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Arnica montana is a clonal, self-incompatible herb of economic and intrinsic ecological value which is declining in large parts of its range. With the employment of microsatellite markers, we characterized the population structure and distribution of genetic diversity of 40 populations of A. montana sampled throughout Europe. We detected a clear geographical pattern of isolation and strong population structure, indicating limited gene flow. We also observed a negative latitudinal gradient in genetic diversity. Such patterns can be explained by paleo-historical colonization routes following the last glacial maximum, with regions characterized by higher genetic diversity corresponding to former glacial refugia. We recommend the implementation of conservation measures such as assisted gene flow in the populations characterized by low genetic diversity under consideration of the observed population structure. For the populations where high levels of genetic diversity are still retained, we recommend the maintenance of suitable habitat conditions. Our study emphasises the importance of conducting large-scale population genetic studies that consider postglacial recolonization history when planning active conservation measures such as assisted gene flow. [ABSTRACT FROM AUTHOR]

Population size, genetic diversity, and performance have fundamental importance for ecology, evolution, and nature conservation of plant species. Despite well‐studied relationships among environmental, genetic, and intraspecific trait variation (ITV), the influence of population size on these aspects is less understood. To assess the sources of population size variation, but also its impact on genetic, functional trait, and performance aspects, we conducted detailed population size estimations, assessed 23 abiotic and biotic environmental habitat factors, performed population genetic analyses using nine microsatellite markers, and recorded nine functional traits based on 260 Trifolium montanum individuals from 13 semi‐dry grassland locations of Central Europe. Modern statistical analyses based on a multivariate framework (path analysis) with preselected linear regression models revealed that the variation of abiotic factors (in contrast to factors per se) almost completely, significantly explained fluctuations in population size (R2 =.93). In general, abiotic habitat variation (heterogeneity) was not affected by habitat area. Population size significantly explained genetic diversity (NA: R2 =.42, Ho: R2 =.67, He: R2 =.43, and I: R2 =.59), inbreeding (FIS: R2 =.35), and differentiation (GST: R2 =.20). We also found that iFDCV (ITV) was significantly explained by abiotic habitat heterogeneity, and to a lesser extent by genetic diversity He (R2 =.81). Nevertheless, habitat heterogeneity did not statistically affect genetic diversity. This may be due to the use of selectively neutral microsatellite markers, and possibly by insufficient abiotic selective pressures on habitats examined. Small T. montanum populations in nonoptimal habitats were characterized by reduced genetic and functional trait diversity, and elevated genetic inbreeding and differentiation. This indicates reduced adaptability to current and future environmental changes. The long‐term survival of small populations with reduced genetic diversity and beginning inbreeding will be highly dependent on habitat protection and adequate land‐use actions. [ABSTRACT FROM AUTHOR]

Harmonia axyridis Pallas (1773) (Coleoptera: Coccinellidae) is one of the most studied invasive species of insects. H. axyridis appeared in Europe in 2000, and from that moment, the expansion of the species to the east has continued in the direction of the native range. To determine the populations that are sources for the formation of the eastern front of invasion, we studied the variability and genetic structure of invasive and native populations of the species using 12 microsatellite markers. We found that there was no decrease in the average expected heterozygosity in invasive populations as compared with native populations; however, a significant decrease in the allelic diversity was observed. It was demonstrated that the allelic diversity in invasive populations depends on their "age." We found that the level of differentiation of invasive populations is significantly higher than in the group of native populations. Cluster analysis demonstrated that European invasive H. axyridis populations are divided into two groups, indicating their origin as a result of several waves of migration. Our analysis demonstrated no significant differences between the groups of native populations, which is most likely a consequence of homoplasy of microsatellite markers that arose in the course of the evolution of the species. Our results suggest that the eastern front of invasion is formed by descendants of northern Italian WNA propagule. [ABSTRACT FROM AUTHOR]

The service tree (Sorbus domestica) is a rare tree species with a scarce distribution across Europe. In Central Europe, where it occurs at northern distribution limits, it is confined to several areas with a very scattered distribution affected by the human impact on the landscape. In this study, we aimed to understand the genetic diversity of its Central European population in a fragmented landscape and its relationship to the origin of different populations. We used 5 microsatellite loci to analyse 189 individuals from 13 populations, mainly from Central Europe with additional sampling from other parts of Europe and Asia. Standard population genetic characteristics and investigation on population structure revealed relatively high genetic diversity within populations, suggesting long-distance pollen dispersal and/or dispersion influenced by humans. All populations showed weak to moderate genetic differentiation, revealing that the marginal Central European population forms clusters that are linked to other Pannonian or Mediterranean populations, whereas Bohemian ones are linked to German populations, suggesting different origins for the populations in the eastern vs. western parts of Central Europe. Genetic variation suggests a natural continuum with neighbouring populations; however, relatively high genetic variation, the character of localities and population structure suggest an anthropogenic origin. [ABSTRACT FROM AUTHOR]

Simple Summary: The pikeperch Sander lucioperca (Linnaeus, 1758) is an important fish species in the development of European aquaculture. The aquaculture of a fish species can be facilitated by knowing the genetic variability within and among populations. Here, we assessed the genetic background of 8 wild populations along with 13 broodstocks (i.e., from fish farms) of pikeperch through a combination of genetic markers. We underlined that current broodstocks have a genetic diversity similar to wild populations. When focusing on genetic differentiation, we highlight that European pikeperch populations are divided into two groups: one predominantly present in Northern Europe and around the Baltic Sea and another mainly in Central Europe. Broodstocks appear to contain fish of a single origin with only a few exceptions. Ultimately, we have proposed baseline information about genetic diversity of pikeperch along with a genetic tool that can help pikeperch producers manage and improve their fish stock. The pikeperch is a freshwater/brackish water fish species with growing interest for European aquaculture. Wild populations show signs of decline in many areas of the species natural range due to human activities. The comparative evaluation of genetic status in wild and domesticated populations is extremely useful for the future establishment of genetic breeding programs. The main objective of the present study was to assess and compare the genetic variability of 13 domesticated populations from commercial farms and 8 wild populations, developing an efficient microsatellite multiplex tool for genotyping. Partial cytochrome b gene sequences were also used to infer phylogeographic relationships. Results show that on average, the domesticated populations do not exhibit significantly lower levels of genetic diversity compared to the wild ones and do not suffer from inbreeding. Nuclear data provide evidence that pikeperch populations in Europe belong to at least two genetically differentiated groups: the first one is predominantly present in Northern Europe and around the Baltic Sea, while the second one comprises populations from Central Europe. In this second group, Hungarian origin populations constitute a differentiated stock that needs special consideration. Aquaculture broodstocks analyzed appear to contain fish of a single origin with only a few exceptions. [ABSTRACT FROM AUTHOR]

Some tree species have distributions on both sides of the Strait of Gibraltar and the Strait of Sicily. It is a challenge to determine whether such distributions result from the Tertiary or Pleistocene or from more recent dispersal related to human activities. Tetraclinis articulata (Cupressaceae) is a gymnosperm that offers an ideal model to deal with this problem because it has a limited area of distribution and has been used only moderately by humans. Three hundred and twenty-three individuals from 30 populations covering the entire distribution of the species were analysed. A multiple approach was developed: (1) by assessing the genetic structure through two molecular techniques, AFLP and nSSR markers, which were used to evaluate the genetic diversity of these populations and the relationships among them and (2) by estimating past distributions. Four lineages of populations that are geographically intermixed to a certain extent are documented here. Results obtained are discussed in the context of palaeontological records and climatic models. There is evidence of an ancient widespread distribution, including Europe, and the subsequent appearance of four isolated lineages that, nowadays, are partially intermixed. Nevertheless, the origin of the current populations could not be fully ascertained through this work, although logical deductions are discussed that consider human activities or, much less probably, wind dispersal of seeds out of refugia in northern Africa-southern Europe during the Quaternary, including shore connections. [ABSTRACT FROM AUTHOR]

