Abstract
A new subgenus, Sonchus subg. Palustres, is established to accommodate S. erzincanicus endemic to Turkey and former Sonchus ser. Palustres including S. palustris and S. sosnowskyi. Although the exclusive placement of S. palustris has already been documented by previous studies based on molecular phylogenetic analyses without morphological evidence, there has not been any study of S. erzincanicus above the specific level. The present study proposes a new subgenus based on chiefly molecular data, and contribute macro- and micro-morphological features (i.e. pollen grains and achenes) of the studied species together with the phylogenetic position based on nrITS and matK with multiple sampling. Further literature and morphological studies evidently showed that S. erzincanicus and S. palustris have slightly heteromorphic achenes which is a subtle character and underestimated up to now in the infrageneric classification of the genus Sonchus. Besides, the molecular analyses revealed that S. erzincanicus and S. palustris are sister taxa, forming an exclusive clade of their own within the genus. Moreover, the Palustres clade is the first diverged one among the clades of the genus Sonchus based on the nrITS
data. Consequently, S. erzincanicus, S. palustris and S. sosnowskyi are treated as members of the suggested new subgenus. Therefore, the slightly heteromorphic achene feature could be taken into consideration for species delimitation in the genus Sonchus as a supportive morphological character. Furthermore, S. araraticus is suggested as a synonym of S. erzincanicus based on its morphological and ecological characteristics.
References
Aslay, M. & Kandemir, A. (2009) The Study of Conservation of Sonchus erzincanicus Matthews (Asteraceae). Fen Bilimleri Enstitüsü Dergisi 2 (1): 1–15.
Babcock, E.B. (1947) The genus Crepis, Part 1: the taxonomy, phylogeny, distribution and evolution of Crepis. University of California Publications in Botany, Berkeley-Los Angeles, 198 pp.
Barthlott, W. (1981) Epidermal and Seed Surface Characters of Plants: Systematic Applicability and Some Evolutionary Aspects. Nordic Journal of Botany 3: 345–355. https://doi.org/10.1111/j.1756-1051.1981.tb00704.x
Blattner, F.R. (1999) Direct amplification of the entire ITS region from poorly preserved plant material using recombinant PCR. Biotechniques 27: 1180–1186. https://doi.org/10.2144/99276st04
Boulos, L. (1960) Cytotaxonomic studies in the genus Sonchus 2. The genus Sonchus, a general treatment. Botaniska Notiser 113: 400–420.
Boulos, L. (1972) Révision systématique du genre Sonchus L. s.l. I. Introduction et classification. Botaniska Notiser 125: 287–305.
Boulos, L. (1973) Révision systématique du genre Sonchus L. s.l. IV. Sousgenre 1. Sonchus. Botaniska Notiser 126: 155–196.
Boulos, L. (1974) Révision systématique du genre Sonchus L. s.l. VI. Sousgenre 3. Origosonchus. Genres Embergeria, Babcockia et Taeckholmia. Botaniska Notiser 127: 402–451.
Bremer, K. (1994) Asteraceae: Cladistics and classification. Timber Press, Portland, Oregon, 752 pp.
Cho, M.-S., Kim, S.-H., Yang, J.Y., Crawford, D.J., Stuessy, T.F., López-Sepúlveda, P. & Kim, S.-C. (2020) Plastid phylogenomics of Dendroseris (Cichorieae; Asteraceae): insights into structural organization and molecular evolution of an endemic lineage from the Juan Fernández Islands. Frontiers in Plant Science 11: e594272. https://doi.org/10.3389/fpls.2020.594272
Cunningham, C.W. (1997) Can three incongruence tests predict when data should be combined? Molecular Biology and Evolution 14: 733–740. https://doi.org/10.1093/oxfordjournals.molbev.a025813
Diez, M.J. & Meijas, J.A. & Moreno-Socías, E. (1999) Pollen morphology of Sonchus and related genera, and a general discussion. Plant Systematics and Evolution 214: 91–102. https://doi.org/10.1007/BF00985733
Doyle, J.J. & Doyle, J.L. (1987) A rapid DNA Isolation Procedure for Small Quantities of Fresh Leaf Tissue. Phytochemical Bulletin 19: 11–15.
