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Sukhorukov AP, Nilova MV, Kushunina M, Mazei Y, Klak C. Evolution of seed characters and of dispersal modes in Aizoaceae. Front Plant Sci 2023; 14:1140069. [PMID: 37035044 PMCID: PMC10073613 DOI: 10.3389/fpls.2023.1140069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 02/24/2023] [Indexed: 06/19/2023]
Abstract
The family Aizoaceae includes ~1880 species and is one of the more diverse groups within Caryophyllales, particularly in arid areas in the western part of southern Africa. Most species are dwarf succulent-leaf shrubs. In response to the harsh climatic conditions prevalent where they occur, many representatives have evolved special reproductive adaptations. These include hygrochastic capsules (mostly found in Mesembryanthemoideae and Ruschioideae), burr-like indehiscent and one-seeded, winged diaspores, and fast germination of seeds after rain. We focused on anatomical features, evolutionary trends, and the ecological significance of various morpho-anatomical structures found in the seeds. The seeds of 132 species from 61 genera were studied, and 18 diagnostic characters were discovered. All studied characters were compared with those of other families from core Caryophyllales. The seed notch and embryo shape were added to the list of characteristics distinguishing major clades within the family. In addition, the presence of longitudinal ridges and a keel on the seed are additional characters of Aizooideae and combined Ruschioideae-Apatesieae, respectively. Puzzle-like borders of testa cells are a common trait in Ruschioideae and Mesembryanthemoideae. Most taxa in Aizoaceae have a thin seed coat, which is the ancestral state within the family. This may facilitate fast germination. We observed several shifts to a medium-thick or thick seed coat in members of Ruschioideae and Acrosanthoideae. These inhabit fire-prone environments (in vegetation types known as fynbos and renosterveld), where the thickened seed coat may protect against damage by fire. Multi-seeded fruits are the ancestral state within Aizoaceae, with several shifts to one-(two-)seeded xerochastic fruits. The latter are dispersed via autochory, zoochory, or anemochory. This trait has evolved mainly in less succulent subfamilies Acrosanthoideae, Aizooideae, and Sesuvioideae. In highly succulent subfamilies Ruschioideae and Mesembryanthemoideae, fruits are almost exclusively multi-seeded and hygrochastic with ombrohydrochoric dispersal. A reduction in the number of seeds within a dispersal unit is rare. Within Apatesieae and Ruschieae, there are also a few unusual genera whose fruits fall apart into one- to two-seeded mericarps (that are mainly dispersed by wind).
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Affiliation(s)
- Alexander P. Sukhorukov
- Department of Higher Plants, Biological Faculty, M.V. Lomonosov Moscow State University, Moscow, Russia
- Laboratory Herbarium (TK), Tomsk State University, Tomsk, Russia
| | - Maya V. Nilova
- Department of Higher Plants, Biological Faculty, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Maria Kushunina
- Laboratory Herbarium (TK), Tomsk State University, Tomsk, Russia
- Department of Plant Physiology, Biological Faculty, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Yuri Mazei
- Department of General Ecology and Hydrobiology, Biological Faculty, M.V. Lomonosov Moscow State University, Moscow, Russia
| | - Cornelia Klak
- Bolus Herbarium, Department of Biological Sciences, University of Cape Town, Cape Town, South Africa
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Albani Rocchetti G, Carta A, Mondoni A, Godefroid S, Davis CC, Caneva G, Albrecht MA, Alvarado K, Bijmoer R, Borosova R, Bräuchler C, Breman E, Briggs M, Buord S, Cave LH, Da Silva NG, Davey AH, Davies RM, Dickie JB, Fabillo M, Fleischmann A, Franks A, Hall G, Kantvilas G, Klak C, Liu U, Medina L, Reinhammar LG, Sebola RJ, Schönberger I, Sweeney P, Voglmayr H, White A, Wieringa JJ, Zippel E, Abeli T. Selecting the best candidates for resurrecting extinct-in-the-wild plants from herbaria. Nat Plants 2022; 8:1385-1393. [PMID: 36536014 DOI: 10.1038/s41477-022-01296-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2022] [Accepted: 10/31/2022] [Indexed: 05/12/2023]
