Indigenous Gene Pool Research Articles

Correlations among morphological traits of sweet chestnut (Castanea sativa Miller) from Bosnia and Herzegovina

Abstract Sweet chestnut forests in Bosnia and Herzegovina are underrepresented in the total forest fund, and their area is declining today. The research aims to determine the correlation relations of morphological traits of chestnut leaves, fruit and cupule in the population of Bosnian Krajina (northwestern Bosnia and Herzegovina) to undertake selection and breeding activities. Eleven traits of fruits, leaves and cupules were measured, seven assessed and six calculated. A mutual correlation for the researched traits was calculated using the Pearson correlation coefficient r. When the fruit traits and cupule traits were compared, the needle length showed a statistically significant correlation with most of the fruit traits. The traits of the number of fruits in the cupule and needle length had a statistically significant correlation coefficient with leaf blade width and leaf petiole length. The correlated traits can be distinguished as important for further selection and breeding of sweet chestnuts. The research results indicate that the genetic material of sweet chestnut is a rich source of genetic diversity and can be used in selection to obtain new varieties and cultivars in Bosnia and Herzegovina and for the protection of the indigenous gene pool.

Diversity of mite fauna and varietal screening against yellow mite, Polyphagotarsonemus latus (Bank) in chilli under Gangetic basin of West Bengal, India

The present study was undertaken to explore the diversity of predatory mites as well as their associated phytophagous prey mites for development of better and ecologically sound mite pest management strategy and to select suitable cultivars from an indigenous gene pool against yellow mite. Eight chilli cultivars were screened and incidence pattern of yellow mite was observed during the period of investigation. Results revealed that none of the cultivars were resistant against the yellow mite but BCCH-SL-4 was found least susceptible to yellow mite. Altogether 12 species of predatory mites belonging to 5 families were encountered in chilli crop. The predatory mite families included Phytoseiidae, Cunaxidae, Bdellidae, Tydeidae, and Ascidae represented by the genera Amblyseius, Typhlodromips, Euseius, Neoseiulus, Paraphytoseius, Scapulaseius, Cunaxa, Bdellodes and Tydeus. The associated phytophagous mite families were recorded like Tetranychidae, Tenuipalpidae and Tarsonemidae represented by the genera Tetranychus, Schizotetranychus, Eutetranychus, Brevipalpus and Polyphagotarsonemus. Mite in the family Phytoseiidae was found to be the most common predators and Typhlodromips syzygii was observed as predominant predory mite species followed by Amblyseius largoensis.

Genetic Diversity of Hatchery-Bred Brown Trout (Salmo trutta) Compared with the Wild Population: Potential Effects of Stocking on the Indigenous Gene Pool of a Norwegian Reservoir

This study was conducted in Lake Savalen in southeastern Norway, focusing on genetic diversity and the structure of hatchery-reared brown trout (Salmo trutta) as compared with wild fish in the lake and in two tributaries. The genetic analysis, based on eight simple sequence repeat (SSR) markers, showed that hatchery bred single cohorts and an age structured sample of stocked and recaptured fish were genetically distinctly different from each other and from the wild fish groups. The sample of recaptured fish showed the lowest estimated effective population size Ne = 8.4, and the highest proportion of siblings, despite its origin from five different cohorts of hatchery fish, counting in total 84 parent fish. Single hatchery cohorts, originating from 13–24 parental fish, showed Ne = 10.5–19.9, suggesting that the recaptured fish descended from a narrow group of parents. BayeScan analysis indicated balancing selection at several loci. Genetic indices of wild brown trout collected in the lake in 1991 and 2010 suggested temporal genetic stability, i.e., the genetic differentiation (FST) was non-significant, although the Ne, the number of alleles per locus and the number of private alleles were lower in the 2010 sample.