Background: Sympatric speciation along ecological gradients has been studied repeatedly, in particular in freshwater fishes. Rapid post-glacial ecological divergence has resulted in numerous endemic species or ecologically distinct populations in lakes of the temperate zones. Here, we focus on the Baltic cisco (Coregonus albula) complex, to study the genetic similarity among two pairs of sympatric autumn- and spring-spawning populations from post-glacial German Lakes Stechlin and Breiter Luzin. For comparison, we included a similar pair of sympatric populations from the Swedish Lake Fegen. We wanted to explore potential genetic similarities between the three sympatric cisco population pairs in the three lakes, to evaluate whether the pairs may have emerged independently in the three lakes, or whether two different species may have colonized all three lakes independently. Furthermore, we considered allopatric C. albula populations from three Polish, three Finnish, and four Swedish locations, added one Siberian population of the sister species C. sardinella and a Swedish C. maraena (whitefish) population. By genotyping nine microsatellite markers in 655 individuals from these 18 populations, we wanted to elucidate how strongly the cisco populations differ across a larger geographical area within Europe. Finally, we compared the genetic differences between the springand autumn-spawning populations of ciscoes in the two German lakes to infer the potentially deteriorating effect of strong anthropogenic pressure on the lakes. Results: Dendrogram, Principal Coordinate Analysis and admixture analysis all indicated strong correspondence between population differentiation and geographical location for most cisco populations in Europe, including the Siberian population of C. sardinella. However, populations from some Swedish lakes deviated from this general pattern, by showing a distinct genetic structure. We found evidence for independent evolution of the three sympatric population pairs, because the populations co-occurring in the same lake were always most closely related. However, genetic differentiation was weak in the two German population pairs, but strong in the Swedish Lake Fegen, indicating that the weak differentiation in the German pairs reported earlier has eroded further. Conclusions: Our results suggest that the genetic differentiation at neutral genetic markers among populations of the Baltic cisco complex has evolved (and is maintained) by random genetic drift in isolated populations. However, earlier studies on the Swedish populations combining mitochondrial DNA and microsatellite data indicate that also post-glacial immigration from separate glacial refugia has shaped the present genetic population structure. The low neutral differentiation of the German sympatric pairs in contrast to the Swedish pair suggests that recent anthropogenic effects on the lakes in Germany may put the endemic spring-spawners at risk to extinction. [ABSTRACT FROM AUTHOR]

Dispersal is a key process for the maintenance of intraspecific genetic diversity by ensuring gene flow within and between populations. Despite the ongoing expansion of large carnivores in Europe, lynx populations remain fragmented, isolated, and threatened by inbreeding and loss of genetic diversity. In the course of large carnivore monitoring in the Czech Republic, several biological samples of Eurasian lynx were collected outside the permanent occurrence of this species. Using microsatellite genotyping we identified these as four dispersing lynx males and applied multiple methods (Bayesian clustering in STRUCTURE, Principal Component Analysis (PCA), frequency-based method in GENECLASS2, and machine-learning framework in assignPOP) to assign them to possible source populations. For this we used genotypes from five European lynx populations: the Bohemian-Bavarian-Austrian (N = 36), Carpathian (N = 43), Scandinavian (N = 20), Baltic (N = 15), and Harz (N = 23) population. All four dispersers were successfully assigned to different source populations within Europe and each was recorded at a distance of more than 98 km from the edge of the distribution of the source population identified. Such movements are among the longest described for lynx in Central Europe to this point. The findings indicate the ability of lynx males to disperse in human-dominated landscape thus facilitation of these movements via creation and/or protection of potential migratory corridors together with protection of dispersing individuals should be of high importance in conservation of this iconic predator in Central Europe. [ABSTRACT FROM AUTHOR]

Invasive species frequently differentiate phenotypically in novel environments within a few generations, often even with limited genetic variation. For the invasive plants Solidago canadensis and S. gigantea, we tested whether such differentiation might have occurred through heritable epigenetic changes in cytosine methylation. In a 2‐year common‐garden experiment, we grew plants from seeds collected along a latitudinal gradient in their non‐native Central European range to test for trait differentiation and whether differentiation disappeared when seeds were treated with the demethylation agent zebularine. Microsatellite markers revealed no population structure along the latitudinal gradient in S. canadensis, but three genetic clusters in S. gigantea. Solidago canadensis showed latitudinal clines in flowering phenology and growth. In S. gigantea, the number of clonal offspring decreased with latitude. Although zebularine had a significant effect on early growth, probably through effects on cytosine methylation, latitudinal clines remained (or even got stronger) in plants raised from seeds treated with zebularine. Thus, our experiment provides no evidence that epigenetic mechanisms by selective cytosine methylation contribute to the observed phenotypic differentiation in invasive goldenrods in Central Europe. [ABSTRACT FROM AUTHOR]

Recurrent polyploid formation and weak reproductive barriers between independent polyploid lineages generate intricate species complexes with high diversity and reticulate evolutionary history. Uncovering the evolutionary processes that formed their present-day cytotypic and genetic structure is a challenging task. We studied the species complex of Cardamine pratensis , composed of diploid endemics in the European Mediterranean and diploid-polyploid lineages more widely distributed across Europe, focusing on the poorly understood variation in Central Europe. To elucidate the evolution of Central European populations we analyzed ploidy level and genome size variation, genetic patterns inferred from microsatellite markers and target enrichment of low-copy nuclear genes (Hyb-Seq), and environmental niche differentiation. We observed almost continuous variation in chromosome numbers and genome size in C. pratensis s.str., which is caused by the co-occurrence of euploid and dysploid cytotypes, along with aneuploids, and is likely accompanied by inter-cytotype mating. We inferred that the polyploid cytotypes of C. pratensis s.str. are both of single and multiple, spatially and temporally recurrent origins. The tetraploid Cardamine majovskyi evolved at least twice in different regions by autopolyploidy from diploid Cardamine matthioli. The extensive genome size and genetic variation of Cardamine rivularis reflects differentiation induced by the geographic isolation of disjunct populations, establishment of triploids of different origins, and hybridization with sympatric C. matthioli. Geographically structured genetic lineages identified in the species under study, which are also ecologically divergent, are interpreted as descendants from different source populations in multiple glacial refugia. The postglacial range expansion was accompanied by substantial genetic admixture between the lineages of C. pratensis s.str., which is reflected by diffuse borders in their contact zones. In conclusion, we identified an interplay of diverse processes that have driven the evolution of the species studied, including allopatric and ecological divergence, hybridization, multiple polyploid origins, and genetic reshuffling caused by Pleistocene climate-induced range dynamics. [ABSTRACT FROM AUTHOR]

The great scallop (Pecten maximus) is a commercially important bivalve in Europe, particularly in the English Channel, where fisheries are managed at regional and local scales through the regulation of fishing effort. In the long term, knowledge about larval dispersal and gene flow between populations is essential to ensure proper stock management. Yet, previous population genetic studies have reported contradictory results.In this study, scallop samples collected across the main fishing grounds along the French and English coasts of the English Channel (20 samples with temporal replicates for three sites, n = 1059 individuals), and the population genetic structure was analysed using 13 microsatellite loci. Coupling empirical genetic data with demogenetic modelling based on a biophysical model simulating larval exchanges among scallop beds revealed a subtle genetic differentiation between south‐west English populations and the rest of the English Channel, which was consistent with larval dispersal simulations.The present study provides a step forward in the understanding of great scallop population biology in the English Channel, underlining the fact that even in a context of potentially high gene flow and recent divergence times since the end of the last glacial maximum, weak but significant spatial genetic structure can be identified at a regional scale. [ABSTRACT FROM AUTHOR]

