A methodological problem in genecology. Seeds versus clones as source material for uniform gardens

1981 ◽  
Vol 59 (5) ◽  
pp. 763-768 ◽  
Author(s):  
L. Hume ◽  
P. B. Cavers
Keyword(s):  
Genetic Heterogeneity ◽  
Methodological Problem ◽  
Flood Plain ◽  
Source Material ◽  
Rumex Crispus ◽  
Contrasting Habitats ◽  
Two Populations

Plants derived from both achenes and rootstock cuttings (ramets) were used to examine genetically based differences between two populations of Rumex crispus L. from two contrasting habitats, i.e., flood plain and pasture. Offspring from both sources were grown under cultivation in a uniform garden. Fifty-eight characters were determined for each individual. Within the pasture population only, seedling offspring differed significantly from plants obtained from ramets. Characteristics of the two populations were compared using (i) seedling offspring and (ii) ramets. More significant differences were found in the former set of comparisons.In the harsh but predictable flood plain habitat, genetic heterogeneity within the population was less than that found among plants from the pasture. Reasons for this difference are discussed.

Geographic variation in a widespread perennial weed, Rumex crispus. The relative amounts of genetic and environmentally induced variation among populations

1982 ◽  
Vol 60 (10) ◽  
pp. 1928-1937 ◽  
Author(s):  
L. Hume ◽  
P. B. Cavers
Keyword(s):  
Genetic Variation ◽  
North America ◽  
Genetic Heterogeneity ◽  
Local Level ◽  
Adaptive Strategy ◽  
Eastern North America ◽  
Rumex Crispus ◽  
Perennial Weed ◽  
Wide Range ◽  
The World

Populations of Rumex crispus were sampled from eastern North America and Europe. The relative amounts of genetic variation and plasticity were examined, using 58 plant characters. About 61% of the total variation occurring in the experimental plants was accounted for by plasticity. The remaining 26% and 13% occurred within populations and among widespread populations, respectively. At the local level, there was little difference between variation occurring within genotypes and that within families (between maternal siblings). This suggests that the species is predominantly inbreeding. The majority of genetic variation occurs within populations at both the local and species' range levels.It was concluded that the species has large amounts of both flexibility and genetic heterogeneity. This adaptive strategy enables the species to survive under a very wide range of environmental situations and largely accounts for its becoming one of the most widely distributed plants in the world.

scholarly journals Variability in colour, metallic lustre, and body size of Carabus arvensis Herbst, 1784 (Coleoptera: Carabidae) in relation to habitat properties

2019 ◽  
Vol 21 (2) ◽  
Author(s):  
Germund Tyler
Keyword(s):  
Body Size ◽  
Genetic Drift ◽  
Agricultural Land ◽  
Pine Forest ◽  
Large Populations ◽  
Contrasting Habitats ◽  
Habitat Properties ◽  
Two Populations

Objectives are to elucidate whether populations of Carabus arvensis Herbst, 1784 from contrasting habitats differ in (i) colour, (ii) brightness of metal lustre, or (iii) body size (length of elytra, of elytra + pronotum, and width of pronotum). Two large populations were studied, originating from (a) open heathland, being a remnant from more widespread heaths during former centuries, and (b) mature pine forest established 100–150 years ago on sandy agricultural land. Heath individuals had significantly more brilliant metal lustre and mostly lighter, vivid copper colour than pine forest individuals, which were typically black with a violet shade and slightly larger in size. The two populations are nowadays isolated, which was probably not the case 1–2 centuries ago, when both sites studied were treeless. The usually blackish colour of the forest population could be a recent adaptation to the changed environment, though some influence of processes such as genetic drift cannot be excluded.

Evaluation of the genetic variability of Ophrys insectifera L. populations growing in Belarus using molecular iPBS markers

2021 ◽  
Vol 66 (2) ◽  
pp. 223-231
Author(s):  
N. V. Samokhvalova ◽  
A. V. Kruchonok ◽  
B. Yu. Anoshenko ◽  
V. V. Titok
Keyword(s):  
Genetic Heterogeneity ◽  
Population Genetic ◽  
Natural Populations ◽  
Biosphere Reserve ◽  
Major Fraction ◽  
Principal Coordinates Analysis ◽  
Molecular Variance ◽  
Intrapopulation Variation ◽  
Principal Coordinates ◽  
Two Populations

