PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Wild population”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed2001

A comparison of biological performances among a laboratory-isolated population and two wild populations of Moniliformis moniliformis.

Divergence of biological performance of a laboratory-reared population of Moniliformis moniliformis (Acanthocephala) was investigated after 31 yr, or approximately 60 generations, of genetic isolation. An isolate of the laboratory-reared population and isolates of 2 wild populations were used to begin 3 independent life cycles that were maintained for 1 generation for interbreeding and life history trait comparison. Both wild population isolates represented populations with open gene flow. One wild population isolate represented a present-day sample of descendants of the parent population of the laboratory isolate. All 3 populations hybridized, and egg production occurred in all mixed-sex pairs of different populations. The 3 populations did not differ significantly in prepatent period, mean daily egg production, or establishment within the definitive host Rattus norvegicus. The 3 populations varied in patent period, but the laboratory-isolated worms differed from the 2 wild population isolates no more than they did from each other. A positive correlation between mean daily egg production and duration of patent period resulted in different cumulative egg productions. A 31-yr period of isolation did not produce greater divergence in a laboratory population of M. moniliformis than occurs between wild populations with respect to the biological parameters measured.

Animals↗
PubMed2006

Effects of competition on the fitness of wild and crop-wild hybrid sunflower from a diversity of wild populations and crop lines.

Gene flow between crop fields and wild populations often results in hybrids with reduced fitness compared to their wild counterparts due to characteristics imparted by the crop genome. But the specifics of the evolutionary outcome of crop-wild gene flow may depend on context, varying due to local environmental conditions and genetic variation within and among wild populations and among crop lines. To evaluate context-dependence of fitness of F1 hybrids, sunflower crop lines were crossed with nine wild populations from across the northern United States. These crop-wild hybrids and their wild counterparts were grown under agricultural conditions in the field with and without wheat competition. Hybrids were far less fecund than wild plants, yet more likely to survive to reproduce. There was considerable variability among wild populations for fecundity and the specific crop line used to generate the crop-wild hybrid significantly affected fecundity. The fitness deficit suffered by crop-wild hybrids varied by population, as did the rankings of the crop-wild hybrids from three different crop lines. Wheat competition decreased fecundity and survival considerably and hampered seed production of wild plants more than that of hybrids. Genotype x environment interactions indicated that the response of fitness to competition differed by population. Consequently, the fitness of hybrids relative to wild plants varied considerably among wild populations and was not consistent across environments. Notably, relative fitness of hybrids was greater under competitive conditions. This research is the first study of its kind to demonstrate that the consequences of crop-wild gene flow are context dependent and contingent on the genetics of the specific wild populations and the local biotic and abiotic conditions.

Biodiversity↗
PubMed2005

[Genetic diversity and molecular authentication of wild populations of Dendrobium officinale by RAPD].

AIM: Genetic diversity, relationship and molecular authentication of total 8 wild populations of Dendrobium officinale were investigated using RAPD markers. METHODS: 10 random decamer primers were screened for Random Amplified Polymophic DNA (RAPD) fragments. A DNA molecular dendrogram was established based on cluster analysis by UPGMA (unweighted pair-group method with arithmetic average), and the relationship of the wild populations were analyzed, and all the wild populations were authenticated. RESULTS: A total of 439 loci with an average of 43.9 loci per primer and 54.9 loci per population were amplified from 8 wild populations by 10 effective primers. In the total 104 amplified bands, 95 were polymorphic, corresponding to 91.35% genetic polymorphism. The genetic distances were 0. 590 to 0. 727, with an average of 0. 686. CONCLUSION: Distinct genetic differences and extensive genetic diversity were presented among the wild populations. RAPD markers were an informative and useful tool for the genetic diversity, evaluation and authentication of wild populations of Dendrobium officinale. Primer S412 could be used to authenticate 8 wild populations completely.

China↗
PubMed2001

A population genetic analysis of chloroplast DNA in wild populations of Prunus avium L. in Europe.

