Genetic variability at allozyme markers in sycamore (Acer pseudoplatanus) populations from northwestern Italy

2007 ◽  
Vol 37 (2) ◽  
pp. 395-403 ◽  
Author(s):  
P. Belletti ◽  
I. Monteleone ◽  
D. Ferrazzini
Keyword(s):  
Genetic Variability ◽  
Single Gene ◽  
Acer Pseudoplatanus ◽  
Effective Number ◽  
Expected Heterozygosity ◽  
Slight Excess ◽  
Forest Reproductive Material ◽  
Native Populations ◽  
Reproductive Material ◽  
The Mean

Genetic diversity and differentiation of 12 native populations of sycamore ( Acer pseudoplatanus L.) from northwestern Italy were investigated by means of variation detected in 10 polymorphic isozyme systems encoded by 16 loci. The trees showed relatively large genetic variability (mean number of alleles per locus = 2.78, effective number of alleles per locus = 1.47, percentage of polymorphic loci = 96.9, expected heterozygosity = 0.280) but small interpopulational variation (FST = 0.019), suggesting the presence of a single gene pool. A slight excess of heterozygotes was found, and the overall inbreeding coefficient (FIS) was –0.038. There was a positive correlation between the age of the individuals sampled and heterozygosity, suggesting the occurrence of natural selection against homozygotes. No significant correlation was detected between genetic and geographic distances of populations, confirming the lack of any barriers to gene flow. Estimate of the mean effective number of migrants exchanged between populations was 4.399, based on the private alleles method. The contribution of the results in relation to terms of the most appropriate strategies to preserve genetic variability of sycamore and to collect forest reproductive material is discussed.

scholarly journals Genetic Diversity of 17 Autochthonous Italian Chicken Breeds and Their Extinction Risk Status

2021 ◽  
Vol 12 ◽  
Author(s):  
Dominga Soglia ◽  
Stefano Sartore ◽  
Emiliano Lasagna ◽  
Cesare Castellini ◽  
Filippo Cendron ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Genetic Variability ◽  
Extinction Risk ◽  
Low Frequency ◽  
Effective Number ◽  
Risk Of Extinction ◽  
Chicken Breeds ◽  
Inbreeding Rate ◽  
The Mean ◽  
Endangered Status

The preservation of genetic variability of autochthonous poultry breeds is crucial in global biodiversity. A recent report revealed small breed size and potential risk of extinction of all native Italian poultry breeds; therefore, a correct assessment of their genetic diversity is necessary for a suitable management of their preservation. In this work, we provided an overview of the contribution to poultry biodiversity of some Italian autochthonous breeds reared in conservation centers devoted to local biodiversity preservation. The level of genetic diversity, molecular kinship, inbreeding, contribution to overall genetic diversity, and rate of extinction of each breed were analyzed with a set of 14 microsatellite loci in 17 autochthonous chicken breeds. To evaluate genetic variability, total number (Na), and effective number (Ne) of alleles, observed (Ho) and expected (He) heterozygosity, and F (Wright’s inbreeding coefficient) index were surveyed. The contribution of each analyzed breed to genetic diversity of the whole dataset was assessed using MolKin3.0; global genetic diversity and allelic richness contributions were evaluated. All the investigated loci were polymorphic; 209 alleles were identified (94 of which private alleles). The average number of alleles per locus was 3.62, and the effective number of alleles was 2.27. The Ne resulted lower in all breeds due to the presence of low-frequency alleles that can be easily lost by genetic drift, thus reducing the genetic variability of the breeds, and increasing their risk of extinction. The global molecular kinship was 27%, the average breed molecular kinship was 53%, and the mean inbreeding rate 43%, with a self-coancestry of 78%. Wright’s statistical analysis showed a 41% excess of homozygous due to breed genetic differences (34%) and to inbreeding within the breed (9%). Genetic variability analysis showed that 11 breeds were in endangered status. The contribution to Italian poultry genetic diversity, estimated as global genetic diversity, and ranged from 30.2 to 98.5%. In conclusion, the investigated breeds maintain a unique genetic pattern and play an important role in global Italian poultry biodiversity, providing a remarkable contribution to genetic variability.

scholarly journals Genetic variability of Nigerian sheep breeds at the insulin-like growth factor-1 (IGF-1) gene locus

