being shorter than the pedicel, and the ovary and legume being glabrous. Phylogenetic tree based on the nuclear ITS and ETS sequences shows that H. qilianshanense is sister to H. przewalskii, while the tree based on the plastid psbA-trnH, trnC-petN, trnL-F, trnS-G and petN-psbM sequences shows H. qilianshanense as sister to a clade consisting of H. hedysaroides, H. inundatum, H. americanum and H. neglectum. The new species is a diploid with the chromosome number 2n = 14. Based on morphological, phylogenetic and karyotypic evidence, the new species may originate from an ancient homoploid hybrid speciation event.
Karyotype, phylogeny, Qinghai-Tibetan Plateau, taxonomy
The genus Hedysarum L. (Fabaceae, Hedysareae) consists of more than 160 species, widely distributed in temperate Asia, Europe, northern Africa and North America (
The Qinghai-Tibetan Plateau (QTP) is the largest and highest plateau on the earth. More than 12,000 species of vascular plants inhabit in QTP and such species richness also exhibit a high level of endemism (
When the first author was examining specimens of Hedysarum deposited in the herbarium of Northwest Normal University (
Samples were collected from three populations of the putative new species, including six individuals from the Xiaogushan population, six individuals from the Wulin’gou population, and five individuals from the Sidalong population. Each of these samples were sequenced for phylogenetic analyses. Other 23 species in H. sect. Hedysarum were selected to test the phylogenetic position of the putative new species. Species in H. sect. Stracheya were selected for outgroup comparison because previous studies showed that H. sect. Stracheya is sister to H. sect. Hedysarum (
Silica-gel dried leaves were used to extract genomic DNA by using the Qiagen DNeasy® Plant Mini Kit (Hilden, Germany). The nuclear ribosomal external transcribed spacer (ETS) and internal transcribed spacer (ITS), and the plastid psbA-trnH, trnC-petN, trnL-F, trnS-G and petN-psbM sequences were amplified using Polymerase chain reaction (PCR). Primers and PCR conditions followed the previous paper (
Phylogenetic trees were reconstructed based on the newly generated sequences together with the previously published data (
One available seed of the putative new species (voucher: P. L. Liu 458, see Appendix
The 17 individuals from three populations (Xiaogushan, Wulin’gou and Sidalong) of the putative new species had identical ETS and ITS sequences. The nuclear phylogenetic tree based on the combined ETS and ITS sequences (Fig.
Bayesian trees based on the combined nuclear ETS and ITS sequences (A) and the combined plastid psbA-trnH, trnC-petN, trnL-F, trnS-G and petN-psbM sequences (B). The Bayesian posterior probabilities (PP), the maximum likelihood and the maximum parsimony bootstrap supports (BML, BMP) are above the branches. A dash indicates a branch that is not found in the maximum parsimony tree. The purple and yellow shades on taxa names indicates corolla colors.
Three plastid haplotypes, namely AG, Agap and Ggap (Table
Haplotypes from the combined plastid psbA-trnH, trnC-petN, trnL-F, trnS-G and petN-psbM sequences of Hedysarum qilianshanense.
Haplotype name | Sequence variation | Distribution in populations (number of individuals) | ||||
---|---|---|---|---|---|---|
psbA-trnH | trnC-petN | trnL-F | trnS-G | petN-psbM | ||
AG | A | G | identical | identical | identical | Xiaogushan (6), Wulin’gou (4) |
Agap | A | gap | identical | identical | identical | Wulin’gou (2), Sidalong (4) |
Ggap | G | gap | identical | identical | identical | Sidalong (1) |
China, Gansu Province, Su’nan County, the Heihe River valley, Xiaogushan, in crevice on stony slope, 2053 m above sea level (a. s. l.), 38°41′6.38″N, 110°3′9.98″E, 21 June 2019, P. L. Liu 458 (Holotype, WUK!, barcode WUK0536471; Isotypes, WUK!, barcodes WUK0536466-WUK0536470, WNU!).
This new species is morphologically similar to H. przewalskii, but can be distinguished by its light purple to purple corolla (vs. light yellow to yellow corolla), 15–19 mm long standard (vs. 10–14 mm long standard), 14–16 mm long wings (vs. 10–14 mm long wings), 16–19 mm long keels (vs. 12–17 mm long keels), and glabrous ovaries and legumes (vs. often pubescent, sometimes glabrate or glabrous ovaries and legumes). The new species can be easily distinguished from H. neglectum by its bract shorter than pedicel (vs. bract longer than pedicel), and glabrous ovaries and legumes (vs. pubescent ovaries and legumes) (Table
Morphological comparison of Hedysarum qilianshanense, H. przewalskii and H. neglectum.