Genotyping of Avasirkhva, an indigenous Abkhasian grapevine variety

Molecular genotyping of native varieties of Vitis vinifera L. from different winegrowing areas is a current trend in the grapevine genetic diversity research. Abkhazia is among the world cradles of tamed grape, and its indigenous gene pool is of particular interest. Avasirkhva is a native Abkhasian grapevine variety mainly grown in the Gudauta District. Te research aimed to obtaining a genetic passport of Avasirkhva grapevine using microsatellite polymorphism data. Te study sampled grape plants from private farmsteads of the Gudauta District. Te plant phenotype corresponded to the variety’s ampelographic description. DNA was isolated from young shoot tip leaves with a CTAB-based protocol. Genotyping was performed with polymerase chain reaction (PCR) followed by capillary fragment separation. High-polymorphic SSR loci (VVS2, VVMD5, VVMD7, VVMD25, VVMD27, VVMD28, VVMD32, VrZAG62, VrZAG79) recommended for grapevine varietal identification were used as markers. Te amplicon size was estimated with an ABI Prism 3130 automated genetic analyser using the GeneMapper and PeakScanner soſtware and Pinot Noir as a reference variety genotype. Four samples exhibited an identical microsatellite profile. Te microsatellite assay-based genetic passport of the Avasirkhva variety is as follows: VVS2141-145 VVMD5234-242 VVMD7239- 249, VVMD25239-249, VVMD27184-190, VVMD28234-248, VVMD32248- 262, VrZAG62200-204, VrZAG79251-257. Te obtained passport is unique with respect to the known genotypes in the Vitis International Variety Catalogue (VIVC). A Principal Coordinate Analysis of microsatellite data was used to infer the genetic relationships between Avasirkhva and the Abkhasian varieties Kachich and Azhizhkvakva genotyped in our earlier studies, as well as nine native grapevines of Georgia, the nearest viticultural area. Te Avasirkhva genetic passport can be used in grapevine genotyping studies to clarify the varietal identity.

Morphometrical characteristics of cryptic invasive and indigenous gene pools of field maple Acer campestre L. in southern Sweden

The northernmost population of Acer campestre L. has its distribution in southern Sweden and consists of just 36 individuals. This particular remnant is considered critically endangered (CE) although the species spreads rapidly as potentially invasive gene pools escaped from gardens and urban plantations. The issue to distinguish between indigenous and introduced gene pools is urgent, since individuals or stands worthy of preservation risk being cut down. This article explores the possibility to use geometric morphometrics by landmarks to characterize shapes of leaves and samaras and to distinguish different gene pools. Bayesian clustering based on microsatellite data clearly distinguished between putatively native and introduced gene pools in southern Sweden. A discriminant analysis of Procrustes coordinates of leaf shapes gave 77% correct classification revealing a strongly concave leaf base for the native gene pool and a convex leaf base for the introduced ones. Corresponding analyses of the samara data resulted in 82% correct classification. In general, the discrimination rate for samara shape was higher than for leaf shape, suggesting a stronger influence of differences between individual and populations. However, PCA clearly showed that the variation in the native gene pool represents a subset of the variation seen in the introduced gene pool, both for leaf and samara shape. An easy to apply method to distinguish between native and introduced gene pools are thus not to be expected from shape data.

