Geographic patterns in the genetic diversity of a northern sedge, Carex rariflora

1999 ◽  
Vol 77 (2) ◽  
pp. 269-278 ◽  
Author(s):  
Mark Vellend ◽  
Marcia J Waterway
Keyword(s):  
Genetic Diversity ◽  
Geographic Distance ◽  
Detrended Correspondence Analysis ◽  
Allozyme Variation ◽  
Glacial Refugium ◽  
Strong Positive Correlation ◽  
Habitat Types ◽  
Low Genetic Diversity ◽  
Habitat Differences ◽  
Geographic Regions

We compared the genetic diversity of a northern wetland sedge, Carex rariflora, both within and between populations, in different habitat types, and across geographic regions with different glacial histories. Twelve populations were sampled: 5 from each of two regions in northern Quebec, and 2 from northern Yukon. Habitat types were medium to rich fens, wet tidal flat, and alpine stream edge. Allele frequency data revealed a low degree of within-population genetic diversity (HS = 0.07) and a high degree of genetic differentiation among populations (GST = 0.47) compared with previously studied northern wetland Carex species. Higher genetic variability found in the Yukon than in Quebec could be explained by the presence of a glacial refugium in much of Alaska and the Yukon throughout the Pleistocene. Low genetic diversity in Quebec suggests the occurrence of genetic bottlenecks resulting from founder effects during postglacial colonization. There was a strong positive correlation between geographic distance and genetic distance among populations, and the three geographic regions were genetically distinct from one another. Detrended correspondence analysis of vegetation data revealed clear differences among the three habitat types, but we found no significant correlation between habitat differences and genetic distance.Key words: allozyme variation, genetic diversity, geographic variation, Carex rariflora.

Weak genetic structuring suggests historically high genetic connectivity among recently fragmented urban populations of the scincid lizard, Ctenotus fallens

2015 ◽  
Vol 63 (4) ◽  
pp. 279 ◽  
Author(s):  
Josef Krawiec ◽  
Siegfried L. Krauss ◽  
Robert A. Davis ◽  
Peter B. S. Spencer
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Large Population ◽  
Geographic Distance ◽  
Genetic Erosion ◽  
Genetic Connectivity ◽  
Genetic Structuring ◽  
Low Genetic Diversity ◽  
Population Sizes

Populations in fragmented urban remnants may be at risk of genetic erosion as a result of reduced gene flow and elevated levels of inbreeding. This may have serious genetic implications for the long-term viability of remnant populations, in addition to the more immediate pressures caused by urbanisation. The population genetic structure of the generalist skink Ctenotus fallens was examined using nine microsatellite markers within and among natural vegetation remnants within a highly fragmented urban matrix in the Perth metropolitan area in Western Australia. These data were compared with samples from a large unfragmented site on the edge of the urban area. Overall, estimates of genetic diversity and inbreeding within all populations were similar and low. Weak genetic differentiation, and a significant association between geographic and genetic distance, suggests historically strong genetic connectivity that decreases with geographic distance. Due to recent fragmentation, and genetic inertia associated with low genetic diversity and large population sizes, it is not possible from these data to infer current genetic connectivity levels. However, the historically high levels of gene flow that our data suggest indicate that a reduction in contemporary connectivity due to fragmentation in C. fallens is likely to result in negative genetic consequences in the longer term.

scholarly journals Origin, Genetic Diversity, and Population Structure of Rabbits (Oryctolagus cuniculus) in Kenya

2019 ◽  
Vol 2019 ◽  
pp. 1-6 ◽  
Author(s):  
Sharon Auma Owuor ◽  
Edward George Mamati ◽  
Remmy Wekesa Kasili
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Western Region ◽  
Eastern Region ◽  
Low Genetic Diversity ◽  
Loop Region ◽  
Agriculture Industry ◽  
D Loop ◽  
Breeding Programmes ◽  
Geographic Regions

To evaluate the origin, genetic diversity, and population structure of domesticated rabbits in Kenya, a 263-base pair region of mtDNA D-loop region of 111 rabbits sampled from Kakamega, Vihiga, and Bungoma counties in the western region, Laikipia and Nyandarua counties in the central region, and Kitui, Machakos, and Makueni in the eastern region of the country were analyzed. The average haplotype (0.40702) and nucleotide (0.01494) diversities observed were low, indicating low genetic diversity of domesticated rabbits in Kenya. This study resolved 5 unique haplotypes in the mtDNA D-loop region. A population genetic structure distinguishing Europe grouping and domesticated rabbits in Kenya was obtained on incorporating 32 known haplotypes. Domesticated rabbits in Kenya clustered together with rabbits from other geographic regions, suggesting common origin. The results suggested that the Kenyan domesticated rabbits may have originated from Europe. Integration of exotic breeds into breeding programmes could have contributed to the low genetic diversity. These results provide useful information for breeding and conservation decisions by the relevant stakeholders in the agriculture industry in Kenya.

