scholarly journals Genetic variation within and between populations of the asexual plant Puccinellia × phryganodes

1983 ◽  
Vol 61 (3) ◽  
pp. 774-779 ◽  
Author(s):  
R. L. Jefferies ◽  
L. D. Gottlieb
Keyword(s):  
Genetic Variation ◽  
Genetic Variability ◽  
Salt Marshes ◽  
Clonal Growth ◽  
Seed Set ◽  
Electrophoretic Mobilities ◽  
Enzyme Systems ◽  
Puccinellia Phryganodes ◽  
Sexual Processes ◽  
High Level

Puccinellia × phryganodes (Trin.) Scriber and Merr is widely distributed in Arctic salt marshes. In North America the species, which is capable of extensive clonal growth, appears to be a sterile triploid (2n = 21); seed set has never been observed. Consequently it was predicted that the level of genetic variation would be low, both within and between populations. Examination of electrophoretic mobilities of isozymes of 12 enzyme systems in plants from three widely separated populations in Arctic Canada indicated a high level of variability both within and between the populations. The unexpected discovery of significant amounts of genetic variability suggests that sexual processes occur in this species.

High Levels of Genetic Variability in an Isolated Colony of Rock-wallabies (Petrogale assimilis): Evidence from Three Classes of Molecular Markers

1997 ◽  
Vol 45 (2) ◽  
pp. 199 ◽  
Author(s):  
Peter B. S. Spencer ◽  
Mark Adams ◽  
Helene Marsh ◽  
David J. Miller ◽  
Mark D. B. Eldridge
Keyword(s):  
Genetic Variation ◽  
Molecular Markers ◽  
Genetic Variability ◽  
Mating Systems ◽  
Selective Pressure ◽  
Multiple Mating ◽  
Dna Fingerprints ◽  
Average Heterozygosity ◽  
Low Levels ◽  
High Level

Estimates of genetic variation for a small (Ne = 39) colony of allied rock-wallabies (Petrogale assimilis) were calculated with three different categories of molecular marker. Average heterozygosity was estimated at 3·8% for allozymes, 47·3% for multilocus ‘DNA fingerprints’ and 85·5% for microsatellite markers. Overall these values indicate that this small isolated colony of rock-wallabies maintains a high level of genetic variation despite its relative isolation and the apparently low levels of migration between colonies. It is likely that mechanisms exist (such as kin avoidance, multiple mating systems, high and variable selective pressure in extreme and fluctuating environmental conditions) that promote the maintenance of high levels of genetic variation in isolated colonies of P. assimilis. These mechanisms are discussed in the context of the results obtained from the molecular markers.

scholarly journals Diversity of Biscogniauxia mediterranea within Single Stromata on Cork Oak

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Joana Henriques ◽  
Filomena Nóbrega ◽  
Edmundo Sousa ◽  
Arlindo Lima
Keyword(s):  
Polymerase Chain Reaction ◽  
Genetic Variation ◽  
Genetic Variability ◽  
Geographical Location ◽  
Cork Oak ◽  
Microsatellite Primers ◽  
Chain Reaction ◽  
Disease Symptoms ◽  
Polymerase Chain ◽  
High Level

Charcoal canker, caused by the fungus Biscogniauxia mediterranea, is one of the most frequent diseases of cork oak in Portugal. The pathogen has been considered a secondary invader that attacks only stressed hosts; however, in recent years, an increasing number of young trees exhibiting the disease symptoms have been recorded. A collection of monoascosporic cultures isolated from single stromata of B. mediterranea in cork oak from different locations was analyzed by means of microsatellite—Primed Polymerase Chain Reaction—using three microsatellite primers, in order to detect the genetic variation of the population thus discussing its plasticity and ability to adapt to different conditions. The results showed a high level of genetic variability among isolates obtained from the same stroma, being impossible to distinguish isolates from individual stromata neither from different geographical location.

scholarly journals Genetic Variability Assay of Different Natural and Hatchery Populations of Rohu (Labeo rohita) in Bangladesh

