Patterns of allozyme variation within and among Douglas-fir breeding zones in southwest Oregon

1987 ◽  
Vol 17 (5) ◽  
pp. 402-407 ◽  
Author(s):  
S. A. Merkle ◽  
W. T. Adams
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Gene Frequency ◽  
Quantitative Traits ◽  
Allozyme Variation ◽  
Douglas Fir ◽  
Expected Heterozygosity ◽  
Breeding Zone ◽  
Southwest Oregon ◽  
Environmental Distance

Gametophytes from wind-pollinated seeds of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco var. menziesii) parent trees (mean 56) in each of 22 breeding zones in southwest Oregon were analyzed electrophoretically for gene frequency patterns at 27 loci. Allozyme variability levels were high, as shown by breeding-zone averages for the percentage of polymorphic loci (71.7%, 0.99 criterion), mean number of alleles per locus (2.46), and expected heterozygosity (0.178). Differences among zones in allele frequency were significant (p < 0.05) for only 2 of the 27 loci surveyed, and analysis of hierarchical population structure showed that less than 1% of genetic diversity was attributable to differences among breeding zones. Genetic distance between zones was small [Formula: see text] and, in general, bore no relation to geographical or environmental distance. The limited allozyme differentiation among zones contrasts strikingly with the environment-related variation in seedling quantitative traits previously reported for southwest Oregon Douglas-fir. Allozymes do not appear to be useful for mapping patterns of adaptive variation or for certifying Douglas-fir seed in this region.

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 Genetic diversity and population structure of date palms (Phoenix dactylifera L.) in Ethiopia using microsatellite markers

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Workia Ahmed ◽  
Tileye Feyissa ◽  
Kassahun Tesfaye ◽  
Sumaira Farrakh
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Microsatellite Markers ◽  
Information Content ◽  
Date Palm ◽  
Polymorphic Information Content ◽  
Phoenix Dactylifera ◽  
Mean Value ◽  
Date Palms ◽  
Expected Heterozygosity

Abstract Background Date palm tree (Phoenix dactylifera L.) is a perennial monocotyledonous plant belonging to the Arecaceae family, a special plant with extraordinary nature that gives eminent contributions in agricultural sustainability and huge socio-economic value in many countries of the world including Ethiopia. Evaluation of genetic diversity across date palms at DNA level is very important for breeding and conservation. The result of this study could help to design for genetic improvement and develop germplasm introduction programmes of date palms mainly in Ethiopia. Results In this study, 124 date palm genotypes were collected, and 10 polymorphic microsatellite markers were used. Among 10 microsatellites, MPdCIR085 and MPdCIR093 loci showed the highest value of observed and expected heterozygosity, maximum number of alleles, and highest polymorphic information content values. A total of 112 number of alleles were found, and the mean number of major allele frequency was 0.26, with numbers ranging from 0.155 (MPdCIR085) to 0.374 (MPdCIR016); effective number of alleles with a mean value of 6.61, private alleles ranged from 0.0 to 0.65; observed heterozygosity ranged from 0.355 to 0.726; expected heterozygosity varied from 0.669 to 0.906, polymorphic information content with a mean value of 0.809; fixation index individuals relative to subpopulations ranged from 0.028 for locus MPdCIR032 to 0.548 for locus MPdCIR025, while subpopulations relative to total population value ranged from − 0.007 (MPdCIR070) to 0.891 (MPdCIR015). All nine accesstions, neighbour-joining clustering analysis, based on dissimilarity coefficient values were grouped into five major categories; in population STRUCTURE analysis at highest K value, three groups were formed, whereas DAPC separated date palm genotypes into eight clusters using the first two linear discriminants. Principal coordinate analysis was explained, with a 17.33% total of variation in all populations. Generally, the result of this study revealed the presence of allele variations and high heterozygosity (> 0.7) in date palm genotypes. Conclusions Microsatellites (SSR) are one of the most preferable molecular markers for the study of genetic diversity and population structure of plants. In this study, we found the presence of genetic variations of date palm genotypes in Ethiopia; therefore, these genetic variations of date palms is important for crop improvement and conservation programmes; also, it will be used as sources of information to national and international genbanks.

scholarly journals Population structure and phylogenetic relationships in Brassica rapa L. subspecies by using isozyme markers

2020 ◽  
Author(s):  
R. H. Sammour ◽  
M. A. Karam ◽  
Y. S. Morsi ◽  
R. M. Ali
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Brassica Rapa ◽  
Phylogenetic Relationships ◽  
Fixation Index ◽  
Distribution Area ◽  
Enzyme Analysis ◽  
Breeding Programs ◽  
Expected Heterozygosity ◽  
Wide Range

