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We studied four currently recognized endemics of Ruta (Rutaceae) from the Canary Islands, an oceanic biodiversity hotspot, to identify genetic variation, reconstruct evolutionary relationships and clarify the taxonomic delimitation of several recently discovered populations. We analysed four plastid DNA regions for a thorough population sampling of Ruta oreojasme on Gran Canaria, R. pinnata on Tenerife and La Palma and R. microcarpa and the only known population of the recently described R. nanocarpa on La Gomera. Bayesian clock dating analysis, haplotype network and ancestral area reconstructions were carried out. Our results reveal a complex, extremely dynamic and largely overlooked pattern of colonization and evolutionary history of Ruta in the archipelago. Thirty haplotypes were found, but only one of them was shared across more than one island. Species divergence and all colonization events in the Canary Islands were dated from the late Pliocene to the Pleistocene, and R. oreojasme has an earlier origin than its Canarian congeners. Multiple secondary colonization events between and within islands account for the diversification of R. pinnata and R. microcarpa. Our data cannot discard a possible independent origin of R. oreojasme and do not support the currently accepted circumscription of R. pinnata and R. microcarpa. Rather, the high levels of genetic differentiation detected suggest the existence of ongoing diversification processes and of new taxa. Urgent population-level conservation efforts should be undertaken, especially focused on the single population on La Gomera that can be attributed to R. microcarpa, R. nanocarpa and genetically distinct populations from La Palma and the palaeo-islands of Tenerife.

Key message Dragon’s blood secretion is an integral part of the normal development of the leaves and of the tissue protecting the trunk of dragon trees. Abstract Dragon’s blood is a common name of a red resin produced in response to wounding by tree-like monocot species of the genus Dracaena (Asparagaceae), known as dragon trees. This resin has important medicinal uses and economic value. However, its ecological significance and mechanism of secretion are understudied. We specifically addressed this knowledge gap through the investigation of leaf shedding, a natural processes in plant development, associated with self-wounding. We aimed to characterize the form of the resin of the Macaronesian (D. draco, D. tamaranae) and Socotran (D. cinnabari) dragon trees, and to explain its role in the development of leaves and of the tissue covering the leafless mature trunks. Based on the NADI test and the analysis of large-area longitudinal sections, we show for the first time that the resin occurs in parenchyma cells in the form of terpene-filled vesicles which tend to aggregate. The resin is an anatomical marker of the area where the leaf’s abscission zone will be formed. After leaf shedding, the resin containing leaf scars completely cover the trunk. This study highlights that dragon’s blood is secreted not only following wounding caused by external biotic and/or abiotic factors, but also in the undisturbed growth of dragon trees.

Aim: We explore the idea that most pre-glacial non-endemic Canarian flora became endemic to the archipelago by the extinction of its mainland populations during the late Pleistocene glaciations, implying that the extant non-endemic flora is mostly post-glacial: the ‘late Pleistocene endemicity increase hypothesis’. Taxon: The native flora of the Canarian archipelago. Methods: We statistically compare the distributions of 2087 Canarian endemic and native non-endemic plants across islands. We also carry out connectivity analyses using their dispersal paths, obtained by connecting all the islands of occurrence for each taxon. Results: While the distribution of the endemic flora is strongly L-shaped (with a much higher proportion of Single-Island Endemics than Multiple-Island Endemics), that of the native non-endemics is U-shaped (i.e. similar prevalence of single-island taxa and taxa distributed on all islands). The native non-endemics have a significantly lower proportion of single-island taxa and a higher proportion of widespread taxa than the endemics. Most dispersal paths in the endemics connect the central and western islands, whereas they are extended across all islands in the native non-endemics. Main conclusions: The contrasting distributional patterns of the endemics and the native non-endemics support an outstanding role of species diversification in the endemic flora, but a still negligible influence of the insular selective and stochastic pressures (including extinction) in the native non-endemic flora, arguably due to its recent origin. Our results suggest that the high endemicity levels of the extant Canarian flora can be explained by two complementary processes: (i) high diversification rates throughout the ontogeny of the archipelago, often from colonisers that attained a widespread distribution prior to speciation, and (ii) an ‘endemicity increase’ during the late Pleistocene glaciations, whereby most of the pre-glacial non-endemic Canarian flora became endemic due to the extinction of its mainland conspecific populations, thus emphasising the role of the Canaries as climatic refugia.

Oceanic islands are natural laboratories where evolutionary processes can be studied more readily. In the present work we use nuclear microsatellites to quantitatively assess the roles of hybridization, colonization, gene flow and geographical barriers in four Parolinia spp. endemic to Gran Canaria in connection with known geological events throughout the dynamic geological ontogeny of the island. Our genetic analyses show that these Parolinia spp. share 69% of all alleles detected and display low genetic divergence among populations, suggesting a close genetic relationship and recent differentiation. This close relationship is more evident between Parolinia platypetala and Parolinia ornata, which were included in the same genetic pool in the STRUCTURE analysis, and probably represent the early stages of an incipient speciation process, as suggested by the absence of gene flow barriers between them. NEWHYBRIDS, STRUCTURE and MIGRATE analyses unequivocally suggest frequent past migration and hybridization from P. ornata to P. filifolia, but contemporary migration is low overall. Despite the overall genetic closeness among the Parolinia spp. assessed, microsatellites dispelled doubts regarding the appropriate name/s for two taxonomically conflicting populations. In line with the predictions of the surfing syngameon hypothesis, ancestral hybridization, vicariance and dispersal events linked to the complex ontogeny of the island may have been key factors to shape the current genetic diversity and structure of Parolinia in Gran Canaria.

Disjunct distribution is a key issue in biogeography and ecology, but it is often difficult to determine relative roles of dispersal vs. vicariance in disjunctions. Conandron ramondioides (Gesneriaceae) is a tertiary relict monotypic species distributed disjunctively in mainland China, Taiwan Island and Japan, where is a key region for understanding evolution and diversification of modern angiosperms. Population phylogenetic and phylogeographic structures of a comprehensive sampling of C. ramondioides by ddRAD sequencing were assessed, combined ABC modeling and SDM to infer the effects of multiple glaciation periods and to survey climatic niche differences by checking putative population divergence models and demographic scenarios. We found a very high degree of genetic differentiation among mainland China, Taiwan Island and Japan, with very limited gene flow between regions and a clear Isolation by Distance pattern. Mainland China and Japan clades diverged first from a widespread ancestral population in middle Miocene, followed by a later divergence between mainland China and Taiwan Island clades at early Pliocene. Three current groups have survived in various glacial refugia during LGM, and experienced contraction and/or bottlenecks since their divergence during Quaternary glacial cycles, with strong niche divergence between mainland China + Japan and Taiwan Island ranges. Overall, we verified a predominant role of vicariance in the current disjunction of monotypic genus Conandron. The sharp phylogenetic separation, ecological niche divergences among these three groups and the great number of private alleles in all populations sampled indicate a considerable time of independent evolution, and suggests the need of a taxonomic survey to detect potentially overlooked taxa.