Edgar, R.C. (2004) MUSCLE: Multiple Sequence Alignment with High Accuracy and High Throughput. Nucleic Acids Research 32: 1792–1797. https://doi.org/10.1093/nar/gkh340
Enke, N. & Gemeinholzer, B. (2008) Babcock revisited: new insights into generic delimitation and character evolution in Crepis L. (Compositae: Cichorieae) from ITS and matK sequence data. Taxon 57: 756–768. https://doi.org/10.1002/tax.573008
Erdtman, G. (1952) Pollen Morphology and Plant Taxonomy. Almqvist and Wiksells, Uppsala, pp. 133–134. https://doi.org/10.1080/11035895209453507
Farris, J.S., Källersjö, M., Kluge, A.G. & Bult, C. (1994) Testing significance of congruence. Cladistics 10: 315–319. https://doi.org/10.1111/j.1096-0031.1994.tb00181.x
Fehrer, J., Gemeinholzer, B., Chrtek, J. & Bräutigam, S. (2007) Incongruent plastid and nuclearDNA phylogenies reveal ancient intergeneric hybridization in Pilosella hawkweeds (Hieracium, Cichorieae, Asteraceae). Molecular Phylogenetics and Evolution 42: 347–361. https://doi.org/10.1016/j.ympev.2006.07.004
Jeffrey, C. (1966) Notes on Compositae: I. The Cichorieae in east tropical Africa. Kew Bulletin 18: 427–486. https://doi.org/10.2307/4115797
Johnson, L. & Soltis, D. (1995) Phylogenetic Inference in Saxifragaceae Sensu Stricto and Gilia (Polemoniaceae) Using matK Sequences. Annals of the Missouri Botanical Garden 82 (2): 149–175. https://doi.org/10.2307/2399875
JSTOR (2000) [continuously updated] Global Plants. Available from: http://plants.jstor.org (accessed 29 June 2021)
Kandemir, A., Makbul, S., Türkme, Z. & Yılmaz, M. (2006) Morphological, Anatomical and Palynological Investigation on Sonchus erzincanicus Matthews (Asteraceae). Turkish Journal of Botany 30: 405–411.
Kavak, S. (2014) Sonchus erzincanicus. The IUCN Red List of Threatened Species e.T19617539A19620981.
Kilian, N. (1997) Revision of Launaea Cass. (Compositae, Lactuceae, Sonchinae). Englera 17: 1–448. https://doi.org/10.2307/3776755
Kilian, N., Gemeinholzer, B. & Lack, H.W. (2009a) Tribe Cichorieae. In: Funk, V.A., Susanna, A., Steussy, T.F. & Bayer, R.J. (Eds.) Systematics, Evolution, and Biogeography of Compositae. IAPT, Vienna, pp. 343–383.
Kilian, N., Hand, R. & Raab-Straube, E von (Eds.) (2009b) [continuously updated] Cichorieae Systematics Portal. Available from: http://cichorieae.etaxonomy.net/portal/ (accessed 29 June 2021)
Kim, S.-C., Crawford, D.J., Francisco-Ortega, J. & Santos-Guerra, A. (1996) A common origin for woody Sonchus and five related genera in the Macaronesian islands: molecular evidence for extensive radiation. Proceedings of the National Academy of Sciences of the United States of America 93: 7743–7748. https://doi.org/10.1073/pnas.93.15.7743
Kim, S.-C., Crawford, D.J. & Jansen, R.K. (1997) Phylogenetic relationships among the genera of the subtribe Sonchinae (Asteraceae): evidence from ITS sequences. Systematic Botany 21: 417–432. https://doi.org/10.2307/2419668
Kim, S.-C., Crawford, D.J., Francisco-Ortega, J. & Santos-Guerra, A. (1999a) Adaptive radiation and genetic differentiation in the woody Sonchus alliance (Asteraceae: Sonchinae) in the Canary Islands. Plant Systematics and Evolution 215: 101–118. https://doi.org/10.1007/BF00984650
Kim, S.-C., Crawford, D.J., Jansen, R.K. & Santos-Guerra, A. (1999b) The use of a non-coding region of chloroplast DNA in phylogenetic studies of the subtribe Sonchinae (Asteraceae: Lactuceae). Plant Systematics and Evolution 215: 85–99. https://doi.org/10.1007/BF00984649
Kim, S.-C., Lu, C.T. & Lepschi, B.J. (2004) Phylogenetic positions of Actites megalocarpa and Sonchus hydrophilus (Sonchinae: Asteraceae) based on ITS and chloroplast non-coding DNA sequences. Australian Systematic Botany 17: 73–81. https://doi.org/10.1071/SB03019
Kim, S.-C., Lee, C. & Mejías, J.A (2007) Phylogenetic analysis of chloroplast DNA matK gene and ITS of nrDNA sequences reveals polyphyly of the genus Sonchus and new relationships among the subtribe Sonchinae (Asteraceae: Cichorieae). Molecular Phylogenetics and Evolution 44: 578–597. https://doi.org/10.1016/j.ympev.2007.03.014
Kim, S.-C., Mejías, J.A. & Pesach, L. (2008) Molecular confirmation of the hybrid origin of the critically endangered western Mediterranean endemic Sonchus pustulatus (Asteraceae: Sonchinae). Journal of Plant Research 121: 357–364. https://doi.org/10.1007/s10265-008-0166-8
Kirpicznikov, M.E. (1964a) Sonchus L. In: Bobrov, E.G. & Tzevlev, N.N. (Eds.) Flora of the USSR, vol. 29, Akademiya Nauk SSSR, Moscow, Leningrad, pp. 243–259.