Genetic diversity and population structure of Piceaglauca on an altitudinal gradient in interior Alaska

1987 ◽  
Vol 17 (12) ◽  
pp. 1519-1526 ◽  
Author(s):  
John Alden ◽  
Carol Loopstra
Keyword(s):  
Genetic Diversity ◽  
Sea Level ◽  
Geographic Distance ◽  
White Spruce ◽  
Geographic Area ◽  
Allozyme Variation ◽  
Interior Alaska ◽  
Provenance Research ◽  
Tree Limit ◽  
Upper Slope

Allozyme variation at 13 loci for 11 enzyme systems was studied in four white spruce (Piceaglauca (Moench) Voss) populations extending from a floodplain at 120 m above sea level to the altitudinal tree limit at 750 m above sea level in interior Alaska. Although 97% of the total genetic diversity was among trees within stands and 1% was among stands within populations, frequencies of several allozymes and allozyme genotypes were significantly different (P < 0.05) among populations. Ninety-two percent of the loci were polymorphic. Total heterozygosity was 0.276. Heterozygosity and allozyme frequencies were not related to altitude. The population at the tree limit was as genetically diverse as populations at low elevations [Formula: see text] and contained four of seven rare alleles observed in all populations. These observations suggested that white spruce is genetically diverse in interior Alaska and the tree-limit population will continue to colonize new habitats. Genetic distance was not related to altitude and geographic distance and was less between the tree-limit and upper slope populations than among other populations A detectable gene substitution rate was estimated at 10−6 per year. Populations on the upper slope and at the tree limit may have diverged about 2500 years ago and reached tree-limit altitudes only recently. Populations at low altitudes may have diverged during early Holocene white spruce expansion. We concluded that white spruce is genetically diverse in a small geographic area in interior Alaska. Results suggested that local white spruce populations should be regenerated from indigenous seed and that provenance research is needed to support afforestation programs.

scholarly journals Population Genetic Structure of Aphis gossypii Glover (Hemiptera: Aphididae) in Korea

Insects ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 319
Author(s):  
Nam ◽  
Park ◽  
Lee
Keyword(s):  
Genetic Diversity ◽  
Genetic Structure ◽  
Isolation By Distance ◽  
Aphis Gossypii ◽  
Geographic Distance ◽  
Mantel Test ◽  
Low Genetic Diversity ◽  
Study Results ◽  
Aphis Gossypii Glover ◽  
Genetic Clusters

Aphis gossypii Glover (Hemiptera: Aphididae) is a serious polyphagous agricultural pest worldwide. In the present study, we used eight microsatellite markers to investigate the genetic structure and diversity of A. gossypii populations in Korea. Samples were collected from 37 locations in Korea (18 populations in 2016, 14 populations in 2017, and five populations in 2018) from pepper plants. A. gossypii had low to moderate genetic diversity, and expected heterozygosity (HE) ranged from 0.354 to 0.719. A Mantel test of isolation by distance indicated no relationship between genetic structure and geographic distance among all populations (r2 = 0.0004, p = 0.370), suggesting high gene flow among populations in Korea. Populations of A. gossypii in Korea were divided into two distinct genetic clusters (ΔK = 2). In 2016 and 2017, the genetic clusters changed into opposite genetic structures within one year mostly in northwest and southeast parts of Korea. Possible relevance of study results was discussed. Chemical control, cyclical parthenogenesis, and immigrants from the exterior might have resulted in this low genetic diversity and opposite genetic clusters.