Key message: Pinus nigraJ.F. Arnold has an ecological and economic interest in Europe, but many of the planted populations have an unknown origin and infraspecific taxonomy. Six PortugueseP. nigrapopulations characterised with microsatellites revealed high intra-population diversity structured into two clusters with low differentiation that might suggest two provenances or infraspecific taxa. Despite compared with foreign samples from different subspecies, we were not able to infer about the origin or infraspecific taxonomy of the Portuguese populations based on the pooled microsatellite data. Context: Many of the European Pinus nigra J.F. Arnold forests were planted with the material of unknown origin. Efforts have been made to determine their provenances and infraspecific taxonomy regarding their relevance for defining strategies of genetic resources conservation, germplasm use, forest management and genetic improvement. The Portuguese P. nigra populations are allochthonous, and their provenance and infraspecific taxonomy are unknown. Aims: With this work, we intended to characterise the Portuguese P. nigra populations regarding its genetic diversity, structure and relationships using simple sequence repeat (SSR) markers and/or to infer about its origin and infraspecific taxonomy by comparing the SSR patterns of foreign P. nigra samples of known taxonomic classification. Methods: A total of 224 Portuguese P. nigra individuals from six populations were characterised using 14 SSR markers developed specifically to different Pinus sp., including P. nigra, by other authors. Results: Thirteen SSR loci were selected and showed 100% of polymorphism among individuals. The genetic diversity was higher within (95%) rather than among (5%) populations. The Portuguese individuals were structured into two main clusters (K = 2) with low genetic differentiation (FST = 0.04), and the foreign samples were genetically distant from the Portuguese individuals. Conclusion: The six Portuguese P. nigra populations revealed high genetic diversity and seemed to be structured into two main clusters with low differentiation suggesting two provenances or infraspecific taxa. Nonetheless, the comparative analyses with foreign samples did not allow a clear inference about its origin and/or infraspecific taxonomy. Additional foreign samples and/or molecular markers will be tested to pursue these goals. [ABSTRACT FROM AUTHOR]

Many ephemeral mudflat species, which rely on a soil seed bank to build up the next generation, are endangered in their natural habitat due to the widespread regulation of rivers. The aim of the present study was to elucidate the role of the soil seed bank and dispersal for the maintenance of genetic diversity in populations of near‐natural river habitats and anthropogenic habitats created by traditional fish farming practices using Cyperus fuscus as a model. Using microsatellite markers, we found no difference in genetic diversity levels between soil seed bank and above‐ground population and only moderate differentiation between the two fractions. One possible interpretation is the difference in short‐term selection during germination under specific conditions (glasshouse versus field) resulting in an ecological filtering of genotypes out of the reservoir in the soil. River populations harbored significantly more genetic diversity than populations from the anthropogenic pond types. We suggest that altered levels and patterns of dispersal together with stronger selection pressures and historical bottlenecks in anthropogenic habitats are responsible for the observed reduction in genetic diversity. Dispersal is also supposed to largely prohibit genetic structure across Europe, although there is a gradient in private allelic richness from southern Europe (high values) to northern, especially north‐western, Europe (low values), which probably relates to postglacial expansion out of southern and/or eastern refugia. [ABSTRACT FROM AUTHOR]

Following its first record in Europe in 2013, the North American ragweed leaf beetle Ophraella communa, used already as a most successful biocontrol agent against common ragweed in China, is spreading rapidly, asking for a detailed analysis of the potential benefit and risk of this introduction for Europe. Here, we report twelve specific and polymorphic tetranucleotide microsatellite markers, which can be used for redrawing its global invasion history and spread across native and introduced ranges. The high level of polymorphism (i.e. from 4 to 18 alleles per locus) and the genetic variation detected within and between one native and two introduced populations provide adequate statistical power for elucidating the beetle's invasion process. [ABSTRACT FROM AUTHOR]

Using 10 polymorphic microsatellites and 1251 individual samples (some dating back to the early 1980s), genetic structure and effective population size in all native and introduced Swedish populations of the European wels catfish or Silurus glanis were studied. Levels of genetic variability and phylogeographic relationships were compared with data from a previous study of populations in other parts of Europe. The genetically distinct Swedish populations displayed comparably low levels of genetic variability and according to one‐sample estimates based on linkage disequilibrium and sib ship‐reconstruction, current local effective population sizes were lower than minimum levels recommended for short‐term genetic conservation. In line with a previous suggestion of postglacial colonisation from a single refugium, all Swedish populations were assembled on a common branch in a star‐shaped dendrogram together with other European populations. Two distinct subpopulations were detected in upper and lower habitats of River Emån, indicating that even minor dispersal barriers may restrict gene flow for wels in running waters. Genetic assignment of specimens encountered in the brackish Baltic Sea and in lakes where the species does not occur naturally indicated presence of long‐distance sea dispersal and confirmed unauthorised translocations, respectively. [ABSTRACT FROM AUTHOR]

The genus Rhagoletis (Diptera: Tephritidae) comprises more than 65 species distributed throughout Europe, Asia and America, including many species of high economic importance. Currently, there are three Rhagoletis species that infest fruits and nuts in Europe. The European cherry fruit fly, Rhagoletis cerasi (may have invaded Europe a long time ago from the Caucasian area of West Asia), and two invasive species (recently introduced from North America): the eastern American cherry fruit fly, R. cingulata , and the walnut husk fly, R. completa. The presence of different Rhagoletis species may enhance population dynamics and establish an unpredictable economic risk for several fruit and nut crops in Europe. Despite their excessive economic importance, little is known on population dynamics, genetics and symbiotic associations for making sound pest control decisions in terms of species-specific, environmental friendly pest control methods. To this end, the current paper (a) summarizes recently accumulated genetic and population data for the European Rhagoletis species and their association with the endosymbiont Wolbachia pipientis , and (b) explores the possibility of using the current knowledge for implementing the innovative biological control methods of sterile insect technique and incompatible insect technique. [ABSTRACT FROM AUTHOR]

Aquaculture finfish production based on floating cage technology has raised increasing concerns regarding the genetic integrity of natural populations. Accidental mass escapes can induce the loss of genetic diversity in wild populations by increasing genetic drift and inbreeding. Farm escapes probably represent an important issue in the gilthead sea bream (Sparus aurata), which accounted for 76.4% of total escapees recorded in Europe during a 3‐year survey. Here, we investigated patterns of genetic variation in farmed and wild populations of gilthead sea bream from the Western Mediterranean, a region of long gilthead sea bream farming. We focused on the role that genetic drift may play in shaping these patterns. Results based on microsatellite markers matched those observed in previous studies. Farmed populations showed lower levels of genetic diversity than wild populations and were genetically divergent from their wild counterparts. Overall, farmed populations showed the smallest effective population size and increased levels of relatedness compared to wild populations. The small broodstock size coupled with breeding practices that may favour the variance in individual reproductive success probably boosted genetic drift. This factor appeared to be a major driver of the genetic patterns observed in the gilthead sea bream populations analysed in the present study. These results further stress the importance of recommendations aimed at maintaining broodstock sizes as large as possible and equal sex‐ratios among breeders, as well as avoiding unequal contributions among parents. [ABSTRACT FROM AUTHOR]

The American rusty crayfish, Faxonius rusticus , is an invasive species in parts of North America where it displaces native crayfish species. In Europe, various invasive North American crayfish species are carriers of the crayfish plague disease agent Aphanomyces astaci that causes devastating population declines of European crayfish. Little is known about either the presence or the influence of A. astaci in North America where it originates. Here, we attempted to isolate A. astaci from North American F. rusticus for the first time and compare it to the strains detected in Europe. We tested the infection status of 84 F. rusticus samples from 10 different locations in the midwestern United States that are outside of the F. rusticus native distribution range. We used quantitative real-time PCR (qPCR) to assess the infection status in each individual, and we determined the mitochondrial haplotypes and multilocus microsatellite genotypes when it was possible. We detected A. astaci DNA in 9 individuals from 4 out of 10 locations. Analyses of the axenic culture isolates and the crayfish tissue samples by sequence analyses, haplotyping, and genotyping confirmed the results and revealed a novel A. astaci microsatellite genotype. Our results clearly identify F. rusticus as a host of A. astaci in North America. The threat of these strains to endangered crayfish species in North America remains unknown, but the potential of A. astaci infections should be considered when developing and implementing invasive species management plans for conservation purposes. [ABSTRACT FROM AUTHOR]

