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1.
European fallow deer are an introduced species classified as partly protected wildlife in Tasmania, Australia. Current management practices are primarily governed under the Quality Deer Management regime, in which animals are harvested during designated hunting seasons. Among populations, prominent morphological differences have been reported; however, the genetic relationship of these populations has until now been poorly understood. Representative animals were sampled from three key areas across their range and genotyped at ten polymorphic microsatellite loci to investigate genetic diversity, population structure, and genetic bottlenecks. Allelic richness was low in all three populations and ranged between 2.20 and 2.49 alleles/locus. A genetic bottleneck was detected in two of the three populations (P < 0.001). Population differentiation was evident between Lake Echo and Benham (q = 0.122; P < 0.001) and Benham and Connorville (q = 0.110; P < 0.001), but not between Lake Echo and Connorville (q = 0.0235), with individuals being identified as belonging to two genetic clusters. The pattern of population differentiation from the three study populations suggests that deer from the western region of their range are genetically distinct to those from the eastern region. This correlates with morphological variation within Tasmanian fallow deer, in which differences between the regions maybe attributable to geographical barriers.  相似文献   

2.
Elzinga JA  Turin H  van Damme JM  Biere A 《Oecologia》2005,144(3):416-426
Habitat fragmentation can affect levels of herbivory in plant populations if plants and herbivores are differentially affected by fragmentation. Moreover, if herbivores are top–down controlled by predators or parasitoids, herbivory may also be affected by differential effects of fragmentation on herbivores and their natural enemies. We used natural Silene latifolia populations to examine the effects of plant population size and isolation on the level of herbivory by the seed predating noctuid Hadena bicruris and the rate of parasitism of the herbivore by its parasitoids. In addition, we examined oviposition rate, herbivory and parasitism in differently sized experimental populations. In natural populations, the level of herbivory increased and the rate of parasitism decreased with decreasing plant population size and increasing degree of isolation. The number of parasitoid species also declined with decreasing plant population size. In the experimental populations, the level of herbivory was also higher in smaller populations, in accordance with higher oviposition rates, but was not accompanied by lower rates of parasitism. Similarly, oviposition rate and herbivory, but not parasitism rate, increased near the edges of populations. These results suggests that in this system with the well dispersing herbivore H. bicruris, habitat fragmentation increases herbivory of the plant through a behavioural response of the moth that leads to higher oviposition rates in fragmented populations with a reduced population size, increased isolation and higher edge-to-interior ratio. Although the rate of parasitism and the number of parasitoid species declined with decreasing population size in the natural populations, we argue that in this system it is unlikely that this decline made a major contribution to increased herbivory.  相似文献   

3.
Javan rusa deer (Cervus timorensis russa) is one of six introduced wild deer species in Australia. The largest population is located in the Royal National Park (RNP), New South Wales, Australia. Although the deer are considered a pest in certain areas, they are also commercially valuable. Using molecular markers we aimed to characterise the level of genetic diversity within the RNP population and identify a possible genetic bottleneck associated with the introduction of seven founding individuals. We also aimed to identify appropriate polymorphic microsatellite loci that could assist in commercial breeding programmes and wild population management in Australia. The results indicate that Javan rusa deer from the RNP (n=37) had an average (±SE) of only 2.29±0.095 alleles/locus, which is substantially lower than that reported in source populations from New Caledonia (7.60±0.933 alleles/locus). These data combined with the presence of genetic reduction signatures (P<0.001) indicate that this population has experienced a population bottleneck possibly at the time of establishment in Australia. Despite low allelic diversity, the large suite of identified polymorphic loci (n=24) shows promise for applications in population genetics, including parentage analysis (total parentage exclusion 0.944) within Australia. These data will contribute significantly to improving commercial breeding programmes and possibly to wild population management plans.  相似文献   

