The ‘paradigm of extremes’: extremely low genetic diversity in an extremely narrow endemic species, Coristospermum huteri (Umbelliferae)

Low levels of genetic diversity in endemic species are generally attributable to the small size of their populations. This lack of genetic variability will, predictably, be more evident in those species that occur in only one or a very few localities with a total population consisting of a few dozen individuals, or sometimes fewer (i.e. ‘extremely narrow endemics’, ENEs). We used allozyme electrophoresis to survey the genetic variability of Coristospermum huteri, an endemic species from the island of Majorca (Balearic Islands, W. Mediterranean Basin) with a single natural population of about 100 individuals. As expected, allozyme variability was virtually nil for this species (P = 8.3 %, A = 1.08, H _e = 0.022), which seems to be a general rule for ENEs (mean H _e = 0.057). A founder effect associated with a dispersal event from the continent is probably behind the lack of genetic diversity in this highly threatened species. Preservation of the mountain summit where the plant is found (Puig Major) is essential for the survival of C. huteri, and would also guarantee the conservation of other ENEs and rare and threatened species.     

High genetic diversity detected in the endemic Primula apennina Widmer (Primulaceae) using ISSR fingerprinting

Primula apennina Widmer is endemic to the North Apennines (Italy). ISSR were used to detect the genetic diversity within and among six populations representative of the species distribution range. High levels of genetic diversity were revealed both at population percentage of polymorphic band (PPB = 75.92%, H _S = 0.204, H _pop = 0.319) and at species level (PPB = 96.95%, H _T = 0.242, H _sp = 0.381). Nei gene diversity statistics (15.7%), Shannon diversity index (16.3%) and AMOVA (14%) detected a moderate level of interpopulation diversity. Principal coordinate and Bayesian analyses clustered the populations in three major groups along a geographic gradient. The correlation between genetic and geographic distances was positive (Mantel test, r = 0.232). All together, these analyses revealed a weak but significant spatial genetic structure in P. apennina, with gene flow acting as a homogenizing force that prevents a stronger differentiation of populations. Conservation measures are suggested based on the observed pattern of genetic variability.     

Contemporary habitat loss reduces genetic diversity in an ecologically specialized butterfly

Aim This study investigated the influence of contemporary habitat loss on the genetic diversity and structure of animal species using a common, but ecologically specialized, butterfly, Theclinesthes albocincta (Lepidoptera: Lycaenidae), as a model. Location South Australia. Methods We used amplified fragment length polymorphism (AFLP) and allozyme datasets to investigate the genetic structure and genetic diversity among populations of T. albocincta in a fragmented landscape and compared this diversity and structure with that of populations in two nearby landscapes that have more continuous distributions of butterflies and their habitat. Butterflies were sampled from 15 sites and genotyped, first using 363 informative AFLP bands and then using 17 polymorphic allozyme loci (n = 248 and 254, respectively). We complemented these analyses with phylogeographic information based on mitochondrial DNA (mtDNA) haplotype information derived from a previous study in the same landscapes. Results Both datasets indicated a relatively high level of genetic structuring across the sampling range (AFLP, F_ST = 0.34; allozyme, F_ST = 0.13): structure was greatest among populations in the fragmented landscape (AFLP, F_ST = 0.15; allozyme, F_ST = 0.13). Populations in the fragmented landscape also had significantly lower genetic diversity than populations in the other two landscapes: there were no detectable differences in genetic diversity between the two continuous landscapes. There was also evidence (r² = 0.33) of an isolation by distance effect across the sampled range of the species. Main conclusions The multiple lines of evidence, presented within a phylogeographic context, support the hypothesis that contemporary habitat fragmentation has been a major driver of genetic erosion and differentiation in this species. Theclinesthes albocincta populations in the fragmented landscape are thus likely to be at greater risk of extinction because of reduced genetic diversity, their isolation from conspecific subpopulations in other landscapes, and other extrinsic forces acting on their small population sizes. Our study provides compelling evidence that habitat loss and fragmentation have significant rapid impacts on the genetic diversity and structure of butterfly populations, especially specialist species with particular habitat preferences and poor dispersal abilities.     