Abstract The present study aimed to assess population structure and phylogenetic relationships of nine subspecies of Brassica rapa L. represented with thirty-five accessions cover a wide range of species distribution area using isozyme analysis in order to select more diverse accessions as supplementary resources that can be utilized for improvement of B. napus. Enzyme analysis resulted in detecting 14 putative polymorphic loci with 27 alleles. Mean allele frequency 0.04 (rare alleles) was observed in Cat4A and Cat4B in sub species Oleifera accession CR 2204/79 and in subspecies trilocularis accessions CR 2215/88 and CR 2244/88. The highest genetic diversity measures were observed in subspecies dichotoma, accession CR 1585/96 (the highest average of observed (H0) and expected heterozygosity (He), and number of alleles per locus (Ae)). These observations make this accession valuable genetic resource to be included in breeding programs for the improvement of oilseed B. napus. The average fixation index (F) is significantly higher than zero for the analysis accessions indicating a significant deficiency of heteozygosity. The divergence among subspecies indicated very great genetic differentiation (FST = 0.8972) which means that about 90% of genetic diversity is distributed among subspecies, while 10% of the diversity is distributed within subspecies. This coincides with low value of gene flow (Nm = 0.0287). B. rapa ssp. oleifera (turnip rape) and B. rapa ssp. trilocularis (sarson) were grouped under one cluster which coincides with the morphological classification.

scholarly journals A new set of microsatellite loci for Cattleya walkeriana Gardner, an endangered tropical orchid species and its transferability to Cattleya loddigesii Lindl. and Cattleya nobilior Reichenbach

2017 ◽  
Vol 16 (3) ◽  
pp. 284-287
Author(s):  
Bruno C. Rossini ◽  
Mariá B. Kampa ◽  
Celso L. Marino ◽  
Fernanda Bortolanza Pereira ◽  
Fábio M. Alves ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Microsatellite Loci ◽  
Null Alleles ◽  
Germplasm Resources ◽  
Significant Linkage Disequilibrium ◽  
Orchid Species ◽  
Expected Heterozygosity ◽  
Tropical Orchid ◽  
Significant Linkage

AbstractIn this study, we isolate and analyse a new set of microsatellite loci for Cattleya walkeriana. Twenty-two primer pairs were screened for C. walkeriana (n = 32) and assessed for their transferability to Cattleya loddigesii (n = 12) and Cattleya nobilior (n = 06). All loci amplified for C. walkeriana; however, for C. loddigesii and C. nobilior, four and five primers, respectively, did not present amplification. The polymorphic loci presented between 2 and 13 alleles per locus for both C. walkeriana and C. loddigesii, with respective averages of 5.1 and 4.2. For C. nobilior, we found between two and five alleles per locus, with an average of 2.6. For C. walkeriana, observed heterozygosity varied from 0.100 to 0.966, whereas expected heterozygosity ranged from 0.097 to 0.900. The observed and expected heterozygosity for C. loddigesii and C. nobilior were also estimated. We found no significant linkage disequilibrium between any pair of loci, and evidence of null alleles at four loci (Cw16, Cw24, Cw30 and Cw31) for C. walkeriana. The combined power to exclude the first parent and combined non-exclusion probability of identity were 0.999 and 2.3 × 10−20, respectively. These new loci can be used in studies of germplasm resources, and assessments of genotypic and genetic diversity and population structure, thus improving the accuracy of such analyses and their applicability in the conservation and protection of these endangered species.

scholarly journals Genetic diversity and population structure of four cattle breeds raised in Turkey using microsatellite markers

2019 ◽  
Vol 64 (No. 10) ◽  
pp. 411-419 ◽  
Author(s):  
Eymen Demir ◽  
Murat Soner Balcioğlu
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Microsatellite Markers ◽  
Factorial Correspondence Analysis ◽  
Cattle Breeds ◽  
Expected Heterozygosity ◽  
Bottleneck Analysis ◽  
Holstein Friesian ◽  
Native Cattle ◽  
Marker Level

In the present study, genetic diversity and population structure of Holstein Friesian and three native cattle breeds of Turkey including Turkish Grey Steppe, Eastern Anatolian Red and Anatolian Black were assessed. Totally 120 individuals of 4 breeds were genotyped using 20 microsatellite markers and 204 different alleles, of which 31 were private alleles, were detected. The average observed and expected heterozygosity values were 0.63 and 0.74, respectively. Observed heterozygosity at the marker level ranged from 0.30 (DRBP1) to 0.88 (ILSTS011), while expected heterozygosity ranged from 0.51 (INRABERN172) to 0.88 (SPS113). Inbreeding coefficient values for Turkish Grey Steppe, Eastern Anatolian Red, Anatolian Black and Holstein Friesian were 0.216, 0.202, 0.128 and 0.069, respectively. The lowest pairwise F<sub>ST</sub> value (0.030) was detected between Turkish Grey Steppe and Anatolian Black breeds, while the highest value (0.070) was detected between Turkish Grey Steppe and Holstein Friesian. Results of structure and factorial correspondence analysis revealed that Turkish native cattle breeds and Holstein Friesian were genetically different enough to separate the two breeds. Results of bottleneck analysis indicated heterozygosity deficiency in Turkish Grey Steppe (P &lt; 0.05).