DNA-fi ngerprinting of local Аbkhazian grape variety Kachich

The study of the indigenous gene pool of Vitis vinifera L. of diff erent zones of viticulture with the involvement of molecular genetic methods is an urgent due to the wide diversity of grape varieties. The territory of Abkhazia is a unique zone, one of the hotbeds of the emergence of cultural grapes. «Kachich» is the oldest Abkhazian grape variety, known for the quality of wines obtained from its harvest. The variety is more resistant to fungal diseases compared to popular European varieties cultivated in modern Abkhazia, and is particularly resistant to rot of berries. However, often the local population calls old bushes by the name «Kachich», which give grapes of good quality for making of red wines and not always these forms correspond to the morphological description of the variety. The aim of the research is DNA fi ngerprinting of the «Kachich» grape variety based on the analysis of polymorphism of microsatellite loci. The object of the study was the plants corresponding to the variety description, growing in the collection of the agricultural company “Wines and waters of Abkhazia” (Sukhum, Abkhazia). DNA was isolated from the young leaves of the top of the shoot of typical plants of the variety by the CTAB-method. Genotyping was carried out by polymerase chain reaction (PCR) with separation of reaction products by capillary electrophoresis. Highly polymorphic SSR-markers recommended for grapes varieties identifi cation were used for study (VVS2, VVMD5, VVMD7, VVMD25, VVMD27, VVMD28, VVMD32, VrZAG62, VrZAG79). The size of amplifi ed fragments was estimated using the automatic genetic analyzer ABI Prism 3130 and special software GeneMapper and PeakScanner. To clarify the size of amplifi ed fragments, the DNA of reference varieties was used. According to the results of microsatellite analysis, the DNA-certifi cate of the genotype of the «Kachich» grape variety was compiled: VVS2153 155 VVMD5234 240 VVMD7239 249 VVMD25239 267 VVMD27186 193 VVMD28234 248 VVMD32262 272 VrZAG62194 196 VrZAG79236 236. The resulting DNA-profi le was checked for matches in the Vitis International Variety Catalogue VIVC. No matches of the obtained DNA-profi le with any other DNA-profi le presented in the Database were found. DNA-certifi cate of genotype «Kachich» can be successfully used for varieties identifi cation of grape plants if necessary to clarify their varietals affi liation.

High SNP diversity in the non-toxic indigenous Jatropha curcas germplasm widens the potential of this upcoming major biofuel crop species.

Jatropha curcas (jatropha) is an oil crop cultivated in (sub)tropical regions around the world, and holds great promise as a renewable energy source. However, efforts to fully commercialize jatropha are currently hampered by the lack of genetic diversity in the extant breeding germplasm, and by the toxicity of its seeds meaning that its seed cake cannot be used as a protein source in animal feed, among other constraints. In Mexico, the species' native range, there are jatropha plants whose seeds are used to prepare traditional meals. This non-toxic jatropha 'type' is considered to harbour low genetic variation due to a presumed domestication bottleneck and therefore to be of limited breeding value; yet, very little is known regarding its origin and genetic diversity. Using genotyping-by-sequencing (GBS), we extensively genotyped both indigenous toxic and non-toxic jatropha collected along roads and home gardens throughout southern Mexico. Single nucleotide polymorphism diversity in non-toxic jatropha is relatively high, particularly in northern Veracruz state, the probable origin of this germplasm. Genetic differences between toxic and non-toxic indigenous genotypes are overall quite small. A a genome-wide association study supported a genomic region (on LG 8, scaffold NW_012130064), probably involved in the suppression of seed toxicity. Conservation actions are urgently needed to preserve this non-toxic indigenous, relatively wild germplasm, having potential as a fuel feedstock, animal feed and food source among other uses. More generally, this work demonstrates the value of conservation genomic research on the indigenous gene pool of economically important plant species.

Genetic Population Structure of Sika Deer, Cervus nippon, Derived from Multiple Origins, Around Toyama Prefecture of Japan.

Recently, expansion of the number and distribution of sika deer, Cervus nippon, in the Japanese Archipelago has resulted in the disturbance of indigenous gene pools and ecosystems. There are also concerns that the artificial introduction of sika deer to certain areas may aggravate this situation. In order to contribute to the conservation of ecosystems, I examined the current state of genetic disturbance and dispersal routes in the sika deer populations around Toyama Prefecture, one of the main areas of expanding sika deer distribution. Of 12 haplotypes detected by mitochondrial DNA D-loop sequence analysis, 10 were found to belong to a previously detected sika deer group in northern Japan, although the remaining two haplotypes corresponded to the southern Japanese sika deer group. The latter two haplotypes were detected at especially high frequencies in the southern area of Toyama Prefecture, suggesting that these haplotypes may derive from artificially introduced individuals. Occurrence patterns of indigenous haplotypes around Toyama Prefecture revealed immigration into Toyama Prefecture through different routes, mainly in the east and south-west. The genetic results presented here may have application in predicting future dispersal routes, as well as aid in the establishment of effective measures for management of sika deer.