Kirpicznikov, M.E. (1964b) The system of Sonchus as accepted in the Flora of the USSR. Novosti Sistematiki Vysshikh Rastenii 1: 341–342.
Lee, C., Kim, S.-C., Lundy, K. & Santos-Guerra, A. (2005) Chloroplast DNA phylogeny of the woody Sonchus alliance (Asteraceae: Sonchinae) in the Macaronesian Islands. American Journal of Botany 92: 2072–2085. https ://doi.org/10.3732/ajb.92.12.2072
Matthews, V.A. (1974) Sonchus erzincanicus V. A. Matthews. Notes from the Royal Botanic Garden, Edinburgh 33: 429.
Matthews, V.A. (1975) Sonchus L. In: Davis, P.H. (Ed.) Flora of Turkey and the East Aegean Islands, vol. 5. Edinburgh Univ. Press, Edinburgh, pp. 690–693.
Mejías, J.A. (1992) Reproductive biology in the Iberian taxa of the genera Sonchus and Aetheorhiza (Asteraceae: Lactuceae). Flora Mediterranea 2: 15–32.
Mejías, J.A. (2017) Sonchus L. In: Talavera, S., Buira, A., Quintanar, A., García, M.Á., Talavera, M., Fernández Piedra, P. & Aedo, C. (Eds.) Flora Iberica XVI (II), Compositae (partim). Real Jardín Botánico, CSIC, Madrid, pp. 871–891.
Mejías, J.A. & Kim, S.-C. (2012) Taxonomic treatment of Cichorieae (Asteraceae) endemic to the Juan Fernandez and Desventuradas Islands (SE Pacific). Annales Botanici Fennici 49 (3): 171–178. https://doi.org/10.5735/085.049.0303
Mejías, J.A. & Valdes, B. (1987) Karyological studies in Sonchus section Maritimi (Asteraceae) from the Iberian Peninsula. Botanical Journal of the Linnean Society 98: 61–69.
Mejías, J.A., Chambouleyron, M., Kim, S.H., Infante, M.D., Kim, S.-C. & Léger, J.F. (2018) Phylogenetic and morphological analysis of a new cliff-dwelling species reveals a remnant ancestral diversity and evolutionary parallelism in Sonchus (Asteraceae). Plant Systematics and Evolution 304: 1023–1040. https://doi.org/10.1007/s00606-018-1523-2
Miller, M.A., Pfeiffer, W. & Schwartz, T. (2010) Creating the CIPRES Science Gateway for inference of large phylogenetic trees. In: Proceedings of the Gateway Computing Environments Workshop (GCE), New Orleans, Louisiana, 14 Nov 2010. pp. 45–52. [Piscataway: IEEE] https://doi.org/10.1109/GCE.2010.5676129
Müller, K. (2004) PRAP-Computation of Bremer Support for Large Data Sets. Molecular Phylogenetics and Evolution 31: 780–782. https://doi.org/10.1016/j.ympev.2003.12.006
Müller, K. (2005a) SeqState: Primer design and sequence statistics for phylogenetic DNA datasets. Applied Bioinformatics 4 (1): 65–69. https://doi.org/10.2165/00822942-200504010-00008
Müller, K. (2005b) The efficiency of different search strategies in estimating parsimony jackknife, bootstrap, and Bremer support. BMC Evolutionary Biology 5: 58.
Müller, K., Müller, J. & Quandt, D. (2010) PhyDE: Phylogenetic Data Editor, version 0.9971. Available from: http://www.phyde.de/index.html (accessed 20 January 2022)
Nazarova, E.A. & Barsegyan, A.M. (1983) Sonchus araraticus (Asteraceeae) – A New Species From Armenia. Botanicheskii Zhurnal 68: 950–952.