An analysis of genetic heterogeneity was performed for two populations of Ophrys insectifera L. located in the Berezinsky Biosphere Reserve and the Verkudy village. The species are critically endangered (CR). The analysis of data obtained using iPBS markers detected the higher risk of extinction of the population in the Berezinsky Biosphere Reserve than the population from the Verkudy village, since the level of population genetic heterogeneity from the Verkudy is higher compared to the Berezinsky Biosphere Reserve. Molecular variance analysis (AMOVA) and other parameters of genetic variation showed the major fraction of intrapopulation variation (64 %, Gst = 0.26). Principal Coordinates Analysis (PCoA) revealed two groups that coincided with natural populations, and confirmed a larger genetic heterogeneity in the population from the Verkudy.

scholarly journals Comparison of Biological Attributes of Culex quinquefasciatus (Diptera: Culicidae) Populations from India

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Mangesh D. Gokhale ◽  
Mandar S. Paingankar ◽  
Sachin D. Dhaigude
Keyword(s):  
Culex Quinquefasciatus ◽  
Control Strategies ◽  
Principal Component ◽  
Biological Data ◽  
Morphological Data ◽  
Insecticide Susceptibility ◽  
Baseline Information ◽  
Biological Attributes ◽  
Contrasting Habitats ◽  
Two Populations

Understanding the population dynamics of mosquito populations through life table analysis and insecticide susceptibility is important to assess the likely impact of vector control strategies as well as to aid the design of novel interventions. Variation in the life tables and other biological data was compared for two populations of Culex quinquefasciatus Say 1823 from geographically isolated regions, Gorakhpur and Pune from India. Under a standardized rearing regime and constant laboratory conditions, mosquitoes were reared and biological attributes of these populations were compared. Development and survival of immature and adult stages of Culex quinquefasciatus were found significantly different in Gorakhpur and Pune populations. Principal component analysis of morphological data revealed that the two populations form significantly different clusters which can be differentiated from each other based on siphon, saddle, anal gills, and pecten teeth related variables. Insecticide susceptibility results suggest that the larvae from both areas were more susceptible to deltamethrin as compared to DDT and malathion. The current study provides baseline information on survivorship, morphological variation and insecticide susceptibility of Culex quinquefasciatus. The results obtained in this study suggest that different geographical areas with contrasting habitats have significant influence on survival and reproductive strategies of Culex quinquefasciatus.

scholarly journals Demography and spatial activity of fire salamanders, Salamandra salamandra (Linnaeus, 1758), in two contrasting habitats in the Vienna Woods

Herpetozoa ◽  
2021 ◽  
Vol 34 ◽  
pp. 23-34
Author(s):  
Stephan Burgstaller ◽  
Christoph Leeb ◽  
Max Ringler ◽  
Günter Gollmann
Keyword(s):  
Population Dynamics ◽  
Beech Forest ◽  
Amphibian Conservation ◽  
Low Density ◽  
Apparent Survival ◽  
Capture Recapture ◽  
Salamandra Salamandra ◽  
Contrasting Habitats ◽  
Study Sites ◽  
Two Populations

Understanding population dynamics is vital in amphibian conservation. To compare demography and movements, we conducted a capture-recapture study over three spring seasons in two populations of Salamandra salamandra in the Vienna Woods. The study sites differ in topography, vegetation, and the type of breeding waters. Population density in a beech forest traversed by a stream was more than twice as high as in an oak-hornbeam forest with temporary pools. Movement distances were on average higher at the latter site whereas home range estimates were similar for both sites. The sexes did not differ significantly in the observed movement patterns at either site. Annual apparent survival was mostly high (~0.85), but the estimate for females from the low-density site was lower (~0.60), indicating a higher rate of emigration or mortality.

scholarly journals Genome-Wide Meta-Analysis Identifies Three Novel Susceptibility Loci and Reveals Ethnic Heterogeneity of Genetic Susceptibility for IgA Nephropathy

2020 ◽  
Vol 31 (12) ◽  
pp. 2949-2963
Author(s):  
Ming Li ◽  
Ling Wang ◽  
Dian-Chun Shi ◽  
Jia-Nee Foo ◽  
Zhong Zhong ◽  
...  
Keyword(s):  
Genetic Heterogeneity ◽  
Meta Analysis ◽  
High Linkage Disequilibrium ◽  
European Ancestry ◽  
Significant Heterogeneity ◽  
Susceptibility Loci ◽  
Genome Wide ◽  
Chinese Descent ◽  
Risk Snps ◽  
Two Populations