Molecular genetic analysis of five extant reserves of black honeybee Apis melifera melifera in the Urals and the Volga region

Local populations of the black honeybee Apis mellifera mellifera from the Urals and the Volga region were examined in comparison with local populations of southern honeybee subspecies A. m. caucasica and A. m. carpatica from the Caucasus and the Carpathians. Genetic analysis was performed on the basis of the polymorphism of nine microsatellite loci of nuclear DNA and the mtDNA COI–COII locus. On the territory of the Urals and the Volga region, five extant populations (reserves) of the black honeybee A. m. mellifera were identified, including the Burzyanskaya, Tatyshlinskaya, Yuzhno-Prikamskaya, Visherskaya, and Kambarskaya populations. These five populations are the basis of the modern gene pool of the black honeybee A. m. mellifera from the Urals and the Volga region. The greatest proportion of the remaining indigenous gene pool of A. m. mellifera (the core of the gene pool of the population of A. m. mellifera) is distributed over the entire territory of Perm krai and the north of the Republic of Bashkortostan. For the population of A. m. mellifera from the Urals and the Volga region, the genetic standards were calculated, which will be useful for future population studies of honeybees.

New approach to the mitotype classification in black honeybee Apis mellifera mellifera and Iberian honeybee Apis mellifera iberiensis

The black honeybee Apis mellifera mellifera L. is today the only subspecies of honeybee which is suitable for commercial breeding in the climatic conditions of Northern Europe with long cold winters. The main problem of the black honeybee in Russia and European countries is the preservation of the indigenous gene pool purity, which is lost as a result of hybridization with subspecies, A. m. caucasica, A. m. carnica, A. m. carpatica, and A. m. armeniaca, introduced from southern regions. Genetic identification of the subspecies will reduce the extent of hybridization and provide the gene pool conservation of the black honeybee. Modern classification of the honeybee mitotypes is mainly based on the combined use ofthe DraI restriction endonuclease recognition site polymorphism and sequence polymorphism of the mtDNA COI-COII region. We performed a comparative analysis of the mtDNA COI-COII region sequence polymorphism in the honeybees ofthe evolutionary lineage M from Ural and West European populations of black honeybee A. m. mellifera and Spanish bee A. m. iberiensis. A new approach to the classification of the honeybee M mitotypes was suggested. Using this approach and on the basis of the seven most informative SNPs of the mtDNA COI-COII region, eight honeybee mitotype groups were identified. In addition, it is suggested that this approach will simplify the previously proposed complicated mitotype classification and will make it possible to assess the level of the mitotype diversity and to identify the mitotypes that are the most valuable for the honeybee breeding and rearing.

Alpine headwater streams as reservoirs of remnant populations of the Danubian clade of brown trout

Summary1. The watercourses of Austria are mainly part of the Danube drainage system. Nonetheless, only few brown trout (Salmo trutta) populations of the Danubian phylogenetic lineage have been found in this region, not being introgressed by hatchery‐reared fish of the allochthonous Atlantic lineage. The present study was aimed at identifying further waterbodies that might harbour the non‐admixed gene pool of the Danubian clade trout.2. In a first step, the complete mitochondrial DNA control region of 447 specimens from 20 sampling sites was sequenced to screen for the presence of specific haplotypes. In a second step, 332 individuals from 15 populations were analysed at 10 microsatellite DNA loci.3. Although sampling concentrated on remote Alpine headwater streams, introgression of hatchery strains was more common than expected from existing stocking records. For seven populations, however, no evidence of recent hatchery trout introgression was found and it is suggested that they might represent the indigenous gene pool.4. Populations showing no evidence of hatchery introgression displayed lower levels of intrapopulation variability and higher degrees of differentiation compared to purported admixed populations.5. Our study demonstrates the necessity of combining different molecular markers to reveal the impact of introgression into wild populations, since at some sampling sites admixture would have remained undetected if only a single molecular technique was applied.6. The identification and characterisation of non‐introgressed populations provides important information for setting conservation priorities and preventing further loss of genetic integrity of a unique element of the native fish fauna.