The importance of phenotypic differentiation and plasticity in the range expansion of the annual Atriplex tatarica (Amaranthaceae)

The ability of a species to adapt to sub-optimal conditions at the margin of its distribution range and to cope with environmental stress is considered to be important for its successful geographic expansion. To ascertain the roles of phenotypic differentiation and plasticity in the expansion of the annual Atriplex tatarica, we compared plants from populations found in Marginal and Central areas of the species’ range. We grew these plants under marginal climatic conditions in pots with different types of substrate. We assessed the population genetic structure at five putatively neutral allozyme loci to evaluate whether there was any evidence of reduced genetic diversity in Marginal populations compared to Central ones. We used the Q_ST vs. F_ST approach (while F_ST gives a standardised measure of the genetic differentiation among populations for a genetic locus, Q_ST measures the amount of genetic variance among populations relative to the total genetic variance) to ascertain the roles of adaptive vs. non-adaptive processes on phenotypic differentiation. Plants native to the Marginal area of the species’ range flowered earlier and had a lower shoot mass and a higher reproductive allocation than plants native to the Central part of the species’ range. The Marginal populations of Atriplex tatarica showed lower genetic diversity at allozyme loci and higher phenotypic differentiation than the Central populations. We recorded similar plastic responses to substrates in plants native to both regions. Our results indicate that Marginal populations of expanding A. tatarica maintain the ability to adapt locally and to elicit a plastic response to environmental stress, despite loss of genetic diversity.     

Genetic diversity and spatial genetic structure of Pinus strobus (Pinaceae) across an island landscape inferred from allozyme and cpDNA markers

The Beaver Island Archipelago (BIA) provides a model system to address the impact of long-term isolation on genetic diversity and gene flow. Low lake levels are assumed to have caused the BIA to be attached to mainland Michigan for at least 4000 years (10000 yr B.P.- 6000 yr B.P.), eventually, rising lake levels would have kept the islands isolated since 6000 yr B.P. If the island populations of a plant species in the BIA were indeed once continuous with the mainland of Michigan, then we would expect similar levels of genetic diversity in populations of such a species on the islands vs. the mainland. We compared levels of allozyme genetic diversity of 20 plots of Pinus strobus in the BIA with two mainland populations in northern Michigan. In addition, if pollen is a primary agent of gene flow across islands, a low degree of allozyme differentiation among the island populations of P. strobus in the BIA would be evident. Furthermore, since seed dispersal is more limited than pollen dispersal in P. strobus, a more pronounced spatial genetic structure (SGS) is expected in allozymes than in cpDNA markers. To gain insights on the pattern of seed and pollen dispersal among the 20 plots, we further analyzed spatial autocorrelation using Moran's I-statistics for both data sets [biparentally inherited, allozymes and paternally inherited, cpDNA microsatellites (cpDNA SSR)]. We found a similar level of allozyme variability in both the BIA (mean H _e = 0.080) and the two mainland populations (mean H _e = 0.078). As predicted, we observed a low but significant degree of genetic divergence among populations for allozymes (mean F _ST = 0.033 across 20 plots). Our allozyme-based SGS analysis revealed significant evidence of SGS (i.e. isolation-by-distance; slope β = ?0.194 from regression analysis of observed averaged Moran's I values against the logarithm of the upper bound of six distance classes). In contrast, little evidence of SGS was found in cpDNA SSR data across the BIA (β = 0.013). These results suggest that although gene flow via seed dispersal is somewhat limited, pollen flow has been sufficient to maintain genetic diversity and prevent differentiation across the island landscape over several thousand years of isolation.     

Population genetic structure in Myrtus communis L. in a chronically fragmented landscape in the Mediterranean: can gene flow counteract habitat perturbation?