In the Western Palearctic, Myotis myotis comprises two morphologically and genetically distinct, Anatolian (eastern) and European (western), populations. The populations are parapatric with a narrow contact zone in Eastern Thrace. Anatolian M. myotis are larger than those in Europe and their size increases eastwards. Genotypes based on seven nuclear markers distinguish between eastern and western populations and indicate that gene flow between these populations is limited and asymmetric. Within a few hundred kilometres of Eastern Thrace, the Anatolian population consists almost entirely of individuals with distinctly eastern genotypes. The European population is composed of both distinctly western individuals and some admixed individuals. Mitochondrial DNA also differs between eastern and western M. myotis, with eastern and western populations of M. myotis sharing only one of 28 unique HVII haplotypes. We propose that partial reproductive isolation between M. myotis populations results from divergent selective forces. Genetically and morphologically, these populations satisfy the criteria of distinct evolutionary significant units. We suggest to expand the distributional range of the Levantine subspecies, M. m. macrocephalicus, to Anatolia and to recognize two subspecies in the species rank of Myotis myotis: M. m. myotis in Europe and M. m. macrocephalicus in Anatolia and Levant. [ABSTRACT FROM AUTHOR]

The rivers in northernmost Europe support many of the largest wild Atlantic salmon stocks supplying up to 60% of the total annual catch in the world, but very little is known about their relative contributions to coastal fisheries. We generated a comprehensive Atlantic salmon genetic baseline consisting of 185 populations along the Norwegian, Barents and White Sea coasts, genotyped for a high number of genetic markers, which has a dense geographical coverage and includes all notable stocks in the region. The hierarchical genetic structure observed was the basis for defining 7 regional and 26 local re3porting groups (RGs) enabling practical implementation of genetic stock identification (GSI). The GSI accuracy varied across populations and the study area, depending on the level of genetic structuring, but a high level of accuracy was achieved when individuals were classified to regional (97%) or to local (90%) RGs. Simulations showed that salmon from the majority of the largest populations in northernmost Europe can be reliably identified in Norwegian and Russian coastal mixed-stock fisheries. The baseline will be an invaluable resource for development of future adaptive management regimes for Atlantic salmon in northern Europe. [ABSTRACT FROM AUTHOR]

Morphological variation in widely distributed plants may be driven by phenotypic plasticity or underlying genetic differences. In the brackish to fresh open waters of San Francisco Estuary, there are at least two distinct growth forms of a native pondweed in the genus Stuckenia. We determined that all plants collected from throughout the region are S. pectinata by sequencing the nuclear ribosomal internal transcribed spacer (ITS) region. This led us to question if different morphologies result from intraspecific genetic differentiation or differences in water flow, which we explored using microsatellites and a common garden experiment, respectively. As only four of nine microsatellite loci developed in Europe were polymorphic for our samples, there was low resolution to detect differences; however, some multilocus genotypes found only in narrow-leaf samples hinted of within-species variation. Further, while morphological traits were plastic in response to flow manipulation, distinct morphotypes did not converge under the same conditions, implicating genetic differences. Regardless of mechanisms for contrasting growth forms, leaf size and quantity may affect available habitat for ecologically-important invertebrates. We found narrow/dense leaves supported greater invertebrate densities at both a low-salinity, and especially, a brackish site. The latter was dominated by an amphipod that we determined strongly prefers to consume narrower leaves. We conclude that both environmental conditions and genetic differentiation play a role in S. pectinata morphology. That these differences propagate to higher trophic levels calls for further investigation into the genetic basis for, as well as spatial extent of, the two morphotypes. • Stuckenia sp. pondweeds in San Francisco Estuary have unusual morphology. • Genetic data show plants ranging in morphology are all Stuckenia pectinata. • Common garden experiments only partially explain the range of variation in the region. • Within-species genetic variation may play a role in the observed variation. • Herbivory experiments suggest morphological differences affect higher trophic levels. [ABSTRACT FROM AUTHOR]

Arion vulgaris (syn. A. lusitanicus) is the most destructive pest slug in Europe. The species has been regarded a classic case of an ongoing biological invasion with negative economic and ecological impact in many European countries, but this status has recently been contested. In this study, we assessed mitochondrial and autosomal genetic diversity in populations of A. vulgaris across the entire distribution range in order to characterize its evolutionary history. Mitochondrial diversity in A. vulgaris was strongly reduced compared with the closely related and largely codistributed noninvasive species A. rufus and A. ater, indicating a very rapid spread of A. vulgaris through Europe. Autosomal diversity assessed in 632 individuals from 32 populations decreased towards eastern and northern Europe which is consistent with the reported expansion of the species towards these regions in the last decades. Demographic simulations supported very recent population founding events in most of the European range. The short periods between the first detection of A. vulgaris in different countries and only a very weak association of genetic structuring among populations with geographical distances suggest a human contribution in the ongoing expansion of the slug. We propose that this contribution may ultimately prevent the exact localization of the debated region of origin of A. vulgaris. However, the reclassification of A. vulgaris as noninvasive would be premature. Without counter measures, the Eastern and Northern European countries can expect to see this biological invasion continued in the future. [ABSTRACT FROM AUTHOR]

In human-altered landscapes, specialist butterflies typically form spatially restricted populations, genetically differentiated due to dispersal restrictions. Generalists, in contrast, display minimum differentiation but high genetic diversity. While local-level actions suffice to conserve specialists and landscape-level actions are necessary for generalists, minimum information exists regarding conservation of species with intermediate features. We targeted two congeneric butterflies, the recently re-expanding Argynnis adippe and the strongly declining A. niobe, co-occurring in the pastoral landscape of the Carpathian Mountains, Czech Republic. We integrated species distribution models, mark-recapture and microsatellite analysis to compare their habitat requirements, adult demography, dispersal and genetic patterns, and expanded the genetic analysis across the Carpathian Arc and beyond to delimit spatial conservation units. In two mountain valleys, both species formed interconnected populations numbering thousands of individuals. Mobility patterns suggested the populations' interconnection across the Czech Carpathians. Genetic diversity was extremely poor in the nonthreatened A. adippe and moderate in the declining A. niobe. No population differentiation was detected within the Czech Carpathians (~1500 km 2 ). Low genetic diversity and no differentiation was preserved in A. adippe across East Central Europe, whereas in A. niobe, populations from Serbia were differentiated from the Carpathian Arc + Alps. The high adult mobility linked to low differentiation probably reflects the distribution of larval resources, historically widespread but sparse and currently declining for A. niobe (grazing-disturbed grounds), while currently increasing for A. adippe (abandonment scrub, disturbed woodlands). Units as large as entire mountain systems define population boundaries, and hence conservation management units, for both species., (© 2022 John Wiley & Sons Ltd.)