Allozyme variation and population structure of Carex humilis var. nana (Cyperaceae) in Korea

2001 ◽  
Vol 79 (4) ◽  
pp. 457-463 ◽  
Author(s):  
Man Kyu Huh
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variation ◽  
North American ◽  
Population Level ◽  
Allozyme Variation ◽  
Population Divergence ◽  
Geographic Ranges ◽  
The Mean ◽  
Allozyme Loci

Genetic diversity and population structure of 22 Carex humilis var. nana Ohwi (Cyperaceae) populations in Korea were determined using genetic variation at 23 allozyme loci. This is a long-lived herbaceous species with a widespread distribution in eastern Asia. The 12 enzymes revealed 23 putative loci, of which 11 were polymorphic (47.8%). Genetic diversity at the varietal level and at the population level was 0.131 and 0.118, respectively. Total genetic diversity (HT = 0.274) and within population genetic diversity (HS = 0.256) were high, whereas the extent of the population divergence was relatively low (GST = 0.068). An indirect estimate of the number of migrants per generation (Nm = 3.42) indicated that gene flow was high among Korean populations. Wide geographic ranges, perennial herbaceous nature, and the persistence of multiple generations are associated with the high level of genetic variation. A distinct difference between Asian and North American Carex is shown in the proportion of genetic variation (GST) (p < 0.001). The mean GST of Asian Carex was estimated as 0.056; thus, only 5.6% of genetic variability was distributed among populations, whereas the mean GST of North American Carex was estimated as 19.5% (3.5 times higher). It is probable that the geographical distance between population pairs and presence or absence of glacial history may play roles in the substantial difference between both groups.Key words: Carex humilis var. nana, genetic diversity, population structure.

Range-wide patterns of allozyme variation in Douglas-fir (Pseudotsugamenziesii)

1989 ◽  
Vol 19 (2) ◽  
pp. 149-161 ◽  
Author(s):  
Peng Li ◽  
W. T. Adams
Keyword(s):  
Genetic Variation ◽  
Sierra Nevada ◽  
Allozyme Variation ◽  
Douglas Fir ◽  
Transition Zones ◽  
Seed Sources ◽  
Expected Heterozygosity ◽  
Major Exception ◽  
History Of ◽  
Geographical Locations

Seeds from 104 geographical locations throughout the range of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were analyzed at 20 enzyme loci to determine patterns of genetic variation and to make phylogenetic inferences. On average, the populations were polymorphic at 37% of the loci (range 5.0–65.0). Mean expected heterozygosity was 0.137 (range 0.021–0.239). Of the total genie diversity (HT = 0.182) observed, 24% was due to differentiation among populations. One Mexican population was genetically distinct from the rest of the species, which suggests the possibility of additional Pseudotsuga species in Mexico. The rest of the populations clustered into two groups corresponding to the recognized coastal and interior varieties. In addition, the interior variety separated into northern and southern subgroups near 44° latitude. Transition zones between the varieties were found to be narrower and more abrupt than has been suggested previously. Populations within the coastal variety and the northern interior subgroup averaged higher expected heterozygosity than the southern interior subgroup, but in the southern interior subgroup, populations were much more highly differentiated. Allozyme variation followed a latitudinal cline in the interior variety, but only weak geographical patterning was observed in the coastal variety. In general, genetic diversity decreased towards the periphery of the species range. Range-wide patterns of allozyme variation were similar to those in terpene studies, with the major exception that the Sierra Nevada seed sources in this study were closely aligned with the coastal variety rather than with the interior variety. Range-wide patterns of genetic variation in Douglas-fir largely reflect the evolutionary history of the species as revealed by paleobotanical studies.

scholarly journals Genetic diversity and population structure of sweet orange [Citrus sinensis (L.) Osbeck] germplasm of India revealed by SSR and InDel markers

2022 ◽  
Author(s):  
Prasanth Tej Kumar Jagannadham ◽  
Thirugnanavel Anbalagan ◽  
Devendra Y Upadhyay ◽  
Snehal A. Kamde ◽  
Prafulla R. Jalamkar ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Citrus Sinensis ◽  
Sweet Orange ◽  
Polymorphic Information Content ◽  
Citrus Fruit ◽  
Molecular Data ◽  
Expected Heterozygosity ◽  
Indel Markers ◽  
Population Structure Analysis

