A three‐marker DNA barcoding approach for ecological studies of xerothermic plants and herbivorous insects from central Europe

The DNA barcoding technique developed for species identification has recently been adapted for ecological studies (e.g. host plant identification). Comprehensive barcode databases, covering most species inhabiting areas, habitats or communities of interest are essential for reliable and efficient identification of plants. Here we present a three‐barcode (plastid rbcL and matK genes and the trnL intron) database for xerothermic plant species from central Europe. About 85% of the xerothermic plant species (126 out of c. 150) known to be associated with xerothermic habitats were collected and barcoded. The database contains barcodes for 117 (rbcL and trnL) and 96 (matK) species. Interspecific nucleotide distances were in the ranges 0–17.9% (0–3.2% within genera) for rbcL, 0–44.4% (0–3.1%) for trnL and 0–52.5% (0–10.9%) for matK. Blast‐searching of each sequence in the database against the entire database showed that species‐level identification is possible for 89.6% (rbcL), 98.4% (trnL) and 96.4% (matK) of examined plant species. The utility of the presented database for identification of host plants was demonstrated using two insect species associated with xerothermic habitats: the oligophagous leaf‐beetle Cheilotoma musciformis (for which two host plants in Fabaceae were identified) and the polyphagous weevil Polydrusus inustus (which was found to feed on 14 host plants, mostly Rosaceae, Asteraceae and Fabaceae). The developed database will be useful in various applications, including biodiversity, phylogeography, conservation and ecology. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 177 , 576–592.     

Phylogeography of the humbug damselfish,Dascyllus aruanus (Linnaeus, 1758): evidence of Indo‐Pacific vicariance and genetic differentiation of peripheral populations

The phylogeographical structure of coral‐associated reef fishes may have been severely affected, more than species from deeper habitats, by habitat loss during periods of low sea level. The humbug damselfish, Dascyllus aruanus, is widely distributed across the Indo‐West Pacific, and exclusively inhabits branching corals. We used mitochondrial cytochrome b sequence and seven microsatellite loci on D. aruanus samples (260 individuals) from 13 locations across the Indo‐West Pacific to investigate its phylogeographical structure distribution‐wide. A major genetic partition was found between the Indian and Pacific Ocean populations, which we interpret as the result of geographical isolation on either side of the Indo‐Pacific barrier during glacial periods. The peripheral populations of the Red Sea and the Society Islands exhibited lower genetic diversity, and substantial genetic differences with the other populations, suggesting relative isolation. Thus, vicariance on either side of the Indo‐Pacific barrier and peripheral differentiation are considered to be the main drivers that have shaped the phylogeographical patterns presently observed in D. aruanus. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 113 , 931–942.     

Phylogeography of a subalpine tall‐herb Ranunculus platanifolius (Ranunculaceae) reveals two main genetic lineages in the European mountains

A phylogeographical analysis of Ranunculus platanifolius, a typical European subalpine tall‐herb species, indicates the existence of two main genetic lineages based on amplified fragment length polymorphism (AFLP) markers. One group comprises populations from the Balkan Peninsula and the south‐eastern Carpathians and the other includes the remaining part of the range of the species, encompassing the western Carpathians, Sudetes, Alps, Pyrenees and Scandinavia. The main phylogeographical break observed in this species runs across the Carpathians and separates the main parts of this range (western and south‐eastern Carpathians), supporting a distinct glacial history of populations in these areas. The high genetic similarity of the Balkan Peninsula and south‐eastern Carpathian populations could indicate a common glacial refugium for these contemporarily isolated areas of species distribution. The western and northern part of the species range displays an additional weak differentiation into regional phylogeographical groups, which could have been shaped by isolation in glacial refugia or even by a postglacial isolation. The observed weak phylogeographical structure could also be linked with ecological requirements, allowing survival along streams in relatively low, forested mountain ranges. © 2013 The Linnean Society of London     

Multiple glacial refugia and postglacial colonization routes inferred for a woodland geophyte,Cyclamen purpurascens: patterns concordant with the Pleistocene history of broadleaved and coniferous tree species