Polyploidization is a rare yet sometimes successful way for animals to rapidly create geno- and phenotypes that may colonize new habitats and quickly adapt to environmental changes. In this study, we use water frogs of the Pelophylax esculentus complex, comprising two species ( Pelophylax lessonae, genotype LL; Pelophylax ridibundus, RR) and various diploid ( LR) and triploid ( LLR, LRR) hybrid forms, summarized as P. esculentus, as a model for studying recent hybridization and polyploidization in the context of speciation. Specifically, we compared the geographic distribution and genetic diversity of diploid and triploid hybrids across Europe to understand their origin, maintenance and potential role in hybrid speciation. We found that different hybrid and parental genotypes are not evenly distributed across Europe. Rather, their genetic diversity is structured by latitude and longitude and the presence/absence of parental species but not of triploids. Highest genetic diversity was observed in central and eastern Europe, the lowest in the northwestern parts of Europe. This gradient can be explained by the decrease in genetic diversity during postglacial expansion from southeastern glacial refuge areas. Genealogical relationships calculated on the basis of microsatellite data clearly indicate that hybrids are of multiple origin and include a huge variety of parental genomes. Water frogs in mixed-ploidy populations without any parental species (i.e. all-hybrid populations) can be viewed as evolutionary units that may be on their way towards hybrid speciation. Maintenance of such all-hybrid populations requires a continuous exchange of genomes between diploids and triploids, but scenarios for alternative evolutionary trajectories are discussed. [ABSTRACT FROM AUTHOR]

Heracleum mantegazzianum is a successful invader in many European countries. Besides its impact on biodiversity, it represents a health hazard because of its phototoxic sap. Population genetic studies may help to predict which species are most likely to become invasive. In this study, we investigated the population genetic variation and structure of Heracleum sp., identified as H. mantegazzianum in Finland, i.e., within its northern range of distribution, using microsatellite markers. Our aims were to reveal the genetic characteristics and evolutionary processes that have resulted in observed patterns. The amount of genetic variation measured as expected heterozygosity was modest (mean H = 0.406), which may be due to relatively small founder populations and/or inbreeding (mean F = 0.268). Mean allele numbers per population ranged from 2.0 to 4.7. The pairwise F values were generally high, and the mean F among all populations equalled 0.498. Based on F values, populations were significantly differentiated from each other, indicating restricted gene flow among the populations. The Bayesian structure analysis provided additional information on population genetic structure. The analysis divided the eight populations into two main clusters. Genetic analyses indicate that H. mantegazzianum has been introduced to Finland multiple times. Distinct population genetic patterns indicate that human-mediated dispersal is important. [ABSTRACT FROM AUTHOR]

Background: The phylogeography of the house mouse (Mus musculus L.), an emblematic species for genetic and biomedical studies, is only partly understood, essentially because of a sampling bias towards its most peripheral populations in Europe, Asia and the Americas. Moreover, the present-day phylogeographic hypotheses stem mostly from the study of mitochondrial lineages. In this article, we complement the mtDNA studies with a comprehensive survey of nuclear markers (19 microsatellite loci) typed in 963 individuals from 47 population samples, with an emphasis on the putative Middle-Eastern centre of dispersal of the species. Results: Based on correspondence analysis, distance and allele-sharing trees, we find a good coherence between geographical origin and genetic make-up of the populations. We thus confirm the clear distinction of the three best described peripheral subspecies, M. m. musculus, M. m. domesticus and M. m. castaneus. A large diversity was found in the Iranian populations, which have had an unclear taxonomic status to date. In addition to samples with clear affiliation to M. m. musculus and M. m. domesticus, we find two genetic groups in Central and South East Iran, which are as distinct from each other as they are from the south-east Asian M. m. castaneus. These groups were previously also found to harbor distinct mitochondrial haplotypes. Conclusion: We propose that the Iranian plateau is home to two more taxonomic units displaying complex primary and secondary relationships with their long recognized neighbours. This central region emerges as the area with the highest known diversity of mouse lineages within a restricted geographical area, designating it as the focal place to study the mechanisms of speciation and diversification of this species. [ABSTRACT FROM AUTHOR]

A number of mammal species in Europe, including the Eurasian otter ( Lutra lutra ), have experienced a decline in population size in the 20th century due to persecution, environmental pollution and ongoing habitat fragmentation. This has often led to a substantial loss of genetic diversity which may threaten population viability. While otters have been studied in some detail genetically, the northern part of the Fennoscandian range has not been covered well so far. By explicitly focussing on the genetics of otter populations from northern Sweden and Finland we aimed at closing that gap. To infer their genetic structure and diversity, we analysed sequences of the mitochondrial control region and 12 nuclear microsatellite markers in 197 Eurasian otters from Sweden and Finland. Variability of the mitochondrial control region was low overall but still revealed previously undetected haplotypes unique to the Finnish otter population. Expected heterozygosities in Fennoscandia were within the range previously reported. Bayesian cluster analysis of our microsatellite data revealed genetic structuring of the Swedish otter populations. In contrast, we observed a high degree of admixture among the Finnish populations that we also found at the geographic border of the two countries (Lapland). Admixed ancestry in Finnish otters suggests that gene flow from the Swedish to Central European populations is potentially facilitated via the Finnish otter populations connecting the Swedish animals with otter populations in mainland Europe. [ABSTRACT FROM AUTHOR]

The most frequent causative agent of diphyllobothriosis, a fish-borne parasitic zoonosis, is the broad fish tapeworm Dibothriocephalus latus distributed mainly throughout the Holarctic region. The larval stages of the tapeworm were also detected in native and introduced freshwater fish in several lakes in South America, particularly in the north-western Patagonia in Argentina. The main objective of the present study was to determine the genetic structure of D. latus from rainbow trout (Oncorhynchus mykiss), brown trout (Salmo trutta), and brook trout (Salvelinus fontinalis) from Gutiérrez Lake and Alicura Reservoir in Argentina using the sequences of three mitochondrial genes (cox1, cob, and nad3) and six polymorphic microsatellite loci. The results were compared with the corresponding molecular data of D. latus from Europe (Switzerland and Italy; the Alpine lakes region) and Asia (Siberia, Russia). Only one concatenated haplotype identical with the con-Ha1 specific for D. latus from the Alpine lakes region was detected in all individuals from Argentina. Three different alleles were detected in five out of six analysed microsatellite loci, indicating the presence of three sets of chromosomes. The same structure of microsatellite loci was recently observed in D. latus from Switzerland and Italy, in which triploidy was previously confirmed by cytogenetic study. The data on the mitochondrial genes, the allelic structure of microsatellite loci, and the principal coordinate analysis showed close genetic relationships between D. latus from Argentina and the Alpine lakes region, thus supporting the hypothesis of the European origin of the broad fish tapeworm from South America., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Cornelian cherry ( Cornus mas L.) is indigenous to central and southeastern Europe and is an ecologically and economically important shrub or small tree. The aim of this study was to develop molecular tools for assessing genetic diversity and provide unique molecular identification of C. mas samples from central Europe and United States. A microsatellite-enriched library was used to develop nine polymorphic microsatellite loci. The loci amplified perfect and imperfect repeats with 2 to 11 alleles detected per locus. Observed heterozygosity ranged from 0.00 to 0.71 and expected heterozygosity ranged from 0.00 to 0.82. Additionally, cross species transfer to Cornus eydeana was observed. The multilocus allelic data was used to cluster 37 C. mas samples and 1 C. eydeana sample based on the allele sharing distance matrix. The similarity coefficient ranged from 0.05 to 0.73 among all genotypes. All C. mas individuals clustered into two main clades, with the single C. eydeana sample used to root the dendrogram. All samples in group I belong to the botanical form Macrocarpa and originated from Austria, Poland, or Ukraine, whereas group II included samples that originated from Poland, Romania, and the United States. Five loci (CM007, CM010, CM031, CM037, and CM043) were used to develop a molecular identification key that successfully delineated all samples. The loci described in this study will facilitate further investigations of genetic diversity, gene flow, and genetic structure among populations of C. mas . [ABSTRACT FROM AUTHOR]

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Aim: This study investigates how founder size may affect local genetic diversity and spatial genetic structure of the invasive American eastern grey squirrel (Sciurus carolinensis) in European areas. It also examines whether dispersal propensity and invasion rate may be related to founder size, genetic diversity and structure. Location: Piedmont, Italy; Northern Ireland, Northumberland and East Anglia, UK. Methods: Across the invaded range in Europe, 315 squirrels from 14 locations, grouped in four areas, were sampled and examined at 12 highly polymorphic microsatellite loci. We estimated both genetic variation and population structure using AMOVA, Mantel tests and Bayesian analysis. We also estimated migration rates and range expansion rates. Results: Genetic diversity varied in accordance with numbers of founders across populations. For instance, the Italian population had the smallest founder size and lowest genetic variability, whereas Northumberland had high values for both. Significant levels of genetic differentiation were observed in all the examined regions. Gene flow, migration and population range expansion rate were also higher in England and Ireland than in Italy. Main conclusions: Populations descending from human‐mediated releases of few individuals were more genetically depauperate and more differentiated than populations established from a greater number of founders. Propagule pressure is therefore a significant factor in squirrel invasions. There is a trend whereby larger founder sizes were associated with greater genetic diversity, more dispersal, less local genetic differentiation and faster range expansion rate in squirrels. These findings have important management implications for controlling spread rate of squirrels and other invasive species: good practice should prioritize preventing further releases and the merging of genetically distinct populations as these events can augment genetic diversity. [ABSTRACT FROM AUTHOR]

