Phylogenomics and phylogeographic model testing using convolutional neural networks reveal a history of recent admixture in the Canarian Kleinia neriifolia.

Multiple-island endemics (MIE) are considered ideal natural subjects to study patterns of island colonization that involve recent population-level genetic processes. Kleinia neriifolia is a Canarian MIE widespread across the archipelago, which exhibits a close phylogenetic relationship with species in northwest Africa and at the other side of the Sahara Desert. Here, we used target sequencing with plastid skimming (Hyb-Seq), a dense population-level sampling of K.

In defence of the entity of Macaronesia as a biogeographical region.

Since its coinage ca. 1850 AD by Philip Barker Webb, the biogeographical region of Macaronesia, consisting of the North Atlantic volcanic archipelagos of the Azores, Madeira with the tiny Selvagens, the Canaries and Cabo Verde, and for some authors different continental coastal strips, has been under dispute. Herein, after a brief introduction on the terminology and purpose of regionalism, we recover the origins of the Macaronesia name, concept and geographical adscription, as well as its biogeographical implications and how different authors have positioned themselves, using distinct terrestrial or marine floristic and/or faunistic taxa distributions and relationships for accepting or rejecting the existence of this biogeographical region.

Multiple introductions, polyploidy and mixed reproductive strategies are linked to genetic diversity and structure in the most widespread invasive plant across Southern Ocean archipelagos.

Biological invasions in remote areas that experience low human activity provide unique opportunities to elucidate processes responsible for invasion success. Here we study the most widespread invasive plant species across the isolated islands of the Southern Ocean, the annual bluegrass, Poa annua. To analyse geographical variation in genome size, genetic diversity and reproductive strategies, we sampled all major sub-Antarctic archipelagos in this region and generated microsatellite data for 470 individual plants representing 31 populations.

Characterization of microsatellite markers for the endangered (Thymelaeaceae) and related species.

Premise: The endangered shrub (Thymelaeaceae) is endemic to the Balearic island of Menorca, where fragmentation and severe population decline are ongoing threats to this taxon. We developed a set of microsatellite markers to analyze the fine-scale genetics of its few extant populations.

Methods And Results: Fifteen microsatellite markers were obtained through Illumina high-throughput sequencing and tested in two populations.

Testing the hypothesis of loss of defenses on islands across a wide latitudinal gradient of Periploca laevigata populations.

Premise Of The Study: We tested a hypothesis that predicts loss of chemical defenses on island plant populations (LCDIH) as an evolutionary response to limited herbivore pressures.

Methods: Using a common garden approach, we grew 16 populations (N = 286 seedlings) of Periploca laevigata, a Mediterranean shrub for which previous studies suggested that animal browsing elicits defensive responses mediated by tannins. Our experimental setting represented a wide latitudinal gradient (37-15°N) encompassing three island systems, virtually free of large herbivores, and three mainland areas.

How repeatable is microevolution on islands? Patterns of dispersal and colonization-related plant traits in a phylogeographical context.

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.

Genetic structure of the Canarian palm tree (Phoenix canariensis) at the island scale: does the 'island within islands' concept apply to species with high colonisation ability?

Oceanic islands are dynamic settings that often promote within-island patterns of strong population differentiation. Species with high colonisation abilities, however, are less likely to be affected by genetic barriers, but island size may impact on species genetic structure regardless of dispersal ability. The aim of the present study was to identify the patterns and factors responsible for the structure of genetic diversity at the island scale in Phoenix canariensis, a palm species with high dispersal potential.

Do island plant populations really have lower genetic variation than mainland populations? Effects of selection and distribution range on genetic diversity estimates.

Ecological and evolutionary studies largely assume that island populations display low levels of neutral genetic variation. However, this notion has only been formally tested in a few cases involving plant taxa, and the confounding effect of selection on genetic diversity (GD) estimates based on putatively neutral markers has typically been overlooked. Here, we generated nuclear microsatellite and plastid DNA sequence data in Periploca laevigata, a plant taxon with an island-mainland distribution area, to (i) investigate whether selection affects GD estimates of populations across contrasting habitats; and (ii) test the long-standing idea that island populations have lower GD than their mainland counterparts.

Polyploidy and microsatellite variation in the relict tree Prunus lusitanica L.: how effective are refugia in preserving genotypic diversity of clonal taxa?