4.
Hippophae rhamnoides ssp. sinensis occurs mainly in the arid regions of northwest China. The wood stands of this subspecies play an important role in maintaining the local ecosystems in these regions. In addition, the genetic characteristics are essential to understand the historical range changes of this subspecies and its morphological differentiation with other subspecies. In this study, we developed nine microsatellite loci for this subspecies for the first time. We used the combining biotin capture method to enrich AG/CT/AC/GT/CG/GTG/CCA microsatellites. Twenty-six microsatellites were isolated from the enriching library and nine of them were found to be polymorphic through screening 12 distantly distributed individuals. The number of alleles per locus ranged from three to twelve and expected heterozygosity from 0.2659 to 0.4767, respectively. We further performed cross-priming tests in another subspecies and two congeneric species. These firstly isolated loci will provide a useful tool to investigate the genetic structure of this subspecies and its morphological differentiation from the other subspecies.  相似文献   

5.
Distribution of black grouse and hazel grouse was evaluated on the basis of the results of bird counts from July 16 to August 31, 1959–2005 over all natural geographical zones and subzones of West Siberia (with fractioning down to the type of landscape tract). Data averaging over groups of vegetation map units (dynamic series) and other specific averaging procedures revealed that black grouse is common in northern-, middle-, and southern-taiga bogs; in subtaiga pine forests; in grassy bogs combined with halophytic meadows within the boundaries of subtaiga forests and the northern forest-steppe; and in agricultural lands in the northern forest-steppe. Hazel grouse is numerous in southern-taiga and dark coniferous middle-taiga forests and their derivatives. The number of hazel grouse individuals in these habitats is larger than in other lands. In general, over the subzones, both black grouse and hazel grouse are most numerous in the middle and southern taiga and in subtaiga forests. To the north and to the south of these subzones, the abundance of these species decreases. They were not encountered in tundras and some open forest-steppe and steppe habitats.  相似文献   

6.
Morishima K  Nakayama I  Arai K 《Genetica》2008,132(3):227-241
In the present study, the first genetic linkage map of the loach Misgurnus anguillicaudatus was constructed with 164 microsatellite markers and a color locus, and it included 155 newly developed markers. A total of 159 microsatellite markers and a color locus were mapped in 27 linkage groups (LGs). The female map covered 784.5 cM with 153 microsatellite markers and a color locus, whereas the male map covered 662.2 cM with 119 microsatellite markers. The centromeric position in each LG was estimated by marker-centromere mapping based on half-tetrad analysis. In 4 LGs (LG2, LG3, LG4, and LG5), the centromere was estimated at the intermediate region. In LG1, LG11, and LG12, the centromere was estimated to shift from the sub-intermediate region to the end (telomeric). The number of these LGs (7) was identical to the collective number of bi-arm metacentric (5) and sub-metacentric chromosome (2) of the haploid chromosome set (n = 5) of the loach. In the other LGs, the position of the centromere was estimated at the end or outside. These results indicate satisfactory compliance between the linkage map and the chromosome set. Our map would cover approximately almost the entire loach genome because most markers were successfully mapped.  相似文献   

7.
The mangrove salt marsh snake (Nerodia clarkii compressicauda) occupies a unique and disappearing habitat in much of coastal southern Florida. Given extensive habitat fragmentation and high predation pressure in open spaces, it seems likely that populations of N. c. compressicauda consist of isolated groups of related individuals. To assess the degree of population subdivision in this species we genotyped a total of 125 individuals from seven locations along the Florida coast at four microsatellite loci. Overall heterozygosity was moderate (57.7%) and somewhat lower than that seen in other snake species. Population subdivision was particularly pronounced with 19 of 21 sample pair-wise ΦST values significantly different from zero and ranging from 0.064 to 0.343 (P ≤ 0.05). About 11 of 39 alleles were private alleles that also tended to be in high frequency in the populations where they occurred (average frequency ~27%). The correlation of genetic and geographic distances was highly significant and positive (r 2 = 0.8733 and P < 0.001) with ΦST increasing by ~0.01 for every 10 km of separation. Overall, salt marsh snake populations appear to be fractured into isolated neighborhoods on the order of 50–80 km. In spite of its apparent local abundance, we believe that N. c. compressicauda is in need of conservation protection. The combination of extremely low dispersal, narrow habitat requirements, and most importantly, extensive habitat alteration resulting from coastal real estate development may mean that N. c. compressicauda is highly susceptible to population extirpation and potentially extinction.  相似文献   