Abstract
Resurrecting extinct species is a fascinating and challenging idea for scientists and the general public. Whereas some theoretical progress has been made for animals, the resurrection of extinct plants (de-extinction sensu lato) is a relatively recently discussed topic. In this context, the term 'de-extinction' is used sensu lato to refer to the resurrection of 'extinct in the wild' species from seeds or tissues preserved in herbaria, as we acknowledge the current impossibility of knowing a priori whether a herbarium seed is alive and can germinate. In plants, this could be achieved by germinating or in vitro tissue-culturing old diaspores such as seeds or spores available in herbarium specimens. This paper reports the first list of plant de-extinction candidates based on the actual availability of seeds in herbarium specimens of globally extinct plants. We reviewed globally extinct seed plants using online resources and additional literature on national red lists, resulting in a list of 361 extinct taxa. We then proposed a method of prioritizing candidates for seed-plant de-extinction from diaspores found in herbarium specimens and complemented this with a phylogenetic approach to identify species that may maximize evolutionarily distinct features. Finally, combining data on seed storage behaviour and longevity, as well as specimen age in the novel 'best de-extinction candidate' score (DEXSCO), we identified 556 herbarium specimens belonging to 161 extinct species with available seeds. We expect that this list of de-extinction candidates and the novel approach to rank them will boost research efforts towards the first-ever plant de-extinction.
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Affiliation(s)
| | | | - Andrea Mondoni
- Department of Earth and Environmental Science, University of Pavia, Pavia, Italy
| | - Sandrine Godefroid
- Research Department, Meise Botanic Garden, Meise, Belgium
- Service général de l'Enseignement supérieur et de la Recherche scientifique, Fédération Wallonie, Brussels, Belgium
- Laboratory of Plant Ecology and Biogeochemistry, Université libre de Bruxelles, Brussels, Belgium
| | - Charles C Davis
- Department of Organismic Biology, Harvard University, Cambridge, MA, USA
- Harvard University Herbaria, Cambridge, MA, USA
| | - Giulia Caneva
- Department of Science, University of Roma Tre, Rome, Italy
| | - Matthew A Albrecht
- Center for Conservation and Sustainable Development, Missouri Botanical Garden, St Louis, MO, USA
| | - Karla Alvarado
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL, USA
| | - Roxali Bijmoer
- Naturalis Biodiversity Center, Botany Section, Leiden, the Netherlands
| | | | | | - Elinor Breman
- Royal Botanic Gardens, Kew, Wakehurst; Ardingly, Haywards Heath, West Sussex, UK
| | | | - Stephane Buord
- Conservatoire botanique national de Brest, Brest, France
| | | | - Nílber Gonçalves Da Silva
- Departamento de Botânica, Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Rachael M Davies
- Royal Botanic Gardens Kew, Seed and Lab-Based Collections, Sussex, UK
| | - John B Dickie
- Royal Botanic Gardens Kew, Seed and Lab-Based Collections, Sussex, UK
| | - Melodina Fabillo
- Queensland Herbarium, Department of Environment and Science, Brisbane Botanic Gardens Mt Coot-tha, Toowong, Queensland, Australia
| | - Andreas Fleischmann
- Botanische Staatssammlung München (SNSB-BSM), and GeoBio-Center LMU, Ludwig-Maximilians-University, Munich, Germany
| | - Andrew Franks
- Queensland Herbarium, Department of Environment and Science, Brisbane Botanic Gardens Mt Coot-tha, Toowong, Queensland, Australia
| | - Geoffrey Hall
- Centre sur la biodiversité de l'Université de Montréal (CITES CA-035), Montréal, Québec, Canada
| | - Gintaras Kantvilas