Plants endemic to oceanic archipelagos are suitable for studying evolution, being isolated on substrates of different ages. Evolution has been recent, rendering traditionally employed sequences insufficiently variable for resolving relationships. This study includes sampling in the genus Tolpis (Asteraceae) from the Azores, Madeira, and Cape Verde, and expands upon an earlier study demonstrating the efficacy of multiplexed shotgun genotyping (MSG) for resolving relationships in Canarian Tolpis.Genomic libraries for 90 accessions of Tolpis and two from the outgroup were generated for genotyping individuals using MSG. Loci were de novo assembled with iPyrad, which clusters MSG loci within and between samples. A maximum likelihood phylogeny was generated with RAxML. Ancestral area reconstruction was inferred using R package BioGeoBEARS.MSG data recovered a highly resolved phylogeny from population to inter-archipelago levels. Ancestral area reconstruction provided biogeographic hypotheses for the radiation of Macaronesian Tolpis.Four major clades were resolved. The Madeiran endemic T. macrorhiza is sister to other Tolpis. Species from the Canaries, Cape Verdes, and the continent are sister to T. succulenta from Madeira, which has a sister subclade of Azorean populations composed of T. succulenta and T. azorica. Population-level resolution suggests unrecognized taxa on several archipelagos. Ancestral reconstruction suggests initial dispersal from the continent to Madeira, with dispersal to the Azores, then dispersal from Madeira to the Canary Islands, with both subsequent dispersal to the Cape Verdes and back-dispersal to the continent. Single-island radiations and inter-island dispersal are implicated in divergence in Macaronesian Tolpis.

Aim: It is predicted that insular plant taxa have evolved reduced defences in response to lower herbivore pressure on islands. However, the few studies testing this hypothesis have addressed variation in individual defensive traits, without paying attention to patterns of correlated trait expression (i.e. defence syndromes). Location: Balearic and Canary Islands. Taxon: Ninety-one woody plant species. Methods: We tested whether plant species with contrasting histories of insularity (namely, endemics, non-endemic natives and exotics) differed in their defensive syndromes using a suite of morphological, physical, and chemical traits putatively associated with herbivory. For this, we measured eight leaf traits of 42 endemic, 29 native non-endemic and 20 introduced species for which specimens were sourced from botanical gardens found in two archipelagos: the Balearic and Canary Islands. Results: We conducted phylogenetic-controlled analyses which showed that, contrary to predictions, insular taxa (endemics and non-endemic natives) across both archipelagos were more defended (thicker, smaller leaves with less nutrients) than exotic species. There were no differences in chemical defence (phenolic compounds) between endemics, non-endemic natives and exotics. Finally, we also found different defence syndromes between archipelagos: whereas species from the Balearic Islands were more physically defended, on average, those from the Canary Islands had higher chemical defences. Main conclusions: Overall, these results point to a defence syndrome based on low-nutrient and physically defended leaves characteristic of insular plant taxa that is indistinct for endemic and non-endemic taxa, relative to introduced species, as well as quantitative and qualitative differences in defences between archipelagos owing to changes in species composition and likely also to different histories of biotic or abiotic pressure., This research was financially supported by a grant from the Spanish Ministry of Science, Innovation and Universities (RTI2018-099322-B- I00) and the Ramón y Cajal Research Programme (RYC-2013- 13230) to XM. CG-V was supported by a Vicenç Mut Grant (Govern de les Illes Balears, Conselleria d'Innovació, Recerca i Turisme and the European Social Fund). No permits were required for this research.

Molecular dating offers a tool for inferring the time of divergence between two lineages. In this study, we discuss how dated molecular reconstructions are informative of two different, albeit often intermingled, time estimates with regard to a fundamental process in island biogeography: the time of island colonization (TIC). We illustrate how stem age estimates provide information on the divergence between the extant island lineage and their closest relatives (i.e. the onset of lineage differentiation). Such estimates, however, are typically poor TIC predictors, as they are strongly affected by spatial and temporal uncertainty, particularly in cases of deep stem ages. Crown ages of endemic island lineages, in contrast, provide information on the temporal onset of island in situ diversification, and may represent a better proxy for TIC when the associated uncertainty is taken into account. Thus, the geographic and temporal distance separating the island and mainland lineages in phylogenetic/phylogeographic reconstructions are key factors for determining the reliability of these two estimates as proxies of TIC. We show how divergence times can be used to investigate the biogeographic patterns of two well-studied oceanic archipelagos: Hawaii and the Canary Islands. A compilation of molecular age estimates for nearly one-third of the endemic plant lineages in each archipelago reveals that Canarian plant lineages exhibit significantly younger mean crown ages (2.1 ± 2.4 Myr) than Hawaiian lineages (3.5 ± 2.9 Myr), despite island substrates being much older in the Canarian archipelago. We postulate that this pattern suggests: (1) a more important role of submerged islands during plant colonization in Hawaii, and (2) higher taxon turnover in the Canaries, mediated by relatively young (Mediterranean) lineages, and probably facilitated by the combination of the high incidence of extinction for the last 5 Myr and the close proximity of mainland source areas as compared to Hawaii.

Subtropical islands are often viewed as refuges where Quaternary climatic shifts driving global episodes of extinction were buffered. Island biodiversity, however, may have been impacted by climatic fluctuations at local scales, particularly in spatially heterogeneous island systems. In this study, we generated a conceptual framework for predicting the potential impact of Pleistocene extinctions on the biogeographical pattern of the Canarian spermatophyte flora, with a focus on the easternmost Canarian islands (ECI). Then, we performed an exhaustive bibliographic revision (270 studies) to examine whether taxonomic, phylogenetic and phylogeographical data support our predictions. Although molecular information is limited for many lineages, the available data suggest that the majority of extant ECI plant taxa may be the result of relatively recent (, C. G.V. was funded by project SV‐17‐GIJON‐BOTANICO. J.P. was funded by the MINECO through the Ramón y Cajal Program (RYC‐2016‐20506), and Marie Sklodowska‐Curie COFUND, Researchers' Night and Individual Fellowships Global (MSCA grant agreement No 747238, 'UNISLAND').

Project NEXTGENDEM (MAC2/4.6d/236, https://lupus.itccanarias.org/nextgendem/es/) complements multiple research disciplines to provide verified and validated scientific data that help managers make more informed conservation decisions. As a result of the mobilization and enrichment of the sample and data banks of the Jardín Botánico Canario “Viera y Clavijo” -UA CSIC and the Instituto Nacional de Investigação e Desenvolvimento Agrário de Cabo Verde, tools will be developed for the estimation of phylogenetic diversity of the terrestrial endemic flora of these islands, the approximation to the molecular taxonomic identification of samples, phylogenetic reconstruction, and territorial analysis merging biotic and abiotic variables. Our main objective is to organise, analyse and apply the most relevant scientific knowledge to guide in situ and ex situ actions to improve the conservation status of the flora of Gran Canaria (Canary Islands) and Santiago (Cape Verde), although we plan to incorporate other Macaronesian territories in future projects, El proyecto NEXTGENDEM (MAC2/4.6d/236, https://lupus.itccanarias.org/nextgendem/es/) complementa múltiples disciplinas de investigación para proporcionar datos científicos contrastados y validados que faciliten a los gestores la toma de decisiones de conservación más informadas. A consecuencia de la movilización y el enriquecimiento de los bancos de muestras y datos del Jardín Botánico Canario ¿Viera y Clavijo¿ ¿ UA CSIC y del Instituto Nacional de Investigação e Desenvolvimento Agrário de Cabo Verde, se pondrán a punto herramientas para la estimación de la diversidad filogenética de la flora terrestre insular, la aproximación a la identificación taxonómica molecular de muestras, la reconstrucción de filogenias, y el análisis territorial integrado con variables bióticas y abióticas. Nuestro objetivo principal es organizar, analizar y aplicar el conocimiento científico más relevante para guiar actuaciones in situ y ex situ que mejoren el estado de conservación de las floras de Gran Canaria (Islas Canarias) y Santiago (Cabo Verde), aunque prevemos incorporar otros territorios macaronésicos en futuros proyectos

