| 1. |
- Antonelli, Alexandre, 1978, et al.
(författare)
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Settling a family feud: a high-level phylogenomic framework for the Gentianales based on 353 nuclear genes and partial plastomes
- 2021
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Ingår i: American Journal of Botany. - : Wiley. - 0002-9122 .- 1537-2197. ; 108:7, s. 1143-1165
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Tidskriftsartikel (refereegranskat)abstract
- Premise: Comprising five families that vastly differ in species richness—ranging from Gelsemiaceae with 13 species to the Rubiaceae with 13,775 species—members of the Gentianales are often among the most species-rich and abundant plants in tropical forests. Despite considerable phylogenetic work within particular families and genera, several alternative topologies for family-level relationships within Gentianales have been presented in previous studies. Methods: Here we present a phylogenomic analysis based on nuclear genes targeted by the Angiosperms353 probe set for approximately 150 species, representing all families and approximately 85% of the formally recognized tribes. We were able to retrieve partial plastomes from off-target reads for most taxa and infer phylogenetic trees for comparison with the nuclear-derived trees. Results: We recovered high support for over 80% of all nodes. The plastid and nuclear data are largely in agreement, except for some weakly to moderately supported relationships. We discuss the implications of our results for the order’s classification, highlighting points of increased support for previously uncertain relationships. Rubiaceae is sister to a clade comprising (Gentianaceae + Gelsemiaceae) + (Apocynaceae + Loganiaceae). Conclusions: The higher-level phylogenetic relationships within Gentianales are confidently resolved. In contrast to recent studies, our results support the division of Rubiaceae into two subfamilies: Cinchonoideae and Rubioideae. We do not formally recognize Coptosapelteae and Luculieae within any particular subfamily but treat them as incertae sedis. Our framework paves the way for further work on the phylogenetics, biogeography, morphological evolution, and macroecology of this important group of flowering plants.
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| 2. |
- Eriksson, Ove, et al.
(författare)
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The evolutionary ecology of dust seeds
- 2011
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Ingår i: Perspectives in plant ecology, evolution and systematics. - : Elsevier BV. - 1433-8319 .- 1618-0437. ; 13:2, s. 73-87
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Forskningsöversikt (refereegranskat)abstract
- Dust seeds are the smallest existing seeds in angiosperms. This paper summarizes taxonomic distribution, phylogeny, ontogeny, morphology, and recruitment behavior of dust seeds, concluding with a general hypothesis on the evolution of dust seeds. Plants with dust seeds depend on external sources of organic carbon for seedling development and are thus parasitic during recruitment. Species with dust seeds are either mycoheterotrophic (fully or partially) or parasitic on plants. Dust seeds are a derived feature which has evolved independently in at least 12 families (Burmanniaceae, Corsiaceae, Orchidaceae, Triuridaceae, Petrosaviaceae, Ericaceae, Gentianaceae, Polygalaceae, Orobanchaceae, Rubiaceae, Buddlejaceae and Gesneriaceae). For the three latter families parasitic behavior during recruitment has not yet been described, and should be considered as a hypothesis. Many, but not all, dust seeds possess features that are likely to have been selected for increasing buoyancy in air or water. Selection for maximal fecundity at the expense of reducing maternal resources per seed is the probable driver of dust seed evolution. As endosperm was reduced, undifferentiated embryo evolved as a by-product due to endosperm mediated control of embryo development. Ultimately, seed size reduction passed a threshold where resource acquisition became dependent on external hosts. In order to embark on an evolutionary trajectory towards host dependence, facultative parasitism must have been established in ancestral lineages. Mycoheterotrophic and mixotrophic plants probably evolved along with the rise of angiosperm dominated tropical forests beginning in the Late Cretaceous. It is suggested that selection for increasing seed size associated with the expansion of modern type tropical forests spurred a competition/colonization trade-off initiating a reversed evolutionary trajectory towards smaller seeds. A different process is suggested for true parasites with dust seeds (Orobanchaceae), where the driver may have been the Mid-Tertiary expansion of grasslands, creating opportunities to exploit grasses and herbs. It is suggested that inequality and asymmetry in resource monopolization in ecosystems promote evolution of subordinate life strategies, and possession of dust seeds is considered as a subordinate strategy in plant communities dominated by other plant strategies. This escape route for ecological losers eventually promoted evolution of one of the most diverse groups of plants, the orchids.
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| 3. |
- Hjertaas, Ane C., et al.