H. qilianshanense | H. przewalskii | H. neglectum | |
---|---|---|---|
Bract | shorter than pedicel | shorter than pedicel | longer than pedicel |
Corolla color | light purple to purple | light yellow to yellow | purple |
Standard length | 15–19 mm | 10–14 mm | 13–14 mm |
Wing length | 14–16 mm | 10–14 mm | 13–14 mm |
Keel length | 16–19 mm | 12–17 mm | 15–16 mm |
Ovary and legume | glabrous | often pubescent, sometimes glabrate or glabrous | pubescent |
Perennial herbs, 30–100 cm tall. Main root stout, woody, up to 1.3 cm in diameter. Stems cespitose, ascending, branched; internodes glabrous or loosely pubescent, nodes pubescent. Leaves imparipinnate, alternate, 12–30 cm long; stipules connate, opposite to leaves, wide triangular, membranous, brown, glabrous, apex shallowly bilobed, lower ones 8–17 mm long, becoming smaller in upper part of stem; rachises sulcate, glabrous or sparsely pubescent; leaflets 9–19, opposite or alternate; petiolules ca. 1 mm long, pubescent; leaflet blades elliptic, ovate-elliptic, oblong, 12–40 × 7–25 mm, adaxial surface glabrous, abaxial surface sparsely pubescent along midvein, base wide cuneate or rounded, apex obtuse, rounded or retuse. Racemes axillary, exceeding leaves, 15–42 cm long, with 15–50 flowers, peduncles pubescent; pedicel 3–6 mm long, pubescent; bracts linear, with brown midvein, pubescent, 2–5 mm long; bracteoles 2, linear, with brown midvein, pubescent, 2–3.5 mm long; calyx tube campanulate, 3–4 mm long, pubescent; calyx teeth 5, pubescent, the two adaxial teeth triangular, ca. 1 mm long, the two lateral teeth narrowly triangular, 1.5–2.5 mm long, the abaxial tooth linear-triangular, 2–3 mm long; corolla light purple to purple; standard obovate, 15–19 × 5.5–7 mm, apex retuse, base attenuate; wings 14–16 × 2–2.5 mm, auricle linear, as long as claw, 2–3 mm long; keels 16–19 × 4–5 mm, auricle triangular, ca. 1 mm long; androecium diadelphous, 12–17 mm long; ovary linear, glabrous, style ca. 13 mm long. Legume a loment, divided into 2–4 articles, with a small beak at apex; articles elliptic, compressed, 8–10 mm × 6–7 mm, glabrous, with reticulate veins, with a narrow wing ca. 0.5 mm wide along the dorsal suture only. Seed reniform, yellow, ca. 3 × 2 mm.
Flowering and fruiting in June.
Hedysarum qilianshanense is only known from Su’nan, Gansu, China. It grows in stony slope and forest edge in valley, 2053–3000 m a. s. l.
The epithet qilianshanense is transliterated from the type location, Qilianshan Mountains in China. The Chinese vernacular name for this new species is 祁连山岩黄耆 (qí lián shān yán huáng qí).
China, Gansu Province, Su’nan County, Sidalong, Wulin’gou, on stony slope, 3000 m a. s. l., 21 June 1986, Sheng Huan Bao Dui 86055 (
The phylogenetic positions of H. qilianshanense are different in the nuclear and plastid trees. Hedysarum qilianshanense and H. przewalskii are similar to each other in well-developed stem and large, elliptic, ovate-elliptic or oblong leaflets. On the other hand, H. qilianshanense is clearly different from H. przewalskii in flower and fruit features (Table
Distributions of Hedysarum qilianshanense and related species and clades. The purple star represents H. qilianshanense; yellow dots and the area surrounded by yellow line represent H. przewalskii; the area surrounded by the purple line represent the circumboreal clade; the area surrounded by the purple dotted line represent the eastern QTP clade. Purple or yellow indicates the corolla color. The black frame in Fig.
In the plastid tree, however, H. qilianshanense is a member of the purple-corolla clade (Fig.
The incongruent position of H. qilianshanense in the nuclear and plastid gene trees indicates that H. qilianshanense may have originated from a hybridization event. The nuclear gene tree tracks one potential parent, probably an ancestor of H. przewalskii, and the plastid gene tree tracks the other potential parent, probably an ancestor in the purple-corolla clade. Morphologically, H. qilianshanense has similar stem, leaf and leaflet features as H. przewalskii, and the same corolla color with species of the purple-corolla clade.
A previous study (
In conclusion, based on the morphological, phylogenetic and karyotypic evidences, H. qilianshanense may have originated from homoploid hybrid speciation. Because of the allopatric distribution of H. qilianshanense, H. przewalskii, the circumboreal clade and the eastern QTP clade, the hybrid speciation is most likely to be an ancient, rather than a recent, event.
We are grateful to Hua Di in Gansu Qilianshan National Nature Reserve Administration for her great help during field expeditions. We thank curators of
The authors have declared that no competing interests exist.