Ancient managed landscapes provide ideal opportunities to assess the consequences of habitat fragmentation on the patterns of genetic diversity and gene flow in long-lived plant species. Using amplified fragment length polymorphism (AFLP) and allozyme markers, we quantified seed-mediated gene flow and population genetic diversity and structure in 14 populations of Myrtus communis (myrtle), a common endozoochorous shrub species of forest patches in lowland agricultural Mediterranean areas. Overall, allozyme diversity for myrtle was low (P₉₅   =   25%; A   =   1.411; H_e = 0.085) compared to other known populations, and a significant portion of populations (57%) had lower levels of allelic diversity and/or heterozygosity than expected at random, as shown by simulated resampling of the whole diversity of the landscape. We found significant correlations between allozyme variability and population size and patch isolation, but no significant inbreeding in any population. Genetic differentiation among populations for both allozyme and AFLP markers was significant (Φ_ST = 0.144 and Φ_ST = 0.142, respectively) but an isolation-by-distance pattern was not detected. Assignment tests on AFLP data indicated a high immigration rate in the populations ( ca. 20–22%), likely through effective seed dispersal across the landscape by birds and mammals. Our results suggest that genetic isolation is not the automatic outcome of habitat destruction since substantial levels of seed-mediated gene flow are currently detectable. However, even moderate rates of gene flow seem insufficient in this long-lived species to counteract the genetic erosion and differentiation imposed by chronic habitat destruction.     

Conservation genetics in two endangered endemics from the Canary Islands, Helianthemum gonzalezferreri Marrero (Cistaceae) and Kunkeliella subsucculenta Kämmer (Santalaceae): different life histories that involve different management strategies

Helianthemum gonzalezferreri and Kunkeliella subsucculenta, two endangered endemic species from the Canary Islands, were analysed to determine the levels and structure of genetic diversity in their natural populations. The mean value of Shannon’s diversity index for H. gonzalezferreri and K. subsucculenta were I = 0.315 and I = 0.331, respectively. AMOVA and Bayesian analysis showed high genetic differentiation between populations in H. gonzalezferreri (F _ST = 0.297). This genetic differentiation was graphically shown with the principal component analysis (PCA), in which the majority of individuals were distributed into two groups. Contrarily, K. subsucculenta populations showed a considerable degree of gene exchange revealed by Bayesian cluster analysis and PCA. The genetic differentiation between the two H. gonzalezferreri populations suggests different management strategies for each population. Translocation between the two natural populations of K. subsucculenta, to increase genetic variation, would not mean outbreeding depression, since both populations share the same genetic pool.     

High genetic structure of the Cozumel Harvest mice,a critically endangered island endemic: conservation implications

We assessed the genetic structure and diversity of Reithrodontomys spectabilis, a critically endangered, endemic rodent from Cozumel Island, México. A total of 90 individuals were trapped from September 2001 to January 2005. Microsatellite data analysis revealed high genetic diversity values: a total of 113 alleles (average 12.5 per locus), H _o  = 0.78, H _e  = 0.80. These high values can be related to Cozumel’s size (478 km²) and extensive native vegetation cover, factors that could be promoting a suitable population size, high heterozygosity and the persistence of rare alleles in the species, as well as some long-term movement of individuals between sampling localities. A strong genetic structure was also observed, with at least four genetic groups, associated with a pattern of isolation by distance. We found a strong allelic and genetic differentiation shown between localities, with negligible recent gene flow and low inbreeding coefficients. The species life history and ecological characteristics—being nocturnal, semi-terrestrial, a good tree climber, having lunar phobia and significant edge effect—are likely affecting its genetic structure and differentiation. The high genetic diversity and population structure award R. spectabilis a significant conservation value. Our results can serve as a basis for future research and conservation of the species, particularly considering the problems the island is facing from habitat perturbation, urbanization and introduction of exotic species. In view of the structure and genetic variability observed, it is essential to establish and reinforce protected areas and management programs for the conservation of the endemic and endangered Cozumel Harvest mice.     