BackgroundEighteen known susceptibility loci for IgAN account for only a small proportion of IgAN risk.MethodsGenome-wide meta-analysis was performed in 2628 patients and 11,563 controls of Chinese ancestry, and a replication analysis was conducted in 6879 patients and 9019 controls of Chinese descent and 1039 patients and 1289 controls of European ancestry. The data were used to assess the association of susceptibility loci with clinical phenotypes for IgAN, and to investigate genetic heterogeneity of IgAN susceptibility between the two populations. Imputation-based analysis of the MHC/HLA region extended the scrutiny.ResultsIdentification of three novel loci (rs6427389 on 1q23.1 [P=8.18×10−9, OR=1.132], rs6942325 on 6p25.3 [P=1.62×10−11, OR=1.165], and rs2240335 on 1p36.13 [P=5.10×10−9, OR=1.114]), implicates FCRL3, DUSP22.IRF4, and PADI4 as susceptibility genes for IgAN. Rs2240335 is associated with the expression level of PADI4, and rs6427389 is in high linkage disequilibrium with rs11264799, which showed a strong expression quantitative trail loci effect on FCRL3. Of the 24 confirmed risk SNPs, six showed significant heterogeneity of genetic effects and DEFA showed clear evidence of allelic heterogeneity between the populations. Imputation-based analysis of the MHC region revealed significant associations at three HLA polymorphisms (HLA allele DPB1*02, AA_DRB1_140_32657458_T, and AA_DQA1_34_32717152) and two SNPs (rs9275464 and rs2295119).ConclusionsA meta-analysis of GWAS data revealed three novel genetic risk loci for IgAN, and three HLA polymorphisms and two SNPs within the MHC region, and demonstrated the genetic heterogeneity of seven loci out of 24 confirmed risk SNPs.  These variants may explain susceptibility differences between Chinese and European populations.

Cell Wall Ultrastructure in Three Strains of a Cariogenic Streptococcus

1971 ◽  
Vol 29 ◽  
pp. 338-339
Author(s):  
M. J. Kramer ◽  
Alan L. Coykendall
Keyword(s):  
Cell Wall ◽  
Dental Caries ◽  
Streptococcus Mutans ◽  
Microscopic Study ◽  
Electron Microscopic Study ◽  
Genetic Heterogeneity ◽  
Morphological Characteristics ◽  
Electron Microscopic ◽  
Dna Reassociation ◽  
Wall Ultrastructure

During the almost 50 years since Streptococcus mutans was first suggested as a factor in the etiology of dental caries, a multitude of studies have confirmed the cariogenic potential of this organism. Streptococci have been isolated from human and animal caries on numerous occasions and, with few exceptions, they are not typable by the Lancefield technique but are relatively homogeneous in their biochemical reactions. An analysis of the guanine-cytosine (G-C) composition of the DNA from strains K-1-R, NCTC 10449, and FA-1 by one of us (ALC) revealed significant differences and DNA-DNA reassociation experiments indicated that genetic heterogeneity existed among the three strains. The present electron microscopic study had as its objective the elucidation of any distinguishing morphological characteristics which might further characterize the respective strains.

Comparison of Principal Component Solutions in Two Populations

Methodology ◽  
2016 ◽  
Vol 12 (1) ◽  
pp. 11-20 ◽  
Author(s):  
Gregor Sočan
Keyword(s):  
Simulation Study ◽  
Principal Components ◽  
Common Factor ◽  
Principal Component ◽  
Component Model ◽  
Bootstrap Procedure ◽  
Factor Loadings ◽  
Component Loadings ◽  
Principal Component Model ◽  
Two Populations

Abstract. When principal component solutions are compared across two groups, a question arises whether the extracted components have the same interpretation in both populations. The problem can be approached by testing null hypotheses stating that the congruence coefficients between pairs of vectors of component loadings are equal to 1. Chan, Leung, Chan, Ho, and Yung (1999) proposed a bootstrap procedure for testing the hypothesis of perfect congruence between vectors of common factor loadings. We demonstrate that the procedure by Chan et al. is both theoretically and empirically inadequate for the application on principal components. We propose a modification of their procedure, which constructs the resampling space according to the characteristics of the principal component model. The results of a simulation study show satisfactory empirical properties of the modified procedure.

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