2020 ◽  
Vol 45 (1) ◽  
pp. 51-60
Author(s):  
A. Mohammed ◽  
A. O. Raji ◽  
J. U. Igwebuike
Keyword(s):  
Genetic Variability ◽  
Random Mating ◽  
General Pattern ◽  
Fixation Index ◽  
Mean Values ◽  
Sheep Breeds ◽  
Expected Heterozygosity ◽  
The Mean ◽  
High Level ◽  
The University

The genetic variability of some Nigerian breeds of sheep at the IGF 1 locus was investigate blood samples from 150 sheep (50 each of Yankasa, Balami and Uda sheep) were collected from the Maiduguri abbatoir and analysed at the Biotechnology centre of the University of Maiduguri. A relatively high level of genetic variability was detected in Nigerian sheep; the mean observed heterozygosity (Ho) and expected heterozygosity (He) values were 0.433 and 0.476, respectively. Comparison of expected heterozygosity of alleles between the populations showed that yankasa was the most heterozygous of the sheep populations though the unbiased expected heterozygosity (0.503) for the Yankasa was the same as that of the Balami. All populations were 100% polymorphic at the IGF 1 locus with fixation index ranging from -0.169 to 0.378 and a mean of 0.093, which suggests a general pattern of random mating. Similarly, low mean values for Fis (0.093), F (0.089), Fis (0.089), Fit (0.130) and Fst (0.045) supports the assertion that inbreeding was limited due to outcrossing with relatively high level of gene-flow (Nm = 5.292). The analysis of molecular variance (AMOVA) revealed that only 1% of the total variations observed in the sampled populations is accounted for by the population differences while individual differences accounted for 85%. The UPGMA phylogenetic tree revealed that the Uda and Yankasa populations are closer to each than each is to Balami. Thus, it can be concluded that sufficient genetic variation exist in the studied Nigerian sheep breeds and these populations are unlikely to decline due to inbreeding.  

scholarly journals Genetic variability in pitch pine (Pinus rigida Mill.) growing in the Niepołomice Forest as determined by ISSR markers

2018 ◽  
Vol 87 (3) ◽  
Author(s):  
Katarzyna Masternak ◽  
Jacek Banach ◽  
Katarzyna Głębocka ◽  
Marek Wajdzik
Keyword(s):  
Genetic Variability ◽  
Issr Markers ◽  
Principal Coordinate Analysis ◽  
Effective Number ◽  
Pinus Rigida ◽  
Expected Heterozygosity ◽  
Pitch Pine ◽  
Pine Trees ◽  
Late Nineteenth ◽  
Different Origin

The study aimed to determine the genetic variability in pitch pine (<em>Pinus rigida</em> Mill.) growing in the Niepołomice Forest (southern Poland). In the late nineteenth and early twentieth century, Adolf Cieślar of the Department of Forestry Research in Mariabrunn near Vienna, Austria established the experimental crops of pitch pine. During the study, 227 trees that grew in seven subunits were considered; an analysis of genetic polymorphism using the intersimple sequence repeats (ISSR) technique revealed that pitch pine is genetically variable. The average number of alleles at a given locus for all the pine trees was 1.649, while the effective number of alleles at the loci was 1.435. The value of expected heterozygosity was 0.254, while the percentage of polymorphic loci was 75.30%. The average genetic distance between the examined pines was 0.082. Principal coordinate analysis (PCoA) divided the examined pines into three groups, which was also confirmed by the structure-analysis results of the software STRUCTURE. The resulting division was mainly generated by the SR70 primer, which was indicated to be the primer that differentiated the examined populations of pitch pine. Affiliation of particular trees to selected groups was based on their occurrence in individual crops. This suggests a different origin of the seeds used to establish the research plots of pitch pine in the Niepołomice Forest.

scholarly journals Genetic Diversity of Populations of Akhal-Teke Horses from the Czech Republic, Russia, Estonia and Switzerland

2016 ◽  
Vol 64 (2) ◽  
pp. 461-466 ◽  
Author(s):  
Iva Jiskrová ◽  
Irena Vrtková ◽  
Michaela Prausová
Keyword(s):  
Genetic Diversity ◽  
Czech Republic ◽  
Genetic Distance ◽  
Genetic Parameters ◽  
Inbreeding Coefficient ◽  
The Other ◽  
Effective Number ◽  
The Czech Republic ◽  
Expected Heterozygosity ◽  
The Mean