The phylogeographical history of mid‐altitude woodland herbs that depend on moist and shaded forest habitats is poorly understood. Here, we analysed the genetic structure of Cyclamen purpurascens, a mountainous calcicolous perennial, to test hypotheses regarding its glacial survival in single or multiple refugia and postglacial colonization routes, and to explore how they are congruent with the histories inferred for temperate trees and other mountainous herbs. We gathered AFLP data and chloroplast DNA sequences (trnD‐trnT region) from 68 populations spanning the entire distribution range (the Jura Mountains, Alps, western Carpathians, Dinarides). Both genetic markers revealed two main phylogeographical groups (phylogroups) in C. purpurascens. Additionally, AFLP data detected a more detailed structure of five phylogroups: two widespread, showing east?west geographical separation, and three local ones, restricted to somewhat disjunct, marginal regions of the species range. We suggest that C. purpurascens survived the last glaciation in two main regions, the foothills of the Southern Limestone Alps and the Karst area of the north‐western Dinarides, and possibly also in microrefugia in the Western Carpathians. The glacial persistence and colonization routes of this woodland herb are highly concordant with those inferred for several temperate trees, especially the European beech. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 105 , 741–760.     

Variability,genetic structure and phylogeography of the dolomitophilous species Convolvulus boissieri (Convolvulaceae) in the Baetic ranges,inferred from AFLPs,plastid DNA and ITS sequences

Convolvulus boissieri is an edaphic endemic plant which grows in the Baetic ranges always in association with high mountain xeric dolomitic outcrops. As these dolomitic areas appear in a ‘soil‐island’ pattern, the distribution of this species is disjunct. Populations of this species frequently include a low number of individuals, which could have an important impact on their genetic diversity and viability. Convolvulus boissieri provides an excellent opportunity to study the genetic and phylogeographical aspects of species linked to dolomites. We used amplified fragment length polymorphism markers and nuclear (internal transcribed spacer region of the nuclear ribosomal cistron) and plastid sequences (trnL‐trnF, rpl32‐trnL and trnQ‐5′rps16). Data were generated from 15 populations, representing the distribution area of the species. For sequence analysis and estimation of divergence times we also used sequences from other Convolvulus species. Results revealed low intrapopulational genetic diversity and a strong interpopulational structure. Furthermore, we found clear‐cut differentiation caused by the existence of two large population groups separated by the Guadiana Menor river basin. Estimation of divergence times indicated that divergence took place during the Pleistocene glaciations. Genetic diversity and differentiation are similar to those other species exhibiting naturally fragmented distribution with a sky islands pattern. In phylogeographical terms, the successive glaciation–interglaciation cycles caused the species to spread from the western sites to eastern sites, the latter being more exposed to the effects of glaciation. © 2014 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 176 , 506–523.     

Haplotype richness in refugial areas: phylogeographical structure of <Emphasis Type="Italic">Saxifraga callosa</Emphasis>

This paper illustrates the phylogeographical structure of Saxifraga callosa in order to describe its genetic richness in refugial areas and to reconstruct its glacial history. S. callosa is a species spread throughout south-east France and Italy with a high distribution in the Maritime Alps. Four chloroplast microsatellite and AFLP markers were analyzed in populations of S. callosa. The size variants of all tested loci amount to 11 different haplotypes. Intrapopulational haplotype variation was found in two of the populations analyzed: on the Mt. Toraggio in the Maritime Alps, and in the Apuan Alps. On the other hand, no intrapopulational variation was found in 25 populations, most of which were sampled from isolated areas. Analysis of the haplotype distribution showed that population subdivision across all populations was high (G _ST = 0.899). Moreover, its genetic structure was studied using AMOVA and STRUCTURE analysis. The study legitimated inferred conclusions about the phylogeographical structure of the species and identified centers of diversity. Considerations concerning genetic structure and divergence among three major clades (Maritime Alps, Apuan Alps and Apennines), the patchy distribution of haplotypes, and the high number of private haplotypes support the proposal that S. callosa survived in some refugia within the Italian Peninsula refugium, and that mainly northern populations of refugia were involved in postglacial recolonization.     