- Tasmanian Herbarium, Tasmanian Museum and Art Gallery, Sandy Bay, Tasmania, Australia
| | - Cornelia Klak
- Bolus Herbarium, Department of Biological Sciences, University of Cape Town, Rondebosch, South Africa
| | - Udayangani Liu
- Royal Botanic Gardens, Kew, Wellcome Trust Millennium Building, West Sussex, England, UK
| | | | | | - Ramagwai J Sebola
- South African National Biodiversity Institute, Pretoria, South Africa
- School of Animal, Plant and Environmental Sciences, University of the Witwatersrand; WITS, Johannesburg, South Africa
| | - Ines Schönberger
- Allan Herbarium, Manaaki Whenua - Landcare Research, Lincoln, New Zealand
| | - Patrick Sweeney
- Peabody Museum of Natural History, Yale University, New Haven, CT, USA
| | - Hermann Voglmayr
- Department for Botany and Biodiversity Research, University of Vienna, Vienna, Austria
| | - Adam White
- CSIRO Black Mountain Laboratories, Black Mountain, Australian Capital Territory, Australia
| | - Jan J Wieringa
- Naturalis Biodiversity Center, Botany Section, Leiden, the Netherlands
| | - Elke Zippel
- Dahlem Seed Bank, Botanical Garden and Botanic Museum Berlin, Berlin, Germany
| | - Thomas Abeli
- Department of Science, University of Roma Tre, Rome, Italy
- IUCN SSC Conservation Translocation Specialist Group, Calgary, Alberta, Canada
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Sukhorukov AP, Nilova MV, Erst AS, Kushunina M, Baider C, Verloove F, Salas-Pascual M, Belyaeva IV, Krinitsina AA, Bruyns PV, Klak C. Diagnostics, taxonomy, nomenclature and distribution of perennial Sesuvium (Aizoaceae) in Africa. PhytoKeys 2018; 92:45-88. [PMID: 29416411 PMCID: PMC5799733 DOI: 10.3897/phytokeys.92.22205] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2017] [Accepted: 01/04/2018] [Indexed: 06/08/2023]
Abstract
The taxonomy of perennial Sesuvium species in Africa has been poorly investigated until now. Previously five perennial species of Sesuvium were recognised in Africa (S. congense, S. crithmoides, S. mesembryanthemoides, S. portulacastrum, and S. sesuvioides). Based on the differing number of stamens, S. ayresii is accepted here as being distinct from S. portulacastrum. Field observations in Angola also led the authors to conclude that S. crystallinum and S. mesembryanthemoides are conspecific with S. crithmoides. A new subspecies, Sesuvium portulacastrum subsp. persoonii, is described from West Africa (Cape Verde, Gambia, Guinea-Bissau, Mauritania, Senegal). The molecular phylogeny indicates the position of S. portulacastrum subsp. persoonii within the "American lineage" as a part of the Sesuvium portulacastrum complex which needs further studies. A diagnostic key and taxonomic notes are provided for the six perennial species of Sesuvium found in Africa and recognised by the authors (S. ayresii, S. congense, S. crithmoides, S. portulacastrum subsp. portulacastrum, S. portulacastrum subsp. persoonii, S. verrucosum and the facultatively short-lived S. sesuvioides). The distribution of S. crithmoides, previously considered to be endemic to Angola, is now confirmed for the seashores of Republic of Congo and DR Congo. The American species S. verrucosum is reported for the first time for Africa (the Macaronesian islands: Cape Verde and the Canaries). It is locally naturalised in Gran Canaria, being a potentially invasive species. These findings as well as new records of S. verrucosum from Asia and the Pacific Islands confirm its proneness to transcontinental introduction. Lectotypes of S. brevifolium, S. crithmoides, S. crystallinum and S. mesembryanthemoides are selected. The seed micromorphology and anatomy of the perennial African species is studied. Compared to the seeds of some annual African Sesuvium investigated earlier, those of perennial species are smooth or slightly alveolate. The aril is one-layered and parenchymatous in all species and usually tightly covers the seed. The aril detachments from the seed coat that form a white stripe near the cotyledon area easily distinguish S. verrucosum from other species under study.