No ethical statement was reported.
This research was funded by the National Natural Science Foundation of China (grant number 31900179) and the Basic Research Program of the Shaanxi Academy of Sciences (grant number 2023K-14).
Conceptualization: PLL, MY. Data curation: PLL, QXG. Funding acquisition: PLL, MY. Investigation: PLL, JQZ, YL, LLX. Methodology: PLL, QXG. Project administration: MY. Resources: PLL, JQZ. Supervision: MY. Visualization: PLL, QXG. Writing - original draft: PLL, QXG. Writing - review and editing: JQZ, YL, LLX, MY.
Pei-Liang Liu https://orcid.org/0000-0001-6566-7824
Qian-Xi Guo https://orcid.org/0009-0002-9144-5752
Lu-Lu Xun https://orcid.org/0000-0002-6861-5883
The newly generated DNA sequences have been deposited in GenBank and the accession numbers can be found in Appendix
Taxon name, geographical locality, voucher, herbarium code, and GenBank accession number for the sequences used in this study. For each sample, accession numbers are given for the ETS, ITS, psbA-trnH, trnC-petN, trnL-F, trnS-G and petN-psbM sequences. A dash (–) indicates a missing sequence. New sequences generated in this study are indicated by an asterisk (*).
Hedysarum algidum L. Z. Shue: China, Gansu, W. Q. Yang 2008010 (WUK), KY365837, KP338149, KP338400, KY366037, KP338272, KY365888, KY365987;
Hedysarum americanum (Michx.) Britton: Canada, Tuktut Nogait National Park, L. J. Gillespie et al. 8934 (US), KY365838, KP338150, KP338402, KY366038, KY366134, KY365889, KY365988;
Hedysarum astragaloides Benth. ex Baker: Pakistan, Punjab, W. Koelz 5024 (US), KY367282, KP338153, KP338405, KY367325, KP338275, OR971769*, KY367309;
Hedysarum cachemirianum Benth. ex Baker: Kashmir, Kishenganga Valley and the road to Nanga Parbat, R.R. & I.D. Stewart 18354 (US), KY367283, KY367300, KY367343, KY367326, OR971763*, –, KY367310;
Hedysarum campylocarpon H. Ohashi: China, Xizang, Jilong, Z.Y. Chang et al. 2013073 (WUK), KY367284, KY367301, KY367344, KY367327, –, –, KY367311;
Hedysarum campylocarpon H. Ohashi: China, Xizang, Nielamu, Z.Y. Chang et al. 2011203 (WUK), –, –, –, –, KP338279, OR971765*, –;
Hedysarum chinense (B. Fedtsch.) Hand.-Mazz.: China, Shaanxi, Ningshan, Z. M. Jiang 1565 (WUK), KY365842, KP338159, KP338412, KY366042, KP338280, KY365891, KY365992;
Hedysarum cisdarvasicum Kamelin & Karimova: Tajikistan, Darvaz, Yakhsu river. basin, R. Kamelin s. n. (TAD), MK639303, MK639233, MK639289, –, MK639275, MK639261, MK639247;
Hedysarum citrinum E. G. Baker: China, Xizang, Longzi, Y. S. Chen et al. 13-468. (WUK), OR971731*, OR982385*, OR971741*, OR971748*, OR971757*, OR971778*, –;
Hedysarum cuonanum P. L. Liu, J. Wen & Zhao Y. Chang: China, Xizang, Cuona, Y. S. Chen et al. 13-0948 (WUK), KY367286, KY367302, KY367345, KY367329, OR971764*, OR971767*, KY367312;
Hedysarum dentatoalatum K. T. Fu: China, Henna, Luanchuan, Z. Y. Chang et al. 2013267 (WUK), KY365844, KP338162, KP338415, KY366044, KP338283, KY365893, KY365994;
Hedysarum denticulatum Regel: Kyrgyzstan, Osh, Alay Valley, I. Sodombekov & N. Rogova KPL_00816 (MO), KY365845, KY366156, KY365760, –, KY366137, KY365894, KY365995;
Hedysarum falconeri Baker, Pakistan, Karakoram, O. Polunin 6096 (F), KY367287, KP338163, KP338416, KY367330, KP338284, OR971768*, KY367313;
Hedysarum hedysaroides Schinz & Thell.: Russia, Kamchatka, Tolbachik Volcano, S. McDonald & N. A. Brummitt 23 (US), KY365847, KP338168, KP338421, KY366046, KP338288, KY365896, KY365997;