Orobanche cumana is an obligate root parasite of sunflower. It represents a major agricultural problem in many countries of southern and eastern Europe. Information on O. cumana population genetics, structure and dynamics is scarce, particularly due to the lack of suitable molecular markers for such studies. The objective of this study was to identify and characterise simple sequence repeat ( SSR) markers for O. cumana. Four thousand two hundred SSR-containing candidate sequences were obtained from O. cumana using next-generation sequencing, from which 298 SSR primer pairs were designed and 217 of them used for validation. Seventy nine SSR primers produced reproducible, high quality amplicons of the expected size that were polymorphic among 18 O. cumana populations from different geographical locations and hosts (sunflower, wild hosts from the Compositae family). The number of alleles per locus ranged from 2 to 10, with an average polymorphism information content value of 0.37. The O. cumana SSR markers were highly transferable to the closely related species Orobanche cernua. SSR markers showed high resolving power; UPGMA cluster analysis allowed proper classification of Orobanche spp. samples into species ( O. cumana and O. cernua), geographical origin and host. The functional SSR markers reported in this study constitute a valuable tool for genetic analyses in O. cumana and related species and will contribute insights into the biology and genetics of this parasitic weed. [ABSTRACT FROM AUTHOR]

The polyploid species complex of Rosa villosa sensu lato ( Rosa section Caninae subsection Vestitae) consists of three morphologically similar polyploid species: R. sherardii, R. mollis and R. villosa. Whereas R. sherardii is distributed in central Europe, R. mollis and R. villosa represent a vicariant species pair occurring in northern Europe and in mountains of central and eastern Europe, respectively. In this study we analysed multiple data sets (morphology, cytology, microsatellites, AFLP and plastid DNA sequences) to re-evaluate the systematics of these species and to examine whether cytological differences are reflected in the taxonomy and geographical distributions. Furthermore, these data sets were used to evaluate hypotheses explaining the vicariant distribution of R. mollis and R. villosa. None of these data sets revealed a clear-cut differentiation between the species. Cytological and molecular data argued for a discrete taxonomic position of the predominantly pentaploid R. sherardii, but these data did not support a separation between the mostly tetraploid R. mollis and R. villosa. Population genetics revealed that samples of the latter species were assembled according to ploidy, but not to species affiliation or geographical distribution. Thus, we assume that the cytologically polymorphic original species had a continuous range prior to the last glaciation period and survived on nunataks or in non-glaciated coastal regions in northern Europe, but that it failed to recover its former range after the retreat of the ice sheets. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2014, 174, 240-256. [ABSTRACT FROM AUTHOR]

Lecanosticta acicola is a pine needle pathogen causing brown spot needle blight that results in premature needle shedding with considerable damage described in North America, Europe, and Asia. Microsatellite and mating type markers were used to study the population genetics, migration history, and reproduction mode of the pathogen, based on a collection of 650 isolates from 27 countries and 26 hosts across the range of L. acicola. The presence of L. acicola in Georgia was confirmed in this study. Migration analyses indicate there have been several introduction events from North America into Europe. However, some of the source populations still appear to remain unknown. The populations in Croatia and western Asia appear to originate from genetically similar populations in North America. Intercontinental movement of the pathogen was reflected in an identical haplotype occurring on two continents, in North America (Canada) and Europe (Germany). Several shared haplotypes between European populations further suggests more local pathogen movement between countries. Moreover, migration analyses indicate that the populations in northern Europe originate from more established populations in central Europe. Overall, the highest genetic diversity was observed in south-eastern USA. In Europe, the highest diversity was observed in France, where the presence of both known pathogen lineages was recorded. Less than half of the observed populations contained mating types in equal proportions. Although there is evidence of some sexual reproduction taking place, the pathogen spreads predominantly asexually and through anthropogenic activity., (© 2022 The Authors. Molecular Plant Pathology published by British Society for Plant Pathology and John Wiley & Sons Ltd.)

The American cherry fruit fly is an invasive pest species in Europe, of serious concern in tart cherry production as well as for the potential to hybridize with the European cherry fruit fly, Rhagoletis cerasi L. ( Diptera: Tephritidae), which might induce new pest dynamics. In the first European reports, the question arose whether only the eastern American cherry fruit fly, Rhagoletis cingulata ( Loew) ( Diptera: Tephritidae), is present, or also the closely related western American cherry fruit fly, Rhagoletis indifferens Curran. In this study, we investigate the species status of European populations by comparing these with populations of both American species from their native ranges, the invasion dynamics in German (first report in 1993) and Hungarian (first report in 2006) populations, and we test for signals of hybridization with the European cherry fruit fly. Although mt DNA sequence genealogy could not separate the two American species, cross-species amplification of 14 microsatellite loci separated them with high probabilities (0.99-1.0) and provided evidence for R. cingulata in Europe. German and Hungarian R. cingulata populations differed significantly in microsatellite allele frequencies, mt DNA haplotype and wing pattern distributions, and both were genetically depauperate relative to North American populations. The diversity suggests independent founding events in Germany and Hungary. Within each country, R. cingulata displayed little or no structure in any trait, which agrees with rapid local range expansions. In cross-species amplifications, signals of hybridization between R. cerasi and R. cingulata were found in 2% of R. cingulata individuals and in 3% of R. cerasi. All putative hybrids had R. cerasi mt DNA indicating that the original between-species mating involved R. cerasi females and R. cingulata males. [ABSTRACT FROM AUTHOR]

Aim General models for understanding the climate-driven processes of post-glacial colonization in European arctic-alpine species are mainly derived from studies on temperate terrestrial taxa. However, cold-adapted freshwater species may tolerate or even thrive under colder climatic conditions as flowing water habitats are thermally buffered against freezing and extremely cold temperatures. Here, we investigate the European Pleistocene and Holocene history of the arctic-alpine stonefly Arcynopteryx dichroa. Location Europe. Methods We used two genetic data sets (mitochondrial sequence data and nuclear microsatellite data) to investigate the glacial survival and post-glacial recolonization routes of A. dichroa. We used species distribution models to critically evaluate our genetic data and phylogeographical interpretations. Results Among 344 sequenced individuals from eight European mountain ranges, 80 unique haplotypes were detected. Of these, 77 haplotypes were endemic to a single mountain range, indicating almost complete lineage sorting. Both sequence and microsatellite data suggested strong population differentiation between mountain ranges. The genetic hotspots were found in the Carpathians, the Balkans and the eastern Alps. The Black Forest and Fennoscandian populations exhibited shared and closely related haplotypes, indicating ancestral polymorphism in two populations that became disjunct due to vicariance or resulting from rare long-distance dispersal among disjunct northern and southern periglacial populations. Main conclusions Arcynopteryx dichroa is a glacial relict that survived glacial cycles through elevation shifts in isolated periglacial populations in the Pyrenees, the central European highlands, the Carpathians, the Balkans and the eastern Alps. The species probably recolonized the formerly glaciated Fennoscandian range from a refugium in the central European highlands, following the retreat of the ice sheet. This study suggests that aquatic organisms may have reacted differently to Pleistocene climate change compared with terrestrial species. [ABSTRACT FROM AUTHOR]