High gene flow in two thrips‐pollinated South‐East Asian pioneer trees: genetic diversity and population structure of Macaranga hypoleuca and M. beccariana (Euphorbiaceae)

As a result of intensive exploitation, disturbed forests now dominate large areas of lowland tropical rainforest in South‐East Asia. The genus Macaranga comprises some of the most important pioneer tree species of the region, among them M. beccariana and M. hypoleuca, two closely related obligate ant‐plants pollinated by thrips. We used nuclear and plastid DNA markers to address questions of genetic diversity and population structure. Twelve plastid haplotypes were detected among 281 samples, three of which were shared between the two study species. Hybrids between the two species appear to be rare. Overall, genetic diversity in both species was moderate to high, with low levels of population differentiation, consistent with other tropical pioneer trees. Genetic structure was generally more pronounced in plastid than in nuclear data, indicating that gene flow via pollen may be more efficient than via seeds. Thrips apparently also serve as efficient pollinators over long distances, perhaps through a combination of passive dispersal by wind and active search for inflorescences in the target area. Our results indicate that M. beccariana and M. hypoleuca populations from recently disturbed habitats do not yet suffer from reduced genetic diversity or increased inbreeding. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 173 , 606–621.     

Cryptic diversity in a widespread live‐bearing fish (Poeciliidae: Belonesox)

Belonesox belizanus Kner (Teleostei: Poeciliidae) is a wide‐spread livebearing species that occurs on the Atlantic Slope of Central America from southern Mexico to northern Costa Rica. Previous work has noted morphological variation within the species, and recognized two subspecies: Belonesox belizanus belizanus and Belonesox belizanus maxillosus. We used 1122 bp of cytochrome b and 617 bp of S7‐1 DNA to conduct a phylogeographical study of Belonesox, aiming to examine the genetic distinctiveness of these taxa and other populations of Belonesox throughout the range. Bayesian phylogenetic and haplotype analyses indicated that B. b. maxillosus is not distinctive from other northern populations of Belonesox. However, a distinct phylogeographical break is evident near the Rio Grande in southern Belize. One clade comprises the putative B. b. maxillosus and all populations sampled north of the Rio Grande. The other clade comprises the Rio Grande and all populations south thereof. Fossil‐calibrated divergence time estimates suggest that isolation of the northern and southern lineages of Belonesox occurred approximately 14.1 Mya. The phylogeographical structure recovered in the present study is interesting, considering that relatively few studies have examined molecular variation across this portion of Middle America in a time‐calibrated framework. Furthermore, the present study suggests that more work is needed to adequately understand the factors that have shaped diversity of this region. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109 , 848–860.     

Comparative phylogeography of Australo‐Papuan mangrove‐restricted and mangrove‐associated avifaunas

The world's richest mangrove‐restricted avifauna is in Australia and New Guinea. The history of differentiation of the species involved and their patterns of intraspecific genetic variation remain poorly known. Here, we use sequence data derived from two mitochondrial protein‐coding genes to study the evolutionary history of eight co‐distributed mangrove‐restricted and mangrove‐associated birds from the Australian part of this region. Utilizing a comparative phylogeographical framework, we observed that the study species present concordantly located phylogeographical breaks across their shared geographical distribution, a plausible signature of common mechanisms of vicariance underlying this pattern. Barriers such as the Canning Gap, Bonaparte Gap, and the Carpentarian Gaps all had important but varying degrees of impact on the studied species. The Burdekin Gap along Australia's eastern seaboard probably had only a minor influence as a barrier to gene flow in mangrove birds. Statistical phylogeographical simulations were able to discriminate among alternative scenarios involving six different geographical and temporal population separations. Species exhibiting recent colonizations into mangroves include Rhipidura phasiana, Myiagra ruficollis, and Myzomela erythrocephala. By contrast, Peneoenanthe pulverulenta, Pachycephala melanura, Pachycephala lanioides, Zosterops luteus, and Colluricincla megarhyncha all had deeper histories, reflected as more marked phylogeographical divisions separating populations on the eastern seaboard/Cape York Peninsula from more western regions such as the Arnhem Land, the Pilbara, and the Kimberley. © 2013 The Linnean Society of London, Biological Journal of the Linnean Society, 2013, 109 , 574–598.     