Hedysarum inundatum Turcz.: China, Shanxi, Huangtudui 01313 (WUK), KY365848, KP338170, KP338423, KY366047, KP338290, KY365897, KY365998;
Hedysarum kumaonense Benth. ex Baker: China, Xizang, Jilong, Z. Y. Chang et al. 2013084 (WUK), KY367288, KP338174, KP338427, KY367331, KP338294, KY365899, KY367314;
Hedysarum lehmannianum Bunge: Tajikistan, Zeravshan range, Pastrud-darya river. basin, Turzun, Abdusalyamova, Zhogoleva & Ovchinnikov 4932 (TAD), MK639308, MK639238, MK639294, –, MK639280, MK639266, MK639252;
Hedysarum longigynophorum C. C. Ni: China, Xizang, Gongbujiangda, Z. Y. Chang. et al. QZ620 (WUK), KY367290, KP338175, KP338428, KY367333, KP338295, KY365900, KY367316;
Hedysarum minjanense Rech. f.: China, Xinjiang, Tashikuergan, Xizhixinjiangdui. 1091 (WUK), KY365852, KY366159, KY365763, –, KY366140, KY365902, KY366001;
Hedysarum nagarzense C. C. Ni: China, Xizang, Langkazi, L.R. Xu 1463 (WUK), KY367292, KY367305, KY367348, KY367335, OR971762*, OR971770*, KY367318;
Hedysarum neglectum Ledeb.: China, Xinjiang, Xinyuan, L. R. Xu 1533 (WUK), KY365853, KY366160, KY365764, KY366050, KY366141, KY365903, KY366002;
Hedysarum polybotrys Hand.-Mazz.: China, Gansu, Xiahe, Z. Y. Chang et al. QZ042. (WUK), KY365854, KP338182, KP338434, KY366051, KP338300, KY365905, KY366003;
Hedysarum przewalskii Yakovlev (Helanshan): China, Ningxia, Helanshan, R. B. Zhu. s. n. (WUK), OR971730*, OR982389*, OR971740*, OR971750*, OR971760*, OR971776*, –;
Hedysarum przewalskii Yakovlev (Jingtai): China, Gansu, Jingtai, Z. Y. Yu & Y. P. Xu 3255 (WUK), OR971729*, OR982390*, –, OR971751*, OR971761*, OR971775*, –;
Hedysarum qilianshanense P. L. Liu (Sidalong or Haplotype Ggap): China, Gansu, Su’nan, Sidalong, P. L. Liu 470 (WUK and WNU), OR971724*, OR982386*, OR971737*, OR971746*, OR971755*, OR971772*, OR971732*;
Hedysarum qilianshanense P. L. Liu (Wulin’gou or Haplotype Agap): China, Gansu, Su’nan, Wulin’gou, P. L. Liu 461 (WUK and WNU), OR971725*, OR982387*, OR971738*, OR971747*, OR971754*, OR971774*, OR971733*;
Hedysarum qilianshanense P. L. Liu (Xiaogushan or Haplotype AG): China, Gansu, Su’nan, Xiaogushan, P. L. Liu 458 (WUK and WNU), OR971726*, OR982388*, OR971739*, OR971745*, OR971756*, OR971773*, OR971734*;
Hedysarum semenowii Regel & Herder: Kazakhstan, Ulken, I. Roldugin 4823 (US), KY365856, KP338183, KP338435, KY366053, KP338301, KY365907, KY366005;
Hedysarum sikkimense Benth. ex Baker: China, Xizang, Yadong Y. S. Chen et al. 13-1772 (WUK), KY367294, KY367306, KY367349, KY367337, OR971753*, OR971771*, KY367320;
Hedysarum taipeicum (Hand.-Mazz.) K. T. Fu: China, Shaanxi, Mt. Taibai, P. L. Liu. 681-1 (WNU), OR971727*, OR982391*, OR971742*, OR971752*, OR971759*, OR971777*, OR971736*;
Hedysarum tanguticum B. Fedtsch.: China, Qinghai, Chengduo, Z. Y. Chang et al. 2010230 (WUK), KY365857, KP338188, KP338440, KY366056, KP338306, KY365910, KY366008;
Hedysarum tibeticum (Benth.) B. H. Choi & H. Ohashi: China, Xizang, Langkazi, Z. Y. Chang et al. 2011111 (WUK), KY367296, KP338189, KP338441, KY367339, KP338307, KY365911, KY367321;
Hedysarum ussuriense I. Schischkin & Kom.: China, Jilin, Mt. Changbai, M. Z. Sun. s. n. (WNU), OR971728*, OR982384*, OR971743*, OR971749*, OR971758*, –, OR971735*;
Hedysarum wangii P. L. Liu & Zhao Y. Chang: China, Gansu, Xiahe, Qu’ao, P. L. Liu. 432 (WUK and WNU), MK639312, MK639242, MK639298, OR971744*, MK639284, MK639270, MK639256;
Hedysarum xizangense C. C. Ni: China, Xizang, Longzi, Sananqulin, Y. S. Chen et al. 13-0886 (WUK), KY367297, KY367307, KY367350, KY367340, KP338310, OR971766*, KY367322.