A population genetic study of chloroplast DNA was carried out in 23 wild populations of Prunus avium sampled from several European deciduous forests. An analysis of approx. 9% of the chloroplast genome detected mostly insertion-deletion mutations and one point mutation. In all, 16 haplotypes were detected. Six haplotypes were shared by two or more populations and 10 were unique. One haplotype was present in 21 of the 23 populations and 161 of 211 individuals, which probably indicates its ancient origin. The level of population subdivision, using unordered and ordered alleles, was low, GSTC=0.29 and NSTC=0.33, respectively. The difference between GSTC and NSTC is nonsignificant, indicating an absence of correlation between haplotype phylogeny and geographical distribution. The absence of phylogeographic structure in wild cherry may be attributed to long distance gene flow among populations by birds, animals and anthropogenic activities. The minimum-length spanning tree depicting the phylogenetic relationships between the haplotypes indicates the possible existence of two lineages represented by the haplotypes H3 and H4. The information about homogeneity or heterogeneity of populations in terms of haplotype constitution and detection of rare haplotypes in some populations will be useful for formulation of conservation and management strategies of wild cherry.

DNA Restriction Enzymes↗
PubMed2003

Polymorphism of a complex resistance gene candidate family in wild populations of common bean (Phaseolus vulgaris) in Argentina: comparison with phenotypic resistance polymorphism.

Fifteen populations of wild bean (Phaseolus vulgaris), located in three provinces in Argentina, were analysed for their polymorphism for a complex resistance gene candidate (RGC) family clustered on the genome and for resistance phenotypes to strains of Colletotrichum lindemuthianum. Results indicate that RGC polymorphism is high. Population structure obtained for markers related to resistance was compared to population structure obtained for RAPD markers in order to infer the evolutionary forces driving polymorphism for resistance in wild populations at both molecular and phenotypic levels. Hierarchical analysis of differentiation showed that, within provinces, populations were differentiated for RAPD as well as for molecular and phenotypic markers of resistance. In contrast, provinces were differentiated only for RAPD and RGC markers and not for resistance phenotypes. The discrepancies found between diversity structures for molecular markers (RAPD and RGCs) and for resistance phenotypes suggest an effect of selection and indicate that diversity for resistance may not be driven by the same selective forces at the molecular and phenotypic levels. We further discuss whether specific selective forces are exerted on RGC markers and underline the importance of spatial scale of analysis for demonstrating an impact of selection.

Argentina↗
PubMed1986

Genetics of a wild population of rhesus monkeys (Macaca mulatta): II. The Dunga Gali population in species-wide perspective.

Genetic variability in a population of wild rhesus monkeys near the village of Dunga Gali, Northwest Frontier Province, Pakistan (Melnick et al., Am. J. Phys. Anthropol. 63:341-360, 1984) was compared to similar variation in other wild-caught rhesus monkeys. Regional samples of rhesus from different parts of Asia all displayed similar amounts of variation (i.e., P and Hi) and were consistently more variable than the Dunga Gali local population. Despite these differences in the level of genetic variation, genetic diversity is fairly evenly distributed across the species range. Thus only 3-9% of the total gene diversity of Macaca mulatta can be attributed to differences among major regions. The differences that do exist tend toward a weak geographic cline with clustering of populations into an eastern and a western group. Both selection and drift/migration models explain this general genetic homogeneity. More genetic (protein and DNA) and zoogeographic data are necessary to choose between these models.

Alleles↗
PubMed2000

Exploiting wild population diversity and somaclonal variation in the salt marsh grass Distichlis spicata (Poaceae) for marsh creation and restoration.

The salt marsh grass Distichlis spicata was regenerated from tissue culture and propagated in a greenhouse. Selected regenerants, along with selections from six wild populations, were grown for two years in a common garden flood-irrigated thrice weekly with tidal creek water. Selected wild and regenerated plants were also planted in a created salt marsh. Significant differences among regenerant and wild population selections were found in several functionally important salt marsh plant characteristics, including potential detritus production, belowground organic matter production, canopy structure, and decomposition rate. A combination of characteristics not found in the wild populations was evident in a regenerated line that exhibited both a high detritus production potential and a high decomposition rate. The amount of variation that occurred among regenerants from one parental line via somaclonal variation was similar to that which occurred among the wild population selections. Results of this study suggest that tissue culture may provide a means of producing marsh grasses with specific characteristics for directing the functional development of newly created salt marshes.