8.
Cupressus chenggiana S. Y. Hu (Cupressaceae) is an endemic and endangered conifer species in southwest China. In order to study the population genetics and design the effective conservation methods, we aimed to develop microsatellite primers for this species in the present study. We developed eight new microsatellite loci for this species through biotin capture method. Polymorphism of each locus was further assessed in 18 individuals from three geographically distant populations. The number of alleles per locus ranged from 6 to 11 with an average of 8.13. The observed and expected heterozygosities ranged from 0.219 to 0.296 and from 0.374 to 0.470, with averages of 0.254 and 0.417, respectively. We further found that three of nine microsatellite loci developed previously for another congeneric species showed polymorphic banding patters. We performed primer-crossing tests of these loci in the other two congeneric species which are closely related to C. chenggiana (C. gigantea and C. duclouxiana). These microsatellite markers would be effective for analyzing genetic diversity and population genetic structure of this species and its morphological differentiation with the close relatives.  相似文献   

9.
Xu S  Sun P  Zhou K  Yang G 《Immunogenetics》2007,59(7):581-592
Major histocompatibility complex (MHC) class II DQB and DRA genes and class I gene of finless porpoises (Neophocaena phocaenoides) were investigated by single-strand conformation polymorphism and sequence analysis. The DRA, DQB, and MHC-I loci each contained 5, 14, and 34 unique sequences, respectively, and considerable sequence variation was found at the MHC-I and DQB loci. Gene duplication was manifested as three to five distinct sequences at each of the DQB and MHC-I loci from some individuals, and these sequences at each of the two loci separately clustered into four groups (cluster A, B, C, and D) based on the phylogenetic trees. Phylogenetic reconstruction revealed a trans-species pattern of evolution. Relatively high rates of non-synonymous (dN) vs synonymous (dS) substitution in the peptide-binding region (PBR) suggested balancing selection for maintaining polymorphisms at the MHC-I and DQB loci. In contrast, one single locus with little sequence variation was detected in the DRA gene, and no non-synonymous substitutions in the PBR indicated no balancing selection on this gene.  相似文献   

10.
A new source of resistance to the pathotype 4 isolate of Turnip mosaic virus (TuMV) CDN 1 has been identified in Brassica napus (oilseed rape). Analysis of segregation of resistance to TuMV isolate CDN 1 in a backcross generation following a cross between a resistant and a susceptible B. napus line showed that the resistance was dominant and monogenic. Molecular markers linked to this dominant resistance were identified using amplified fragment length polymorphism (AFLP) and microsatellite bulk segregant analysis. Bulks consisted of individuals from a BC1 population with the resistant or the susceptible phenotype following challenge with CDN 1. One AFLP and six microsatellite markers were associated with the resistance locus, named TuRB03, and these mapped to the same region on chromosome N6 as a previously mapped TuMV resistance gene TuRB01. Further testing of TuRB03 with other TuMV isolates showed that it was not effective against all pathotype 4 isolates. It was effective against some, but not all pathotype 3 isolates tested. It provided further resolution of TuMV pathotypes by sub-dividing pathotypes 3 and 4. TuRB03 also provides a new source of resistance for combining with other resistances in our attempts to generate durable resistance to this virus.  相似文献   