The phylogeographical and population genetic approach to the investigation of the genetic diversity patterns in self‐incompatible clonal and polyploid Linnaea borealis subsp. borealis

Surveys of genetic diversity patterns of self‐incompatible clonal polyploid plant species are still scarcer than those of diploid plant species. Therefore, I studied the phylogeographical history of Linnaea borealis subsp. borealis to shed light on the colonization history of this clonal self‐incompatible polyploid plant in Eurasia using selected regions of plastid DNA and genetic diversity patterns of 22 populations of this species employing AFLP markers. I also addressed the question of whether the genetic diversity patterns in L. borealis subsp. borealis in Eurasia are similar to those of earlier published studies of clonal self‐incompatible diploid or polyploid plants. This survey revealed that the shallow phylogeographical history (six plastid haplotypes forming one haplogroup, 100% bootstrap support) and moderate genome‐wide diversity estimated using AFLP markers (Frag_poly = 10.8–38.9%, I = 0.060–0.180, F_ST = 0.289) were general characteristics of L. borealis subsp. borealis in its Eurasian range. The sampling strategy, in most cases at 1–2‐m or even 3–5‐m intervals, showed that a balance between vegetative and sexual reproduction and limited pollen dispersal among compatible mates can be important for genetic diversity patterns in populations of this taxon. Despite the fact that one‐half of the investigated populations were strongly isolated, they still preserved similar levels of genetic diversity across the geographical range. I found no support for the hypothesis that a bottleneck and/or inbreeding had accompanied habitat fragmentation as factors shaping genetic diversity. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 173 , 64–76.     

Long‐term ‘islands’ in the landscape: low gene flow,effective population size and genetic divergence in the shrub Hakea oldfieldii (Proteaceae)

The genetic structure of disjunct populations is determined by founding genetic properties, demographic processes, gene flow, drift and local selection. We aim to identify the genetic consequences of natural population disjunction at regional and local scales in Hakea oldfieldii using nuclear and plastid markers to investigate long‐term effective population sizes and gene flow, and patterns of diversity and divergence, among populations. Regional divergence was significant as shown by a consistent pattern in principal coordinates, neighbor‐joining and Bayesian analyses, but divergence at the local level was also significant with localized distribution of plastid haplotypes and populations clustering separately in Bayesian analyses. Historical, recent and first‐generation gene flow was low, suggesting that recent habitat fragmentation has not reduced gene migration significantly. Genetic bottlenecks were detected in three populations. Long‐term effective population size was significantly correlated with the number of alleles/locus and observed heterozygosity, but not with census population size, suggesting that the loss of diversity is associated with long‐term changes rather than recent fragmentation. Inbreeding coefficients were significant in only three populations, suggesting that the loss of diversity is linked to drift and bottlenecks associated with demographic processes (local extinction by fires) rather than inbreeding. Historical disjunction as a result of specific ecological requirements, contraction of habitats following drying during the Pleistocene, low gene flow and changes in population size are likely to have been important forces driving divergence through isolation by distance and drift. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 319–334.     

The molecular population structure of the tall forb Cicerbita alpina (Asteraceae) supports the idea of cryptic glacial refugia in central Europe

There is an ongoing debate about the glacial history of non‐arctic species in central and northern Europe. The two main hypotheses are: (1) postglacial colonization from refugia outside this region; (2) glacial survival in microclimatically favourable sites within the periglacial areas. In order to clarify the glacial history of a boreo‐montane tall forb, we analysed AFLPs from populations of Cicerbita alpina through most of its range (Scandinavia, the mountains of central Europe, the Alps, the Pyrenees and the Balkan Peninsula). We found a major differentiation between the Pyrenean population and all others, supported by principal coordinate, neighbour joining and STRUCTURE analyses. Furthermore, three populations from the central and north‐eastern Alps were genetically distinct from the bulk of populations from Scandinavia, central Europe, the Alps and the Balkan Peninsula. Most populations, including those from central and northern Europe, had moderate to high levels of genetic diversity (mean Shannon index H_Sh = 0.292, mean percentage of polymorphic loci P = 54.1%, mean Nei's gene diversity H = 0.195). The results indicate separate glacial refugia in the Pyrenean region and the Italian Alps. Furthermore, they provide evidence of glacial persistence in cryptic refugia north of the Alps, from where Scandinavia and most of the Alps are likely to have been colonized following deglaciation. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 164 , 142–154.     

