Phylogenetic analyses of Tolpis Adans. (Asteraceae) reveal patterns of adaptive radiation, multiple colonization and interspecific hybridization

The plant genus Tolpis (Asteraceae) has been the subject of several investigations on the evolution of oceanic island plants. Its insular species were utilized in studies of artificial hybrid fertility, testing the validity of Baker’s law, the application of DNA barcodes, and the phylogenetic utility of inter-simple sequence repeat markers. Despite this considerable interest in Tolpis, little is known about its phylogenetic history. Past investigations were unable to resolve most of the interspecific relationships, especially within the Canary Islands, where the genus is particularly diverse. Incomplete taxon sampling, the use of ambiguous outgroups and the limited utility of slowly evolving chloroplast DNA markers precluded detailed reconstructions. The present investigation presents a comprehensive molecular phylogeny of Tolpis. By utilizing highly variable nuclear DNA markers and a comprehensive taxon set, we have resolved the majority of interspecific relationships in the genus. Evaluations of competing tree topologies and ancestral area reconstructions complemented the analyses. Our results highlight the presence of three dominant mechanisms of island plant evolution—island colonization, adaptive radiation and interspecific hybridization—in Tolpis: (i) the extant distribution of the genus is the result of two independent colonization pathways, (ii) Tolpis has colonized at least one archipelago multiple times, (iii) the present insular diversity is the product of adaptive radiation, (iv) potential hybridization was detected between species now inhabiting different islands and archipelagoes, indicating sympatric historical distributions, and (v) several undescribed species await taxonomic recognition

Multiple colonizations, in situ speciation, and volcanism-associated stepping-stone dispersals shaped the phylogeography of the Macaronesian red fescues (Festuca L., Gramineae)

Whereas examples of insular speciation within the endemic-rich Macaronesian hotspot flora have been documented, the phylogeography of recently evolved plants in the region has received little attention. The Macaronesian red fescues constitute a narrow and recent radiation of four closely related diploid species distributed in the Canary Islands (F. agustinii), Madeira (F. jubata), and the Azores (F. francoi and F. petraea), with a single extant relative distributed in mainland southwest Europe (F. rivularis). Bayesian structure and priority consensus tree approaches and population spatial correla tions between genetic, geographical, and dispersal distances were used to elucidate the phylogeographical patterns of these grasses. Independent versus related origins and dispersal versus isolation by distance (IBD) hypotheses were tested to explain the genetic differentiation of species and populations, respectively. Genetic structure was found to be geographi cally distributed among the archipelagos and the islands endemics. The high number of shared AFLP fragments in all four species suggests a recent single origin from a continental Pliocene ancestor. However, the strong allelic structure detected among the Canarian, Madeiran, and Azorean endemics and the significant standardized residual values obtained from structured Bayesian analysis for pairwise related origin hypotheses strongly supported the existence of three independent continental-oceanic colonization events. The Canarian F. agustinii, the Madeiran F. jubata, and the two sister F. francoi and F. petraea Azorean species likely evolved from different continental founders in their respective archipelagos. Despite the short span of time elapsed since colonization, the two sympatric Azorean species probably diverged in situ, following eco logical adaptation, from a common ancestor that arrived from the near mainland. Simple dispersal hypotheses explained most of the genetic variation at the species level better than IBD models. The optimal dispersal model for F. agustinii was a bidirectional centripetal stepping-stone colonization pattern, an eastern-to-western volcanism-associated dispersion was fa vored for F. francoi, whereas for the recently derived F. petraea a counterintuitive direction of colonization (west-to-east) was suggested. The population-based phylogeographical trends deduced from our study could be used as predictive models for other Macaronesian plant endemics with similar distribution areas and dispersal abilities. [Bayesian genetic analyses; colonization of oceanic islands; dispersal models; Festuca sect. Aulaxyper; Macaronesia; phylogeography.]info:eu-repo/semantics/publishedVersio

Statistical hybrid detection and the inference of ancestral distribution areas in Tolpis (Asteraceae)