The genus Dracaena in Macaronesia comprises two threatened species of arborescent monocots that are often associated with one of the most intriguing biogeographic disjunctions: the Rand Flora pattern. Molecular information is, however, largely missing for the Macaronesian Dracaena taxa (“MDT”, hereafter), and the biogeographic or population genetic patterns of this lineage have not yet been thoroughly assessed. To fill this gap, we generated plastid DNA sequence data of 14 Dracaena populations representing the entire natural distribution of MDT (including mainland Morocco and all recognized subspecies), 9 additional populations of subspontaneous origin, and a set of related species of the genus. We performed phylogenetic, biogeographic, and population genetic analyses at different spatial scales and conducted a comparative review on plant haplotype diversity in Macaronesian plants. The results of our phylogenetic analyses indicated the monophyly of the MDT and an origin separate from a clade of geographically distant species that so far were postulated as their closest living relatives (D. cinnabari, D. ombet, D. schizantha, D. serrulata). The results of our phylogeographic analyses indicated that diversification within D. draco occurred throughout the Pleistocene and that wild peripheral populations (Madeira, mainland Morocco) may have a recent origin from Canarian source populations. Recent dispersals, coupled with remarkably low levels of haplotype diversity, probably account for the weak phylogeographic signal observed across wild populations. However, our results suggested that human‐assisted expansion of Dracaena inflates the extant phylogeographic signal by non‐random translocation of a specific subset of haplotypes. Our study demonstrates that many of the previous biogeographic scenarios on MDT are not supported by molecular data. Instead, our results highlight (i) the impact that human activity may have on the phylogeographic pattern of island plants, and (ii) the need of a deeper taxonomic sampling in future investigations on MDT and close relatives., This research was funded by the European Regional Development Fund (Intereg projects CAVEGEN and ENCLAVES). JP was funded by the Marie Sklodowska‐Curie COFUND, Researchers’ Night and Individual Fellowships Global (MSCA grant agreement No 747238, “UNISLAND”’), and the Ramón y Cajal program (RYC‐2016‐20506). CG‐V was financially supported by a “Vicenç Mut” postdoctoral fellowship (Conselleria d'Innovació, Recerca i Turisme, Govern de les Illes Balears and the European Social Fund).

[EN] Islands provide unique opportunities to integrated research approaches to study evolution and conservation because boundaries are circumscribed, geological ages are often precise, and many taxa are greatly imperiled. We combined morphological and hybridization studies with high-throughput genotyping platforms to streamline relationships in the endangered monophyletic and highly diverse lineage ofSolanumin the Canarian archipelago, where three endemic taxa are currently recognized. Inter-taxa hybridizations were performed, and morphological expression was assessed with a common-garden approach. Using the eggplant Single Primer Enrichment Technology (SPET) platform with 5,093 probes, 74 individuals of three endemic taxa (Solanum lidii,S. vespertiliosubsp.vespertilio, andS. vespertiliosubsp.doramae) were sampled for SNPs. While morphological and breeding studies showed clear distinctions and some continuous variation, inter-taxon hybrids were fertile and heterotic for vigor traits. SPET genotyping revealed 1,421 high-quality SNPs and supported four, not three, distinct taxonomic entities associated with post-emergence geological, ecological and geographic factors of the islands. Given the lack of barriers to hybridization among all the taxa and their molecular differences, great care must be taken in population management. Conservation strategies must take account of the sexual and breeding systems and genotypic distribution among populations to successfully conserve and restore threatened/endangered island taxa, as exemplified bySolanumon the Canary Islands., This work was supported by funds from project DEMIURGO to the Jardin Botanico Canario "Viera y Clavijo" -Unidad Asociada al CSIC of the Cabildo de Gran Canaria. Consumables and genotyping were funded by the Jardin Botanico Canario "Viera y Clavijo" -Unidad Asociada al CSIC. Participation of authors from Universitat Politecnica de Valencia has been partially funded by the European Union's Horizon 2020 Research and Innovation Programme under the Grant Agreement No. 677379 (G2P-SOL project: Linking genetic resources, genomes, and phenotypes of solanaceous crops). PG was grateful to Universitat Politecnica de Valencia and to Japan Society for the Promotion of Science for their respective Postdoctoral Grants [PAID-10-18 and FY2019-P19105 JSPS Postdoctoral Fellowship for Research in Japan (Standard)].

We use the molecular data available for the plant genera currently distributed in the Canaries to propose a hypothetical framework that updates the Surfing Syngameon Hypothesis (SSH) to explain the origins of the high genetic diversity of this flora in connection with the General Dynamic Model of Island Ontogeny and the available knowledge on the geology of the islands. Based on our review, we propose that (i) secondary contact and subsequent gene flow among genotypes previously confined to the mainland or to other insular regions generated syngameons across the archipelago, whose temporal extent and distribution were influenced by the ontogenetic stages of each island; and (ii) the resulting high levels of genetic variation were critical to the successful colonization of many other regions in the Canaries, especially those where more complex geographical and ecological features promoted gene flow cessation, drift, and/or eventual selection processes leading to species radiations. Under the updated SSH, the colonizing contingents of the islands would not necessarily have low genetic variation, because multiple colonizations followed by secondary contact among different genotypes would enhance genetic diversity through introgressive hybridization. As with other theories, the SSH contends that the monophyly detected in a large proportion of its lineages is artifactual. However, the SSH further differs from past hypotheses in (i) suggesting a spatio-temporal sequence of events giving rise to syngameons in different islands and island regions, (ii) showing that the ontogenetic mismatch among the Canarian islands should be largely responsible for similar levels of population genetic diversity in many congeneric endemics distributed in several islands, (iii) hypothesizing a substantial role for both allopolyploid and homoploid hybridization in the origins of the Canarian flora, and (iv) positing that, in many cases, the admixture processes in the syngameons formed at different stages of the islands’ ontogeny made possible the rapid colonization of multiple environments, and the generation of the current floristic diversity.

We developed and characterized microsatellite markers for the genus Lotus, a large genus of leguminous plants containing many endemic species of conservation interest. The marker system was then used to survey patterns of population genetic variation of Lotus sessilifolius, a Canary Island endemic occurring on four islands (La Palma, El Hierro, La Gomera and Tenerife) with the aim of determining whether any of its populations are worthy of special conservation because of genetic distinctiveness. We found strong differentiation between populations with conspicuous geographical signal revealed by population clustering. Generally, populations from each island grouped together. A very striking exception to this pattern is a single population from Tenerife (Tejina-Milan: Anaga Peninsula), which is separated from other Tenerife populations by both genetic clustering and a STRUCTURE analysis, and also shows signs of inbreeding. The genetic distinctiveness of this population deserves especial conservation attention, and may be related to the ancient geological history of the Anaga Peninsula. Importantly, this investigation sets the stage for conservation genetics research in other highly threatened species in the same genus.

La relacion entre las Islas Canarias y el llamado “enclave continental Macaronesico” ha sido ampliamente investigada en estudios que han indicado una elevada relacion floristica, taxonomica y genetica entre estas dos regiones (Caujape-Castells et al., 2017; Garcia-Verdugo et al., 2019). Sin embargo, la comparacion de la variacion genetica entre endemismos insulares y sus congeneres continentales sigue siendo extremadamente rara, a excepcion de algunos casos (Garcia-Verdugo et al., 2017). Ademas, salvo en las excepciones comentadas, la mayoria de las investigaciones se caracterizan por un pobre muestreo, tanto en el numero de poblaciones, como en la representatividad de la distribucion de los taxones estudiados o el numero de efectivos recolectados, por lo que carecemos de indicadores adecuados para interpretar los origenes de la alta diversidad genetica detectada en la flora Canaria.

