scholarly journals Geographical Gradients of Genetic Diversity and Differentiation among the Southernmost Marginal Populations of Abies sachalinensis Revealed by EST-SSR Polymorphism

Forests ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 233 ◽  
Author(s):  
Keiko Kitamura ◽  
Kentaro Uchiyama ◽  
Saneyoshi Ueno ◽  
Wataru Ishizuka ◽  
Ikutaro Tsuyama ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Local Population ◽  
Distribution Center ◽  
Population History ◽  
Peripheral Populations ◽  
Abies Sachalinensis ◽  
Marginal Populations ◽  
Local Populations ◽  
Longitudinal Gradients

Research Highlights: We detected the longitudinal gradients of genetic diversity parameters, such as the number of alleles, effective number of alleles, heterozygosity, and inbreeding coefficient, and found that these might be attributable to climatic conditions, such as temperature and snow depth. Background and Objectives: Genetic diversity among local populations of a plant species at its distributional margin has long been of interest in ecological genetics. Populations at the distribution center grow well in favorable conditions, but those at the range margins are exposed to unfavorable environments, and the environmental conditions at establishment sites might reflect the genetic diversity of local populations. This is known as the central-marginal hypothesis in which marginal populations show lower genetic variation and higher differentiation than in central populations. In addition, genetic variation in a local population is influenced by phylogenetic constraints and the population history of selection under environmental constraints. In this study, we investigated this hypothesis in relation to Abies sachalinensis, a major conifer species in Hokkaido. Materials and Methods: A total of 1189 trees from 25 natural populations were analyzed using 19 EST-SSR loci. Results: The eastern populations, namely, those in the species distribution center, showed greater genetic diversity than did the western peripheral populations. Another important finding is that the southwestern marginal populations were genetically differentiated from the other populations. Conclusions: These differences might be due to genetic drift in the small and isolated populations at the range margin. Therefore, our results indicated that the central-marginal hypothesis held true for the southernmost A. sachalinensis populations in Hokkaido.

scholarly journals Genetic variation and population structure of clonal Zingiber zerumbet at a fine geographic scale: a comparison with two closely related selfing and outcrossing Zingiber species

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Rong Huang ◽  
Yu Wang ◽  
Kuan Li ◽  
Ying-Qiang Wang
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
Plant Species ◽  
Population Genetic ◽  
Clonal Plants ◽  
Zingiber Zerumbet ◽  
Population Genetic Diversity ◽  
Local Populations ◽  
High Level

Abstract Background There has always been controversy over whether clonal plants have lower genetic diversity than plants that reproduce sexually. These conflicts could be attributed to the fact that few studies have taken into account the mating system of sexually reproducing plants and their phylogenetic distance. Moreover, most clonal plants in these previous studies regularly produce sexual progeny. Here, we describe a study examining the levels of genetic diversity and differentiation within and between local populations of fully clonal Zingiber zerumbet at a microgeographical scale and compare the results with data for the closely related selfing Z. corallinum and outcrossing Z. nudicarpum. Such studies could disentangle the phylogenetic and sexually reproducing effect on genetic variation of clonal plants, and thus contribute to an improved understanding in the clonally reproducing effects on genetic diversity and population structure. Results The results revealed that the level of local population genetic diversity of clonal Z. zerumbet was comparable to that of outcrossing Z. nudicarpum and significantly higher than that of selfing Z. corallinum. However, the level of microgeographic genetic diversity of clonal Z. zerumbet is comparable to that of selfing Z. corallinum and even slightly higher than that of outcrossing Z. nudicarpum. The genetic differentiation among local populations of clonal Z. zerumbet was significantly lower than that of selfing Z. corallinum, but higher than that of outcrossing Z. nudicarpum. A stronger spatial genetic structure appeared within local populations of Z. zerumbet compared with selfing Z. corallinum and outcrossing Z. nudicarpum. Conclusions Our study shows that fully clonal plants are able not only to maintain a high level of within-population genetic diversity like outcrossing plants, but can also maintain a high level of microgeographic genetic diversity like selfing plant species, probably due to the accumulation of somatic mutations and absence of a capacity for sexual reproduction. We suggest that conservation strategies for the genetic diversity of clonal and selfing plant species should be focused on the protection of all habitat types, especially fragments within ecosystems, while maintenance of large populations is a key to enhance the genetic diversity of outcrossing species.

scholarly journals ISSR analysis points to relict character of Aconitum bucovinense Zapał. (Ranunculaceae) at the range margin

2011 ◽  
Vol 80 (4) ◽  
pp. 315-326 ◽  
Author(s):  
Piotr Boroń ◽  
Joanna Zalewska-Gałosz ◽  
Agnieszka Sutkowska ◽  
Bogdan Zemanek ◽  
Józef Mitka
Keyword(s):  
Genetic Diversity ◽  
Population Genetic ◽  
Diversity Indices ◽  
High Mountain ◽  
Peripheral Populations ◽  
Marginal Populations ◽  
Issr Analysis ◽  
The Core ◽  
Eastern Carpathians ◽  
Scale Population