2015 ◽  
Vol 9 (1) ◽  
pp. 30-36
Author(s):  
Shikder Saiful Islam ◽  
Md. Saifuddin Shah ◽  
Foyez Ibn Shams ◽  
Md. Rayhan Ali ◽  
Md. Lifat Rahi
Keyword(s):  
Genetic Variation ◽  
Genetic Variability ◽  
Labeo Rohita ◽  
Genetic Distances ◽  
Raw Material ◽  
Group Method ◽  
Pair Group ◽  
Fish Samples ◽  
Population Genetic Variation ◽  
High Level

The level of genetic variation determines the genetic status and provides the raw material for selective improvement of a stock. Randomly amplified polymorphic DNA (RAPD) technique was used to assess the genetic variability of 7 different natural (2) and hatchery (5) populations of Indian Major Carp, Labeo rohita (Rohu) in Bangladsh. In total, 140 fish samples were collected (20 from each of the populations). Genomic DNA was extracted from the muscle tissue, and 5 different oligonucleotide primers were used which revealed 80% polymorphic DNA bands. The polymorphic loci proportions were 0.71, 0.75, 0.75, 0.85, 0.84, 0.86 and 0.89 for Ma-Fatema hatchery, Chowdhuri hatchery, Niribili hatchery, Sonali hatchery, Kapotakha hatchery, the Halda river and the Baluhor Baor populations respectively. The pair-wise population differentiation (FST) values indicated a high level of genetic variation between different populations. The Unweighted Pair Group Method of Arithmetic Mean (UPGMA) dendogram based on Nei’s genetic distances also revealed high level of inter-population genetic variation among the populations. The populations were segregated into two groups: the Halda River and Baluhar Baor hatchery in one group and Kapotakha, Ma-Fatema, Chowdhuri, Niribili and Sonali hatcheries in another group. Overall, RAPD results clearly indicate the reduced genetic quality of the hatchery seeds.DOI: http://dx.doi.org/10.3126/ijls.v9i1.11923 International Journal of Life Sciences Vol.9(1) 2015 30-36

scholarly journals ISSR-PCR analysis of genetic variation in populations of Achillea L. species in southern part of Krasnoyarsk Territory and Republic of Khakassia

2020 ◽  
Vol 19 (2) ◽  
pp. 090-093
Author(s):  
E. E. Stoyanova ◽  
I. E. Yamskikh
Keyword(s):  
Genetic Variation ◽  
Genetic Variability ◽  
Pcr Analysis ◽  
Minor Variation ◽  
The Republic ◽  
Satisfactory State ◽  
High Level ◽  
A Minor ◽  
Issr Pcr ◽  
Intrapopulation Diversity

ISSR-PCR analysis of populations of two species of the genus Achillea, growing in the southern part ofthe Krasnoyarsk Territory and the Republic of Khakassia, was carried out. The results of the study showed that a highlevel of intrapopulation variability is characteristic of Achillea asiatica and A. millefolium. Relatively low indicators ofgenetic variability are noted for populations Aa3 (A. asiatica) and Ak (A. kuprijanovii). The gene pool of all the studiedpopulations is characterized by a satisfactory state and can independently reproduce. Most of the genetic variability ofAchillea millefolium, A. asiatica, and A. kuprijanovii (74.7 %) accounts for the share of intrapopulation diversity, and25.3 % is a minor variation. The studied populations are characterized by a high level of differentiation and are dividedaccording to a systematic criterion.

scholarly journals POPULATION GENETICS OF ALLOZYME VARIATION IN NEUROSPORA INTERMEDIA

Genetics ◽  
1975 ◽  
Vol 80 (4) ◽  
pp. 785-805
Author(s):  
P T Spieth
Keyword(s):  
Genetic Variation ◽  
Vegetative Reproduction ◽  
Vascular Plant ◽  
Natural Populations ◽  
Allozyme Variation ◽  
Regular Feature ◽  
Local Populations ◽  
Neurospora Intermedia ◽  
Pattern Of Variation ◽  
High Level

