120 research outputs found
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
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
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
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
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
A Test of Baker’s Law: Breeding Systems and the Radiation of Tolpis (Asteraceae) in the Canary Islands
Baker’s law posits that self‐compatible (SC) plants will be more successful than self‐incompatible (SI) plants in long‐distance colonization because a single propagule can establish a viable population. Oceanic islands represent ideal systems to test Baker’s law because insular lineages have, without question, originated from long‐distance dispersal. The dilemma of Baker’s law is that one propagule of an SC plant would establish a population with low genetic diversity, which could limit subsequent evolution. By contrast, a single propagule from an SI ancestor, having originated from an outcrossing source population, would provide more diversity but could not undergo sexual reproduction. We examined this issue by studying the breeding system of members of the flowering plant genus Tolpis (Asteraceae), a small (nine to 13 species), monophyletic lineage in the Canary Islands archipelago. A combination of floral morphology, pollen‐ovule ratio, autogamous seed set, and genetic data indicates that only one endemic species (T. coronopifolia) is effectively SC. The remainder of the endemics are pseudo‐self‐compatible, i.e., are largely SI but capable of low levels of seed set from self‐fertilization. Pseudo‐self‐compatibility remedies the dilemma of Baker’s law: a single propagule can establish a sexual population and yet have sufficient variation to facilitate diversification
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