MOROCCAN FIG PRESENTS SPECIFIC GENETIC RESOURCES: A HIGH POTENTIAL OF LOCAL SELECTION

Abstract Molecular characterisation of Moroccan fig germplasm mainly originated from northern areas showed that cultivars are highly local. The few widespread denominations correspond to several distinct genotypes. The lack of widespread homogenous cultivars suggests a local fig selection process and hence local domestication. Were fig natural populations present in the region before domestication? Mitochondrial DNA RFLP data showed that Mediterranean fig populations are structured into three groups: Balearic, West and East Mediterranean. The low genetic diversity and the strong differentiation of Balearic populations support the ancient origin hypothesis and the presence of natural populations in the western Mediterranean region before domestication. Analysis of western populations using nuclear SSR loci showed genetic structuring at the regional scale (South France, Corsica, Balearic islands and northern Morocco) but also at the local scale (Tetouan – Beni Hassan and Akchour – Mokrisset). This study indicates that Moroccan fig populations may constitute indigenous gene pools for fig cultivar selection. Clonal diversity, ancient cultivation, indigenous gene pool and genetic structuring at a local scale suggest a high potential for local selection of cultivars. INTRODUCTION

Disturbance of the indigenous gene pool of the threatened brook lamprey Lethenteron sp. S by intraspecific introgression and habitat fragmentation

Artificial introduction and habitat fragmentation affect the indigenous gene pools of fluvial animals. To investigate the effect of human activities on the genetic population structure of vulnerable brook lamprey Lethenteron sp. S in a single river system, samples from 12 tributaries of the Jinzu River, Japan, were analyzed using mitochondrial and microsatellite DNA markers. Exogenous Lake Biwa (Japan) haplotypes and alleles were detected in lampreys from several Jinzu River tributaries. Since Lake Biwa is the source of the commercial ayu fish Plecoglossus altivelis that is introduced in the Jinzu River, the exogenous Lake Biwa lamprey genotypes in the Jinzu River probably originated from the Lake Biwa lampreys that were unintentionally introduced along with the ayu fish. Bayesian admixture and mitochondrial DNA analyses revealed various genetic disturbance phases of the exogenous genotypes in the Jinzu River, such as the six indigenous populations, four admixed populations with low frequencies (average admixture proportion = 0.02–0.04; exogenous haplotype proportion <0.01), one introgressed population (0.71 and 0.57) and one population almost displaced by exogenous genotypes (0.93 and 0.96). Samples from three tributaries with weirs were genetically differentiated from the others by using pairwise F ST and Bayesian analyses; the results suggested isolation by the weirs. Reduced mitochondrial DNA diversity was observed in 1 of the 3 samples probably due to reduced population size. These findings indicate that the indigenous lamprey populations in the Jinzu River are seriously affected by introgression with exogenous genotypes via unintentional introduction and habitat fragmentation by weirs.

Monitoring and Source Tracking of Tetracycline Resistance Genes in Lagoons and Groundwater Adjacent to Swine Production Facilities over a 3-Year Period

To monitor the dissemination of resistance genes into the environment, we determined the occurrence of tetracycline resistance (Tc(r)) genes in groundwater underlying two swine confinement operations. Monitoring well networks (16 wells at site A and 6 wells at site C) were established around the lagoons at each facility. Groundwater (n = 124) and lagoon (n = 12) samples were collected from the two sites at six sampling times from 2000 through 2003. Total DNA was extracted, and PCR was used to detect seven Tc(r) genes [tet(M), tet(O), tet(Q), tet(W), tet(C), tet(H), and tet(Z)]. The concentration of Tc(r) genes was quantified by real-time quantitative PCR. To confirm the Tc(r) gene source in groundwater, comparative analysis of tet(W) gene sequences was performed on groundwater and lagoon samples. All seven Tc(r) genes were continually detected in groundwater during the 3-year monitoring period at both sites. At site A, elevated detection frequency and concentration of Tc(r) genes were observed in the wells located down-gradient of the lagoon. Comparative analysis of tet(W) sequences revealed that the impacted groundwater contained gene sequences almost identical (99.8% identity) to those in the lagoon, but these genes were not found in background libraries. Novel sequence clusters and unique indigenous resistance gene pools were also found in the groundwater. Thus, antibiotic resistance genes in groundwater are affected by swine manure, but they are also part of the indigenous gene pool.