Many historical biogeographic studies do not account for the effect of hybrid taxa on phylogenetic tree inference, despite recent advances in the statistical identification of such taxa. This investigation aims to illustrate the impact that hybrid taxa can have on ancestral area reconstructions of the plant genus Tolpis, which displays an evolutionary history possibly indicative of a back-colonization of the continental Mediterranean. We evaluate and apply two statistical hybrid detection methods, JML and STEM-hy, which assist in identifying reticulate patterns of allele coalescence. We also evaluate and apply a software tool, P2C2M, to test the fit of genetic loci to the multispecies coalescent model (MSCM). The application of these tools to a previously published data set of three nuclear DNA markers indicates the presence of several potential hybrid taxa in Tolpis. One nuclear marker is found to display a reduced level of reticulate history, a good fit to the MSCM and minimal signal of gene flow across archipelagoes. Ancestral distribution areas are reconstructed on gene and species trees of Tolpis before and after the exclusion of putative hybrid taxa using stochastic character mapping, parameterized likelihood reconstructions, and reconstructions under continuous-time Markov chain models. The results of these reconstructions indicate that taxa of hybrid origin may have a considerable impact on ancestral area reconstruction and that it is important to account for such taxa prior to biogeographic analysis. We conclude that Tolpis has likely had a time-consistent distribution in island habitats and originated on the Canary Islands

Ammodaucus nanocarpus (Beltrán) P. Pérez & Velasco, un nuevo endemismo canario-marroquí

Ammodaucus nanocarpus (Beltrán) P.Pérez & Velasco, a new Canary-Moroccan endemismPalabras clave. Ammodaucus, Apiaceae, Canarias, Marruecos, endemismo, especie amenazada.Key words. Ammodaucus, Apiaceae, Canary Islands, Morocco, endemism, threatened species

Apuntes florísticos y taxonómicos para la flora de las Islas Canarias

En el presente trabajo damos a conocer un total de 30 nuevas citas florísticas para las Islas Canarias. Algunas de ellas son adiciones para la flora de una determinada isla, mientras que otras incrementan la fitodiversidad del Archipiélago en general. De alguno de estos taxones se conoce su gran potencial invasor y por lo tanto con esta nota se pretende dar una voz de alerta sobre su presencia/introducción en unas islas con frágiles ecosistemas. Por otro lado confirmamos para la isla de Lanzarote la presencia de Astragalus hamosus L. Para la nominación de los taxones se han seguido principalmente las floras básicas de Castroviejo (1986-2009) y de Tutin et al. (1964-1980). Para aquellos taxones que no se hallan en los anteriores tratados así como para aquellos grupos conflictivos (p.e. Orobanche) se sigue la bibliografía referenciada en cada uno de ellos. El material al que se hace referencia bajo cada uno de los taxones se encuentra depositado en los herbarios ORT o TFC. Para cada una de las especies se anota, cuando es posible, su distribución, ecología y ubicación fitosociológica, así como comentarios sobre su problemática taxonómica o nomenclatural si las hubiere y consideraciones acerca de su potencial capacidad de expansión en los ecosistemas de las islas. Respecto a la nominación de los sintáxones seguimos la nomenclatura fitosociológica de Rodríguez Delgado et al. (1998) y Rivas-Martínez et al. (2001, 2002)

Botánica macaronésica y el viaje del Endeavour: las colecciones y observaciones de Joseph Banks y Daniel Solander de Madeira

Se examinaron, en el herbario del Museo de Historia Natural de Londres, las recolecciones de plantas vasculares, briófitos, hongos, algas y líquenes realizadas por Joseph Banks y Daniel Solander en Madeira durante el primer viaje de James Cook alrededor del mundo (1768-1771). El diario de Banks (en la Biblioteca Estatal de Nueva Gales del Sur, Australia) aporta detalles sobre las especies observadas en esta expedición y también incluye un registro de 330 entradas con las especies que se observaron durante su estancia en dicha isla portuguesa. Las especies de esta lista se estudiaron y cotejaron, cuando fue posible, con los ejemplares correspondientes del herbario del Museo de Historia Natural de Londres, donde se encuentra el herbario de Joseph Banks. Se hicieron comparaciones de este registro con datos de dos documentos que también se encuentran en este museo, a saber: la flora inédita que Solander preparó para Madeira (Primitiae Florae Maderensis, sive catalogus Plantarum en Insula Madera) y el inventario hecho por Banks y Solander de los especímenes recolectados durante la expedición que fueron preservados dentro de los libros que se usaron para secar plantas durante el viaje.The efforts of Joseph Banks and Daniel Solander to document the vascular plant, bryophyte, fungal, algal, and lichen flora of Madeira during the first circumnavigation of James Cook on Her Majesty’s Bark Endeavour (1768-1771) are documented. Banks’s journal (at the State Library of New South Wales, Australia) provides accounts pertinent to the species observed in this visit and also includes a list of 330 entries that were recorded during their stay in this Portuguese island. Where possible, the species documented in this list were matched with corresponding herbarium collections held in the herbarium of the Natural History Museum, London, where the herbarium of Joseph Banks is now housed. Comparisons were made with two documents also housed in this Museum, namely: Solander’s unpublished flora of Madeira (Primitiae Florae Maderensis, sive catalogus Plantarum in Insula Madera) and an inventory of specimens that were collected and stored inside drying books during the expedition