ABSTRACT Electrophoretically detectable variation in the fungus Neurospora intermedia has been surveyed among isolates from natural populations in Malaya, Papua, Australia and Florida. The principal result is a pattern of genetic variation within and between populations that is qualitatively no different than the well documented patterns for Drosophila and humans. In particular, there is a high level of genetic variation, the majority of which occurs at the level of local populations. Evidence is presented which argues that N. intermedia has a population structure analogous to that of an annual vascular plant with a high level of vegetative reproduction. Sexual reproduction appears to be a regular feature in the biology of the species. Substantial heterokaryon function seems unlikely in natural populations of N. intermedia. Theoretical considerations concerning the mechanisms underlying the observed pattern of variation most likely should be consistent with haploid selection theory. The implications of this constraint upon the theory are discussed in detail, leading to the presentation of a model based upon the concept of environmental heterogeneity. The essence of the model, which is equally applicable to haploid and diploid situations, is a shifting distribution of multiple adaptive niches among local populations such that a given population has a small net selective pressure in favor of one allele or another, depending upon its particular distribution of niches. Gene flow among neighboring populations with differing net selective pressures is postulated as the principal factor underlying intrapopulational allozyme variation.

Assessment of genetic variability amongst cultivated populations of Khasi mandarin (Citrus reticulata Blanco) detected by ISSR

2021 ◽  
pp. 1-11
Author(s):  
Karishma Kashyap ◽  
Rasika M. Bhagwat ◽  
Sofia Banu
Keyword(s):  
Genetic Diversity ◽  
Genetic Variability ◽  
Inter Simple Sequence Repeat ◽  
Northeast India ◽  
Issr Markers ◽  
Citrus Reticulata ◽  
Brahmaputra Valley ◽  
Indian Food ◽  
Cultivated Populations ◽  
High Level

Abstract Khasi mandarin (Citrus reticulata Blanco) is a commercial mandarin variety grown in northeast India and one of the 175 Indian food items included in the global first food atlas. The cultivated plantations of Khasi mandarin grown prominently in the lower Brahmaputra valley of Assam, northeast India, have been genetically eroded. The lack in the efforts for conservation of genetic variability in this mandarin variety prompted diversity analysis of Khasi mandarin germplasm across the region. Thus, the study aimed to investigate genetic diversity and partitioning of the genetic variations within and among 92 populations of Khasi mandarin collected from 10 cultivated sites in Kamrup and Kamrup (M) districts of Assam, India, using Inter-Simple Sequence Repeat (ISSR) markers. The amplification of genomic DNA with 17 ISSR primers yielded 216 scorable DNA amplicons of which 177 (81.94%) were polymorphic. The average polymorphism information content was 0.39 per primer. The total genetic diversity (HT = 0.28 ± 0.03) was close to the diversity within the population (HS = 0.20 ± 0.01). A high mean coefficient of gene differentiation (GST = 0.29) reflected a high level of gene flow (Nm = 1.22), indicating high genetic differentiation among the populations. Analysis of Molecular Variance (AMOVA) showed 78% of intra-population differentiation, 21% among the population and 1% among the districts. The obtained results indicate the existence of a high level of genetic diversity in the cultivated Khasi mandarin populations, indicating the need for preservation of each existing population to revive the dying out orchards in northeast India.

Comparison of human and murine isolates of Schistosoma mansoni from Richard-Toll, Senegal, by isoelectric focusing

1997 ◽  
Vol 71 (2) ◽  
pp. 175-181 ◽  
Author(s):  
M. Sène ◽  
P. Brémond ◽  
J.P. Hervé ◽  
V.R. Southgate ◽  
B. Sellin ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Acid Phosphatase ◽  
Lactate Dehydrogenase ◽  
Schistosoma Mansoni ◽  
Isoelectric Focusing ◽  
Glucose Phosphate Isomerase ◽  
Glucose Phosphate ◽  
Enzyme Systems ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Arvicanthis Niloticus