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Affiliation(s)
- Alexander P. Sukhorukov
- Department of Higher Plants, Biological Faculty, Lomonosov Moscow State University, Leninskie gory 1/12, Moscow 119234, Russia
| | - Maya V. Nilova
- Department of Higher Plants, Biological Faculty, Lomonosov Moscow State University, Leninskie gory 1/12, Moscow 119234, Russia
| | - Andrey S. Erst
- Central Siberian Botanical Garden SB RAS, Zolotodolinskaya st. 101, Novosibirsk 630090, Russia
- Tomsk State University, Laboratory of Phylogeny and Systematics, Lenin st. 36, Tomsk 634050, Russia
| | - Maria Kushunina
- Department of Plant Physiology, Biological Faculty, Lomonosov Moscow State University, Leninskie gory 1/12, Moscow 119234, Russia
| | - Cláudia Baider
- The Mauritius Herbarium, RE Vaughan Building, Agricultural Services, Ministry of Agro-Industry and Food Security, Réduit, 80835, Mauritius
| | - Filip Verloove
- Botanic Garden of Meise, Nieuwelaan 38, B-1860 Meise, Belgium
| | - Marcos Salas-Pascual
- Institute for Environmental Studies and Natural Resources (i-UNAT), University of Las Palmas de Gran Canaria (ULPGC), Las Palmas de Gran Canaria, Gran Canaria, Canary Islands, Spain
| | | | - Anastasiya A. Krinitsina
- Department of Higher Plants, Biological Faculty, Lomonosov Moscow State University, Leninskie gory 1/12, Moscow 119234, Russia
| | - Peter V. Bruyns
- Bolus Herbarium, Department of Biological Sciences, University of Cape Town, Rhodes Gift, 7707 South Africa
| | - Cornelia Klak
- Bolus Herbarium, Department of Biological Sciences, University of Cape Town, Rhodes Gift, 7707 South Africa
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Klak C, Hanáček P, Bruyns PV. Out of southern Africa: Origin, biogeography and age of the Aizooideae (Aizoaceae). Mol Phylogenet Evol 2016; 109:203-216. [PMID: 27998816 DOI: 10.1016/j.ympev.2016.12.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 12/07/2016] [Accepted: 12/12/2016] [Indexed: 01/28/2023]
Abstract
The Aizooideae is an early-diverging lineage within the Aizoaceae. It is most diverse in southern Africa, but also has endemic species in Australasia, Eurasia and South America. We derived a phylogenetic hypothesis from Bayesian and Maximum Likelihood analyses of plastid DNA-sequences. We find that one of the seven genera, the fynbos-endemic Acrosanthes, does not belong to the Aizooideae, but is an ancient sister-lineage to the subfamilies Mesembryanthemoideae & Ruschioideae. Galenia and Plinthus are embedded inside Aizoon and Aizoanthemum is polyphyletic. The Namibian endemic Tetragonia schenckii is sister to Tribulocarpus of the Sesuvioideae. For the Aizooideae, we explored their possible age by means of relaxed Bayesian dating and used Bayesian Binary MCMC reconstruction of ancestral areas to investigate their area of origin. Early diversification occurred in southern Africa in the Eocene-Oligocene, with a split into a mainly African lineage and an Eurasian-Australasian-African-South American lineage. These subsequently radiated in the early Miocene. For Tetragonia, colonisation of Australasia via long-distance dispersal from Eurasia gave rise to the Australasian lineage from which there were subsequent dispersals to South America and Southern Africa. Despite the relatively old age of the Aizooideae, more than half the species have radiated since the Pleiocene, coinciding with the large and rapid diversification of the Ruschioideae. The lineage made up of Tetragonia schenckii &Tribulocarpus split from the remainder of the Sesuvioideae already in the mid Oligocene and its disjunct distribution between Namibia and north-east Africa may be the result of a previously wider distribution within an early Arid African flora. Our reconstruction of ancestral character-states indicates that the expanding keels giving rise to hygrochastic fruits originated only once, i.e. after the split of the Sesuvioideae from the remainder of the Aizoaceae and that they were subsequently lost many times. Variously winged and spiky fruits, adapted to dispersal by wind and animals, have evolved independently in the Aizooideae and the Sesuvioideae. There is then a greater diversity of dispersal systems in the earlier lineages than in the Mesembryanthemoideae and Ruschioideae, where dispersal is mainly achieved by rain.