11.
Allothrombium pulvinum Ewing is a common natural enemy of aphids and some other arthropods. So far, there are no studies that have addressed genetic variation of this predatory mite. We investigated genetic variation of A. pulvinum across its whole known range in Iran. A 410 bp portion of the mitochondrial cytochrome c oxidase subunit I gene (coxI) and 797–802 bp portion of the internal transcribed spacer 2 of rDNA (ITS2) were sequenced for 55 individuals from 11 populations, resulting in 12 and 26 haplotypes, respectively. In the coxI region, haplotype and nucleotide diversities varied among populations from 0.00 to 0.90 and from 0.0000 to 0.0110, respectively. In the ITS2 region they varied from 0.20 to 0.91 and from 0.0006 to 0.0023, respectively. For both gene regions the highest haplotype and nucleotide diversities were detected in population Mahmoud Abad from northern Iran. Statistically significant population differentiation (F ST) was detected in most pair-wise population comparisons. The results of population differentiation for both gene regions were generally congruent indicating that A. pulvinum from Iran consists of genetically different populations. This suggests that A. pulvinum comprises at least two geographically distinct populations or even more than one species. This study is an initial step towards understanding genetic variation of A. pulvinum, a taxon for which little molecular information is available. More intensive sampling and analysis of additional DNA regions are necessary for more detailed classification of this taxon.  相似文献   

12.
Cedrus libani of Lebanon is a valuable natural resource and the dominant species in its natural ecosystem. Intense and diverse anthropogenic pressures over historical times raised concerns about its genetic vigor and continued survival. Our investigation of the genetic diversity included samples from all remnant natural populations. Assessment of the genetic diversity using random amplified polymorphic DNA markers revealed the persistence of considerable variation distributed within populations with low population differentiation corroborated by Bayesian and analysis of molecular variance estimates (G ST = 0.07, Φ ST = 0.09). Individual assignment tests were carried out to investigate measures of gene flow. Inferences concluded that this natural heritage is not currently threatened by inbreeding or by random genetic drift. Correlation studies investigated possible effects of spatial distribution and environmental conditions on genetic structure. A climatic trend corresponding to a temperature–humidity gradient correlated significantly with the level of genetic diversity, while the edaphic variation did not.  相似文献   

13.
Ardisia crenata, an evergreen shrub native to East Asia, has been a serious invasive plant to the southeastern USA. Here 13 polymorphic microsatellite loci were isolated and characterized from an enrichment genomic library of A. crenata. The average allele number of these microsatellites was four per locus, ranging from two to seven. The ranges of observed and expected heterozygosity were 0.000–1.000 and 0.239–0.789, respectively. These microsatellite markers will be useful for investigating population genetics and reproductive ecology of A. crenata.  相似文献   

14.
During the last years, the population of Italian hare decreased significantly in central and south Italy. This is imputable to harvest, poaching, habitat fragmentation, and the probable competition with congeneric European hare introduced in the last decades by man for hunt. The goal of our work is to define the ecological characteristics of the two aforementioned species in order to understand how landscape facilitates or impedes movement. Spatially explicit models are used to identify a species ecological niche and to build a landscape model of suitability. To validate ecological modeling of landscape, we performed a population genetic analysis. Results suggest that the Italian hare shows an ecological requirement close to average of available resources in the considered landscape. The genetic structure of this autochthonous species validates the habitat suitability model and highlights the differences with European hare. This work analyzes for the first time the ecological relationship between those two sympatric species.  相似文献   

15.
The relationship between Sporidiobolus johnsonii and S. salmonicolor was investigated using rDNA sequence data. Two statistically well-supported clades were obtained. One clade included the type strain of S. johnsonii and the other included the type strain of S. salmonicolor. However, some mating strains of S. salmonicolor were found in the S. johnsonii group. These strains belonged to mating type A2 and were sexually compatible with mating type A1 strains from the S. salmonicolor group. DNA–DNA reassociation values were high within each clade and moderate between the two clades. In the re-investigation of teliospore germination, we observed that the basidia of S. salmonicolor were two-celled. In S. johnsonii, basidia were not formed and teliospore germination resulted in direct formation of yeast cells. We hypothesize that the S. johnsonii clade is becoming genetically isolated from the S. salmonicolor group and that a speciation process is presently going on. We suspect that the observed sexual compatibility between strains of the S. johnsonii and S. salmonicolor groups and the possible genetic flow between the two species has little biological relevance because distinct phenotypes have been fixed in the two taxa and intermediate (hybrid) sequences for LSU and ITS rDNAs have not been detected. An erratum to this article can be found at  相似文献   