Allozyme Variation and Population Substructuring in the Caucasian Ground Lizards Lacerta derjugini and Lacerta praticola

2011 ◽  
Vol 4 (2) ◽  
pp. 115-119 ◽  
Author(s):  
Ross D. MacCulloch ◽  
Ilya S. Darevsky ◽  
Robert W. Murphy ◽  
Jinzhong Fu
Keyword(s):  
Genetic Diversity ◽  
Allozyme Variation ◽  
Close Proximity ◽  
Geographic Separation ◽  
Population Substructuring ◽  
Allozyme Loci ◽  
Two Populations

Genetic diversity at 35 allozyme loci was surveyed in Lacerta derjugini (3 populations) and L. praticola (2 populations). Indices of variability were consistent with those found in other Caucasian Lacerta. There was little genetic substructuring between two populations of L. praticola despite considerable geographic separation. Conversely, populations of L. derjugini in close proximity to one another exhibited considerable substructuring.

The Response to Past Climate Perturbations Explains Extremely Low Genetic Diversity in the Genome of an Abundant Ice-Age Remnant, the Alpine Marmot

2018 ◽  
Author(s):  
Toni I. Gossmann​ ◽  
Achchuthan Shanmugasundram​ ◽  
Stefan Börno ◽  
Ludovic Duvaux ◽  
Christophe Lemaire​ ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Ice Age ◽  
Past Climate ◽  
Low Genetic Diversity ◽  
Alpine Marmot

Allozyme variation and an estimate of the inbreeding coefficient in the coffee berry borer, Hypothenemus hampei (Coleoptera: Scolytidae)

1995 ◽  
Vol 85 (1) ◽  
pp. 21-28 ◽  
Author(s):  
Philippe Borsa ◽  
D. Pierre Gingerich
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Population Genetic ◽  
New Caledonia ◽  
Allozyme Variation ◽  
Inbreeding Coefficient ◽  
Hypothenemus Hampei ◽  
Coffee Berry ◽  
Biological Features ◽  
High Degree

AbstractSeven presumed Mendelian enzyme loci (Est-2, Est-3, Gpi, Idh-l, Idh-2, Mdh-2 and Mpi) were characterized and tested for polymorphism in coffee berry borers, Hypothenemus hampei (Ferrari), sampled in Côte d′Ivoire, Mexico and New Caledonia. The average genetic diversity was H = 0.080. Two loci, Mdh-2 and Mpi were polymorphic, and thus usable as genetic markers. The population structure of H. hampei was analysed using Weir & Cockerham's estimators of Wright's F-statistics. A high degree of inbreeding (f = 0.298) characterized the elementary geographic sampling unit, the coffee field. The estimate of gene flow between fields within a country was Nm = 10.6 and that between countries was Nm = 2. The population genetic structure in H. hampei could be related to its known population biological features and history.

scholarly journals Phylogeography of Prunus armeniaca L. revealed by chloroplast DNA and nuclear ribosomal sequences

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wen-Wen Li ◽  
Li-Qiang Liu ◽  
Qiu-Ping Zhang ◽  
Wei-Quan Zhou ◽  
Guo-Quan Fan ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variation ◽  
Chloroplast Dna ◽  
Population Expansion ◽  
Prunus Armeniaca ◽  
River Valley ◽  
Nuclear Ribosomal Dna ◽  
Glacial Refugium ◽  
Ili River Valley ◽  
Wild Apricot

AbstractTo clarify the phytogeography of Prunus armeniaca L., two chloroplast DNA fragments (trnL-trnF and ycf1) and the nuclear ribosomal DNA internal transcribed spacer (ITS) were employed to assess genetic variation across 12 P. armeniaca populations. The results of cpDNA and ITS sequence data analysis showed a high the level of genetic diversity (cpDNA: HT = 0.499; ITS: HT = 0.876) and a low level of genetic differentiation (cpDNA: FST = 0.1628; ITS: FST = 0.0297) in P. armeniaca. Analysis of molecular variance (AMOVA) revealed that most of the genetic variation in P. armeniaca occurred among individuals within populations. The value of interpopulation differentiation (NST) was significantly higher than the number of substitution types (GST), indicating genealogical structure in P. armeniaca. P. armeniaca shared genotypes with related species and may be associated with them through continuous and extensive gene flow. The haplotypes/genotypes of cultivated apricot populations in Xinjiang, North China, and foreign apricot populations were mixed with large numbers of haplotypes/genotypes of wild apricot populations from the Ili River Valley. The wild apricot populations in the Ili River Valley contained the ancestral haplotypes/genotypes with the highest genetic diversity and were located in an area considered a potential glacial refugium for P. armeniaca. Since population expansion occurred 16.53 kyr ago, the area has provided a suitable climate for the population and protected the genetic diversity of P. armeniaca.

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