With a wide distribution range including Europe and Asia, Lotus (Leguminosae) represents the largest genus within Loteae. It is particularly diverse in the Mediterreanean region and in the five archipelagos of Macaronesia (Atlantic Ocean). However, little is known about the relationships among the 14 sections currently recognized within Lotus and about the timing and patterns of its colonization in the Macaronesian region. In this investigation, we use four DNA regions (nuclear ribosomal ITS plus three plastid regions) in the most comprehensive sampling of Lotus species to date (some endemic species within the Canary Islands were poorly represented in previous phylogenetic analyses) to infer relationships within this genus and to establish patterns of colonization in Macaronesia. Divergence time estimates and habitat reconstruction analyses indicate that Lotus likely diverged about 7.86 Ma from its sister group, but all colonization events to Macaronesia occurred more recently (ranging from the last 0.23 to 2.70 Ma). The diversification of Lotus in Macaronesia involved between four and six independent colonization events from four sections currently distributed in Africa and Europe. A major aspect shaping the current distribution of taxa involved intra-island colonization of mainly new habitats and inter-island colonization of mostly similar habitats, with Gran Canaria and Tenerife as the major sources of diversification and of further colonization events. Section Pedrosia is the most diverse in terms of colonization events, number of species, and habitat heterogeneity, including a back-colonization event to the continent. Subsections within Pedrosia radiated into diverse habitat types recently (late Pleistocene, ca 0.23–0.29 Ma) and additional molecular markers and sampling would be necessary to understand the most recent dispersal events of this group within the Canary Islands and Cape Verde.

We used data from 12 allozyme loci for two endemic Brassicaceae from Gran Canaria (the endangered narrow endemic Crambe tamadabensis and its more widespread congener C. pritzelii) to assess whether their genetic diversity patterns reflect their phylogenetic closeness and contrasting population sizes and distribution areas, and to derive conservation implications. Genetic diversity values are high for both species and slightly higher in C. tamadabensis, despite its narrow distribution in north‐western Gran Canaria. At odds with the generally high interpopulation diversity levels reported in Canarian endemics, values of GST in C. tamadabensis and C. pritzelii are rather low (0.067 and 0.126, respectively). We construe that the higher genetic structure detected in C. pritzelii is mainly a result of unbalanced allele frequencies and low population sizes at the edges of its distribution. The overall high allozyme variation detected in C. tamadabensis and C. pritzelii is nevertheless compatible with an incipient but consistent genetic differentiation between the two species, modulated by recurrent bottlenecks caused by grazing and drift. Our data suggest that conservation efforts aimed at maintaining the existing genetic connectivity in each species and ex situ conservation of seeds are the best strategies to conserve their genetic diversity.

We review the conservation status and threats to the endemic vascular flora of the Cape Verde islands, mostly based on the past two decades of collecting, literature review and herbarium specimens. The application of IUCN Red List criteria and categories using RAMAS software reveals that 78% of the endemic plants are threatened (29.3% Critically Endangered, 41.3% Endangered, 7.6% Vulnerable). Most of these endemics have a limited geographical range, and half of them have Areas of Occupancy and Extents of Occurrence of

[Background and Aims] Archipelagos provide a valuable framework for investigating phenotypic evolution under different levels of geographical isolation. Here, we analysed two co-distributed, widespread plant lineages to examine if incipient island differentiation follows parallel patterns of variation in traits related to dispersal and colonization., [Methods] Twenty-one populations of two anemochorous Canarian endemics, Kleinia neriifolia and Periploca laevigata, were sampled to represent mainland congeners and two contrasting exposures across all the main islands. Leaf size, seed size and dispersability (estimated as diaspore terminal velocity) were characterized in each population. For comparison, dispersability was also measured in four additional anemochorous island species. Plastid DNA data were used to infer genetic structure and to reconstruct the phylogeographical pattern of our focal species., [Key Results] In both lineages, mainland-island phenotypic divergence probably started within a similar time frame (i.e. Plio-Pleistocene). Island colonization implied parallel increases in leaf size and dispersability, but seed size showed opposite patterns of variation between Kleinia and Periploca species pairs. Furthermore, dispersability in our focal species was low when compared with other island plants, mostly due to large diaspore sizes. At the archipelago scale, island exposure explained a significant variation in leaf size across islands, but not in dispersability or seed size. Combined analyses of genetic and phenotypic data revealed two consistent patterns: (1) extensive within-island but very limited among-island dispersal, and (2) recurrent phenotypic differentiation between older (central) and younger (peripheral) island populations., [Conclusions] Leaf size follows a more predictable pattern than dispersability, which is affected by stochastic shifts in seed size. Increased dispersability is associated with high population connectivity at the island scale, but does not preclude allopatric divergence among islands. In sum, phenotypic convergent patterns between species suggest a major role of selection, but deviating traits also indicate the potential contribution of random processes, particularly on peripheral islands., C.G.-V. was supported by a ‘Juan de la Cierva’ fellowship (JCI-2012–15220), cofunded by the Ministerio de Economía y Competitividad and the Cabildo of Gran Canaria. This work was supported by the project ENCLAVES (MAC/3/C141).

Plumbaginaceae is characterized by a history of multiple taxonomic rearrangements and lacks a broad molecular phylogenetic framework. Limonium is the most species‐rich genus of the family with ca. 600 species and cosmopolitan distribution. Its center of diversity is the Mediterranean region, where ca. 70% of all Limonium species are endemic. In this study, we sample 201 Limonium species covering all described infrageneric entities and spanning its wide geographic range, along with 64 species of other Plumbaginaceae genera, representing 23 out of 29 genera of the family. Additionally, 20 species of the sister family Polygonaceae were used as outgroup. Sequences of three chloroplast (trnL‐F, matK, and rbcL) and one nuclear (ITS) loci were used to infer the molecular phylogeny employing maximum likelihood and Bayesian analyses. According to our results, within Plumbaginoideae, Plumbago forms a non‐monophyletic assemblage, with Plumbago europaea sister to Plumbagella, while the other Plumbago species form a clade sister to Dyerophytum. Within Limonioideae, Ikonnikovia is nested in Goniolimon, rejecting its former segregation as genus distinct from Goniolimon. Limonium is divided into two major clades: Limonium subg. Pteroclados s.l., including L. sect. Pteroclados and L. anthericoides, and L. subg. Limonium. The latter is divided into three well‐supported subclades: the monospecific L. sect. Limoniodendron sister to a clade comprising a mostly non‐Mediterranean subclade and a Mediterranean subclade. Our results set the foundation for taxonomic proposals on sections and subsections of Limonium, namely: (a) the newly described L. sect. Tenuiramosum, created to assign L. anthericoides at the sectional rank; (b) the more restricted circumscriptions of L. sect. Limonium (= L. sect. Limonium subsect. Genuinae) and L. sect. Sarcophyllum (for the Sudano‐Zambezian/Saharo‐Arabian clade); (c) the more expanded circumscription of L. sect. Nephrophyllum (including species of the L. bellidifolium complex); and (d) the new combinations for L. sect. Pruinosum and L. sect. Pteroclados subsect. Odontolepideae and subsect. Nobiles.