Our research objective was to evaluate the genetic parameters in the populations of Akhal-Teke horses in 4 countries: Czech Republic, Russia, Estonia and Switzerland. The experiment involved a total of 325 Akhal-Teke horses; 121 horses came from the Czech Republic, 152 were from Russia, 28 were from Estonia and 24 horses came from Switzerland. For the divided database of micro satellites we evaluated the following parameters: effective number of alleles, frequency of alleles for the groups of horses; the observed heterozygosity (HO); the expected heterozygosity (HE); the inbreeding coefficient (Fis); and the genetic distance. The researched population is polymorphous. The population in the Czech Republic differs from the other three countries in the numbers of alleles per locus. The Czech population also includes Akhal-Teke horses which are not purebred Akhal-Teke horses. A confirmation of this fact is the effective number of alleles. The population in the Czech Republic exhibits the highest mean number of effective alleles. The Akhal-Teke population in Estonia exhibits the highest mean observed heterozygosity. By contrast, the population in the Czech Republic exhibits the lowest mean observed heterozygosity. In the Czech Republic the mean Fis value is a positive number indicating a reduced number of heterozygotes in the Czech Akhal-Teke population. The genetic distance is the highest between populations of horses bred in Russia and Estonia. The genetic distance is the lowest between populations of Akhal-Teke horses bred in Russia and in the Czech Republic.

Isozyme analysis of genetic variability and population structure of Lathyrus sativus L. germplasm

2019 ◽  
Author(s):  
R. H. Sammour ◽  
A-E. Mustafa ◽  
M.- El-Sheikh ◽  
A. A. Alatar ◽  
W. Taher
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variability ◽  
Random Mating ◽  
Lathyrus Sativus ◽  
Isozyme Analysis ◽  
Expected Heterozygosity ◽  
The Mean ◽  
Low Levels ◽  
Lathyrus Sativus L

This work aimed at exploring the genetic variability, population structure and relationships of Lathyrus sativus L. germplasm using isozyme analysis. The data of isozyme analysis revealed 12 putative polymorphic loci of a total 33 alleles, indicating that studied accessions express good allelic richness and had an apparent rate of allogamy. The mean average of the expected heterozygosity (0.483) was more than the mean average of the observed heterozygosity (0.449) suggesting an apparent rate of allogamy taking place in Lathyrus sativus L. The average of total heterozygosity (HT) and intra-accessional genetic diversity (HS) were 0.559 and 0.428 respectively indicating that majority of genetic diversity was intra-accessional. The low levels and non-significant of genetic diversity among accessions (DST = 0.190, X2 = 62.59, p = 0.029) were probably indicative of occurrence of several gene flows. The coefficient of gene differentiation (GST) showed significant variation, suggesting the heterogonous distribution of L. sativus accessions among different geographic regions. The mean average of FST was 0.327, suggesting the occurrence of random mating system for the studied accessions and reflecting adaptation to strong environmental dissimilarities. Cluster analysis based on isozyme data suggested that the environment had no influence on the genetic diversity and confirmed that Lathyrus sativus L. had a polyphyletic origin.

scholarly journals Isoenzymatic variation in the germplasm of Brazilian races of maize (Zea mays L.)

2000 ◽  
Vol 23 (2) ◽  
pp. 375-380 ◽  
Author(s):  
Marcos Aparecido Gimenes ◽  
Catalina Romero Lopes
Keyword(s):  
Genetic Diversity ◽  
Zea Mays ◽  
Genetic Variability ◽  
Zea Mays L ◽  
Polymorphic Locus ◽  
Maize Breeding ◽  
Breeding Programs ◽  
Expected Heterozygosity ◽  
Total Genetic Diversity ◽  
The Mean