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Affiliation(s)
- Cornelia Klak
- Bolus Herbarium, Department of Biological Sciences, University of Cape Town, 7701 Rondebosch, South Africa.
| | - Pavel Hanáček
- Department of Plant Biology, Mendel University in Brno, Zemědělská 1, 613 00 Brno, Czech Republic
| | - Peter V Bruyns
- Bolus Herbarium, Department of Biological Sciences, University of Cape Town, 7701 Rondebosch, South Africa
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Bruyns P, Klak C, Hanáček P. Recent radiation of Brachystelma and Ceropegia (Apocynaceae) across the Old World against a background of climatic change. Mol Phylogenet Evol 2015; 90:49-66. [DOI: 10.1016/j.ympev.2015.04.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Revised: 04/17/2015] [Accepted: 04/19/2015] [Indexed: 10/23/2022]
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Ripley BS, Abraham T, Klak C, Cramer MD. How succulent leaves of Aizoaceae avoid mesophyll conductance limitations of photosynthesis and survive drought. J Exp Bot 2013; 64:5485-96. [PMID: 24127513 PMCID: PMC3871808 DOI: 10.1093/jxb/ert314] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
In several taxa, increasing leaf succulence has been associated with decreasing mesophyll conductance (g M) and an increasing dependence on Crassulacean acid metabolism (CAM). However, in succulent Aizoaceae, the photosynthetic tissues are adjacent to the leaf surfaces with an internal achlorophyllous hydrenchyma. It was hypothesized that this arrangement increases g M, obviating a strong dependence on CAM, while the hydrenchyma stores water and nutrients, both of which would only be sporadically available in highly episodic environments. These predictions were tested with species from the Aizoaceae with a 5-fold variation in leaf succulence. It was shown that g M values, derived from the response of photosynthesis to intercellular CO2 concentration (A:C i), were independent of succulence, and that foliar photosynthate δ(13)C values were typical of C3, but not CAM photosynthesis. Under water stress, the degree of leaf succulence was positively correlated with an increasing ability to buffer photosynthetic capacity over several hours and to maintain light reaction integrity over several days. This was associated with decreased rates of water loss, rather than tolerance of lower leaf water contents. Additionally, the hydrenchyma contained ~26% of the leaf nitrogen content, possibly providing a nutrient reservoir. Thus the intermittent use of C3 photosynthesis interspersed with periods of no positive carbon assimilation is an alternative strategy to CAM for succulent taxa (Crassulaceae and Aizoaceae) which occur sympatrically in the Cape Floristic Region of South Africa.
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Affiliation(s)
- Brad S. Ripley
- Department of Botany, Rhodes University, 6140 Grahamstown, South Africa
| | - Trevor Abraham
- Department of Botany, Rhodes University, 6140 Grahamstown, South Africa
| | - Cornelia Klak
- Bolus Herbarium, Department of Biological Sciences, University of Cape Town, 7701 Rondebosch, South Africa
| | - Michael D. Cramer
- Department of Biological Sciences, University of Cape Town, 7701 Rondebosch, South Africa
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Abstract
We present a new infrageneric classification for Mesembryanthemum L. (Aizoaceae: Mesembryanthemoideae), based on a phylogeny of the genus published in 2007. We re-affirm that a broad generic circumscription for Mesembryanthemum (including all 103 species of the Mesembryanthemoideae) is the only group in the subfamily that can be recognized unambiguously by synapomorphies. We divide Mesembryanthemum into five subgenera, of which two are new: M. subg. Mesembryanthemum, M. subg. Cryophytum (N.E. Br.) Bittrich, M. subg. Opophytum (N.E. Br.) Bittrich, M. subg. Phyllobolus (N.E. Br.) Klak and M. subg. Volkeranthus (Gerbaulet) Klak. Furthermore, we recognize five sections in subg. Mesembryanthemum, six sections in subg. Phyllobolus and two sections in M. subg. Cryophytum. Descriptions and keys to all infrageneric taxa are provided.