Conservation genetics of the rare Iberian endemic Cheirolophus uliginosus (Asteraceae)

Cheirolophus uliginosus is a rare species, endemic to the south‐western Iberian Peninsula, and listed as a characteristic taxon from the temperate Atlantic wet heaths, a priority habitat for conservation by the European Union. The conservation status of this species in most of its distribution area is poorly known, but, in recent times, some populations have disappeared and there has been a reduction in the number of individuals in others. In this context, we analysed the effects of population size on genetic diversity, revealing that genetic erosion and inbreeding depression could be having a significant impact on smaller populations. Furthermore, we studied the patterns of genetic structure and variability at the species level, finding a strikingly low within‐population diversity and high among‐population genetic differentiation. Finally, the genetic structure analyses suggested a long and complex phylogeographical history of C. uliginosus in the region, in agreement with the climate relict status proposed for this species. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 157–171.     

Southern isolation and northern long‐distance dispersal shaped the phylogeography of the widespread,but highly disjunct,European high mountain plant Artemisia eriantha (Asteraceae)

We investigated the range dynamics of Artemisia eriantha, a widespread, but rare, mountain plant with a highly disjunct distribution in the European Alpine System. We focused on testing the roles of vicariance and long‐distance dispersal in shaping the current distribution of the species. To this end, we collected AFLP and plastid DNA sequence data for 17 populations covering the entire distributional range of the species. Strong phylogeographical structure was found in both datasets. AFLP data suggested that almost all populations were genetically strongly differentiated, with 58% of the overall genetic variation partitioned among populations. Bayesian clustering identified five groups of populations: Balkans, Pyrenees, Central Apennines, one southwestern Alpine population and a Widespread cluster (eastern Pyrenees, Alps, Carpathians). Major groups were supported by neighbor‐joining and NeighbourNet analyses. Fourteen plastid haplotypes were found constituting five strongly distinct lineages: Alps plus Pyrenees, Apennines, Balkans, southern Carpathians, and a Widespread group (eastern Pyrenees, northern Carpathians, Mt. Olympus). Plastid DNA data suggested that A. eriantha colonized the European Alpine System in a westward direction. Although, in southern Europe, vicariant differentiation among the Iberian, Italian and Balkan Peninsulas predominated, thus highlighting their importance as glacial refugia for alpine species, in temperate mountain ranges, long‐distance dispersal prevailed. This study emphasizes that currently highly disjunct distributions can be shaped by both vicariance and long‐distance dispersal, although their relative importance may be geographically structured along, for instance, latitude, as in A. eriantha. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 174 , 214–226.     

Disjunct distribution of Hypericum nummularium L. (Hypericaceae): molecular data suggest bidirectional colonization from a single refugium rather than survival in distinct refugia

Hypericum nummularium has a strongly disjunct, bi‐areal distribution in Europe: it is abundant in the Pyrenees and grows in a very restricted part of the Alps, more than 1000 km away. My aim was to estimate the genetic divergence between these areas and to identify the factors responsible for the disjunction: glacial relicts, bidirectional colonization from a common refugium, long‐distance dispersal and/or human introduction? Internal transcribed spacers (ITS) sequencing (680 bp) and amplified fragment length polymorphism (AFLP) fingerprinting (104 polymorphic markers) showed very low differentiation between populations in the Alps and the Pyrenees, indicating that H. nummularium probably survived in a single refugium. Moreover, levels of genetic diversity were similar in the two areas, making human introduction and long‐distance dispersal unlikely. Thus, the species probably survived in one refugium, subsequently colonizing both areas more or less simultaneously. The comparison of genetic and geographical distances suggested a step by step migration in the Alps (isolation by distance), whereas random dispersal events were more likely in the Pyrenees. Finally, I discuss possible causes for the restricted distribution area of H. nummularium in the Alps (e.g. unsuitable habitat, low dispersal capacities) and conclude that strong human disturbance is probably the major limit to the expansion of the species in this region. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society, 2006, 87 , 437–447.     