<p><em>Aconitum bucovinense</em>, a high-mountain species endemic to the Eastern and Southern Carpathians, including the Apuseni Mountains, is legally protected and classified in the Polish Red Data Book of Plants. It attains its NW geographical range in two peripheral populations in the Western Bieszczady Mountains (Polish Eastern Carpathians), isolated by a distance of 13.1 km. PCR-ISSR analysis has been used to elucidate the within- and among-populational levels of species genetic diversity. A UPGMA and block clustering showed discreteness of the populations and subpopulations based on ISSR banding pattern. Analysis of Molecular Variance (AMOVA) revealed significant divergence (<em>P </em>= 0.024) of the two marginal populations and highly significant (<em>P </em>&lt; 0.001) differentiation of subpopulations within populations. The theta index calculated for the two marginal populations and the core population in the Carpathians was 0.131 ±0.030 S.D. Most of the population-genetic diversity indices of the mar­ginal populations were not different from those in the core area but the Shannon’s and rarity indices were lower in the marginal populations. It seems that founder effect and subsequent genetic bottleneck resulted in a fine-scale population genetic structure. The marginal populations under study need a relevant recovery program to maintain their genetic diversity.</p>

scholarly journals When ecological marginality is not geographically peripheral: exploring genetic predictions of the centre-periphery hypothesis in the endemic plantLilium pomponium

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11039
Author(s):  
Gabriele Casazza ◽  
Carmelo Macrì ◽  
Davide Dagnino ◽  
Maria Guerrina ◽  
Marianick Juin ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Environmental Gradients ◽  
Population Connectivity ◽  
Peripheral Populations ◽  
Effective Population ◽  
Population Isolation ◽  
Genetic Traits ◽  
Range Dynamics ◽  
Center Periphery

BackgroundQuantifying variation of genetic traits over the geographical range of species is crucial for understanding the factors driving their range dynamics. The center-periphery hypothesis postulates, and many studies support, the idea that genetic diversity decreases and genetic differentiation increases toward the geographical periphery due to population isolation. The effects of environmental marginality on genetic variation has however received much less attention.MethodsWe tested the concordance between geographical and environmental gradients and the genetic predictions of center-periphery hypothesis for endemicLilium pomponiumin the southern Alps.ResultsWe found little evidence for concordance between genetic variation and both geographical and environmental gradients. Although the prediction of increased differentiation at range limits is met, genetic diversity does not decrease towards the geographical periphery. Increased differentiation among peripheral populations, that are not ecologically marginal, may be explained by a decrease in habitat availability that reduces population connectivity. In contrast, a decrease of genetic diversity along environmental but not geographical gradients may be due to the presence of low quality habitats in the different parts of the range of a species that reduce effective population size or increase environmental constraints. As a result, environmental factors may affect population dynamics irrespective of distance from the geographical center of the range. In such situations of discordance between geographical and environmental gradients, the predictions of decreasing genetic diversity and increasing differentiation toward the geographical periphery may not be respected.

scholarly journals Genetic Variation and Population Structure in Jamunapari Goats Using Microsatellites, Mitochondrial DNA, and Milk Protein Genes

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
P. K. Rout ◽  
K. Thangraj ◽  
A. Mandal ◽  
R. Roy
Keyword(s):  
Genetic Diversity ◽  
Mitochondrial Dna ◽  
Genetic Variation ◽  
Population Size ◽  
Microsatellite Loci ◽  
Milk Protein ◽  
Gene Diversity ◽  
Population History ◽  
Dairy Goat ◽  
The Mean

Jamunapari, a dairy goat breed of India, has been gradually declining in numbers in its home tract over the years. We have analysed genetic variation and population history in Jamunapari goats based on 17 microsatellite loci, 2 milk protein loci, mitochondrial hypervariable region I (HVRI) sequencing, and three Y-chromosomal gene sequencing. We used the mitochondrial DNA (mtDNA) mismatch distribution, microsatellite data, and bottleneck tests to infer the population history and demography. The mean number of alleles per locus was 9.0 indicating that the allelic variation was high in all the loci and the mean heterozygosity was 0.769 at nuclear loci. Although the population size is smaller than 8,000 individuals, the amount of variability both in terms of allelic richness and gene diversity was high in all the microsatellite loci except ILST 005. The gene diversity and effective number of alleles at milk protein loci were higher than the 10 other Indian goat breeds that they were compared to. Mismatch analysis was carried out and the analysis revealed that the population curve was unimodal indicating the expansion of population. The genetic diversity of Y-chromosome genes was low in the present study. The observed mean M ratio in the population was above the critical significance value (Mc) and close to one indicating that it has maintained a slowly changing population size. The mode-shift test did not detect any distortion of allele frequency and the heterozygosity excess method showed that there was no significant departure from mutation-drift equilibrium detected in the population. However, the effects of genetic bottlenecks were observed in some loci due to decreased heterozygosity and lower level of M ratio. There were two observed genetic subdivisions in the population supporting the observations of farmers in different areas. This base line information on genetic diversity, bottleneck analysis, and mismatch analysis was obtained to assist the conservation decision and management of the breed.