Theodoridis, Spyros/0000-0001-5188-7033; Fernandez-Palacios, Jose Maria/0000-0001-9741-6878; Celep, Ferhat/0000-0003-3280-8373; Moura, Monica/0000-0001-5555-2388; Koutroumpa, Konstantina/0000-0001-9391-874X; Romeiras, Maria/0000-0002-9373-6302 WOS: 000454523500010 PubMed: 30619554 Plumbaginaceae is characterized by a history of multiple taxonomic rearrangements and lacks a broad molecular phylogenetic framework. Limonium is the most species-rich genus of the family with ca. 600 species and cosmopolitan distribution. Its center of diversity is the Mediterranean region, where ca. 70% of all Limonium species are endemic. In this study, we sample 201 Limonium species covering all described infrageneric entities and spanning its wide geographic range, along with 64 species of other Plumbaginaceae genera, representing 23 out of 29 genera of the family. Additionally, 20 species of the sister family Polygonaceae were used as outgroup. Sequences of three chloroplast (trnL-F, matK, and rbcL) and one nuclear (ITS) loci were used to infer the molecular phylogeny employing maximum likelihood and Bayesian analyses. According to our results, within Plumbaginoideae, Plumbago forms a non-monophyletic assemblage, with Plumbago europaea sister to Plumbagella, while the other Plumbago species form a clade sister to Dyerophytum. Within Limonioideae, Ikonnikovia is nested in Goniolimon, rejecting its former segregation as genus distinct from Goniolimon. Limonium is divided into two major clades: Limonium subg. Pteroclados s.l., including L. sect. Pteroclados and L. anthericoides, and L. subg. Limonium. The latter is divided into three well-supported subclades: the monospecific L. sect. Limoniodendron sister to a clade comprising a mostly non-Mediterranean subclade and a Mediterranean subclade. Our results set the foundation for taxonomic proposals on sections and subsections of Limonium, namely: (a) the newly described L. sect. Tenuiramosum, created to assign L. anthericoides at the sectional rank; (b) the more restricted circumscriptions of L. sect. Limonium (= L. sect. Limonium subsect. Genuinae) and L. sect. Sarcophyllum (for the Sudano-Zambezian/Saharo-Arabian clade); (c) the more expanded circumscription of L. sect. Nephrophyllum (including species of the L. bellidifolium complex); and (d) the new combinations for L. sect. Pruinosum and L. sect. Pteroclados subsect. Odontolepideae and subsect. Nobiles. European Union's Seventh Framework Programme (FP7/2007-2013)European Union (EU) [226,506, GB-TAF-5704]; Georges-und-Antoine-Claraz-Schenkung; University of Zurich (Department of Systematic and Evolutionary Botany); Seventh Framework ProgrammeEuropean Union (EU) [FP7, 2007, 2013]; University of Zurich European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 226,506, Grant/Award Number: SYNTHESYS project GB-TAF-5704; Georges-und-Antoine-Claraz-Schenkung; University of Zurich (Department of Systematic and Evolutionary Botany); Seventh Framework Programme, Grant/Award Number: FP7, 2007 and 2013; University of Zurich

Aim: Species–area relationships (SARs) on oceanic archipelagos are shaped at least as much by speciation as by immigration–extinction dynamics. We examine three well‐studied Atlantic archipelagos to quantify the relative contributions of colonization and diversification to individual and whole‐archipelago floras. Location: Three Macaronesian archipelagos: the Azores, Madeira and Canary Islands. Methods: We assessed the floras of all three archipelagos in order to compare SARs and numbers of endemic species with respect to the physical characteristics of each archipelago (geological age, isolation, and environmental diversity). Utilizing a large number of available phylogenies, we partitioned each flora into putative colonist lineages. These were used to determine: (a) the number of original colonists of each archipelago, (b) degree of relatedness among these, and (c) the degree to which internal diversification contributes to species numbers for islands and archipelagos with different physical characteristics. Results: Archipelagos varied in the parameters of the SARs in relation to their physical characteristics. The Canarian and Madeiran floras demonstrate remarkably similar SARs with z values (slopes) near 0.3, while the Azorean flora exhibits fewer species per given area and a modest z value of 0.15. The Canarian and Madeiran endemic species are concentrated in a small number of diversifying lineages, whereas the Azorean endemics were mostly in anagenetic lineages (indicating minimal internal diversification). Lineages that do not diversify within a given archipelago significantly tend not to diversify in others, whereas diversifying lineages tend to have more species in the Canarian flora when compared with related lineages in the others. Main conclusions: Although a strong independent effect of island area on species richness exists for the whole Macaronesian region, colonization and diversification are also influenced by geological age and environmental diversity of archipelagos, overriding characteristics of individual islands (“archipelago effect”). The “Azorean diversity enigma” likely results from a combination of geological youth, low environmental diversity and disproportionate human alteration.

Background and Aims Various studies and conservationist reports have warned about the contraction of the last subtropical Afro-Macaronesian forests. These relict vegetation zones have been restricted to a few oceanic and continental islands around the edges of Africa, due to aridification. Previous studies on relict species have generally focused on glacial effects on narrow endemics; however, little is known about the effects of aridification on the fates of previously widespread subtropical lineages. Methods Nuclear microsatellites and ecological niche modelling were used to understand observed patterns of genetic diversity in two emblematic species, widely distributed in these ecosystems: Canarina eminii (a palaeoendemic of the eastern Afromontane forests) and Canarina canariensis (a palaeoendemic of the Canarian laurel forests). The software DIYABC was used to test alternative demographic scenarios and an ensemble method was employed to model potential distributions of the selected plants from the end of the deglaciation to the present. Key Results All the populations assessed experienced a strong and recent population decline, revealing that locally widespread endemisms may also be alarmingly threatened. Conclusions The detected extinction debt, as well as the extinction spiral to which these populations are subjected, demands urgent conservation measures for the unique, biodiversity-rich ecosystems that they inhabit., This work was supported by a PhD research grant (BES-2010–037261) to M.M., including short research stays at JBCVC-CSIC (J.C.C.), University of Lausanne (N.A.) and University of Fribourg (L.P. and M.H.) funded by MINECO (grants CGL2009-1332-C03-01 (MICINN), CGL2012- 40129-C02-01 and CGL2015-67849-P) (MINECO/FEDER) to I.S.; grant CGL2012-40129-C02-02 (MINECO) and a Marie Curie Intra-European Fellowship (PIEF-GA-2012-329088) to M.H. and project grant DEMIURGO MAC/1/C20) to J.C.C.

Understanding patterns of community structure and the causes for their variation can be furthered by comparative biogeographic analyses of island biotas. We used woody plant data at the local scale to investigate variations in species rarity, alpha, beta, and gamma diversity within and between three islands from the oceanic archipelagoes of Azores, Canaries and Mascarene. We used standardized protocols to sample ten 50 m × 50 m forest plots in each of the three islands with contrasting climate and regional species pools: Terceira (Azores), Tenerife (Canaries), and Reunion (Mascarene Islands). Occupancy frequency distributions and species abundance distributions were used to investigate rarity. The partitioning of beta diversity in a distance-decay framework was used to test for spatial patterns of community composition. Rarity was much more pronounced in the highly diverse islands of Tenerife and Reunion than in the regionally poorer island of Terceira. The number of species rose faster with increasing sample area in both Tenerife and Reunion. The slope of the species rank abundance curve was steeper in Terceira whereas the richer island assemblages approached a lognormal model. Compositional changes according to spatial distance were mostly due to replacement of species in Terceira and Reunion. Our results point to important differences in the community structure of Terceira, which is the less diverse and temperate region in comparison to Tenerife and Reunion which are highly diverse., This research was supported by the ERA-Net Net -Biome research framework, financed through the: Canary Islands Government ACIISI grants SE-12/02 (PO), SE-12/03 (JCC), SE-12/04 (BE), co-financed by FEDER; Portuguese FCT-NETBIOME grant 0003/2011 (PB); French ANR-NETBIOME grant n°11-EBIM-001-01 (CT); Région Reunion council for research activities (DS), Universitéde La Reunion contract DGADD/PE/20120585 (DS). CR, FR and IRA were supported by grants from Fundação da Ciência e Tecnologia - FCT-SFRH/BPD/91357/2012, FCT-PTDC/BIA-BIC/119255/2010, FCT-SFRH/BPD/102804/2014 respectively. MF has been funded by Direcção Regional da Ciência e Tecnologia, DRCT-M3.1.7/F/002/2011 and the Conselho Nacional de Desenvolvimento Científico e Tecnológico-CNPq (401045/2014-5), Programa Ciência sem Fronteiras; the current MF’s contract is supported by the Universidad de Alcalá. The work of LBD in this manuscript was performed within the scope of the project MOMENTOS (PTDC/BIA-BIC/5558/2014).