(författare)
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Convergent evolution of the annual life history syndrome from perennial ancestors
- 2023
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Ingår i: Frontiers in Plant Science. - : Frontiers Media SA. - 1664-462X. ; 13
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Forskningsöversikt (refereegranskat)abstract
- Despite most angiosperms being perennial, once-flowering annuals have evolved multiple times independently, making life history traits among the most labile trait syndromes in flowering plants. Much research has focused on discerning the adaptive forces driving the evolution of annual species, and in pinpointing traits that distinguish them from perennials. By contrast, little is known about how ‘annual traits’ evolve, and whether the same traits and genes have evolved in parallel to affect independent origins of the annual syndrome. Here, we review what is known about the distribution of annuals in both phylogenetic and environmental space and assess the evidence for parallel evolution of annuality through similar physiological, developmental, and/or genetic mechanisms. We then use temperate grasses as a case study for modeling the evolution of annuality and suggest future directions for understanding annual-perennial transitions in other groups of plants. Understanding how convergent life history traits evolve can help predict species responses to climate change and allows transfer of knowledge between model and agriculturally important species.
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| 4. |
- Kainulainen, Kent
(författare)
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A taxonomic revision of the Malagasy endemic genus Nematostylis (Rubiaceae), with description of two new species
- 2023
-
Ingår i: Candollea. - 0373-2967. ; 78:2, s. 177-188
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Tidskriftsartikel (refereegranskat)abstract
- Nematostylis Hook. f. (Rubiaceae) is a genus of semi-succulent shrubs endemic to Madagascar, mostly found growing on rocky outcrops in the Northern, Central, and Southern Highlands. This paper provides a revision of the genus in which three species are recognized: N. anthophylla (A. Rich. ex DC.) Baill. and the newly described N. citriflora Kainul. and N. incarnata Kainul. An identification key of the genus is presented, as well as a distribution map, field pictures, line drawings, and species risk of extinction assessments. A neotype is designated for N. anthophylla and a lectotype for N. loranthoides Hook. f.
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| 5. |
- Kainulainen, Kent, et al.
(författare)
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Chapelieria magna, a new species of Rubiaceae from eastern Madagascar
- 2015
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Ingår i: PhytoKeys. - : Pensoft Publishers. - 1314-2011 .- 1314-2003. ; 44, s. 89-95
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Tidskriftsartikel (refereegranskat)abstract
- A new species of Chapelieria was discovered during a recent field trip to the Masoala National Park in eastern Madagascar, and is described here as Chapelieria magna Kainul., sp. nov. This species is readily distinguishable from previously described species of the genus by its quadrangular shoots, triangular-calyptrate stipules, sessile leaves, pubescent styles, and ridged fruits. It also differs in the larger number of ovules and the much larger size of leaves and fruits.
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| 6. |
- Kainulainen, Kent, 1978-
(författare)
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Evolution and biodiversity of the Ixoroideae (Rubiaceae)
- 2010
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The phylogenetic relationships within subfamily Ixoroideae of the coffee family are investigated by phylogenetic reconstruction of molecular data, including regions of the chloroplast DNA (matK, ndhF, rbcL, rps16, trnH-psbA, trnS-G, and trnT-F), and the nuclear ribosomal DNA (ITS). The evolution of morphological characters within the group are inferred, with focus on characters used in classification. Ixoroideae have primarily been characterized by secondary pollen presentation, contorted corolla aestivation, and fleshy fruits. Secondary pollen presentation appears synapomorhic of a clade comprising the Ixoroideae crown group together with Retiniphyllum, whereas contorted corolla aestivation has evolved earlier and is synapomorphic for the crown group, Retiniphyllum, and Steenisia. Capsules likely represent a plesiomorphy from which various dry or fleshy indehiscent fruits have evolved independently in different clades. Reductions in seed number have also occured in many clades, none of which shows a secondary increase in the number of seeds. Within Ixoroideae, the phylogeny and tribal delimitations of Alberteae and Condamineeae are studied in more detail. The former appears restricted to Alberta, Nematostylis, and Razafimandimbisonia, a new genus described here. The Condamineeae are a diverse tribe largely unresolved in previous molecular phylogenetic studies. Our results support a synonymization of both Calycophylleae and Hippotideae, because these are nested within the Condamineeae. Ancestral state reconstructions indicate that intrapetiolar stipules, poricidal anthers, and protogyny, otherwise uncommon characters in Rubiaceae, all have evolved more than once in the Condamineeae. The rare genera Jackiopsis, Glionnetia, and Trailliaedoxa previously not included in molecular phylogenetic analyses, are all found nested within the Ixoroideae, and their systematic positions are discussed. The genera Bathysa, Calycophyllum, Elaeagia, and Rustia do not appear monophyletic. Consequently, resurrections of the names Holtonia, Schizocalyx, and Semaphyllanthe, and synonymizations of Phitopis (as Schizocalyx) and Tresanthera (as Rustia) are proposed. Also proposed are five new tribal names for clades that are not associated with any previously described tribes in the phylogenetic hypotheses presented.