Journal Article↗
PubMed2001

Analysis of dentition of a living wild population of ring-tailed lemurs (Lemur catta) from Beza Mahafaly, Madagascar.

Detailed descriptions of the dentition of many strepsirhine primate taxa are rare, despite their importance in understanding primate evolutionary biology. While several researchers have provided detailed morphological descriptions of ring-tailed lemur dentition (e.g., Schwartz and Tattersall [1985] Am. Mus. Nat. Hist. Anthropol. Pap. 60:1-100; Tattersall and Schwartz [1991] Am. Mus. Nat. Hist. Anthropol. Pap. 69:2-18), there are few studies (e.g., Eaglen [1986] Am. J. Phys. Anthropol. 71:185-201) that present quantitative data on the dentition of this species. Furthermore, prior analyses were based on museum specimens from various populations and locations. We present here quantitative and morphological data on the dentition of a population of wild Lemur catta from Beza Mahafaly Special Reserve, Madagascar. Measurements were made on dental casts (n = 39) taken from living members of this L. catta population. Our analysis indicates that no significant (P > 0.05) sexual dimorphism exists for the 30 dental measurements collected. These data support the generalizations (e.g., Plavcan and van Schaik [1994] Evol. Anthropol. 2:208-214; Kappeler [1996] J. Evol. Biol. 9:43-65) that little sexual dimorphism in dentition exists among Malagasy strepsirhines. In addition, the overall patterns of metric variation in this sample compare favorably with patterns seen among other primates, e.g., premolar measurements varying more than molars (e.g., Gingerich [1974] J. Paleontol. 48:895-903). However, there is a degree of intraspecific morphological variation indicated, with one of the morphological traits discussed in other studies as being species-specific for L. catta (absence of P(4) metaconids) observed to vary between specimens. Because the patterns of variation seen in this sample are from a known breeding population, the data presented here provide an important reference for interpreting and understanding the fossil record.

Animals↗
PubMed2003

Phytochemistry of wild populations of Panax quinquefolius L. (North American ginseng).

A survey of the phytochemistry of Panax quinquefolius L. (North American ginseng) collected from wild populations in Ontario, Quebec, Maine, Vermont, and Wisconsin was undertaken. Reverse-phase HPLC was used to determine the natural variation of levels of ginsenosides Rg1, Re, Rf, Rb1, Rc, Rb2, and Rd and their total in leaf, stem, and root of authentic wild-grown material. The totals in roots varied from 1 to 16%, with the greatest number of individual samples having 4-5% total ginsenosides. The lack of ginsenoside Rf in roots of authentic wild populations confirmed its status as a phytochemical marker differentiating American and Asian ginseng. Ten geographically isolated wild populations were collected, and several showed significant variation in the levels of major ginsenosides. There was no statistical difference in mean ginsenoside content between wild and cultivated P. quinquefolius roots at 4 years of age, suggesting there is no phytochemical justification for wild crafting. Baseline data on total ginsenoside levels for authentic wild P. quinquefolius reported here provide reference levels for quality assurance programs.

Canada↗
PubMed2002

The origin of Russian cultivars of red clover ( Trifolium pratense L.) and their genetic relationships to wild populations in the Urals.

Propagation and breeding of red clover ( Trifolium pratense L.) in Russia was initiated about 200 years ago but the origin of present-day cultivars is disputed. Some authors argue that most Russian cultivars were derived from western European ones, whereas others support a Russian origin of the cultivars from local wild populations. In the present study we assessed the genetic variation at 17 allozyme loci in seven Russian cultivars, bearing the names of localities of the Urals, two American ones that have been used in Russia for scientific experiments and seven wild populations of the Urals and Western Siberia. Variation at the 17 protein loci supports the western European origin of the cultivars and also indicates that gene flow between cultivars and wild populations was limited or has not acted sufficiently long to affect the genetic composition of the red clover wild populations of the Urals.

