Genetic structure of brown trout (<Emphasis Type="Italic">Salmo trutta</Emphasis> L.) from the Hardangervidda mountain plateau (Norway) analyzed by microsatellite DNA: a basis for conservation guidelines

The Hardangervidda in southern Norway, the largest mountain plateau in Europe, has thousands of lakes and streams, mainly between 1000 and 1300 m above sea level, where brown trout is the only fish species. To describe the current genetic diversity of brown trout in this area, a total of 863 fish from 20 lakes were genotyped with eleven microsatellites. Most diversity is within lake populations, but diversity among geographical groups and populations within groups was significant, too. Neighbor-joining, principle coordinate analysis and Bayesian clustering show three major geographic groups in accordance with the river systems. Bias was caused by recent stocking in two lakes. Low/no genetic differentiation among some populations indicates that intermixing is common when lakes are well-connected, as was also shown by assignment test. We recommend preserving the genetic diversity of brown trout in this unique area by managing stocking in lake systems according to genetic structure.     

Characterization of novel microsatellite loci in rare minnow (<Emphasis Type="Italic">Gobiocypris rarus</Emphasis>) and amplification in closely related species in Gobioninae

Rare minnow (Gobiocypris rarus) is an endangered small fish endemic to upper reach of the Yangtze River. From a (GT)n enriched genomic library, 32 microsatellites were isolated and characterized. Nineteen of these loci were polymorphic in a test population with alleles ranging from 2–7, and observed and expected heterozygosities from zero to 0.8438, and 0.2679 to 0.8264, respectively. In the cross-species amplifications, 13 out of 19 polymorphic loci were found to be also polymorphic in at least one of the 7 closely related species of the subfamily Gobioninae. These polymorphic microsatellite loci should provide sufficient level of genetic diversity to evaluate the fine-scale population structure in rare minnow and its closely related species for the conservation purpose.     

Development and characterization of new microsatellite markers for ginseng (<Emphasis Type="Italic">Panax ginseng</Emphasis> C. A. Meyer)

Panax ginseng C.A. Meyer, commonly known as Korean or Asian ginseng, is a perennial herb native to Korea and China. Its roots are highly prized for several medicinal properties. The present study describes development and characterization of twenty-two polymorphic microsatellite markers for this species. A total of 99 alleles were detected with an average of 4.5 alleles per locus across 20 accessions. Values for observed (H _O ) and expected (H _E ) heterozygosities ranged from 0.05 to 1.00 and from 0.18 to 0.73, respectively. Eleven loci deviated from Hardy–Weinberg equilibrium (P < 0.001). Significant (P < 0.05) heterozygote deficiency was observed at 13 loci. Exact test for linkage disequilibrium showed significant values (P < 0.05) between 12 pairs of loci. These microsatellite markers provide powerful tools for understanding population and conservation genetics of this species and also for genetic differentiation and authentication of different Panax species being used in commercial ginseng products.     

Isolation and characterization of microsatellites in Primula glaucescens Moretti and their cross-species amplification in P. spectabilis Tratt.

The hexaploid herbaceous species Primula glaucescens Moretti and Primula spectabilis Tratt. (2n = 6x = 66) are two endemics of the Italian Pre-Alps protected by national and international laws. In order to plan conservation strategies for natural populations and to study the influence of the latest glaciation on them we developed a set of microsatellites markers for the endangered Primula species: ten primer pairs allowed analysis of polymorphic disomic loci in P. glaucescens samples and seven of them also amplified polymorphic disomic markers in P. spectabilis. Kirsten Wolff and Giorgio Binelli contributed equally to the paper     

Delimiting species boundaries for endangered Canary Island grasshoppers based on DNA sequence data

Mitochondrial DNA cytochrome oxidase subunit I and nuclear ITS2 sequences were surveyed from Canary Islands threatened species of the genera Purpuraria and Acrostira (Orthoptera: Pamphagidae). Phylogenetic and population analyses show that the two previously recognized Purpuraria erna subspecies are not valid as conservation units, and that there is a new unrecognized species of Purpuraria, coincident with recently discovered morphological variation within the genus. In addition, mitochondrial introgression seems to occur between the two Purpuraria species in southwest Lanzarote. Species-delimitation based on the morphological taxonomy of Acrostira, which recognizes four single-island endemics, is only partially supported by the genetic data. It shows that currently admitted species from the central and western islands of Tenerife, La Gomera and La Palma are closely related, with evidence of recent gene flow between the Tenerife and La Gomera populations. MtDNA variation also showed that A. euphorbiae, currently considered as the most critically endangered grasshopper species in the Canaries, has lower population diversity than its close relatives.     