Conservation genetics of the annual hemiparasitic plant <Emphasis Type="Italic">Melampyrum sylvaticum</Emphasis> (Orobanchaceae) in the UK and Scandinavia

Melampyrum sylvaticum is an endangered annual hemiparasitic plant that is found in only 19 small and isolated populations in the United Kingdom (UK). To evaluate the genetic consequences of this patchy distribution we compared levels of diversity, inbreeding and differentiation from ten populations from the UK with eight relatively large populations from Sweden and Norway where the species is more continuously distributed. We demonstrate that in both the UK and Scandinavia, the species is highly inbreeding (global F _IS = 0.899). Levels of population differentiation were high (F’_ST = 0.892) and significantly higher amongst UK populations (F’_ST = 0.949) than Scandinavian populations (F’_ST = 0.762; P < 0.01). The isolated populations in the UK have, on average, lower genetic diversity (allelic richness, proportion of loci that are polymorphic, gene diversity) than Scandinavian populations, and this diversity difference is associated with the smaller census size and population area of UK populations. From a conservation perspective, the naturally inbreeding nature of the species may buffer the species against immediate effects of inbreeding depression, but the markedly lower levels of genetic diversity in UK populations may represent a genetic constraint to evolutionary change. In addition, the high levels of population differentiation suggest that gene flow among populations will not be effective at replenishing lost variation. We thus recommend supporting in situ conservation management with ex situ populations and human-mediated seed dispersal among selected populations in the UK.     

Comparative Genetic Diversity of Wild and Captive Populations of the Bare-Faced Curassow (Crax fasciolata) Based on Cross-Species Microsatellite Markers: Implications for Conservation and Management

The bare-faced curassow (Crax fasciolata) is a large Neotropical bird that suffers anthropogenic pressure across much of its range. A captive population is maintained for conservation management, although there has been no genetic screening of stocks. Based on the six microsatellite markers developed for Crax globulosa, the genetic variability of C. fasciolata and possible differences between a wild and a captive population were investigated. Only three loci were polymorphic, with a total of 27 alleles. More than half of these alleles were private to the wild (n = 8) or captive (n = 7) populations. Significant deviations from Hardy–Weinberg equilibrium were restricted to the captive population. Despite the number of private alleles, genetic drift has probably promoted differentiation between populations. Our results indicate that wild C. fasciolata populations are genetically impoverished and structured, but species-specific microsatellite markers will be necessary for a more reliable assessment of the species’ genetic diversity.     

Allozyme variation and population genetic structure of common wild rice Oryza rufipogon Griff. in China

In order to determine the genetic diversity and genetic structure of populations in common wild rice Oryza rufipogon, an endangered species, allozyme diversity was analyzed using 22 loci in 607 individuals of 21 natural populations from the Guangxi, Guangdong, Hainan, Yunnan, Hunan, Jiangxi and Fujian provinces in China. The populations studied showed a moderate allozyme variability (A=1.33, P=22.7%, Ho=0.033 and He=0.068), which was relatively high for the genus Oryza. The levels of genetic diversity for Guangxi and Guangdong were significantly higher than those for the other regions, and thus South China appeared to be the center of genetic diversity of O. rufipogon in China. A moderate genetic differentiation (F_ST=0.310, I=0.964) was found among the populations studied. Interestingly, the pattern of population differentiation does not correspond to geographic distance. An estimate of the outcrossing rate (t=0.324) suggests that the species has a typical mixed-mating system. The deficit of heterozygotes (F=0.511) indicates that some inbreeding may have taken place in outcrossing asexual populations because of intra-clone outcrossing events and ”isolation by distance” as a result of human disturbance. In order to predict the long-term genetic survival of fragmented populations, further studies on gene flow among the remaining populations and the genetic effects of fragmentation are proposed. Finally, some implications for the conservation of endangered species are suggested. Received: 22 June 1999 / Accepted: 20 December 1999     

Chloroplast DNA haplotype diversity and postglacial recolonization of Hagenia abyssinica (Bruce) J.F. Gmel. in Ethiopia