Genetic Variation↗
PubMed2003

Geographic variation and diversity of the cytochrome b gene in Japanese wild populations of medaka, Oryzias latipes.

We conducted a polymerase chain reaction--restriction fragment length polymorphism (PCR-RFLP) analysis of the mitochondrial cytochrome b gene to elucidate the detailed genetic population structure of Japanese wild populations of medaka, Oryzias latipes. The analysis of 1,225 specimens collected from 303 sites identified 67 mitotypes. Subsequently we determined the nucleotide sequences of the complete cytochrome b gene (1141-bp) to clarify the phylogenetic relationships among mitotypes. The phylogenetic tree based on nucleotide sequences indicated three major clades (A, B and C) that differed by 11.3-11.8%, corresponding to three clusters previously identified by RFLP analysis of entire mitochondrial DNAs. The geographic distribution of mitotypes in clades A and B was fully concordant with the Northern and Southern Populations defined by allozymes. Clade A could be subdivided into three subclades and clade B into eleven, with sequence divergences among subclades of 1.3-5.8%. Each distribution of mitotypes in subclades roughly corresponded to that of mtDNA haplotypes in subclusters previously identified. Mitotypes in clade C were found only in the Kanto district. The phylogenetic relationships and the estimated divergence times suggest that three Japanese clades originated from a common ancestor and were separated during the Pliocene, and that the regional differentiation of subclades was closely connected with the geological history of the Quaternary. This study has also demonstrated the possibility of artificial disturbance of natural distribution especially in the Kanto district and the superior efficacy of PCR-RFLP analysis as a simple method for detecting genetic variation and artificial gene flow of medaka.

Animals↗
PubMed2002

Microsatellites uncover extraordinary diversity in native American land races and wild populations of cultivated sunflower.

The contemporary oilseed sunflower (Helianthus annuus L.) gene pool is a product of multiple breeding and domestication bottlenecks. Despite substantial phenotypic diversity, modest differences in molecular genetic diversity have been uncovered in anciently and recently domesticated sunflowers. The paucity of molecular marker polymorphisms in early analyses led to the hypothesis of a single domestication origin. Phylogenetic analyses were performed on 47 domesticated and wild germplasm accessions using 122 microsatellite loci distributed throughout the sunflower genome. Extraordinary allelic diversity was found in the Native American land races and wild populations, and progressively less allelic diversity was found in germplasm produced by successive cycles of domestication and breeding. Of 1,341 microsatellite alleles, 489 were unique to land races, exotic domesticates and wild populations, whereas only 15 were unique to elite inbred lines. The number of taxon-specific alleles was 35-fold greater among wild populations (26.27) than elite inbred lines (0.75). Microsatellite genotyping uncovered the possibility of multiple domestication origins. Land races domesticated by Native Americans of the southwestern US (Hopi and Havasupai) formed a clade independent of land races domesticated by Native Americans of the Great Plains and eastern US (Arikara and Seneca). Predictably, domestication and breeding have ratcheted genetic diversity down in sunflower. The contemporary oilseed sunflower gene pool, while not imperiled, could profit from an infusion of novel alleles from the reservoir of latent genetic diversity present in wild populations and Native American land races.

Alleles↗
PubMed2005

How to use molecular marker data to measure evolutionary parameters in wild populations.

Estimating the genetic basis of phenotypic traits and the selection pressures acting on them are central to our understanding of the evolution and conservation of wild populations. However, obtaining such evolutionary-related parameters is not an easy task as it requires accurate information on both relatedness among individuals and their breeding success. Polymorphic molecular markers are very useful in estimating relatedness between individuals and parentage analyses are now extensively used in most taxa. The next step in the application of molecular data to wild populations is to use them to derive estimates of evolutionary-related parameters for quantitative traits, such as quantitative genetic parameters (e.g. heritability, genetic correlations) and measures of selection (e.g. selection gradients). Despite their great appeal and potential, the optimal use of molecular tools is still debated and it remains unclear how they should best be used to obtain reliable estimates of evolutionary parameters in the wild. Here, we review the methods available for estimating quantitative genetic and selection parameters and discuss their merits and shortcomings, to provide a tool that summarizes the potential uses of molecular data to obtain such parameters in wild populations.