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| 7. |
- Kainulainen, Kent, 1978-, et al.
(författare)
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Island hopping, long-distance dispersal and species radiation: historical biogeography of the Coffeeae alliance (Rubiaceae)
- 2017
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Ingår i: Journal of Biogeography. - : Wiley. - 0305-0270 .- 1365-2699. ; 44, s. 1966-1979
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Tidskriftsartikel (refereegranskat)abstract
- Aim. The Western Indian Ocean region (WIOR) is home to a very diverse and largely unique flora that has mainly originated via long-distance dispersals. The aim of this study is to gain insight into the origins of the WIOR biodiversity and to understand the dynamics of colonization events between the islands. We investigate spatial and temporal hypotheses of the routes of dispersal, and compare the dispersal patterns of plants of the Coffeeae alliance (Rubiaceae) and their dispersers. Rubiaceae is the second most species-rich plant family in Madagascar, and includes many endemic genera. The neighbouring archipelagos of the Comoros, Mascarenes and Seychelles also harbour several endemic Rubiaceae.Location. The islands of the Western Indian Ocean.Methods. Phylogenetic relationships and divergence times were reconstructed from plastid DNA data of an ingroup sample of 340 species, using Bayesian inference. Ancestral areas and range evolution history were inferred by a maximum likelihood method that takes topological uncertainty into account.Results. At least 15 arrivals to Madagascar were inferred, the majority of which have taken place within the last 10 Myr. Most dispersal events were supported as being from mainland Africa, but Catunaregam may have dispersed from Asia. Although most Coffeeae alliance lineages are zoochorous, the general pattern of dispersals from Africa is incongruent with the biogeographic origins of the extant Malagasy volant frugivores. Several out-of-Madagascar dispersals were inferred to the neighbouring islands, as well as back-colonizations of Africa.Main conclusions. The African flora has been of foremost importance as source of dispersal to the islands of the Western Indian Ocean. Following the colonization of Madagascar, rapid radiations appear to have taken place in some clades, and Madagascar has also been an important source area for subsequent dispersal to the Comoros, Mascarenes and Seychelles.
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| 8. |
- Kainulainen, Kent, et al.
(författare)
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Island hopping, long-distance dispersal and species radiation in the Western Indian Ocean : historical biogeography of the Coffeeae alliance (Rubiaceae)
- 2017
-
Ingår i: Journal of Biogeography. - : Wiley. - 0305-0270 .- 1365-2699. ; 44:9, s. 1966-1979
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Tidskriftsartikel (refereegranskat)abstract
- Aim The Western Indian Ocean region (WIOR) is home to a very diverse and largely unique flora that has mainly originated via long-distance dispersals. The aim of this study is to gain insight into the origins of the WIOR biodiversity and to understand the dynamics of colonization events between the islands. We investigate spatial and temporal hypotheses of the routes of dispersal, and compare the dispersal patterns of plants of the Coffeeae alliance (Rubiaceae) and their dispersers. Rubiaceae is the second most species-rich plant family in Madagascar, and includes many endemic genera. The neighbouring archipelagos of the Comoros, Mascarenes and Seychelles also harbour several endemic Rubiaceae.Location The islands of the Western Indian Ocean.Methods Phylogenetic relationships and divergence times were reconstructed from plastid DNA data of an ingroup sample of 340 species, using Bayesian inference. Ancestral areas and range evolution history were inferred by a maximum likelihood method that takes topological uncertainty into account.Results At least 15 arrivals to Madagascar were inferred, the majority of which have taken place within the last 10 Myr. Most dispersal events were supported as being from mainland Africa, but Catunaregam may have dispersed from Asia. Although most Coffeeae alliance lineages are zoochorous, the general pattern of dispersals from Africa is incongruent with the biogeographic origins of the extant Malagasy volant frugivores. Several out-of-Madagascar dispersals were inferred to the neighbouring islands, as well as back-colonizations of Africa.Main conclusions The African flora has been of foremost importance as source of dispersal to the islands of the Western Indian Ocean. Following the colonization of Madagascar, rapid radiations appear to have taken place in some clades, and Madagascar has also been an important source area for subsequent dispersal to the Comoros, Mascarenes and Seychelles.
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| 9. |
- Kainulainen, Kent, 1978-, et al.