We investigated genetic variation of 273 individuals from 25 populations of the monotypic species Hagenia abyssinica (Rosaceae) from the highlands of Ethiopia at three chloroplast microsatellite loci. The objectives were to infer the factors that shaped the genetic structure and to reconstruct the recolonization history of the species. Six haplotypes that were phylogenetically grouped into two lineages were identified. Homology of the three loci to the respective regions of the chloroplast genome was confirmed by sequencing. The chloroplast haplotypes found in Hagenia showed a clear pattern of congruence between their geographical distribution and genealogical relationships. A very low haplotype diversity within populations (h _S = 0.079, v _S = 0.058) and a very high population differentiation (G _ST = 0.899, N _ST = 0.926) was observed, reflecting very low mixing between recolonizing lineages. Restricted gene flow through seeds, rare long-distance dispersal, contiguous range expansion and mutation shaped the genetic structure of Hagenia. Fossil pollen records suggested that the trend of postglacial recolonization of Hagenia was first in the south and latter went to the north in Ethiopia.     

The genetic signature of ecologically different grassland Lepidopterans

The level of genetic diversity found for species is strongly influenced by properties of the species’ ecology, abundance and behaviour (as dispersal). To address this coherence, we selected twenty-two grassland butterfly and burnet moth species, which were previously analysed by allozyme electrophoresis (using 15–25 loci per species) over a study area in western Germany with adjoining areas of Luxembourg and north-eastern France. For this study area, we calculated the species’ specific climatic niche breadths and derived various ecological parameters from literature and own field observations. The obtained parameters of genetic diversity (heterozygosity, number of alleles and percentage of polymorphic loci), genetic differentiation (D _est as well as F _ST and F _IS values as proxis for genetic differentiation among populations and inbreeding within populations), as well as ecological and climatic niche dimensions did not show significant differences among the different Lepidoptera families; therefore taxonomic assignment apparently has a negligible influence on the genetic structure of taxa. Genetic diversity and differentiation showed a significant correlation with the ecological and climatic niche-breadth of species in many cases: generalistic species with rather unspecific ecological characteristics and climatic niche had higher genetic diversities and tend to have lower differentiation and inbreeding, whereas specialist taxa (i.e. with narrow ecological and climatic niches) have lower genetic diversities and higher differentiation and inbreeding. The results might reflect contrasting population structures of specialist species with lower abundances compared with the more common generalists. The more restricted and isolated occurrence of specialists might consequence a reduction in genetic diversity and an increase in genetic differentiation among local populations. In contrast, generalists with unspecific habitat requirements occur in higher abundances and in consequence show a more homogenous genetic structure with higher diversities.     

The role of golf courses in maintaining genetic connectivity between common frog (Rana temporaria) populations in an urban setting

We studied population size, genetic diversity and differentiation of common frog (Rana temporaria) populations at urban golf courses and reference natural ponds in the greater Helsinki region, southern Finland. A total of 248 tadpoles from 12 locations (six golf courses, six reference sites) were genotyped with 13 polymorphic microsatellite markers. The most urban populations, situated in northern Helsinki, were the largest breeding sites having >120 (golf courses) and >200 (reference sites) spawn clumps at the time of sampling. On average, there was no difference in the number of spawns between the anthropogenic ponds at golf courses and the natural water bodies. Genetic variation within populations was substantial (H _O = 0.68) while genetic differentiation between populations was low (F _ST = 0.016; average distance = 17.6 km). The golf course populations did not differ from natural populations in terms of genetic variability or differentiation. Hence, our results suggest that golf courses contribute positively to urban amphibian populations by providing suitable water bodies for reproduction and green corridors for dispersal, thus preventing isolation and loss of genetic variability within populations.     