AbstractStudies on human and murine isolates of Schistosoma mansoni, from Richard-Toll, Senegal, were carried out by isoelectric focusing in polyacrylamide gels. Seven enzyme systems; lactate dehydrogenase (LDH), malate dehydrogenase (MDH), glucose-6-phosphate dehydrogenase (G6PD), acid phosphatase (AcP), hexokinase (HK), glucose phosphate isomerase (GPI), and phosphoglucomutase (PGM), were used to compare the two isolates. All systems tested, apart from LDH, were found to be polymorphic for both isolates. Interestingly, one phenotype is more frequent than the remainder. The results show that there is no significant genetic variation between the S. mansoni isolates from man and the rodents, Arvicanthis niloticus and Mastomys huberti.

Genetic variability in the natural populations of Lasioderma serricorne (F.) (Coleoptera: Anobiidae), detected by RAPD markers and by esterase isozymes

2015 ◽  
Vol 106 (1) ◽  
pp. 47-53 ◽  
Author(s):  
T. Coelho-Bortolo ◽  
C.A. Mangolin ◽  
A.S. Lapenta
Keyword(s):  
Genetic Variability ◽  
Random Amplified Polymorphic Dna ◽  
Natural Populations ◽  
Electrophoretic Analysis ◽  
Effective Control ◽  
Lasioderma Serricorne ◽  
Control Programs ◽  
Dried Fruit ◽  
High Level ◽  
High Degree

AbstractLasioderma serricorne (F.) is a small cosmopolitan beetle regarded as a destructive pest of several stored products such as grains, flour, spices, dried fruit and tobacco. Chemical insecticides are one of the measures used against the pest. However, intensive insecticide use has resulted in the appearance of resistant insect populations. Therefore, for the elaboration of more effective control programs, it is necessary to know the biological aspects of L. serricorne. Among these aspects, the genetic variability knowledge is very important and may help in the development of new control methods. The objective of this study was to evaluate the genetic variability of 11 natural populations of L. serricorne collected respectively in three and four towns in the states of Paraná and São Paulo, Brazil, using 20 primers random amplified polymorphic DNA (RAPD) and polymorphisms of esterases. These primers produced 352 polymorphic bands. Electrophoretic analysis of esterases allowed the identification of four polymorphic loci (Est-2, Est-4, Est-5 and Est-6) and 18 alleles. Results show that populations are genetically differentiated and there is a high level of genetic variability within populations. The high degree of genetic differentiation is not directly correlated to geographical distance. Thus, our data indicate that movement of infested commodities may contribute to the dissemination of L. serricorne, facilitating gene flow.

Intraspecific genetic variability of isozymes in the ectomycorrhizal fungus Suillus tomentosus

1988 ◽  
Vol 66 (3) ◽  
pp. 588-594 ◽  
Author(s):  
Hong Zhu ◽  
Kenneth O. Higginbotham ◽  
Bruce P. Dancik ◽  
Stan Navratil
Keyword(s):  
Genetic Variability ◽  
Host Selection ◽  
Gel Electrophoresis ◽  
Genetic Similarity ◽  
Ectomycorrhizal Fungus ◽  
Habitat Isolation ◽  
Starch Gel Electrophoresis ◽  
Enzyme Systems ◽  
Forest Regions ◽  
Starch Gel

Mycelial extracts of 43 isolates of Suillus tomentosus (Kauffm.) Singer, Snell & Dick collected from four boreal forest regions in Alberta were subjected to starch gel electrophoresis. A total of 21 bands was resolved from eight different enzyme systems presumably representing 13 loci. Six loci were polymorphic among these isolates. Cluster and principal components analyses demonstrated that intraspecific genetic variability of this fungus existed among and within forest regions. Polymorphic loci of acid phosphatase and alkaline phosphatase exhibited the greatest genetic similarity among the isolates within forest regions. Habitat isolation and host selection could be the major sources of genetic variation among forest regions.

Sign in / Sign up

Export Citation Format

Share Document