(författare)
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Molecular phylogenetic analysis of the tribe Alberteae (Rubiaceae), with description of a new genus, Razafimandimbisonia
- 2009
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Ingår i: Taxon. - Wien : International Association for Plant Taxonomy. - 0040-0262 .- 1996-8175. ; 58:3, s. 757-768
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Tidskriftsartikel (refereegranskat)abstract
- The tribe Alberteae, presently classified in the subfamily Ixoroideae (Rubiaceae), has historically been an artificial grouping of genera. In the present study, phylogenetic analyses of the chloroplast DNA markers rbcL, ndhF, trnS-G, trnT-F and trnH-psbA as well as the ITS region of the nuclear ribosomal DNA, are done to assess the delimitation of Alberteae. The resulting phylogenetic hypothesis is highly resolved, with most clades strongly supported. The genus Alberta is found to be paraphyletic as presently circumscribed. As a consequence, we propose the new genus Razafimandimbisonia Kainul. & B. Bremer to accommodate the Malagasy species. The newly delimited Alberta is distinguished by having two calycophylls that expand after anthesis as well as awl-shaped stigma lobes. Razafimandimbisonia is distinguished from the remaining Alberteae by having dehiscent fruits and anthers without basal appendages. We demonstrate that the genera Airosperma, Boholia and Crossopteryx are not associated with Alberteae, as has previously been suggested. Alberteae is considered restricted to the genus Alberta endemic to Southeast Africa, and the two Malagasy endemic genera Nematostylis and Razafimandimbisonia.
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| 10. |
- Kainulainen, Kent, 1978-, et al.
(författare)
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Molecular systematics and morphological character evolution of the Condamineeae (Rubiaceae)
- 2010
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Ingår i: American Journal of Botany. - : Wiley. - 0002-9122 .- 1537-2197. ; 97:12, s. 1961-1981
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Tidskriftsartikel (refereegranskat)abstract
- • Premise of the study: The Condamineeae have in previous molecular studies been shown to be part of an early-divergent cladewithin the subfamily Ixoroideae, together with the tribes Calycophylleae, and Hippotideae, and genera of the former Cinchoneae and Rondeletieae. Generic relationships within this clade have, however, remained largely unresolved .• Methods: In this study, the systematics of the Condamineeae was further examined by phylogenetic reconstruction of six cpDNA regions and one nrDNA region using parsimony and Bayesian Markov chain Monte Carlo inference. Morphological character evolution within the tribe was assessed by ancestral state reconstruction using likelihood optimization of characters onto Bayesian trees. • Key results: Calycophylleae appears polyphyletic. “Hippotideae” is monophyletic but nested within the Condamineeae. The phylogenetic hypotheses presented support a resurrection of the genera Holtonia, Schizocalyx, and Semaphyllanthe. Furthermore, Bathysa is found to be polyphyletic, Tresanthera is found nested within Rustia, and the taxonomically disputed genus Dialypetalanthus is here shown to be sister to a Bothriospora–Wittmackanthus clade. Morphological ancestral state reconstructions indicate that protogyny have evolved at least two times within the tribe and that indehiscent fruits, loculicidal fruit dehiscence, and intrapetiolar stipules have evolved independently several times. The occurrence of calycophylls (leaf-like calyx lobes), poricidal anthers, and winged seeds also appear homoplastic within the tribe. • Conclusions : A diagnosis and delimitation of the tribe Condamineeae is presented, with taxonomic proposals to synonymize Tresanthera and to transfer several species of Bathysa as well as Phitopis to a resurrected Schizocalyx.
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| 11. |
- Kainulainen, Kent, 1978-, et al.
(författare)
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New taxonomic combinations in West Indian Ocean Vanguerieae (Rubiaceae)
- 2016
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Ingår i: Phytotaxa. - : Magnolia Press. - 1179-3155 .- 1179-3163. ; 282:4, s. 267-272
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Tidskriftsartikel (refereegranskat)abstract
- This paper provides new combinations for two species endemic to the Seychelles, Canthium carinatum and C. sechellarum, which are transferred to Peponidium (tribe Vanguerieae, Ixoroideae, Rubiaceae), as supported by recent molecular phylogenetic analyses. Several new combinations in Vanguerieae from Madagascar are also proposed, based on morphological studies. Canthium bakerianum and C. homolleanum are transferred to Peponidium, whereas C. andringitrense, C. mandrarense, and Peponidium montana are transferred to Pyrostria. The names Pyrostria angustifolia, P. media, and P. major, previously invalid, are here validly published.
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| 12. |
- Kainulainen, Kent, et al.