Biological Evolution↗
PubMed2005

Reproductive ageing and sexual selection on male body size in a wild population of antler flies (Protopiophila litigata).

Little is known about the importance of trade-offs between ageing and other life history traits, or the effects of ageing on sexual selection, particularly in wild populations suffering high extrinsic mortality rates. Life history theory suggests that trade-offs between reproduction and somatic maintenance may constrain individuals with higher initial reproductive rates to deteriorate more rapidly, resulting in reduced sexual selection strength. However, this trade-off may be masked by increased condition dependence of reproductive effort in older individuals. We tested for this trade-off in males in a wild population of antler flies (Protopiophila litigata). High mating rate was associated with reduced longevity, as a result of increased short-term mortality risk or accelerated ageing in traits affecting viability. In contrast, large body size was associated with accelerated ageing in traits affecting mating success, resulting in reduced sexual selection for large body size. Thus, ageing can affect sexual selection and evolution in wild populations.

Aging↗
PubMedDate not supplied

[Variation in fruit and seed size from 38 wild populations of Phaseolus lunatus (Fabaceae) from Central Valley, Costa Rica].

We studied the morfological diversity in fruits and seeds in 38 wild populations of Phaseolus lunatus var. lunatus (lima beans) in the central valley of Costa Rica. In order to do so, measured the length and width of the fruits and the length, width and thickness of seeds. We also calculated the ratio between these traits and determined the weight of 100 seeds. In general, we found significant variation between populations for all variables. When we grouped the 38 populations into eight geographical regions within the study area, we found significant differences between regions. However, the levels of variation between populations within geographical regions was larger than that found between geographical regions. These findings suggested that there is no clear relationship between these variables and the geographical grouping established in this study. The implications of these findings for the establishment of strategies for in situ conservation of wild populations of lima beans are discussed.

Costa Rica↗
PubMed1972

Experimental introduction of a microsporidian into a wild population of Culex pipiens fatigans Wied.

Chemical control of C. p. fatigans frequently fails because the mosquito rapidly develops resistance to insecticides. A possible alternative or complementary method is biological control, including the introduction of pathogens. The microsporidian Plistophora culicis was known to infect readily and have an adverse effect on C. p. fatigans populations in the laboratory, so an attempt was made to introduce and establish this pathogen in a wild population of the mosquito on the Pacific island of Nauru. Two years after introduction the pathogen was still present in the wild population. However, the infection rate was similar to that found in naturally occurring infections in other mosquitos and is almost certainly not high enough to affect a natural population of C. p. fatigans adversely.

Animals↗
PubMed2003

Accumulation of lead, zinc, and cadmium in a wild population of Clethrionomys glareolus from an abandoned lead mine.

Lead, zinc, and cadmium were determined in a range of tissues from wild populations of bank voles (Clethrionomys glareolus) trapped on an abandoned metalliferous mine site and a reference site. Estimated dietary intakes indicated that animals were exposed to elevated levels of all three metals at the mine site, and this was generally reflected in metal residues in body tissues. Lead concentrations were significantly higher in all tissues of animals from the mine compared to the reference site, while Cd was higher only in the kidney. There was evidence of age-accumulation (using total body weight as an index of age) of Cd in both the liver and kidney of mine site animals but no evidence of such accumulation of lead in bone. In contrast to Cd and Pb, Zn was lower in the tissues of mine site animals compared to the reference site. Based on critical tissue concentrations, the ecotoxicological risk to a wild population of bank voles (Clethrionomys glareolus), associated with total substrate levels of 1 microg g(-1) dry weight Cd and 700 microg g(-1) dry weight Zn at this mine site is negligible, but that associated with 4000 microg g(-1) dry weight Pb may be considered significant.

Aging↗