The characterization of livestock genetic diversity can inform breed conservation initiatives. The genetic diversity and genetic structure were assessed in 685 individual genotypes sampled from 24 British chicken breeds. A total of 239 alleles were found across 30 microsatellite loci with a mean number of 7.97 alleles per locus. The breeds were highly differentiated, with an average FST of 0.25, similar to that of European chicken breeds. The genetic diversity in British chicken breeds was comparable to that found in European chicken breeds, with an average number of alleles per locus of 3.59, ranging from 2.00 in Spanish to 4.40 in Maran, and an average expected heterozygosity of 0.49, ranging from 0.20 in Spanish to 0.62 in Araucana. However, the majority of breeds were not in Hardy-Weinberg Equilibrium, as indicated by heterozygote deficiency in the majority of breeds (average FIS of 0.20), with an average observed heterozygote frequency of 0.39, ranging from 0.15 in Spanish to 0.49 in Cochin. Individual-based clustering analyses revealed that most individuals clustered to breed origin. However, genetic subdivisions occurred in several breeds, and this was predominantly associated with flock supplier and occasionally by morphological type. The deficit of heterozygotes was likely owing to a Wahlund effect caused by sampling from different flocks, implying structure within breeds. It is proposed that gene flow amongst flocks within breeds should be enhanced to maintain the current levels of genetic diversity. Additionally, certain breeds had low levels of both genetic diversity and uniqueness. Consideration is required for the conservation and preservation of these potentially vulnerable breeds. [ABSTRACT FROM AUTHOR]

The allotetraploids (2 n = 24) Tragopogon mirus and T. miscellus have become textbook examples of recently and recurrently formed allopolyploids. Both species formed following the introduction of three diploids, T. dubius, T. porrifolius and T. pratensis (each with 2 n = 12), from Europe into the Palouse region of eastern Washington and adjacent Idaho, USA, in the early 1900s. The parentage of both allotetraploids is well documented ( T. mirus = T. dubius × T. porrifolius; T. miscellus = T. dubius × T. pratensis), and both allotetraploids have formed repeatedly in the past approximately 80 years in the Palouse. On a larger geographical scale, T. mirus has also been reported from Flagstaff, Arizona (AZ), and more recently from Oregon (OR). However, the populations from OR and AZ have not been previously analysed with molecular markers to test the hypothesis of separate origin (vs. long-distance dispersal). Here, we show that both the AZ and OR collections of T. mirus combine distinctive parental genotypes and are genetically differentiated from the T. mirus genotypes found in the Palouse. The OR sample of T. mirus has a genetically distinct T. dubius contribution that forms a clade in our analyses with a sample of what has been referred to as T. major (now considered a subspecies of T. dubius). Consistent with other naturally occurring T. mirus populations, plastid sequences indicate that T. porrifolius was the maternal parent for both the AZ and OR collections. Microsatellite data are also consistent with local formation of T. mirus from co-occurring populations of T. dubius and T. porrifolius in OR and AZ. As with sequence data, T. dubius from OR is distinct from other samples of T. dubius at microsatellite loci, contributing a unique signature to T. mirus from this location. It will be useful to include these additional geographical origins of T. mirus, particularly the more genetically distant sample from OR, in ongoing investigations of the genetic and genomic consequences of recent allopolyploidy. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 169, 297-311. [ABSTRACT FROM AUTHOR]

Loss of connectivity and habitat destruction may lead to genetic depletion of wild animal populations, especially in species requiring large, connected territories as the brown bear ( Ursus arctos). Brown bear populations of North Western Russia, Finland and Northern Norway have been assumed to form one large, continuous population; however this hypothesis has not been tested sufficiently. We have genotyped 1,887 samples from 2005 to 2008 from four distinct areas and used the resulting DNA profiles from 146 different individuals to analyze the genetic diversity, population structure, and the migration rates among groups. In addition, we have tested for traces of previous genetic bottlenecks. Individuals from Eastern Finland and Russian Karelia were grouped in the same cluster ('Karelia'), while distinctive subpopulations of brown bears were detected in the north ('Pasvik'), and the east ('Pinega'). All three subpopulations displayed high genetic variation, with expected heterozygosities ( H) of 0.77-0.81, but differentiation among the clusters was relatively low (average F = 0.051, P < 0.001). No evidence of genetic bottlenecks in the past was found. We detected a highly significant isolation-by-distance (IBD) pattern. For Pasvik, self-recruitment was found to be very high (96%), pointing to the possibility of genetic isolation. In contrast, between Karelia and Pinega we detected high, bi-directional migration rates (~30%), indicating genetic exchange. Conclusively, despite of a substantial influence of IBD on the genetic structure in the region, we detected considerable variation in connectivity among the identified clusters that could not be explained solely by the distance between them. [ABSTRACT FROM AUTHOR]

Abstract: Ixodes ricinus is a European tick that transmits numerous pathogenic agents, including the bacteria that cause Lyme disease (some genospecies of Borrelia burgdorferi sensu lato complex). This tick has been considered as a classic example of an extreme generalist vector. However, host-associations in such vector species are difficult to determine from field observations alone and recent work suggests that host specificity may be more frequent in ticks than previously thought. The presence of host-associated vector groups can significantly alter the circulation and evolutionary pathway of associated pathogens. In this paper, we explicitly test for host-associated genetic structure in I. ricinus. We analyzed genetic variability at 11 microsatellite markers in a large sample of ticks collected directly from trapped wild animals (birds, rodents, lizards, wild boar and roe deer) at five sites in Western and Central Europe. We found significant levels of genetic structure both among host individuals and among host types within local populations, suggesting that host use is not random in I. ricinus. These results help explain previous patterns of structure found in off-host tick samples, along with epidemiological observations of Lyme disease. [Copyright &y& Elsevier]

Abstract: The taxonomic status of Allolobophora chlorotica is still the subject of considerable discussion. After the recent experimental demonstration that the two regularly observed colour morphs (pink and green) were not fully interfertile and likely represent two distinct species, molecular analyses revealed a more complex picture with the occurrence of five mitochondrial lineages (named L1 to L5) in A. chlorotica, two within the green morph and three within the pink morph. Although nuclear markers (AFLPs) confirmed that the pink morph might consist of three different taxa, AFLPs data suggested that the green morph may be a single taxon. In order to further characterize the population genetic structure within A. chlorotica in addition to test for reproductive isolation between lineages, eight polymorphic microsatellite loci were developed using a microsatellite-enriched genomic library from an individual belonging to lineage L2. The number of alleles per locus varied from 9 to 29 in a set of individuals belonging to L2. Considerable sub-structure was observed within L2 populations suggesting a low dispersal capability in this species and a distribution of the individuals in patches that could function as panmictic units. These markers were transferable to the other lineages but only five loci could be amplified consistently in four of the lineages (L1, L2, L3 and L4). Microsatellite data confirmed that the green morph represents a single taxon. Although the integrity of the three previously documented lineages within the pink morph was also generally supported by the data, microsatellites provided evidence for hybridization between lineages and between morphs in the field. Moreover, mitochondrial data revealed the existence of two additional mitochondrial lineages within the pink morph. The taxonomic status of the pink morph remains thus unclear, requiring a thorough and comprehensive study. [Copyright &y& Elsevier]

Leucorrhinia caudalis is a dragonfly species threatened throughout Europe. Despite evidence of the recent extension of its distribution range, it is unknown whether L. caudalis regularly or hardly ever migrates among ponds. The contemporary migration patterns of the species were investigated using Bayesian assignment tests and the migration rates related to landscape structural and thematic variables (distance between ponds, forest area, area of water body, area of hedgerow). Migration rates of L. caudalis are independent of any landscape element. Thus, landscape structure is not a barrier or corridor for migration in this species. The tendency of L. caudalis to disperse is largely independent of the nature of the landscape, at least at the scale of the present study. [ABSTRACT FROM AUTHOR]