Analysis of mitochondrial DNA in honey bees (Apis mellifera) from Serbia

In this study mitochondrial DNA of the indigenous honey bee populations from Serbia was analysed. Three ecotypes were comprised in the investigation: Banat (B), Syenichko-Peshterski (S) and Timok (T). The results show that all investigated samples of honey bees from Serbia belong to one mtDNA haplotype of the C phylogenetic lineage, previously designated as C2D haplotype, though with three additional polymorphic sites. For the novel mtDNA haplotype, the designation C2E is proposed. The novel C2E haplotype differs from C2D in two A-T transversions and in one insertion. Moreover, within the T honey bee ecotype, two additional polymorphic sites were observed; a deletion of a T nucleotide and a T-C transition. Our results suggest that the Carniolan honey bee populations from Serbia may represent an indigenous gene pool within A. m. carnica. The mtDNA haplotype (C2D), previously found in A. m. macedonica, was found in all samples of Serbian A. m. carnica. This suggests that the C2D haplotype may be found within both subspecies. This study represents the first effort to characterize the indigenous honey bee populations in Serbia using molecular techniques with the objective of improving our understanding of the phylogeography of Apis mellifera.

Migration barriers protect indigenous brown trout (Salmo trutta) populations from introgression with stocked hatchery fish

Brown trout populations in the Belgian rivers Scheldt and Meuse have been intensively stocked in the past decades, often with material of uncertain origin. Moreover, the species habitat has become increasingly fragmented, preventing gene flow between neighboring populations. We assessed how this impacted genetic diversity and population structure by analyzing 12 wild populations (total n=309) and seven hatchery stocks (n=200) at the mitochondrial control region with SSCP and at 27 RAPD loci. Historical records indicate that brown trout from distant locations have been used to supplement hatchery stocks; nevertheless we detected non-Atlantic mitochondrial genomes in only one population of the Scheldt basin and in one hatchery. In general, the hatchery samples displayed a higher genetic diversity and differentiated less among each other (global F-ST(mtDNA)=0.311/F-ST(RAPD)=0.029) compared to the wild populations (global F-ST(mtDNA)=0.477/F-ST(RAPD)=0.204). This is due to frequent exchanges between hatcheries and regular supplementation from several indigenous populations. Gene pools present in most downstream sections from tributaries of the Meuse were similar to each other and to the hatchery samples, despite the presence of migration barriers. Assignment analyses indicated that the contribution of hatchery material to the upstream parts was limited or even completely absent in populations separated by a physical barrier. Intensive stocking and exchange between hatcheries has homogenized the downstream sections of the Meuse River, whereas the migration barriers preserved the indigenous upstream populations. As such, uncontrolled removal of barriers might result in an irreversible loss of the remnant indigenous gene pools.

Molecular characterisation of indigenous Apis mellifera carnica in Slovenia

The genetic structure of Apis mellifera carnica bee from Slovenia, collected from 269 localities of ten Slovenian districts, was assessed by mitochondrial and nuclear DNA analyses. The level of genetic variability within and among districts was low. All of the samples were fixed for one newly found mtDNA haplotype of the C phylogenetic lineage, designated as C2C. A low level of variability was observed for all microsatellite loci, showing a very homogenous structure of the Carniolan bee population. Samples collected in the neighbouring district of Croatia expressed very similar results. On the other hand, high genetic differentiation was observed in comparison with A. m. macedonica population. Present study represents the first attempt to characterise indigenous honeybee populations in Slovenia using molecular methods. Furthermore, it indicates that the Carniolan bee from Slovenia still represents an indigenous gene pool within A. m. carnica. A. m. carnica / A. m. macedonica / mtDNA / COI-COII / microsatellite C