Local genetic structure of a montane herb among isolated grassland patches: implications for the preservation of genetic diversity under climate change

Habitat loss, fragmentation of meadow patches, and global climate change (GCC) threaten plant communities of montane grasslands. We analyzed the genetic structure of the montane herb Geranium sylvaticum L. on a local scale in order to understand the effects of habitat fragmentation and potential GCC impacts on genetic diversity and differentiation. Amplified fragment length polymorphism (AFLP) fingerprinting and cpDNA sequencing was performed for 295 individuals of 15 G. sylvaticum populations spanning the entire distribution range of the species in the Taunus mountain range in Germany. We found patterns of substantial genetic differentiation among populations using 150 polymorphic AFLP markers (mean F _ST = 0.105), but no variation in 896 bp of plastid DNA sequences. While populations in the center of their local distribution range were genetically diverse and less differentiated, higher F _ST values and reduced genetic variability was revealed for the populations at the low-altitudinal distribution margins. Projections of GCC effects on the distribution of G. sylvaticum in 2050 showed that GCC will likely lead to the extinction of most edge populations. To maintain regional genetic diversity, conservation efforts should focus on the diverse high-altitude populations, although a potential loss of unique variations in genetically differentiated peripheral populations could lower the overall genetic diversity and potentially the long-term viability in the study region. This study documents the usefulness of fine-scale assessments of genetic population structure in combination with niche modeling to reveal priority regions for the effective long-term conservation of populations and their genetic variation under climate change.     

Geographic variation in relict populations: genetics and phenotype of bush-cricket Pholidoptera frivaldskyi (Orthoptera) in Carpathians

A decreasing population size is often causing species extinction, however, relict species persisting in small-sized populations counter this. We analysed spatial genetic variation and past changes in population size at the maternally-inherited mitochondrial DNA level to clarify the origin of all recently known isolated populations of Pholidoptera frivaldskyi occurring in the range of Carpathian Mountains. Along with that we analysed also morphological variation as some phenotypic traits can retain useful information on population genetic structure. We found a relatively low genetic diversity within isolated populations as 778 bp COI gene sequences revealed only 13 unique haplotypes (n = 173 individuals from 10 populations). The spatial analysis of molecular variance identified three geographically homogenous genetic clusters (one in Slovakia and two in Romania) with a high level of differentiation among them, suggesting restricted gene flow, whilst Bayesian skyline simulation reconstructed a negative demographic change through evolutionary time. Inferred genetic pattern clearly coincides with differences in males’ colour phenotype as the extent of pigmentation on the lateral pronotum varied significantly among genetic lineages. We suggest that geographical variation in the species populations has relict-like character and their isolated occurrence is not a result of recent introduction events. Identification of ‘evolutionary units’ may help in the conservation and management of this rare insect species.     

Influence of geographical isolation on genetic diversity ofHimantoglossum hircinum (Orchidaceae)

Many plants live in habitats that are becoming increasingly rare and fragmented due to human disturbance. Studies of genetic diversity are necessary for understanding and evaluating the impact of habitat fragmentation, and land-use change on the dynamics of rare species to help in setting priorities for their management. We used AFLP markers to study variation in genetic structure within and among three border populations of the orchidHimantoglossum hircinum. Study sites were located in central Germany, which represents the north-eastern border of distribution, and they were separated from each other by a maximum distance of 10 km. Landscape between the populations was characterized by man-made habitat features including agricultural fields, major roads and settlements. We compared pairs of populations to evaluate genetic variation, genetic differentiation, and the current level of gene flow between them. Genetic diversity was high within the populations and higher within than between the populations. Population genetic differentiation was relatively high compared to other orchid species (G _st=0.20). Gene flow between pairs of the populations varied and appeared to be influenced by landscape characteristics separating the localities. Recommendations for conservation ofH. hircinum are provided. Management activities should concentrate on maintenance or enlargement of habitat size to prevent loss of genetic diversity due to genetic drift. Sites are genetically relatively isolated, but using stepping stones to improve gene exchange would be problematic because of the intense land-use in the area.     