Redescubrimiento del endemismo tinerfeño Micromeria densiflora Benth. (Labiatae)

The present study confirms the existence of Micromeria densiflora Benth. on the Tenerife Island, Teno Massif, and detailed information on morphology, chorology and conservation status are provided. A natural hybrid of this species with Micromeria varia Benth. is described.Se confirma la presencia actual de Micromeria densiflora Benth. en la isla de Tenerife, en el macizo de Teno, y se aporta información sobre su caracterización morfológica, corología y estatus de conservación. Además se describe un híbrido natural de esta especie con Micromeria varia Benth

Redescubrimiento del endemismo tinerfeño Micromeria densiflora Benth. (Labiatae)

The present study confirms the existence of Micromeria densiflora Benth. on the Tenerife Island, Teno Massif, and detailed information on morphology, chorology and conservation status are provided. A natural hybrid of this species with Micromeria varia Benth. is described.Se confirma la presencia actual de Micromeria densiflora Benth. en la isla de Tenerife, en el macizo de Teno, y se aporta información sobre su caracterización morfológica, corología y estatus de conservación. Además se describe un híbrido natural de esta especie con Micromeria varia Benth

Little or unknown plants of the wild vascular flora of the Canary Island

Se añaden al catálogo florístico vascular canario un total de 29 taxones. Se confirma además la presencia Epilobium angustifolium y de Chamaesyce serpens para las islas de Tenerife y La Palma respectivamente y se amplia la corología de Eleocharis palustris para la Gomera. Por otro lado reavivamos la complejidad de Sida rhombifolia L. en el Archipiélago. Twenty nine new taxa are added to the checklist of the canarian vascular flora. We also confirm that Epilobium angustifolium and Chamaecyse serpens are present in Tenerife and La Palma, respectively, and the chorology of Eleocharis palustris in La Gomera is extended. On the other hand Sida rhombifolia complex is revived in the Archipelago

Maximize Resolution or Minimize Error? Using Genotyping-By-Sequencing to Investigate the Recent Diversification of Helianthemum (Cistaceae)

A robust phylogenetic framework, in terms of extensive geographical and taxonomic sampling, well-resolved species relationships and high certainty of tree topologies and branch length estimations, is critical in the study of macroevolutionary patterns. Whereas Sanger sequencing-based methods usually recover insufficient phylogenetic signal, especially in recently diversified lineages, reduced-representation sequencing methods tend to provide well-supported phylogenetic relationships, but usually entail remarkable bioinformatic challenges due to the inherent trade-off between the number of SNPs and the magnitude of associated error rates. The genus Helianthemum (Cistaceae) is a species-rich and taxonomically complex Palearctic group of plants that diversified mainly since the Upper Miocene. It is a challenging case study since previous attempts using Sanger sequencing were unable to resolve the intrageneric phylogenetic relationships. Aiming to obtain a robust phylogenetic reconstruction based on genotyping-by-sequencing (GBS), we established a rigorous methodological workflow in which we i) explored how variable settings during dataset assembly have an impact on error rates and on the degree of resolution under concatenation and coalescent approaches, ii) assessed the effect of two extreme parameter configurations (minimizing error rates vs. maximizing phylogenetic resolution) on tree topology and branch lengths, and iii) evaluated the effects of these two configurations on estimates of divergence times and diversification rates. Our analyses produced highly supported topologically congruent phylogenetic trees for both configurations. However, minimizing error rates did produce more reliable branch lengths, critically affecting the accuracy of downstream analyses (i.e. divergence times and diversification rates). In addition to recommending a revision of intrageneric systematics, our results enabled us to identify three highly diversified lineages in Helianthemum in contrasting geographical areas and ecological conditions, which started radiating in the Upper Miocene.España, MINECO grants CGL2014- 52459-P and CGL2017-82465-PEspaña, Ministerio de Economía, Industria y Competitividad, reference IJCI-2015-2345