(författare)
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Phylogenetic relationships and new tribal delimitations in subfamily Ixoroideae (Rubiaceae)
- 2013
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Ingår i: Botanical journal of the Linnean Society. - : Oxford University Press (OUP). - 0024-4074 .- 1095-8339. ; 173:3, s. 387-406
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Tidskriftsartikel (refereegranskat)abstract
- Subfamily Ixoroideae is one of three major lineages in Rubiaceae, with approximately 4000 species. Previous molecular phylogenetic studies have indicated that many genera and tribes previously placed in other subfamilies are better considered as part of Ixoroideae. However, the internal resolution and clade support have generally been low, and several genera found to be nested in the subfamily do not appear to be associated with any described tribe. In order to resolve the phylogeny and assess the tribal delimitations in the expanded Ixoroideae, phylogenetic reconstructions were performed using Bayesian and parsimony analyses of six plastid DNA regions and a broad sampling of genera from all tribes of the subfamily. In the inferred phylogenetic hypotheses, the tribal relationships were mostly well supported, with Ixoroideae consisting of the Coffeeae and the Vanguerieae alliances as sister groups and a grade comprising Condamineeae, Henriquezieae, Posoquerieae, Retiniphylleae, Sipaneeae and the genus Steenisia. A revised tribal classification, including the description of five new tribes, Airospermeae, Augusteae, Scyphiphoreae, Steenisieae and Trailliaedoxeae, is provided.
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| 13. |
- Kainulainen, Kent, 1978-, et al.
(författare)
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Phylogeny and evolution of secondary pollen presentation, corolla aestivation patterns, fruit types, and seed number in the Ixoroideae (Rubiaceae)
-
Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Phylogenetic reconstructions using Bayesian and parsimony analyses of six chloroplast DNA region were performed in order to investigate character evolution and tribal relationships within the subfamily Ixoroideae (Rubiaceae). In the inferred phylogenetic hypotheses, the tribal relationships were mostly well supported, with the subfamily comprised of a crown group of two major sister clades termed the Coffeeae-alliance and Vanguerieae-alliance respectively, and a basal grade comprising Condamineeae, Henriquezieae, Posoquerieae, Retiniphyleae, Sipaneeae, and Steenisia. Five new tribes are here recognized (Airospermeae, Augusteae, Scyphiphoreae, Steenisieae and Trailliaedoxeae). Secondary pollen presentation, corolla aestivation patterns,fruit types, and number of ovules are all characters that have been considered of great importance in the classification of Rubiaceae. Ancestral state reconstructions of these characters using likelihood optimization indicate that secondary pollen presentation is synapomorphic for a clade comprising the Ixoroideae crown group and Retiniphyllum, whereas left-contorted corolla aestivation is synapomorphic for a clade comprising the crown group, Retiniphyllum, and Steenisia. Capsular fruits with numerous seeds are plesiomorphic in Ixoroideae, from which dry or fleshy indehiscent fruits have evolved numerous times independently. Reductions in seed number appears to have occurred within several lineages, none of which show a secondary increase in the number of seeds.
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| 14. |
- Kainulainen, Kent, et al.
(författare)
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Phylogeny of Euclinia and allied genera of Gardenieae (Rubiaceae), and description of Melanoxerus, an endemic genus of Madagascar
- 2014
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Ingår i: Taxon. - : Wiley. - 0040-0262 .- 1996-8175. ; 63:4, s. 819-830
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Tidskriftsartikel (refereegranskat)abstract
- We performed molecular phylogenetic analyses of the Randia clade of the tribe Gardenieae using both plastid and nuclear DNA data. In the phylogenetic hypotheses presented, the African genera Calochone, Euclinia, Macrosphyra, Oligocodon, Pleiocoryne, and Preussiodora are resolved as a monophyletic group. Support is also found for a clade of the Neotropical genera Casasia, Randia, Rosenbergiodendron, Sphinctanthus, and Tocoyena. This Neotropical clade is resolved as sister group to the African clade in analyses of combined plastid and nuclear data. The genus Euclinia appears polyphyletic. The species described from Madagascar represent an independent lineage, the position of which is moreover found to be incongruent between datasets. Plastid and ribosomal DNA data support a sister-group relationship to the mainland African clade, whereas the low-copy nuclear gene Xdh supports a closer relationship to the Neotropical genera. The phylogenetic reconstructions also indicate that Casasia and Randia are not monophyletic as presently circumscribed. A taxonomic proposal is made for the recognition of the Malagasy taxon at generic level as Melanoxerus.
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| 15. |
- Kainulainen, Kent, et al.
(författare)
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The Coffeeae alliance (subfamily Ixoroideae)
- 2022
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Ingår i: The new Natural History of Madagascar. - USA : Princeton University Press. ; , s. 759-761
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 16. |
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| 17. |
- Mouly, Arnaud, et al.