Sweet orange (Citrus sinensis (L.) Osbeck) is an important commercial citrus fruit crop, cultivated in India and across the world. In India most of the cultivated sweet orange species were introduced varieties. In this study, we used two molecular markers, SSR and InDels, to understand the genetic diversity and population structure of seventy-two sweet orange genotypes. Genetic parameters consisted of a total number of alleles, a number of polymorphic alleles (effective alleles); genetic diversity (G.D.), expected heterozygosity (He), and the polymorphic information content (PIC) were calculated based on molecular data. Two dendrograms were constructed based on the InDels and SSR. In both the cases, they formed three major clusters showing various degrees of variations with respect to members of the clusters. Population structure analysis revealed the presence of two distinct subpopulations. Therefore, in order to address various challenges and develop sweet orange varieties with desirable traits, there is a need to broaden the genetic base of sweet orange through the intensive collection in the northeastern region. These results of intraspecific genetic variability of the collections will dictate the path for the sweet orange breeding and conservation programs in India.

scholarly journals Genetic Diversity, Population Structure and Marker-Trait Association for 100-Seed Weight in International Safflower Panel Using SilicoDArT Marker Information

Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 652 ◽  
Author(s):  
Fawad Ali ◽  
Muhammad Azhar Nadeem ◽  
Muzaffer Barut ◽  
Ephrem Habyarimana ◽  
Hassan Javed Chaudhary ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Seed Weight ◽  
Mixed Linear Model ◽  
Oilseed Crop ◽  
Trait Association ◽  
Information Index ◽  
Expected Heterozygosity ◽  
Two Populations ◽  
100 Seed Weight

Safflower is an important oilseed crop mainly grown in the arid and semi-arid regions of the world. The aim of this study was to explore phenotypic and genetic diversity, population structure, and marker-trait association for 100-seed weight in 94 safflower accessions originating from 26 countries using silicoDArT markers. Analysis of variance revealed statistically significant genotypic effects (p < 0.01), while Turkey samples resulted in higher 100-seed weight compared to Pakistan samples. A Constellation plot divided the studied germplasm into two populations on the basis of their 100-seed weight. Various mean genetic diversity parameters including observed number of alleles (1.99), effective number of alleles (1.54), Shannon’s information index (0.48), expected heterozygosity (0.32), and unbiased expected heterozygosity (0.32) for the entire population exhibited sufficient genetic diversity using 12232 silicoDArT markers. Analysis of molecular variance (AMOVA) revealed that most of the variations (91%) in world safflower panel are due to differences within country groups. A model-based structure grouped the 94 safflower accessions into populations A, B, C and an admixture population upon membership coefficient. Neighbor joining analysis grouped the safflower accessions into two populations (A and B). Principal coordinate analysis (PCoA) also clustered the safflower accessions on the basis of geographical origin. Three accessions; Egypt-5, Egypt-2, and India-2 revealed the highest genetic distance and hence might be recommended as candidate parental lines for safflower breeding programs. The mixed linear model i.e., the Q + K model, demonstrated that two DArTseq markers (DArT-45483051 and DArT-15672391) had significant association (p < 0.01) for 100-seed weight. We envisage that identified DArTseq markers associated with 100-seed weight will be helpful to develop high-yielding cultivars of safflower through marker-assisted breeding in the near future.

scholarly journals Evaluation of genetic diversity and population structure of five Chinese indigenous donkey breeds using microsatellite markers

2017 ◽  
Vol 62 (No. 5) ◽  
pp. 219-225 ◽  
Author(s):  
R. Di ◽  
Q.Y. Liu ◽  
F. Xie ◽  
W.P. Hu ◽  
X.-Y. Wang ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Microsatellite Markers ◽  
Principal Component ◽  
Principal Component Analysis Plot ◽  
Animal Conservation ◽  
Mean Values ◽  
Expected Heterozygosity ◽  
The Mean ◽  
Near Future

China had the largest population of raising donkeys in the world, however the number of Chinese indigenous donkey decreased dramatically due to the increase of agriculture mechanization in the last century. The species has still been important in China because of its edible and medical value, therefore the survey on its genetic diversity in China is necessary for its conservation and utilization. In this study, 15 microsatellite markers were used to evaluate genetic diversity and population structure of five Chinese indigenous donkey breeds. The mean values of expected heterozygosity, allelic richness, and total number of alleles for all the tested Chinese donkeys were 0.70, 6.04, and 6.28 respectively, suggesting that the genetic diversity of Chinese indigenous donkeys is rich. The Bayesian analysis and principal component analysis plot yielded the same clustering result, which revealed that Guanzhong donkey was the most differentiated breed in all detected samples, and Jinnan (JN) and Guangling (GL) were genetically closed together. Additionally, our results indicated that the heterozygote deficit was severe in two Chinese indigenous donkey breeds (GL and JN), and it warned us that animal conservation activities on this species should be considered carefully in near future.

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