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Illing N, Klak C, Johnson C, Brito D, Negrao N, Baine F, van Kets V, Ramchurn KR, Seoighe C, Roden L. Duplication of the Asymmetric Leaves1/Rough Sheath 2/Phantastica (ARP) gene precedes the explosive radiation of the Ruschioideae. Dev Genes Evol 2009; 219:331-8. [PMID: 19554349 DOI: 10.1007/s00427-009-0293-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Accepted: 05/31/2009] [Indexed: 11/28/2022]
Abstract
The Mesembryanthemoideae and Ruschioideae subfamilies are a major component of the Greater Cape Floristic Region in southern Africa. The Ruschioideae show an astonishing diversity of leaf shape and growth forms. Although 1,585 species are recognised within the morphologically diverse Ruschioideae, these species show minimal variation in plastid DNA sequence. We have investigated whether changes in selected leaf development transcription factors underpin the recent, rapid diversification of this large group of succulent plants. Degenerate primers designed to conserved regions of Asymmetric Leaves1/Rough Sheath 2/Phantastica (ARP) and the Class III HD-ZIP family of genes, were used to amplify sequences corresponding to these genes from several species within the Mesembryanthemoideae and Ruschioideae subfamilies. Two members of the Class III HD-ZIP family were identified in both the Mesembryanthemoideae and Ruschioideae, and were derived from an ancient gene duplication event that preceded the divergence of gymnosperms and angiosperms. While a single ARP orthologue was identified in the Mesembryanthemoideae, two paralogues, ARPa and ARPb, were identified in the Ruschioideae subfamily. ARPa was present in all species of Ruschioideae analysed in this study. ARPb has been lost from the Apatesieae and Dorotheantheae tribes, which form an early evolutionary branch from the Ruschieae tribe, as well as from selected species within the Ruschieae. The recent duplication and subsequent selected gene loss of the ARP transcription factor correlates with the rapid diversification of plant forms in the Ruschioideae.
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Affiliation(s)
- Nicola Illing
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, South Africa.
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Abstract
The Succulent Karoo is an arid region, situated along the west coast of southern Africa. Floristically this region is part of the Greater Cape Flora and is considered one of the Earth's 25 biodiversity hotspots. Of about 5,000 species occurring in this region, more than 40% are endemic. Aizoaceae (ice plants) dominate the Succulent Karoo both in terms of species numbers (1,750 species in 127 genera) and density of coverage. Here we show that a well-supported clade within the Aizoaceae, representing 1,563 species almost exclusively endemic to southern Africa, has diversified very recently and very rapidly. The estimated age for this radiation lies between 3.8 and 8.7 million years (Myr) ago, yielding a per-lineage diversification rate of 0.77-1.75 per million years. Both the number of species involved and the tempo of evolution far surpass those of any previously postulated continental or island plant radiation. Diversification of the group is closely associated with the origin of several morphological features and one anatomical feature. Because species-poor clades lacking these features occur over a very similar distribution area, we propose that these characteristics are key innovations that facilitated this radiation.
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Affiliation(s)
- C Klak
- Bolus Herbarium, Department of Botany, University of Cape Town, 7701 Rondebosch, South Africa.