(författare)
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Phylogenetic structure and clade circumscriptions in the Gardenieae complex (Rubiaceae)
- 2014
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Ingår i: Taxon. - : Wiley. - 0040-0262 .- 1996-8175. ; 63:4, s. 801-818
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Tidskriftsartikel (refereegranskat)abstract
- In this study we investigate the large and diverse Rubiaceae-Gardenieae and closely related tribes Bertiereae, Coffeeae, Cremasporeae, Octotropideae, and Pavetteae. Some of the tribes or groups have been shown to be monophyletic and strongly supported, but the phylogeny of this large complex is still far from being satisfactorily elucidated particularly for Gardenieae, both in terms of intertribal relationships as well as tribal delimitations. We reconstruct the phylogeny of the complex using an extensive sampling of 108 genera and five plastid DNA regions. Phylogenetic relationships demonstrate that Gardenieae sensu Andreasen & Bremer is polyphyletic, as Burchellia, Didymosalpinx, Monosalpinx, and Mantalania are closer to Octotropideae-Cremasporeae. In addition, Pavetteae and the investigated members of Aulacocalyceae are nested in a supported but partially unresolved Gardenieae-Pavetteae clade. Within this clade, several strongly supported groups are resolved: an Aidia group, an Alibertia group, a Gardenia group, Pavetteae including Pelagodendron, a Porterandia group, a Randia group, a Rothmannia group (including Aulacocalyx and Heinsenia), a Sherbournia group, and the two isolated genera Massularia and Schumanniophyton. The latter genus presented a high rate of genetic substitutions, which resulted in perturbations of the phylogenetic reconstruction. A revised tribal circumscription is given for Gardenieae, the Alibertia group is recognized at tribal level as an emended Cordiereae, and a new tribe, Sherbournieae, is described to accommodate the members of the Sherbournia group.
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| 18. |
- Nuppenau, Jan-Niklas, et al.
(författare)
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Phylogeography of Icelandic Agrostis (Poaceae) Reveals a New Geothermal Lineage
- 2023
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Ingår i: International journal of plant sciences. - : University of Chicago Press. - 1058-5893 .- 1537-5315. ; 184:6, s. 413-428
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Tidskriftsartikel (refereegranskat)abstract
- Premise of research. Geothermal areas create living conditions strikingly different from their surroundings, providing opportunities for studying organisms' thermal adaptations and responses to climate warming. However, the origins of geothermal organisms are poorly known, limiting our ability to design and interpret experimental studies. To address this, we tested whether geothermal populations of Agrostis (Poaceae) in Iceland represent a single lineage (clade) and, if so, whether that lineage originated in adjacent, nonthermal areas or elsewhere.Methodology. We studied the phylogeography of A. stolonifera and A. vinealis from geothermally heated and nonheated areas in Iceland, using whole plastome data and Bayesian and likelihood phylogenetic analyses. Having identified an exclusively geothermal clade for A. stolonifera, we performed a common-garden experiment to test for heritable phenotypic differences between geothermal and nonthermal plants.Pivotal results. At least two lineages of A. stolonifera have colonized Iceland independently, one being exclusively geothermal and the other exclusively nonthermal. The geothermal lineage is phylogenetically isolated, and its geographical origin could not be determined. Grown in a common garden, geothermal A. stolonifera produced significantly shorter stolons than nonthermal plants. In contrast, geothermal A. vinealis did not form a clade. Instead, all Icelandic A. vinealis formed a clade with nonthermal A. vinealis from outside of Iceland, plus geothermal A. rossiae and A. scabra.Conclusions. We demonstrate the existence of an exclusively geothermal lineage of A. stolonifera, which also shows heritable phenotypic differences, but not of A. vinealis. These contrasting findings possibly reflect different growth forms and life histories. Our results provide a phylogenetic hypothesis to be tested with nuclear data and a framework for future experimental studies, highlighting the importance of a historical perspective for understanding the peculiar plant communities that thrive in geothermal areas. Finally, our results suggest A. vinealis is in need of taxonomic revision.
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| 19. |
- Razafimandimbison, Sylvain G., et al.