Use of micreosatellite markers for identification of indigenous brown trout in a geographical region heavily influenced by stocked domensticated trout

Based on estimates of genetic differentiation between populations, assignment tests and analysis of isolation by distance, stocked populations of brown trout Salmo trutta of Funen Island, Denmark, had been genetically affected by domesticated trout, whereas the stocking of wild exogenous trout into one of the rivers had little or no impact. At the same time, there were clear indications of remaining indigenous gene pools in the Funen populations. The management implications of these findings are discussed and changes in trout release activity are recommended to avoid further mixing of trout gene pools.

BROWN TROUT (SALMO TRUTTA) STOCKING IMPACT ASSESSMENT USING MICROSATELLITE DNA MARKERS

The genetic integrity of many salmonid fish populations is threatened by stocking of domesticated conspecifics. The purpose of this study was to assess the utility of microsatellite DNA markers for detecting loss of genetic diversity in hatchery strains, for estimating their genetic relationships, and for monitoring the genetic impact of stocking activity on wild populations of salmonid fishes. Brown trout from ten hatchery strains, one supportive breeding “strain,” and five wild populations were screened for variation at eight loci. In most hatchery strains, genetic variation was comparable to that of wild populations, but three strains showed loss of allelic variation. In six of the hatchery strains, significant differentiation was observed between age classes. Genetic differentiation among all populations was moderate (FST = 0.065, ρST = 0.076), and only a minor part of genetic diversity was distributed between the wild and hatchery populations. We assessed whether wild populations were introgressed by stocked hatchery trout by performing assignment tests to determine population of origin and estimating maximum potential introgression rates. The results suggested that genetic introgression by hatchery trout had occurred for only two of the five populations potentially influenced by stocking. In one of these two rivers, microsatellite data obtained from a limited number of old scale samples indicated that individuals from the original population were genetically divergent from those of the present population, suggesting that extinction of the original population had taken place. The study demonstrates that microsatellite analysis provides a useful tool for distinguishing heavily introgressed populations from those unaffected by stocking. The information can be used to assist in (1) prioritizing populations for conservation and (2) the choice of wild populations to be used as sources for the reintroduction of salmonids in areas where local, indigenous gene pools have been extirpated.

Notice to Contributors

Changes in forestry policy have increased the importance and extended the scope of genetic management of native species. Recent debate on genetic management prescriptions has been conducted with insufficient access to sound scientific information. This paper attempts to remedy this by: (1) presenting an overview of genetic variation and the processes which control it; (2) reviewing current measures; and (3) proposing a range of improvements to policy and practice. Genetic variation in Scottish tree and shrub populations is a neglected field of research, except for Scots pine ( Pinus sylvestris ). Some useful information can be provided by considering the history, ecology and biology of species together with genetic theory. Current patterns of variation reflect both the historical origins (as demonstrated by biochemical markers) and adaptation through natural selection (as indicated by provenance research). Existing populations probably still retain significant elements of adaptive variation; though this will vary according to species, with some showing close correlation between patterns of adaptive variation and environmental factors and others being more plastic. Indigenous genepools have been modified by fragmentation, changes in the forest environment, and introduction of foreign material, much of which is maladapted to upland sites. With some exceptions, the levels of genetic variation in existing indigenous populations comprise an adequate basis for restoring and expanding native woodland. The current undiscriminating use of continental provenances needs to be strongly discouraged; but equally restricting choice of seed sources to the most local provenances can also be inappropriate. Use of Scottish material from the same region and similar site type as the planting site needs to be encouraged. Current genetic management measures are rudimentary and fail to address adequately key issues of provenance choice, genetic conservation, seed supply or provision of selected or improved materials especially in broadleaves. Changes in legislation, regulation, seed supply, advice and research are proposed to address these shortcomings. The need for more provenance research is highlighted.