Stocking may increase mitochondrial DNA diversity but fails to halt the decline of endangered Atlantic salmon populations

Over the last 50 years, Spanish Atlantic salmon (Salmo salar) populations have been in decline. In order to bolster these populations, rivers were stocked with fish of northern European origin during the period 1974–1996, probably also introducing the furunculosis-inducing pathogen, Aeromonas salmonicida. Here we assess the relative importance of processes influencing mitochondrial (mt)DNA variability in these populations from 1948 to 2002. Genetic material collected over this period from four rivers in northern Spain (Cantabria) was used to detect variability at the mtDNA ND1 gene. Before stocking, a single haplotype was found at high frequency (0.980). Following stocking, haplotype diversity (h) increased in all rivers (mean h before stocking was 0.041, and 0.245 afterwards). These increases were due principally to the dramatic increase in frequency of a previously very low frequency haplotype, reported at higher frequencies in northern European populations proximate to those used to stock Cantabrian rivers. Genetic structuring increased after stocking: among-river differentiation was low before stocking (1950s/1960s Φ _ST = –0.00296–0.00284), increasing considerably at the height of stocking (1980s Φ _ST = 0.18932) and decreasing post-stocking (1990s/2002 Φ _ST = 0.04934–0.03852). Gene flow from stocked fish therefore seems to have had a substantial role in increasing mtDNA variability. Additionally, we found significant differentiation between individuals that had probably died from infectious disease and apparently healthy, angled fish, suggesting a possible role for pathogen-driven selection of mtDNA variation. Our results suggest that stocking with non-native fish may increase genetic diversity in the short term, but may not reverse population declines.     

Assessing threats and mapping sandal resources to identify genetic ‘hot-spot’ for in-situ conservation in peninsular India

Santalum album L. is an economically important tropical tree species. Owing to extensive logging, changes in land-use patterns and poor natural regeneration, the natural sandal populations are rapidly dwindling. It is feared that such threats could easily undermine the genetic diversity of sandal populations. Effective measures to prevent such loss are prerequisite. We have developed baseline data on the levels of genetic diversity and its distribution on a geographic scale for sandal in India. Based on Geographic Information System, distribution map of sandal was developed and found that the populations were geographically more concentrated in the Deccan plateau. It was found that, for past 53 years, there was a monotonic decrease in the extraction of sandal in the state of Karnataka, India. Using allozyme markers, the genetic diversity of 19 sandal populations in peninsular India were determined and over all observed heterzygosity (H_o) was found to be 31%. The percent H_o was positively correlated with the density of the sandal populations (r = 0.44) and with increasing longitude it was found to be negatively correlated (r = −0.51). The dendrogram analysis indicated a clear clustering of sandal populations based on their geographic occurrence. The Deccan plateau populations were found to be genetically the most diverse and seemed to represent the ‘hot-spot’ of sandal genetic resources in peninsular India. Our results have important implications for the conservation strategies for sandal populations in peninsular India and can be applied for the conservation of other taxa as well.     

Development of microsatellite markers for <Emphasis Type="Italic">Echinops setifer</Emphasis> (Asteraceae), an endangered grassland plant species in Japan

Echinops setifer is an endangered grassland plant species in Japan. We isolated and characterized nine microsatellite loci in this species. The number of alleles ranged from 3 to 7 and expected heterozygosities from 0.108 to 0.761. These markers described here will be useful for investigating the genetic diversity, genetic structure and gene flow, and planning for conservation of E. setifer.     

Impact of urban fragmentation on the genetic structure of the eastern red-backed salamander

Urban development is a major cause of habitat loss and fragmentation. Few studies, however, have dealt with fragmentation in an urban landscape. In this paper, we examine the genetic structure of isolated populations of the eastern red-backed salamander (Plethodon cinereus) in a metropolitan area. We sampled four populations located on a mountain in the heart of Montréal (Québec, Canada), which presents a mosaic of forested patches isolated by roads, graveyards and buildings. We assessed the genetic structure of these populations using microsatellite loci and compared it to the genetic structure of four populations located in a continuous habitat in southern Québec. Our results indicate that allelic richness and heterozygosity are lower in the urban populations. Exact differentiation tests and pairwise F _ST also show that the populations found in the fragmented habitat are genetically differentiated, whereas populations located in the continuous habitat are genetically homogeneous. These results raise conservation concerns for these populations as well as for rare or threatened species inhabiting urban landscapes.