(författare)
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Molecular support for a basal grade of morphologically distinct, monotypic genera in the species-rich Vanguerieae alliance (Rubiaceae, Ixoroideae) : Its systematic and conservation implications
- 2011
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Ingår i: Taxon. - 0040-0262 .- 1996-8175. ; 60:4, s. 941-952
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Tidskriftsartikel (refereegranskat)abstract
- Many monotypic genera with unique apomorphic characters have been difficult to place in the morphology-based classifications of the coffee family (Rubiaceae). We rigorously assessed the subfamilial phylogenetic position and generic status of three enigmatic genera, the Seychellois Glionnetia, the Southeast Asian Jackiopsis, and the Chinese Trailliaedoxa within Rubiaceae, using sequence data of four plastid markers (ndhF, rbcL, rps16, trnT-F). The present study provides molecular phylogenetic support for positions of these genera in the subfamily Ixoroideae, and reveals the presence of a basal grade of morphologically distinct, monotypic genera (Crossopteryx,Jackiopsis,Scyphiphora,Trailliaedoxa, and Glionnetia, respectively) in the species-rich Vanguerieae alliance. These five genera may represent sole representatives of their respective lineages and therefore may carry unique genetic information. Their conservation status was assessed, applying the criteria set in IUCN Red List Categories. We consider Glionnetia and Jackiopsis Endangered. Scyphiphora is recognized as Near Threatened despite its extensive range and Crossopteryx as Least Concern. Trailliaedoxa is poorly known (Data Deficient). Finally, the generic status of Glionnetia,Jackiopsis, and Trailliaedoxa and the monogeneric tribe Jackieae as defined by Ridsdale are supported.
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| 20. |
- Razafimandimbison, Sylvain, 1964-, et al.
(författare)
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Historical biogeography and phylogeny of the pantropical Psychotrieae alliance (Rubiaceae), with particular emphasis on the Western Indian Ocean Region
- 2017
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Ingår i: American Journal of Botany. - : Wiley. - 0002-9122 .- 1537-2197. ; 104:9, s. 1407-1423
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Tidskriftsartikel (refereegranskat)abstract
- PREMISE OF THE STUDY: The Western Indian Ocean Region (WIOR) is a biodiversity hotspot providing an ideal setting for exploring the origins of insular biodiversity and dynamics of island colonization. We aimed to investigate the origins of the WIOR Psychotrieae alliance (Rubiaceae) with typically small, probably mainly bird-dispersed drupes, and the timing and direction or sequence of its colonization events in the region.METHODS: We used the program BEAST to estimate divergence times and Lagrange for biogeographic reconstruction.KEY RESULTS: The alliance has reached the WIOR at least 14 times via dispersals from Africa along with Asia and the Pacific mostly during the last 10 My, with at least one back-colonization to Africa. We inferred the earliest dispersal to Madagascar from the Pacific or Asia in the Miocene and numerous out-of-Madagascar dispersals to the nearby archipelagos but no dispersal out of those archipelagos. Gynochthodes with multiple fruits reached Madagascar twice from the Pacific possibly via ocean drifting. Psychotria with dry fruits (schizocarps) colonized Madagascar from the Pacific or Asia before reaching the Comoros from Madagascar possibly via wind dispersal.CONCLUSIONS: This study reinforces the pivotal role of dispersal in shaping the WIOR biodiversity and as the critical initiating step in the generation of endemic biodiversity on its islands. The WIOR alliance shows strong Asian and Pacific affinities despite the proximity of the region to Africa. Madagascar has served as a stepping-stone for subsequent dispersal to the rest of the region. The Afro-Malagasy-Seychelles genus Craterispermum and the Malagasy Puffia may represent relictual lineages.
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| 21. |
- Razafimandimbison, Sylvain, et al.
(författare)
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Molecular support for a basal grade of morphologically peculiar, monotypic genera in the species-rich Vanguerieae alliance (Rubiaceae): its systematic and conservation implications
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The species-rich coffee family (Rubiaceae) contains 211 monotypic genera, representing 34.5% of the total number of rubiaceous genera. We rigorously assessed the generic status and phylogenetic positions of the enigmatic, monotypic genera, the Seychellean Glionnetia, the Southeast Asian Jackiopsis, and the Chinese Trailliaedoxa, in Rubiaceae using sequence data from four plastid markers (ndhF, rbcL, rps16, and trnT-F). The present study provides molecular support for isolated phylogenetic positions of these genera in the subfamily Ixoroideae, and reveals the presence of a basal grade of morphologically odd, monotypic genera (Crossopteryx, Jackiopsis, Scyphiphora, Trailliaedoxa, and Glionnetia, respectively) in the species-rich Vanguerieae alliance. We consider these phylogenetically isolated genera potential candidates for a high conservation priority, as they appear to be sole representatives of their respective lineages and therefore carry unique genetic information and evolutionary history. The monogeneric tribe Jackieae as defined by Ridsdale is supported.