Islands contain some of the most remarkable yet imperiled plants anywhere on Earth. Despite remarkable ecological/morphological diversity, insular endemics often retain the ability to hybridize and produce vigorous, fertile progeny. This study over several generations of synthetic interspecific hybrids between two species endemic to the Canary Islands shows that gene exchange between species can produce novel traits, transgressive phenotypes and novel combinations of features not seen in their parents. Results of this study provide experimental evidence of the potential of hybridization to promote diversification and possibly generate stabilized hybrid derivatives in plants in an oceanic archipelago., Hybridization is recognized as an important process in plant evolution, and this may be particularly true for island plants where several biotic and abiotic factors facilitate interspecific hybridization. Although rarely done, experimental studies could provide insights into the potential of natural hybridization to generate diversity when species come into contact in the dynamic island setting. The potential of hybridization to generate morphological variation was analysed within and among 12 families (inbred lines) of an F4 hybrid generation between two species of Tolpis endemic to the Canary Islands. Combinations of characters not seen in the parents were present in hybrids. Several floral and vegetative characters were transgressive relative to their parents. Morphometric studies of floral, vegetative and fruit characters revealed that several F4 families were phenotypically distinct from other families, and from their parents. The study demonstrates that morphologically distinct pollen-fertile lines, potentially worthy of taxonomic recognition if occurring in nature, can be generated in four generations. The ability of the hybrid lines to set self-seed would reduce gene flow among the lines, and among the hybrids and their parental species. Selfing would also facilitate the fixation of characters within each of the lines. Overall, the results show the considerable potential of hybridization for generating diversity and distinct phenotypes in island lineages.

Oceanic archipelagos are typically rich in endemic taxa, because they offer ideal conditions for diversification and speciation in isolation. One of the most remarkable evolutionary radiations on the Canary Islands comprises the 16 species included in Limonium subsection Nobiles, all of which are subject to diverse threats, and legally protected. Since many of them are single-island endemics limited to one or a few populations, there exists a risk that a loss of genetic variation might limit their long-term survival. In this study, we used eight newly developed microsatellite markers to characterize the levels of genetic variation and inbreeding in L. macrophyllum, a species endemic to the North-east of Tenerife that belongs to Limonium subsection Nobiles. We detected generally low levels of genetic variation over all populations (H = 0.363), and substantial differentiation among populations (F = 0.188; R = 0.186) coupled with a negligible degree of inbreeding (F = 0.042). Obligate outcrossing may have maintained L. macrophyllum relatively unaffected by inbreeding despite the species’ limited dispersal ability and the genetic bottlenecks likely caused by a prolonged history of grazing. Although several factors still constitute a risk for the conservation of L. macrophyllum, the lack of inbreeding and the recent positive demographic trends observed in the populations of this species are factors that favour its future persistence., This research was funded with a post-doctoral fellowship of the Spanish Ministry of Education to A. Jiménez, with a G. and A. ClarazSchenkung Foundation grant to (A) Jiménez and (B) Weigelt for field work, and with funding from the University of Zurich

Aim: The loss of dispersal on islands hypothesis (LDIH) posits that wind-dispersed plants should exhibit reduced dispersal potential, particularly if island populations are old. In this study, we tested this hypothesis using a detailed phylogeographical framework across different geographical scales. Location: Mainland and island areas of the Atlantic and Mediterranean regions, including Macaronesia (Canary Islands and Cape Verde) and Mediterranean islands in the strait of Sicily. Methods: Forty-five populations of Periploca laevigata, a wind-dispersed shrub, were sampled. Plastid and nuclear microsatellite data were used to reconstruct spatio-temporal patterns of island colonization, and estimates of seed terminal velocity used as a surrogate for dispersal ability under both field and common garden conditions. Results: Our findings did not provide evidence of loss of dispersability in any island lineage. In all of the regions considered, dispersal ability was similar on island and mainland populations, or higher on islands. Contrary to LDIH expectations, lineages inferred as the oldest (western Canaries and Cape Verde) converged towards the most dispersive seed phenotype. This pattern was supported by data obtained under common garden conditions. Within the western Canarian lineage, successful dispersal was shown to be very rare among islands and extensive within islands, but dispersability did not vary significantly from older to more recent sublineages. Considering all the study islands, we found a strong, positive correlation between dispersal ability and estimates of within-island habitat availability. Main conclusions: This study suggests that dispersal ability can be favoured on islands, possibly because traits enhancing wind dispersal are positively selected when habitat availability is high. Our results challenge broad generalizations of the LDIH, but we discuss how overlooking species′ phylogeographical history may give rise to misleading conclusions., PCT‐MAC Ministerio de Economia y Competitividad Cabildo de Gran Canaria. Grant Numbers: ENCLAVES (MAC/3/C141), JCI‐2012‐15220

Using a series of standardized sampling plots within forest ecosystems in remote oceanic islands, we reveal fundamental differences between the structuring of aboveground and belowground arthropod biodiversity that are likely due to large-scale species introductions by humans. Species of beetle and spider were sampled almost exclusively from single islands, while soil-dwelling Collembola exhibited more than tenfold higher species sharing among islands. Comparison of Collembola mitochondrial metagenomic data to a database of more than 80 000 Collembola barcode sequences revealed almost 30% of sampled island species are genetically identical, or near identical, to individuals sampled from often very distant geographic regions of the world. Patterns of mtDNA relatedness among Collembola implicate human-mediated species introductions, with minimum estimates for the proportion of introduced species on the sampled islands ranging from 45% to 88%. Our results call for more attention to soil mesofauna to understand the global extent and ecological consequences of species introductions., This research was supported by the ERA‐Net Net‐Biome research framework, financed through: Canary Island Government ACIISI grants SE‐12/02 (PO), SE‐12/03 (JCC), SE‐12/04 (BE), cofinanced by FEDER; Portuguese FCT‐NETBIOME grant 0003/2011 (PB); French ANR‐NETBIOME grant no 11‐EBIM‐001‐01 (CT); Région Réunion council for research activities (DS), Université de La Réunion contract DGADD/PE/20120585 (DS). B.C.E. was also supported by Spanish MINECO grant CGL2013‐42589‐P, co‐financed by FEDER, and Spanish MAGRAMA grant S20141203_002597 from the Organismo Autonomo Parques Nacionales.