Refugia are expected to preserve genetic variation of relict taxa, especially in polyploids, because high gene dosages could prevent genetic erosion in small isolated populations. However, other attributes linked to polyploidy, such as asexual reproduction, may strongly limit the levels of genetic variability in relict populations. Here, ploidy levels and patterns of genetic variation at nuclear microsatellite loci were analysed in Prunus lusitanica, a polyploid species with clonal reproduction that is considered a paradigmatic example of a Tertiary relict.

Temporal matching among diurnal photosynthetic patterns within the crown of the evergreen sclerophyll Olea europaea L.

Trees are modular organisms that adjust their within-crown morphology and physiology in response to within-crown light gradients. However, whether within-plant variation represents a strategy for optimizing light absorption has not been formally tested. We investigated the arrangement of the photosynthetic surface throughout one day and its effects on the photosynthetic process, at the most exposed and most sheltered crown layers of a wild olive tree (Olea europaea L.

The relevance of gene flow in metapopulation dynamics of an oceanic island endemic, Olea europaea subsp. guanchica.

Theoretical and empirical studies suggest that geographical isolation and extinction-recolonization dynamics are two factors causing strong genetic structure in metapopulations, but their consequences in species with high dispersal abilities have not been tested at large scales. Here, we investigated the effect of population age structure and isolation by distance in the patterns of genetic diversity in a wind-pollinated, zoochorous tree (Olea europaea subsp. guanchica) sporadically affected by volcanic events across the Canarian archipelago.

Contrasting patterns of morphological and physiological differentiation across insular environments: phenotypic variation and heritability of light-related traits in Olea europaea.

Phenotypic variation of traits can reflect the ability of plants to adjust to particular environments, but how much of this variation is heritable is not frequently analyzed in natural populations. In the present paper, we investigated the patterns of phenotypic expression in light-related leaf traits of Olea europaea subsp. guanchica, a woody sclerophyllous species endemic to the Canary Islands.

Phenotypic plasticity and integration across the canopy of Olea europaea subsp. guanchica (Oleaceae) in populations with different wind exposures.

Woody plants, as sessile and long-lived organisms, are expected to have effective mechanisms for dealing with recurrent environmental stresses. In the present study, we hypothesized that phenotypic plasticity (the ability to express alternative phenotypes) and integration (covariation among functionally related traits) are elicited in plants under stressful wind speed conditions. We investigated the within-crown variation of nine vegetative traits of a tree species (Olea europaea subsp.

Variation in sclerophylly among Iberian populations of Quercus coccifera L. is associated with genetic differentiation across contrasting environments.

Evergreen oaks are an emblematic element of the Mediterranean vegetation and have a leaf phenotype that seems to have remained unchanged since the Miocene. We hypothesise that variation of the sclerophyll phenotype among Iberian populations of Quercus coccifera is partly due to an ulterior process of ecotypic differentiation. We analysed the genetic structure of nine Iberian populations using ISSR fingerprints, and their leaf phenotypes using mean and intracanopy plasticity values of eight morphological (leaf angle, area, spinescence, lobation and specific area) and biochemical traits (VAZ pool, chlorophyll and beta-carotene content).

Genetic diversity and differentiation processes in the ploidy series of Olea europaea L.: a multiscale approach from subspecies to insular populations.

Geographical isolation and polyploidization are central concepts in plant evolution. The hierarchical organization of archipelagos in this study provides a framework for testing the evolutionary consequences for polyploid taxa and populations occurring in isolation. Using amplified fragment length polymorphism and simple sequence repeat markers, we determined the genetic diversity and differentiation patterns at three levels of geographical isolation in Olea europaea: mainland-archipelagos, islands within an archipelago, and populations within an island.

Polyploidy in the olive complex (Olea europaea): evidence from flow cytometry and nuclear microsatellite analyses.

Background: Phylogenetic and phylogeographic investigations have been previously performed to study the evolution of the olive tree complex (Olea europaea). A particularly high genomic diversity has been found in north-west Africa. However, to date no exhaustive study has been addressed to infer putative polyploidization events and their evolutionary significance in the diversification of the olive tree and its relatives.

Field patterns of leaf plasticity in adults of the long-lived evergreen Quercus coccifera.

Background And Aims: Quercus coccifera, as a long-lived sprouter, responds plastically to environmental variation. In this study, the role of foliar plasticity as a mechanism of habitat selection and modification within the canopy and across contrasted habitats was characterized. An examination was made of the differential contribution of inner and outer canopy layers to the crown plasticity expressed in the field by adult individuals and its dependence on environmental and genetic factors.