Genetic diversity and local population structure in Ambrosina bassii (Araceae,Ambrosineae), a Mediterranean relict species

The effects of habitat fragmentation on the genetic structure of Ambrosina bassii are analyzed. The species, whose reproductive biology is mostly unknown, is the only representative of its genus and tribe and it is endemic to the central Mediterranean area. The selected study area was the island of Sicily, in which wild populations show a wide morphological variability and ecological amplitude. Patterns of within- and among-population genetic diversity in eleven Sicilian populations, occurring in six disjunct areas, were examined by means of allozyme electrophoresis. High levels of genetic diversity were found as shown by the mean expected heterozygosity (H_e = 0.263), the percentage of polymorphic loci (P₉₅ = 65.3), the mean number of alleles per locus (A = 2.0). Genetic differentiation between populations was relatively low (mean F_ST = 0.091 and Nm = 1.98). A very weak correlation exists between genetic distances and geographic distances between populations. Despite its restricted and fragmented geographical range, A. bassii showed (i) high levels of genetic diversity, mainly within populations; (ii) no genetic differentiation between populations and morphotypes.     

Genetic diversity of Asian chum salmon <Emphasis Type="Italic">Oncorhynchus keta</Emphasis> (Salmonidae,Salmoniformes) and the dynamics of gene pools in Sakhalin populations under artificial reproduction

The estimates of genetic diversity in populations of chum salmon Oncorhynchus keta from different regions of Sakhalin Island, Iturup Island, and the Anadyr’ River were obtained on the basis of analysis of allozyme variability. These estimates together with our published earlier data on chum salmon from the Amur River basin and the rivers of the northern coast of the Sea of Okhotsk demonstrate pronounced regional genetic differentiation in the Asian part of the fish range. The intraregional level of interpopulation genetic diversity was maximum on Sakhalin Island (G _ST = 6.6%) and was small on Iturup Island (G _ST = 0.9%) and the northern coast of the Sea of Okhotsk (G _ST = 0.6%). Interpopulation genetic diversity of Sakhalin chum salmon was almost commensurable to the diversity of the whole pool of studied Asian populations (G _ST = 7.6%) and would be presented more completely in baselines assigned for genetic identification of mixed stocks. It was demonstrated that the character and degree of genetic differentiation between populations of chum salmon from the main hatcheries situated in different regions of the Sakhalin oblast and connected to one another by numerous transplantations of fertilized eggs did not change significantly during an approximately 20-year period of our observation, and this fact suggests low efficiency of such transplantations.     

Genetic composition and differentiation of sloe (Prunus spinosa L.) populations in Germany with respect to the tracing of reproductive plant material

Sloe (Prunus spinosa L.) is a shrub native to Europe. In Germany, 50–80 % of all planted sloe is imported. Little is known about the genetic diversity patterns within and between German sloe populations. Thus, a debate arose how to avoid risks for nature and landscape by planting potentially maladapted material. The main objectives of our study are to analyse the genetic differentiation pattern of sloe populations in Germany, to identify geographic/genetic structures and to evaluate their potential for tracing reproductive material. 17 natural populations from Germany and 1 from Italy and Hungary were investigated by Amplified Fragment Length Polymorphisms (AFLP) and PCR–RFLP techniques. The AMOVA analyses based on AFLPs for all populations and for the German populations only result in equally high differentiation values of Φ_PT = 15 % of molecular variance between populations. The analysis of cpDNA PCR–RFLPs resulted in 24 haplotypes with 30 % showing genetic variation between populations. Overall values of genetic variability over all loci and populations are: Na = 0.832, Ne = 1.114 and He = 0.072. Mantel tests for AFLPs and cpDNA haplotypes reveal no association between geographic and genetic distances between populations as a result of a lack of differentiation between German populations and those from southern and southeastern Europe. Weak geographic/genetic patterns were observed on a large scale. However, these concern the German populations only. Our results indicate that vegetative regeneration in combination with founder effects may influence the level of differentiation between populations. Populations with a large amount of vegetative propagation are more differentiated from other populations than those populations which exhibit less vegetative regeneration. The assignment of reproductive material (i.e. plant material) to potential source populations resulted in high values of correct allocations. Hence, such methods can be applied to trace reproductive material of unknown origin.