16.
Two repeated DNA sequences isolated from a partial genomic DNA library of Helianthus annuus, p HaS13 and p HaS211, were shown to represent portions of the int gene of a Ty3 /gypsy retroelement and of the RNase-Hgene of a Ty1 /copia retroelement, respectively. Southern blotting patterns obtained by hybridizing the two probes to BglII- or DraI-digested genomic DNA from different Helianthus species showed p HaS13 and p HaS211 were parts of dispersed repeats at least 8 and 7 kb in length, respectively, that were conserved in all species studied. Comparable hybridization patterns were obtained in all species with p HaS13. By contrast, the patterns obtained by hybridizing p HaS211 clearly differentiated annual species from perennials. The frequencies of p HaS13- and p HaS211-related sequences in different species were 4.3x10(4)-1.3x10(5) copies and 9.9x10(2)-8.1x10(3) copies per picogram of DNA, respectively. The frequency of p HaS13-related sequences varied widely within annual species, while no significant difference was observed among perennial species. Conversely, the frequency variation of p HaS211-related sequences was as large within annual species as within perennials. Sequences of both families were found to be dispersed along the length of all chromosomes in all species studied. However, Ty3 /gypsy-like sequences were localized preferentially at the centromeric regions, whereas Ty1/ copia-like sequences were less represented or absent around the centromeres and plentiful at the chromosome ends. These findings suggest that the two sequence families played a role in Helianthusgenome evolution and species divergence, evolved independently in the same genomic backgrounds and in annual or perennial species, and acquired different possible functions in the host genomes.  相似文献   

17.
The flagfish (Jordanella floridae) is commonly used in studies of wetlands ecology. Here we describe the isolation of ten microsatellite loci, six of which were polymorphic. The observed number of alleles ranged from 4 to 24 and observed heterozygosities ranged from 0.59 to 0.81 for the polymorphic loci. The isolation of these markers will enable estimations of genetic diversity in natural populations.  相似文献   

18.
New combinations are proposed in anticipation of the Polygonaceae treatment in the forthcoming volume of Intermountain Flora: Polygonum kelloggii var. esotericum, P. kelloggii var. watsonii , Rumex densiflorus var. pycnanthus , R. salicifolius var. utahensis, and R. occidentalis var. tomentellus. Typifications are proposed to facilitate ongoing studies in Polygonaceae and to maintain current usage.  相似文献   

19.
20.
Habitat fragmentation is believed to be a key threat to biodiversity, with habitat specialists being stronger affected than generalists. However, pioneer species might be less affected by fragmentation, as their high colonization potential should increase gene flow. Here, we present an analysis of the genetic structure of populations of the solitary bee Andrena vaga, which naturally occurs in sandy habitats and is specialized on willow (Salix) pollen as larval food and sandy soils as nesting sites. While the species is widespread in the young sandy landscapes of our main study area (Emsland, northwestern Germany), it occurs less frequently in the Lower Rhine valley. Our analyses of six polymorphic microsatellites show that the populations are only slightly differentiated, suggesting a relatively strong gene flow. No genetic structure corresponding to the geographic origin was found as the variability within populations accounted for the major proportion of variation. FST values were higher and allelic richness was lower in the Lower Rhine valley, supporting the hypothesis that habitat availability affects the degree of genetic exchange between populations. Inbreeding coefficients were generally high and nearly all populations had a heterozygote deficiency, which could be explained by the breeding strategy of A. vaga, which nests in aggregations.  相似文献   

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