Nixon, K.C. (1999) The parsimony ratchet, a new method for rapid parsimony analysis. Cladistics 15: 407–414. https://doi.org/10.1111/j.1096-0031.1999.tb00277.x
Nylander, J.A.A. (2004) MrModeltest, version 2. Evolutionary Biology Centre, Uppsala University. [https://www.abc.se/~nylander/mrmodeltest2/mrmodeltest2.html]
Punt, W., Hoen, P.P., Blackmore, S., Nilsson, S. & Thomas, L.A. (2007) Glossary of pollen and spore terminology. Review of Palaeobotany and Palynology 143: 1–81. https://doi.org/10.1016/j.revpalbo.2006.06.008
Ronquist, F., Teslenko, M., Mark, P.V.D., Ayres, D.L., Darling, A., Hohna, S., Larget, B., Liu, L., Suchard, M.A. & Huelsenbeck, J.P. (2012) MrBayes 3.2: efficient Bayesian phylogenetic inference and model choice across a large model space. Systematic Biology 61: 539–542. https://doi.org/10.1093/sysbio/sys029
Saad, S.I. (1961) Pollen morphology in the genus Sonchus. Pollen & Spores 3: 247–260.
Sennikov, A.N. & Illarionova, I.D. (2001) Morphological and anatomical structure of achenes in some species of the genus Sonchus (Asteraceae). Botanicheskii Zhurnal 86 (5): 65–79, Tab. I–II. [in Russian]
Stebbins, G.L. (1953) A new classification of the tribe Cichorieae, family Compositae. Madroño 12: 65–81.
Simmons, M.P. & Ochoterena, H. (2000) Gaps as characters in sequence-based phylogenetic analyses. Systematic Biology 49: 369–381. https://doi.org/10.1093/sysbio/49.2.369
Stamatakis, A. (2006) RAxML-VI-HPC: Maximum Likelihood-Based Phylogenetic Analyses with Thousands of Taxa and Mixed Models. Bioinformatics 22: 2688–2690. https://doi.org/10.1093/bioinformatics/btl446
Stöver, B.C. & Müller, K.F. (2010) TreeGraph 2: Combining and visualizing evidence from different phylogenetic analyses. BMC Evolutionary Biology 11: 7. https://doi.org/10.1186/1471-2105-11-7
Sullivan, J. (1996) Combining data with different distributions of among-site variation. Systematic Biology 45: 375–380. https://doi.org/10.1093/sysbio/45.3.375
Swofford, D.L. (2003) PAUP*: Phylogenetic Analysis Using Parsimony (*and other methods), version 4.0b 10. Sunderland, Massachusetts, Sinauer.
Tamanyan, K. (2014) Sonchus sosnowskyi. The IUCN Red List of Threatened Species 2014: e.T200516A2665823. http://dx.doi.org/10.2305/IUCN.UK.2014-1.RLTS.T200516A2665823.en
Turland, N.J., Wiersema, J.H., Barrie, F.R., Greuter, W., Hawksworth, D., Herendeen, P.S., Knapp, S., Kusber, W.H., Li, D.Z. & Marhold, K. (2018) International code of nomenclature for algae, fungi, and plants (Shenzhen Code) adopted by the Nineteenth International Botanical Congress Shenzhen, China, July 2017. Koeltz Botanical Books, Glashütten. https://doi.org/10.12705/Code.2018
Wang, Z.H., Peng, H. & Kilian, N. (2013) Molecular phylogeny of the Lactuca alliance (Cichorieae subtribe Lactucinae, Asteraceae) with focus on their Chinese centre of diversity detects potential events of reticulation and chloroplast capture. Plos One 8: 1–20. https://doi.org/10.1371/journal.pone.0082692
Zhang, J.W., Boufford, D.E. & Sun, H. (2013) Systematic significance of achene morphology in Soroseris, Syncalathium and Parasyncalathium (Asteraceae: Cichorieae). Botanical Journal of the Linnean Society 173 (3): 476–486. https://doi.org/10.1111/boj.12046
Zhu, S.X., Qin, H.N. & Shih, C. (2006) Achene wall anatomy and surface sculpturing of Lactuca L. and related genera (Compositae: Lactuceae) with notes on their systematic significance. Journal of Integrative Plant Biology 48: 390–399. https://doi.org/10.1111/j.1744-7909.2006.00245.x