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Klak C, Khunou A, Reeves G, Hedderson T. A phylogenetic hypothesis for the Aizoaceae (Caryophyllales) based on four plastid DNA regions. Am J Bot 2003; 90:1433-1445. [PMID: 21659095 DOI: 10.3732/ajb.90.10.1433] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The Aizoaceae is the largest family of leaf succulent plants, and most of its species are endemic to southern Africa. To evaluate subfamilial, generic, and tribal relationships, we produced two plastid DNA data sets for 91 species of Aizoaceae and four outgroups: rps16 intron and the trnL-F gene region (both the trnL intron and the trnL-F intergenic spacer). In addition, we generated two further plastid data sets for 56 taxa restricted to members of the Ruschioideae using the atpB-rbcL and the psbA-trnH intergenic spacers. In the combined tree of the rps16 intron and trnL-F gene region, three of the currently recognized subfamilies (Sesuvioideae, Mesembryanthemoideae, and Ruschioideae) are each strongly supported monophyletic groups. The subfamily Tetragonioideae is polyphyletic, with Tribulocarpus as sister to the Sesuvioideae and Tetragonia embedded in the Aizooideae. Our study showed that the group consisting of the Sesuvioideae, Aizooideae, and Tetragonioideae does not form a monophyletic entity. Therefore, it cannot be recognized as a separate family in order to accommodate the frequently used concept of the Mesembryanthemaceae or "Mesembryanthema," in which the subfamilies Mesembryanthemoideae and Ruschioideae are included. We also found that several genera within the Mesembryanthemoideae (Mesembryanthemum, Phyllobolus) are not monophyletic. Within the Ruschioideae, our study retrieved four major clades. However, even in the combined analysis of all four plastid gene regions, relationships within the largest of these four clades remain unresolved. The few nucleotide substitutions that exist among taxa of this clade point to a rapid and recent diversification within the arid winter rainfall area of southern Africa. We propose a revised classification for the Aizoaceae.
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Affiliation(s)
- Cornelia Klak
- Bolus Herbarium, Department of Botany, University of Cape Town, 7701 Rondebosch, South Africa
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Klak C, Khunou A, Reeves G, Hedderson T. A phylogenetic hypothesis for the Aizoaceae (Caryophyllales) based on four plastid DNA regions. Am J Bot 2003; 90:1433-1445. [PMID: 21659095 DOI: 10.2307/4123697] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The Aizoaceae is the largest family of leaf succulent plants, and most of its species are endemic to southern Africa. To evaluate subfamilial, generic, and tribal relationships, we produced two plastid DNA data sets for 91 species of Aizoaceae and four outgroups: rps16 intron and the trnL-F gene region (both the trnL intron and the trnL-F intergenic spacer). In addition, we generated two further plastid data sets for 56 taxa restricted to members of the Ruschioideae using the atpB-rbcL and the psbA-trnH intergenic spacers. In the combined tree of the rps16 intron and trnL-F gene region, three of the currently recognized subfamilies (Sesuvioideae, Mesembryanthemoideae, and Ruschioideae) are each strongly supported monophyletic groups. The subfamily Tetragonioideae is polyphyletic, with Tribulocarpus as sister to the Sesuvioideae and Tetragonia embedded in the Aizooideae. Our study showed that the group consisting of the Sesuvioideae, Aizooideae, and Tetragonioideae does not form a monophyletic entity. Therefore, it cannot be recognized as a separate family in order to accommodate the frequently used concept of the Mesembryanthemaceae or "Mesembryanthema," in which the subfamilies Mesembryanthemoideae and Ruschioideae are included. We also found that several genera within the Mesembryanthemoideae (Mesembryanthemum, Phyllobolus) are not monophyletic. Within the Ruschioideae, our study retrieved four major clades. However, even in the combined analysis of all four plastid gene regions, relationships within the largest of these four clades remain unresolved. The few nucleotide substitutions that exist among taxa of this clade point to a rapid and recent diversification within the arid winter rainfall area of southern Africa. We propose a revised classification for the Aizoaceae.
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Affiliation(s)
- Cornelia Klak
- Bolus Herbarium, Department of Botany, University of Cape Town, 7701 Rondebosch, South Africa
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Abstract
Two new species of Brownanthus, B glareicola Klak and B fratemus Klak and one new species of Scopelogena, S. bruynsii Klak are described. S. gracilis L.Bolus is reduced to synonymy under S. verruculata (L.) L Bolus. Three new combinations are made: Antimima excedens (L.Bolus) Klak. Erepsia dunensis (Sond.) Klak and Hammeria meleagris (L.Bolus) Klak and full synonomy is given Lampranthus maximilianii (Schltr. A.Berger) L Bolus is transferred back to Braunsia maximilianii (Schltr. A Berger) Schwantes and the identity of Ruschia polita L Bolus is discussed. The taxonomic position of Mesembryanthemum purpureostylum L.Bolus is clarified.
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