Historical divergence vs. contemporary gene flow: evolutionary history of the calcicole Ranunculus alpestris group (Ranunculaceae) in the European Alps and the Carpathians

Although many species have similar total distributional ranges, they might be restricted to very different habitats and might have different phylogeographical histories. In the European Alps, our excellent knowledge of the evolutionary history of silicate‐dwelling (silicicole) plants is contrasted by a virtual lack of data from limestone‐dwelling (calcicole) plants. These two categories exhibit fundamentally different distribution patterns within the Alps and are expected to differ strongly with respect to their glacial history. The calcicole Ranunculus alpestris group comprises three diploid species of alpine habitats. Ranunculus alpestris s. str. is distributed over the southern European mountain system, while R. bilobus and R. traunfellneri are southern Alpine narrow endemics. To explore their phylogenetic relationships and phylogeographical history, we investigated the correlation between information given by nuclear and chloroplast DNA data. Analyses of amplified fragment length polymorphism fingerprints and matK sequences gave incongruent results, indicative for reticulate evolution. Our data highlight historical episodes of range fragmentation and expansion, occasional long‐distance dispersal and on‐going gene flow as important processes shaping the genetic structure of the group. Genetic divergence, expressed as a rarity index (‘frequency‐down‐weighted marker values’) seems a better indicator of historical processes than patterns of genetic diversity, which rather mirror contemporary processes as connectivity of populations and population sizes. Three phylogeographical subgroups have been found within the R. alpestris group, neither following taxonomy nor geography. Genetic heterogeneity in the Southern Alps contrasts with Northern Alpine uniformity. The Carpathians have been stepwise‐colonised from the Eastern Alpine lineage, resulting in a marked diversity loss in the Southern Carpathians. The main divergence within the group, separating the ancestor of the two endemic species from R. alpestris s. str., predates the Quaternary. Therefore, range shifts produced by palaeoclimatic oscillations seem to have acted on the genetic structure of R. alpestris group on a more regional level, e.g. triggering an allopatric separation of R. traunfellneri from R. bilobus.     

Phylogeography and palaeodistribution modelling of Nassauvia subgenus Strongyloma (Asteraceae): exploring phylogeographical scenarios in the Patagonian steppe

The Patagonian steppe is an immense, cold, arid region, yet phylogeographically understudied. Nassauvia subgen. Strongyloma is a characteristic element of the steppe, exhibiting a continuum of morphological variation. This taxon provides a relevant phylogeographical model not only to understand how past environmental changes shaped the genetic structure of its populations, but also to explore phylogeographical scenarios at the large geographical scale of the Patagonian steppe. Here, we (1) assess demographic processes and historical events that shaped current geographic patterns of haplotypic diversity; (2) analyze hypotheses of isolation in refugia, fragmentation of populations, and/or colonization of available areas during Pleistocene glaciations; and (3) model extant and palaeoclimatic distributions to support inferred phylogeographical patterns. Chloroplast intergenic spacers, rpl32–trnL and trnQ–5′rps16, were sequenced for 372 individuals from 63 populations. Nested clade analysis, analyses of molecular variance, and neutrality tests were performed to assess genetic structure and range expansion. The present potential distribution was modelled and projected onto a last glacial maximum (LGM) model. Of 41 haplotypes observed, ten were shared among populations associated with different morphological variants. Populations with highest haplotype diversity and private haplotypes were found in central‐western and south‐eastern Patagonia, consistent with long‐term persistence in refugia during Pleistocene. Palaeomodelling suggested a shift toward the palaeoseashore during LGM; new available areas over the exposed Atlantic submarine platform were colonized during glaciations with postglacial retraction of populations. A scenario of fragmentation and posterior range expansion may explain the observed patterns in the center of the steppe, which is supported by palaeomodelling. Northern Patagonian populations were isolated from southern populations by the Chubut and the Deseado river basins during glaciations. Pleistocene glaciations indirectly impacted the distribution, demography, and diversification of subgen. Strongyloma through decreased winter temperatures and water availability in different areas of its range.     