Genetic diversity is one of the most important criteria to identify unique populations for conservation purposes. In this study we analyze the genetic population structure of the endangered montane mayfly Ameletus inopinatus in its European range. The species is restricted to unpolluted cold-water streams, and exhibits an insular distribution across highlands of Central Europe and a more continuous distribution across Fennoscandia and Northern Euro-Siberia. We genotyped 389 individuals from 31 populations for eight highly polymorphic microsatellite loci to investigate genetic diversity and population structure within and among European mountain ranges. Genetic diversity of A. inopinatus decreases along an east-west gradient in Central Europe and along a north-south gradient in Fennoscandia, respectively. Centres of exceptionally high genetic diversity are located in the Eastern Alps (Andertal Moor, Austria), the High Tatra, the Beskides, the Sudety Mountains and the Eastern German Highlands. Species distribution modelling for 2080 projects major regional habitat loss, particularly in Central Europe mountain ranges. By relating these range shifts to our population genetic results, we identify conservation units primarily in Eastern Europe, that if preserved would maintain high levels of the present-day genetic diversity and continue to provide long-term suitable habitat under future climate warming scenarios. [ABSTRACT FROM AUTHOR]

The European cherry fruit fly, Rhagoletis cerasi (Diptera: Tephritidae), is a major pest of cherries in Europe and parts of Asia. Despite its big economic significance, there is a lack of studies on the genetic structure of its natural populations. Knowledge about an insect pest on molecular, genetic and population levels facilitates the development of environmentally friendly control methods. In this study, we present the development of 13 microsatellite markers for R. cerasi, through cross-species amplification. These markers have been used for the genotyping of 130 individuals from five different sampling sites in Greece. Our results indicate that (i) cross-species amplification is a versatile and rapid tool for developing microsatellite markers in Rhagoletis spp., (ii) the microsatellite markers presented here constitute an important tool for population studies on this pest, and (iii) there is clear structuring of natural European cherry fly populations. [ABSTRACT FROM AUTHOR]

Hybridization is a significant threat for endangered species and could potentially even lead to their extinction. This concern applies to the globally vulnerable Greater Spotted Eagle Aquila clanga, a species that co-occurs, and potentially interbreeds, with the more common Lesser Spotted Eagle Aquila pomarina in a vast area of Eastern Europe. We applied single nucleotide polymorphism (SNP) and microsatellite markers in order to study hybridization and introgression in 14 European spotted eagle populations. We detected hybridization and/or introgression in all studied sympatric populations. In most regions, hybridization took place prevalently between A. pomarina males and A. clanga females, with introgression to the more common A. pomarina. However, such a pattern was not as obvious in regions where A. clanga is still numerous. In the course of 16 years of genetic monitoring of a mixed population in Estonia, we observed the abandonment of A. clanga breeding territories and the replacement of A. clanga pairs by A. pomarina, whereby on several occasions hybridization was an intermediate step before the disappearance of A. clanga. Although the total number of Estonian A. clanga × A. pomarina pairs was twice as high as that of A. clanga pairs, the number of pairs recorded yearly were approximately equal, which suggests a higher turnover rate in interbreeding pairs. This study shows that interspecific introgressive hybridization occurs rather frequently in a hybrid zone at least 1700-km wide: it poses an additional threat for the vulnerable A. clanga, and may contribute to the extinction of its populations. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 100, 725–736. [ABSTRACT FROM AUTHOR]

Background and Aims: Black cherry (Prunus serotina) is a North American tree that is rapidly invading European forests. This species was introduced first as an ornamental plant then it was massively planted by foresters in many countries but its origins and the process of invasion remain poorly documented. Based on a genetic survey of both native and invasive ranges, the invasion history of black cherry was investigated by identifying putative source populations and then assessing the importance of multiple introductions on the maintenance of gene diversity. [ABSTRACT FROM PUBLISHER]

Eurasian otter populations strongly declined and partially disappeared due to global and local causes (habitat destruction, water pollution, human persecution) in parts of their continental range. Conservation strategies, based on reintroduction projects or restoration of dispersal corridors, should rely on sound knowledge of the historical or recent consequences of population genetic structuring. Here we present the results of a survey performed on 616 samples, collected from 19 European countries, genotyped at the mtDNA control-region and 11 autosomal microsatellites. The mtDNA variability was low (nucleotide diversity = 0.0014; average number of pairwise differences = 2.25), suggesting that extant otter mtDNA lineages originated recently. A star-shaped mtDNA network did not allow outlining any phylogeographic inference. Microsatellites were only moderately variable (Ho = 0.50; He = 0.58, on average across populations), the average allele number was low (observed Ao = 4.9, range 2.5-6.8; effective Ae = 2.8; range 1.6-3.7), suggesting small historical effective population size. Extant otters likely originated from the expansion of a single refugial population. Bayesian clustering and landscape genetic analyses however indicate that local populations are genetically differentiated, perhaps as consequence of post-glacial demographic fluctuations and recent isolation. These results delineate a framework that should be used for implementing conservation programs in Europe, particularly if they are based on the reintroduction of wild or captive-reproduced otters. [ABSTRACT FROM AUTHOR]

The dry rot fungus Serpula lacrymans is a devastating basidiomycete occurring in wooden constructions in temperate regions worldwide. In this study, we compare the genetic structures of two invasive populations from Europe and Japan. Microsatellite data from 14 loci and DNA sequences from four loci demonstrated that the two populations were highly differentiated. Significant isolation by distance effect was observed in Europe and Japan. Higher genetic variation was observed within the Japanese population than within the European population, corresponding with the observed higher richness of vegetative compatibility types in Japan, indicating that there has been a higher level of gene flow from the Asian source populations to Japan than to Europe. The European population is genetically more homogenous with only six detected vegetative compatibility types. Various tests indicate that both the European and the Japanese populations have gone through population bottlenecks prior to population expansion. No identical multi-locus genotypes were observed within Japan and very few within Europe, indicating limited clonal dispersal. Deviations from Hardy Weinberg expectations were observed both in Europe and Japan and heterozygote excess were observed at several loci, especially in Europe. Possible explanations for this pattern are discussed. [ABSTRACT FROM AUTHOR]

The pied flycatcher is one of the most phenotypically variable bird species in Europe. The geographic variation in phenotypes has often been attributed to spatial variation in selection regimes that is associated with the presence or absence of the congeneric collared flycatcher. Spatial variation in phenotypes could however also be generated by spatially restricted gene flow and genetic drift. We examined the genetic population structure of pied flycatchers across the breeding range and applied the phenotypic QST ( PST)– FST approach to detect indirect signals of divergent selection on dorsal plumage colouration in pied flycatcher males. Allelic frequencies at neutral markers were found to significantly differ among populations breeding in central and southern Europe whereas northerly breeding pied flycatchers were found to be one apparently panmictic group of individuals. Pairwise differences between phenotypic ( PST) and neutral genetic distances ( FST) were positively correlated after removing the most differentiated Spanish and Swiss populations from the analysis, suggesting that genetic drift may have contributed to the observed phenotypic differentiation in some parts of the pied flycatcher breeding range. Differentiation in dorsal plumage colouration however greatly exceeded that observed at neutral genetic markers, which indicates that the observed pattern of phenotypic differentiation is unlikely to be solely maintained by restricted gene flow and genetic drift. [ABSTRACT FROM AUTHOR]

In times of rapid global and unforeseeable environmental changes, there is an urgent need for a sustainable cattle breeding policy, based on a global view. Most of the indigenous breeds are specialized in a particular habitat or production system but are rapidly disappearing. Thus, they represent an important resource to meet present and future breeding objectives. Based on 105 microsatellites, we obtained thorough information on genetic diversity and population structure of 16 cattle breeds that cover a geographical area from the domestication centre near Anatolia, through the Balkan and alpine regions, to the North-West of Europe. Breeds under strict artificial selection and indigenous breeds under traditional breeding schemes were included. The overall results showed that the genetic diversity is widespread in Buša breeds in the Anatolian and Balkan areas, when compared with the alpine and north-western European breeds. Our results reflect long-term evolutionary and short-term breeding events very well. The regular pattern of allele frequency distribution in the entire cattle population studied clearly suggests conservation of rare alleles by conservation of preferably unselected traditional breeds with large effective population sizes. From a global and long-term conservation genetics point of view, the native and highly variable breeds closer to the domestication centre could serve as valuable sources of genes for future needs, not only for cattle but also for other farm animals. [ABSTRACT FROM AUTHOR]