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| 22. |
- Razafimandimbison, Sylvain, 1964-
(författare)
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Phylogenetic affinity of an enigmatic Rubiaceae from the Seychelles revealing a recent biogeographic link with Central Africa: gen. nov. Seychellea and trib. nov. Seychelleeae
- 2020
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Ingår i: Molecular Phylogenetics and Evolution. - : Elsevier BV. - 1055-7903 .- 1095-9513. ; 143
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Tidskriftsartikel (refereegranskat)abstract
- there. The Seychelles biota contains a mix of ancient taxa with Gondwanan origins and young taxa that arrived there via dispersals. We investigate the phylogenetic position of an enigmatic, critically endangered, Seychellean endemic of the coffee family (Rubiaceae), Psathura/Psychotria sechellarum, and assess whether its presence on the granitic islands of the Seychelles is the result of vicariance or long-distance dispersal. Phylogenetic relationships of the family were reconstructed based on the Bayesian and maximum-likelihood phylogenetic analyses of sequence data from five plastid markers of 107 terminals. Divergence times were estimated using a Bayesian-based method. Psathura/Psychotria sechellarum is distantly related to Psychotria s.l. (including Psathura), and is strongly supported as sister to the Central African genus Colletoecema. Their striking morphological differences, coupled with their geographic separation and genetic distinctness, support the recognition of the new genus Seychellea and new tribe Seychelleeae to accommodate the Seychellean species. The Colletoecema-Seychellea clade constitutes an early-divergent lineage in the subfamily Rubioideae, with an old stem and a young crown ages estimated to be in the Late Cretaceous and late Oligocene-early Pliocene, respectively. Colletoecema diverged from Seychellea in the late Oligocene-early Pliocene and their respective crown ages are inferred to be late Miocene-middle Pleistocene and Pleistocene, respectively. The ancestor of the two genera was likely present in Africa, and reached the Seychelles via avian dispersal. Unlike Colletoecema with three species, Seychellea is monospecific, with very few individuals left in the wild. The species should be a top candidate for conservation priority, as its extinction would cause loss of genetic diversity of this entire lineage.
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| 23. |
- Razafimandimbison, Sylvain, 1964-, et al.
(författare)
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Rubiaceae of Madagascar: progress since 2003
- 2022
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Ingår i: The new Natural History of Madagascar. - USA : Princeton University Press. ; , s. 744-752
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 24. |
- Rydin, Catarina, et al.
(författare)
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Deep divergences in the coffee family and the systematic position of Acranthera
- 2009
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Ingår i: Plant Systematics and Evolution. - : Springer Science and Business Media LLC. - 0378-2697 .- 1615-6110. ; 278, s. 101-123
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Tidskriftsartikel (refereegranskat)abstract
- Despite extensive efforts, there are unresolved questions on evolutionary relationships in the angiosperm family Rubiaceae. Here, information from six loci and 149 Rubiaceae taxa provide new insights. Acranthera and Coptosapelta are strongly supported as sisters. Pollen grains of Acranthera possess several features common in Rubiaceae, but amongst potential similarities with the unusual grains of Coptosapelta are the nature of the apertures andthe structure of the sexine. Luculia, Acranthera and Coptosapelta are excluded from the three subfamilies Ixoroideae, Cinchonoideae and Rubioideae. Sipaneeae and Condamineeae form a clade, sister to remaining Ixoroideae. Rondeletieae and Guettardeae are sisters to remaining Cinchonoideae. Colletoecema is sister to remaining Rubioideae, followed by the Urophylleae–Ophiorrhizeae clade. Nuclear ITS provided structured information at all phylogenetic levels, but the main gain from adding nrITS was the increased resolution. Average support values also increased but were generally high also without nrITS andthe increase was not statistically significant.
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| 25. |
- Wikström, Niklas, et al.
(författare)
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A Revised Time Tree of the Asterids : Establishing a Temporal Framework For Evolutionary Studies of the Coffee Family (Rubiaceae)
- 2015
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- Divergence time analyses in the coffee family (Rubiaceae) have all relied on the same Gentianales crown group age estimate, reported by an earlier analysis of the asterids, for defining the upper age bound of the root node in their analyses. However, not only did the asterid analysis suffer from several analytical shortcomings, but the estimate itself has been used in highly inconsistent ways in these Rubiaceae analyses. Based on the original data, we here reanalyze the divergence times of the asterids using relaxed-clock models and 14 fossil-based minimum age constraints. We also expand the data set to include an additional 67 taxa from Rubiaceae sampled across all three subfamilies recognized in the family. Three analyses are conducted: a separate analysis of the asterids, which completely mirrors the original asterid analysis in terms of taxon sample and data; a separate analysis of the Gentianales, where the result from the first analysis is used for defining a secondary root calibration point; and a combined analysis where all taxa are analyzed simultaneously. Results are presented in the form of a time-calibrated phylogeny, and age estimates for asterid groups, Gentianales, and major groups of Rubiaceae are compared and discussed in relation to previously published estimates. Our updated age estimates for major groups of Rubiaceae provide a significant step forward towards the long term goal of establishing a robust temporal framework for the divergence of this biologically diverse and fascinating group of plants.
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