Cytotype distribution and phylogeography of Hieracium intybaceum (Asteraceae)

Using flow cytometry and amplified fragment length polymorphism (AFLP), we explored the cytogeography and phylogeography of Hieracium intybaceum, a silicicolous species distributed in the Alps and spatially isolated in the Vosges Mountains and the Schwarzwald Mountains. We detected two ploidies, diploid and tetraploid, but no triploid or mixed‐ploidy populations. Whereas diploids are sexual and distributed all across the Alps, tetraploids are apomictic and seem to be confined to the western Alps and the Vosges. We detected a low level of genetic variation. Bayesian clustering identified four clusters/genetic groups, which are partly congruent with the ploidal pattern. The first two groups consisting exclusively of diploids dominate the whole distribution range in the Alps and show east–west geographical separation with a diffuse borderline running from eastern Switzerland to the eastern part of North Tyrol. The third genetic group lacks a defined geographical range and includes diploid and tetraploid plants. The last genetic group comprises tetraploid plants in the French Alps and the Vosges. We suppose that diploids colonized the deglaciated areas from source populations most likely located mainly in the southern part of the recent distribution range and occasionally also in the western Alps. Gene flow and further differentiation likely took place. Apomictic tetraploids most likely originated in the western Alps or in the refugium at the south‐western foot of the Alps. Their rather limited geographical range (partly contrasting with the theory of geographical parthenogenesis) can be explained by their rather recent origin. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 487–498.     

Genetic diversity and gene flow within and between two different habitats of Primula merrilliana (Primulaceae), an endangered distylous forest herb in eastern China

Understanding whether and how different habitats shape population genetics is a fundamental question and a specific goal for evolutionary and conservation biology research. This study examined genetic diversity and gene flow within and between mountain and foothill habitats of Primula merrilliana, an endangered distylous forest herb in eastern China. Eleven population characteristics, including area, size and density variation, from the two habitats were also investigated. Mountain populations had significantly higher mean genetic diversity than foothill populations, which may be explained by stronger self‐incompatibility breeding system, more opportunity to use elevational shifts to track suitable sites under conditions of climate change and more heterogeneous environments in the former habitat, rather than by the differences of population size, gene flow and genetic drift intensity between them. Genetic analysis revealed that two distinct lineages, corresponding to the two habitats, diverged at China's ‘Last Glaciation’ (11 700–67 500 yr BP), suggesting this divergence was probably triggered by warmer climates during inter‐ (or post‐) glacial periods. Low unidirectional gene flow from mountain to foothill habitats, chiefly by seed dispersal, played a more important role in overall gene flow between habitats than within‐habitat gene flow. Within habitats, pollen contributes more substantially to gene flow than seed dispersal, especially in foothill habitats, possibly due to higher individual density and larger population sizes. These results have implications for the conservation in this and similar landscape areas and indicate the need to protect suitable habitats with wide elevational spans and sufficient size to permit ecological and elevational shifts in response to climatic changes. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 172–189.     

Genetic drift drives evolution in the bird‐pollinated,terrestrial island endemic Grevillea georgeana (Proteaceae)

Plant species distributed across terrestrial islands can show significant genetic divergence among populations if seed and pollen dispersal are restricted. We assessed the genetic connectivity between populations of Grevillea georgeana, restricted to seven disjunct inselbergs in semi‐arid Western Australia. The phylogeographical pattern and population genetics of populations were determined using sequence data from two plastid DNA intergenic spacers and ten nuclear microsatellite loci. The plastid DNA markers indicated high genetic differentiation among the majority of populations. Haplotypes were restricted to individual inselbergs, with the exception of two that were shared among three isolated populations that formed part of an elongated greenstone belt and that may be connected via inaccessible populations of G. georgeana. There was also strong differentiation within some of the populations, suggesting long‐term isolation and persistence of G. georgeana on these terrestrial islands. Overall, the genetic patterns suggest limited seed dispersal, with differentiation in the plastid DNA genome being driven by genetic drift. In contrast, pollen movement, although generally restricted, may occur between neighbouring populations, resulting in a pattern of isolation by distance in the nuclear markers. This potential for limited or no seed dispersal, but connectivity via pollen flow, should be considered, given that many of the inselbergs are under consideration for resource development. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 178 , 155–168.