We use a comprehensive subset of Canarian angiosperms corresponding to 23 families, 35 genera and 60 Canarian endemic taxa to test whether this flora is suitable to taxonomic identification with the two proposed plant DNA barcode sequences and whether these sequences may reveal the existence of cryptic species overlooked by morphology. The rate of discrimination success between the insular congeneric samples using the rbcL+matK combination and a 'character-based' approach (where we use only the combination of nucleotide positions in an alignment that allows unambiguous species identification) is higher (82.29%) than that obtained with the 'distance-based' approach (80.20%) used by the CBOL Plant Working Group in 2009 and also when compared with tests conducted in other floras. This suggests that the molecular identification of the Canarian endemic flora can be achieved as successfully as in other floras where the incidence of radiation is not as relevant. The facts that (i) a distance-based criterion was unable to discriminate between congeneric and conspecific comparisons and (ii) only the character-based discrimination criterion resolved cases that the distance-based criterion did not, further support the use of a character discrimination approach for a more efficient DNA barcoding of floras from oceanic islands like the Canaries. Thus, a barcoding gap seems not to be necessary for the correct molecular characterization of the Canarian flora. DNA barcodes also suggest the possible existence of cryptic taxa to be further investigated by morphology and that the current taxonomic status of some of the taxa analysed may need revision.

We used plastid sequences (trnL, trnL-trnF, petN-psbM and trnT-trnL) to infer the phylogenetic relationships and inter-island connections of the Canarian Juniperus cedrus, and AFLP fingerprints to assess its genetic diversity patterns. Maximum Likelihood, Maximum Parsimony and Bayesian methods suggest independent colonization events for the three Macaronesian junipers and support the monophyly of J. cedrus. Plastid sequences reveal a low genetic diversity (three haplotypes) and do not provide sufficient information to resolve its temporal and geographical origin. AFLPs indicate a greater isolation in J. cedrus than in other Macaronesian trees with similar distributions and dispersal syndromes. Gran Canaria harbours the least genetically diverse population, which justifies immediate conservation actions. This island and Tenerife also show independent genetic structure, meaning that genetic exchange from other islands should be avoided in eventual reinforcements. Populations from La Palma and La Gomera show the highest genetic diversity levels and number of polymorphic AFLPs, probably because a lower incidence of felling has allowed a less dramatic influence of genetic bottlenecks. We suggest that management efforts should prioritize populations from these islands to preserve the evolutionary potential of the species, but we also stress the importance of knowledge of the evolutionary history, genetic structure and ecological interactions in conservation strategies. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 175, 376–394.

Background and aims Seed dormancy varies within species in response to climate, both in the long term (through ecotypes or clines) and in the short term (through the influence of the seed maturation environment). Disentangling both processes is crucial to understand plant adaptation to environmental changes. In this study, the local patterns of seed dormancy were investigated in a narrow endemic species, Centaurium somedanum, in order to determine the influence of the seed maturation environment, population genetic composition and climate. Methods Laboratory germination experiments were performed to measure dormancy in (1) seeds collected from different wild populations along a local altitudinal gradient and (2) seeds of a subsequent generation produced in a common garden. The genetic composition of the original populations was characterized using intersimple sequence repeat (ISSR) PCR and principal co-ordinate analysis (PCoA), and its correlation with the dormancy patterns of both generations was analysed. The effect of the local climate on dormancy was also modelled. Key results An altitudinal dormancy cline was found in the wild populations, which was maintained by the plants grown in the common garden. However, seeds from the common garden responded better to stratification, and their release from dormancy was more intense. The patterns of dormancy variation were correlated with genetic composition, whereas lower temperature and summer precipitation at the population sites predicted higher dormancy in the seeds of both generations. Conclusions The dormancy cline in C. somedanum is related to a local climatic gradient and also corresponds to genetic differentiation among populations. This cline is further affected by the weather conditions during seed maturation, which influence the receptiveness to dormancy-breaking factors. These results show that dormancy is influenced by both long-and short-term climatic variation. Such processes at such a reduced spatial scale highlight the potential of plants to adapt to fast environmental changes.

We assess population genetic structure and variability in the endangered Azorean endemic Viburnum treleasei Gand., an evergreen shrub or small tree, occurring in eight out of nine islands of the archipelago. We combine RAPD and ISSR markers in eight populations and four islands covering the three subgroups of islands that compose the archipelago, and one population of V. tinus from the Portuguese mainland. Most of the genetic variability was found within populations, which is in accordance with the bi-parental reproductive strategy favored by the taxon. Gene flow estimations for the combined RAPD and ISSR markers suggest that the main cause for population variability between the studied populations is genetic drift. In accordance with the genetic structure indicators obtained, conservation measures should consider that translocation of individuals between islands must be avoided. In specific cases, the analysed populations may require the implementation of augmentation strategies due to their depleted state. With this study, a genetic background is now available to better define conservation measures for the taxon.

Background and Aims Allozyme and reproductive data sets for the Canarian flora are updated in order to assess how the present levels and structuring of genetic variation have been influenced by the abiotic island traits and by phylogenetically determined biotic traits of the corresponding taxa; and in order to suggest conservation guidelines. Methods Kruskal-Wallis tests are conducted to assess the relationships of 27 variables with genetic diversity (estimated by A, P, Ho and He) and structuring (GST) of 123 taxa representing 309 populations and 16 families. Multiple linear regression analyses (MLRAs) are carried out to determine the relative influence of the less correlated significant abiotic and biotic factors on the genetic diversity levels. Key Results and Conclusions The interactions between biotic features of the colonizing taxa and the abiotic island features drive plant diversification in the Canarian flora. However, the lower weight of closeness to the mainland than of (respectively) high basic chromosome number, partial or total self-incompatibility and polyploidy in the MLRAs indicates substantial phylogenetic constraint; the importance of a high chromosome number is feasibly due to the generation of a larger number of linkage groups, which increase gametic and genotypic diversity. Genetic structure is also more influenced by biotic factors (long-range seed dispersal, basic chromosome number and partial or total self-incompatibility) than by distance to the mainland. Conservation-wise, genetic structure estimates (FST/GST) only reflect endangerment under intensive population sampling designs, and neutral genetic variation levels do not directly relate to threat status or to small population sizes. Habitat protection is emphasized, but the results suggest the need for urgent implementation of elementary reproductive studies in all cases, and for ex situ conservation measures for the most endangered taxa, even without prior studies. In non-endangered endemics, multidisciplinary research is needed before suggesting case-specific conservation strategies. The molecular information relevant for conservation should be conserved in a standardized format to facilitate further insight.

Summary We analyzed the ITS2 primary and secondary structure (including Compensatory Base Changes (CBCs)) of 17 new Dunaliella strains (11 D. viridis, two D. tertiolecta, and four Dunaliella sp.), and compared these with other Dunaliella sequences available from the ITS2 database to circumscribe their taxonomic position. The ITS2 primary and secondary structure analysis positioned the majority of D. viridis strains in four main clades, showing that D. viridis is polyphyletic. The detection of at least one CBC among these clades strongly suggests that they could correspond to different biological species. Unexpectedly, while D. viridis var. euchlora (CCAP19/21) was positioned within the subgenus Dunaliella, D. viridis var. palmelloides (CCAP11/34) was positioned clearly outside this subgenus, suggesting that this taxon may not be properly placed in Dunaliella. Furthermore, the detection of at least three compensatory base changes (CBCs) between D. viridis var. palmelloides (CCAP11/34) and the other strains analyzed, confirm that this strain is a different species. For these reasons we propose re-naming D. viridis var. palmelloides (CCAP11/34) to incertae sedis, and D. viridis var. euchlora (CCAP19/21) to Dunaliella sp. Therefore, the ITS2 primary and secondary structure data suggest a taxonomic re-structuring of D. viridis.