scholarly journals Life writing as a source for local population history

2019 ◽  
pp. 64-75
Author(s):  
Colin G Pooley ◽  
Marilyn E Pooley
Keyword(s):  
Statistical Analysis ◽  
Life Events ◽  
Local Population ◽  
Life Writing ◽  
Population History ◽  
Local Populations ◽  
Different Types ◽  
Community Impacts ◽  
Forms Of Life ◽  
Personal Accounts

Diaries and other forms of life writing can add significantly to the study of local populations and societies, especially when used in conjunction with more conventional aggregate sources. All the key demographic events have important personal and emotional resonances that can never be revealed by statistical analysis of births, marriages or deaths. Personal accounts can add meaning to population history and demonstrate the familial and community impacts of key life events. In this paper we examine the strengths and weaknesses of different types of life writing, and then focus on the ways in which personal diaries may provide insights into the meanings and implications of life events such as courtship, marriage, childbirth, illness and death. Examples are drawn from a range of diaries written in Britain between the 1840s and 1950s.

scholarly journals On valuing patches: estimating contributions to metapopulation growth with reverse-time capture–recapture modelling

2011 ◽  
Vol 279 (1728) ◽  
pp. 480-488 ◽  
Author(s):  
Jamie S. Sanderlin ◽  
Peter M. Waser ◽  
James E. Hines ◽  
James D. Nichols
Keyword(s):  
Population Growth ◽  
Local Population ◽  
Peripheral Populations ◽  
Reverse Time ◽  
Genetic Population ◽  
Local Populations ◽  
Local Survival ◽  
Capture Recapture ◽  
Local Recruitment ◽  
Analytical Approaches

Metapopulation ecology has historically been rich in theory, yet analytical approaches for inferring demographic relationships among local populations have been few. We show how reverse-time multi-state capture–recapture models can be used to estimate the importance of local recruitment and interpopulation dispersal to metapopulation growth. We use ‘contribution metrics’ to infer demographic connectedness among eight local populations of banner-tailed kangaroo rats, to assess their demographic closure, and to investigate sources of variation in these contributions. Using a 7 year dataset, we show that: (i) local populations are relatively independent demographically, and contributions to local population growth via dispersal within the system decline with distance; (ii) growth contributions via local survival and recruitment are greater for adults than juveniles, while contributions involving dispersal are greater for juveniles; (iii) central populations rely more on local recruitment and survival than peripheral populations; (iv) contributions involving dispersal are not clearly related to overall metapopulation density; and (v) estimated contributions from outside the system are unexpectedly large. Our analytical framework can classify metapopulations on a continuum between demographic independence and panmixia, detect hidden population growth contributions, and make inference about other population linkage forms, including rescue effects and source–sink structures. Finally, we discuss differences between demographic and genetic population linkage patterns for our system.

Genetic Analysis of Chinese Cucumber Collections in the U.S. National Germplasm Collection

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 534e-534 ◽  
Author(s):  
J. Staub ◽  
Felix Sequen ◽  
Tom Horejsi ◽  
Jin Feng Chen
Keyword(s):  
Genetic Diversity ◽  
Principal Component Analysis ◽  
Genetic Variation ◽  
Genetic Analysis ◽  
Allelic Variation ◽  
Germplasm Collection ◽  
Principal Component ◽  
Isozyme Loci ◽  
National Plant Germplasm System ◽  
The U.S

Genetic variation in cucumber accessions from China was assessed by examining variation at 21 polymorphic isozyme loci. Principal component analysis of allelic variation allowed for the depiction of two distinct groupings of Chinese accessions collected in 1994 and 1996 (67 accessions). Six isozyme loci (Gpi, Gr, Mdh-2, Mpi-2, Pep-gl, and Pep-la) were important in elucidating these major groups. These groupings were different from a single grouping of Chinese 146 accessions acquired before 1994. Allelic variation in Chinese accessions allowed for comparisons with other accessions in the U.S. National Plant Germplasm System (U.S. NPGS) collection grouped by continent and sub-continent. When Chinese accessions taken collectively were compared with an array of 853 C. sativus U.S. NPGS accessions examined previously, relationships differed between accessions grouped by country or subcontinent. Data indicate that acquisition of additional Chinese and Indian cucumber accessions would be strategically important for increasing genetic diversity in the U.S. NPGS cucumber collection.

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