Transformer-4 version 2.0.1 (T4) is a multi-platform freeware programmed in java that can transform a genotype matrix in Excel or XML format into the input formats of one or several of the most commonly used population genetic software, for any possible combination of the populations that the matrix contains. T4 also allows the users to (i) draw allozyme gel interpretations for any number of diploid individuals, and then generate a genotype matrix ready to be used by T4; and (ii) produce basic reports about the data in the matrices. Furthermore, T4 is the only way to optionally submit 'genetic diversity digests' for publication in the Demiurge online information system (http://www.demiurge-project.org). Each such digest undergoes peer-review, and it consists of a geo-referenced data matrix in the tfm4 format plus any ancillary document or hyperlink that the digest authors see fit to include. The complementarity between T4 and Demiurge facilitates a free, safe, permanent, and standardized data archival and analysis system for researchers, and may also be a convenient resource for scientific journals, public administrations, or higher educators. T4 and its converters are freely available (at, respectively, http://www.demiurge-project.org/download_t4 and http://www.demiurge-project.org/converterstore) upon registration in the Demiurge information system (http://demiurge-project.org/register). Users have to click on the link provided on an account validation email, and accept Demiurge's terms of use (see http://www.demiurge-project.org/termsofuse). A thorough user's guide is available within T4. A 3-min promotional video about T4 and Demiurge can be seen at http://vimeo.com/29828406.

Sobre la base de un estudio morfológico detallado, apoyado además por los resultados previamente publicados relativos a la filogenia del género Matthiola, llegamos a la conclusión de que en las islas Canarias la sect. Acinotum de este género sólo se encuentra representda por dos especies. Una de ellas posee una amplia distribución mediterránea (M. parviflora) y la otra (M. bolleana), de distribución principalmente canaria aunque abarcando también la costa atlántica de Marruecos a través del enclave macaronésico, se encuentra probablemente sometida a fenómenos de radiación incipiente. Dentro de ésta última distinguimos tres taxones de rango subespecífico.

Bird pollination has evolved in four species of Macaronesian Lotus from a bee-pollinated ancestor. The transition is associated with the modification of several floral traits, including flower color and size, relative size and orientation of the petals, and nectar composition and quantity. Here, we examine petal surface micromorphology in relation to pollination type, using SEM and LM. In the bee-pollinated Lotus (the majority of the genus), papillose conical cells (PCS) are the most abundant epidermal type on dorsal and lateral petals. However, bird-pollinated species completely lack PCS on their dorsal petals and have only a small patch of PCS in a highly localized region of the lateral petal. In the bee-pollinated species (including those most closely related to the bird-pollinated species), PCS develop early in floral development. In contrast, the small amount of residual PCS in bird-pollinated species forms later in development, after the other two major epidermal types have been formed. The almost c...

The four red-flowered, apparently bird-pollinated Lotus species from the Canary Islands have previously been classified in their own genus, Rhyncholotus. Currently, they are considered as a separate section within genus Lotus, distinct from other herbaceous Canarian congeners which are yellow-flowered and bee-pollinated. A combined analysis of four nuclear regions (including ITS and three homologues of CYCLOIDEA) and three plastid regions (CYB6, matK and trnH-psbA) nests the four bird-pollinated species within a single extant species of bee-pollinated Lotus (L. sessilifolius), in a very extreme example of species paraphyly. Therefore, our data compellingly support the hypothesis that the Macaronesian Lotus species with a bird pollination syndrome are recently derived from entomophilous ancestors. Calibration of the phylogenetic trees using geological age estimates of the most recent islands (La Palma and El Hierro) together with oldest ages of Fuerteventura indicates that bird pollination evolved ca. 1.7 Ma in the Canarian Lotus. These four bird-pollinated species share a most recent common ancestor (MRCA) with L. sessilifolius that dates to about 2.2 Ma. Our analyses further suggest that the evolution of the bird pollination syndrome was likely triggered by the availability of new niches in La Palma and Tenerife as a result of recent volcanic activity.

Dunaliella acidophila is one of the most extreme acidophiles on earth and is able to survive in highly acidic habitats. This characteristic has made this organism the universal model for the study of abiotic stress. Although D. acidophila is currently circumscribed to the subgenus Pascheria within Dunaliella Teodoresco (Chlorophyceae), its taxonomic position has stirred controversy. The comparison of D. acidophila CCAP19/35 internal transcribed spacers (including ITS2 secondary structure analysis) and RuBisCo large subunit (rbcL) sequences with other Dunaliella species confirms that D. acidophila should maintain its phylogenetic position within the genus Dunaliella, suggesting its inclusion within the subgenus Dunaliella. Furthermore, the ITS1 and ITS2 data revealed that D. acidophila was highly divergent from the other freshwater species assessed, D. lateralis, with which it barely shares a 56.8% similarity.

Current threats to the planet's biodiversity are unprecedented, and they particularly imperil insular floras. In this investigation, we use the threat factors identified by the Millennium Ecosystem Assessment as the main drivers of biodiversity loss on islands to define and rank 13 current, continuing threats to the plant diversity of nine focal archipelagos where volcanic origin (or in the Seychelles a prolonged isolation after a continental origin) has produced a high degree of endemicity and fragility in the face of habitat alteration. We also conduct a global endangerment assessment based on the numbers of insular endemic plants in the endangered (EN) and critically endangered (CR) IUCN categories for 53 island groups with an estimated 9951 endemic plant species, providing a representative sample of the world's insular systems and their floristic richness. Our analyses indicate that isolation does not significantly influence endangerment, but plant endemics from very small islands are more often critically endangered. We estimate that between 3500 and 6800 of the estimated 70,000 insular endemic plant species worldwide might be highly threatened (CR+EN) and between ca. 2000 and 2800 of them in critical danger of extinction (CR). Based on these analyses, and on a worldwide literature review of the biological threat factors considered, we identify challenging questions for conservation research, asking (i) what are the most urgent priorities for the conservation of insular species and floras, and (ii) with the knowledge and assets available, how can we improve the impact of conservation science and practice on the preservation of island biodiversity? Our analysis indicates that the synergistic action of many threat factors can induce major ecological disturbances, leading to multiple extinctions. We review weaknesses and strengths in conservation research and management in the nine focal archipelagos, and highlight the urgent need for conservation scientists to share knowledge and expertise, identify and discuss common challenges, and formulate multi-disciplinary conservation objectives for insular plant endemics worldwide. To our knowledge, this is the most up-to-date and comprehensive survey yet to review the threat factors to native plants on oceanic islands and define priority research questions.

We combined reproductive and allozyme data to assess the levels and structuring of genetic variation and propose conservation guidelines in Limonium dendroides, a critically endangered Canarian endemic Plumbaginaceae featuring the floral and pollen pap/cob dimorphisms associated with the heteromorphic diallelic self-incompatibility system described for this family. Although seed germination has been reported in greenhouse conditions, the detection of individuals of only one morph in all wild subpopulations surveyed explains the extremely limited seed production and recruitment in nature. The geographical proximity and genetic closeness between some subpopulations, together with absence of inbreeding depression symptoms, and a higher allozyme variation in the cultured or reintroduced offspring than in their parental wild subpopulations indicate the viability of occasional compatible matings, thereby suggesting that even low levels of gene flow could mitigate the deleterious effects of fragmentation on subpopulation survival. However, our overall results indicate that L. dendroides is in a critical conservation situation where the utter scarcity of compatible mates within the subpopulations, radically low subpopulation sizes, poor inter-subpopulation gene flow, impoverished genetic variation, herbivore grazing, and the extreme habitat topography have overridden the reproductive capabilities of the species. According to our results, once morph types in all wild and cultured specimens can be determined, inducing fertile crosses through mixed reinforcements is advisable only in the most extremely isolated and small subpopulations (Argaga and Guarimiar) using individuals from the nearest ones (Azadoe and Palmarejo), whilst non-mixed reinforcements seem viable in the remaining subpopulations. Only when the subpopulations attain higher seed production and recruitment rates will it be adequate to collect seeds for their storage at a germplasm bank facility.