There are more than 200 races of maize (Zea mays L.) divided into three groups (ancient commercial races, the recent commercial races, and indigenous races). Although the indigenous races have no commercial value, they have many important characteristics which can be incorporated into maize breeding programs. Most Brazilian indigenous germplasm race stocks were collected at least 40 years ago, and nothing is known of the genetic variability present in this germplasm. The genetic variability was assayed in 15 populations from four indigenous races of maize (Caingang, Entrelaçado, Lenha and Moroti) and five indigenous cultivars, using five isoenzymatic systems encoded by 14 loci. The analysis revealed a low level of variability among the samples studied. Overall, the mean number of alleles/polymorphic locus was three, 64.3% of the loci analyzed being polymorphic and the estimated heterozygosity was 0.352. The mean number of alleles/polymorphic locus per population was 1.6. A mean of 47.5% of the loci were polymorphic. The mean expected heterozygosity was 0.195, the mean genetic identity was 0.821 and the proportion of total genetic diversity partitioned among populations (Gst) was 0.156. A founder effect could explain the low variability detected.

scholarly journals Genetic variability of Scots pine (Pinus sylvestris L.) in maternal regions of provenance

2015 ◽  
Vol 57 (2) ◽  
pp. 112-119 ◽  
Author(s):  
Paweł Przybylski ◽  
Jan Matras ◽  
Małgorzata Sułkowska
Keyword(s):  
Genetic Variability ◽  
Pinus Sylvestris ◽  
Scots Pine ◽  
Genetic Parameters ◽  
Fixation Index ◽  
Effective Number ◽  
Expected Number ◽  
Expected Heterozygosity ◽  
Rare Alleles ◽  
Fixation Indices

Abstract The analysis of chosen selected Scots Pine (Pinus sylvestris L.), populations representing different seed regions: 107 (Międzyzdroje), 305 (Woziwoda), 206 (Strzałowo), 208 (Białowieża), 504 (Bolesławiec), 606 (Józefów) were performed using 10 isoensyme markers: Gdh (E.C.1.4.1.2), Sdh-A, Sdh-B (E.C.1.1.1.25), Pgd-B (E.C.1.1.1.44), Mdh-A, Mdh-C (E.C.1.1.1.37), Got-A, Got-B, Got-C (E.C.2.6.1.1), Dia-C (E.C.1.8.1.4). There were calculated following genetic parameters: allelic frequencies, observed and expected heterozygosities, and Wright’s fixation indexes. In populations, the results of analysis indicated presence of rare alleles. In all study populations, the average effective number of alleles per locus was 1.46 and was lower than expected number of alleles per locus of 1.93. The results for the effective number of alleles of the population per locus were as follows: Strzałowo and Białowieża 1.54, Bolesławiec 1.48, Jozefów 1.44, Świnoujście 1.42, Woziwoda 1.35. Average observed heterozygosity in the studied populations was calculated at the level of 0.26 and it was lower than the expected heterozygosity at 0.28. For populations, the level of heterozygosities were as follow: Strzałowo 0.35, Bolesławiec and Białowieża 0.25, Józefów 0.27, Świnoujście 0.23, Woziwoda 0.26. In particular loci level of heterozygosity was different, as the most heterozygous Mdh-C locus was estimated, while minimum Got-C. Significant differences in allele frequency of Hardy-Weinberg deviation equilibrium were found in 10 cases: Strzałowo (Got-C), Bolesławiec (Got-B), Białowieża (Got-B, Gdh), Józefów (Mdh-C), Międzyzdroje (Got-B, Got-C, Mdh-C), Woziwoda (Got-C, Gdh). All studied populations had a lower effective number of alleles per locus (Ne) comparing to the observed number of alleles (Na). Wright’s fixation indices were negative for populations: Strzałowo (-0.09), Józefów (-0.03), Międzyzdroje (-0.01) and positive for: Białowieża (0.12), Woziwoda and Bolesławiec (0.07). The extremely high Wright’s fixation index (0.12) was observed for Białowieża population.

scholarly journals Hybridisation of Malus sylvestris (L.) Mill. with Malus × domestica Borkh. and Implications for the Production of Forest Reproductive Material

Forests ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 367
Author(s):  
Mateja Kišek ◽  
Kristjan Jarni ◽  
Robert Brus
Keyword(s):  
Malus Domestica ◽  
Natural Populations ◽  
Morphological Characteristics ◽  
Apple Trees ◽  
Genetic Characteristics ◽  
Malus Domestica Borkh ◽  
Malus Sylvestris ◽  
Forest Reproductive Material ◽  
Reproductive Material ◽  
Crab Apple

This study focuses on the morphological and genetic characteristics of European crab apple (Malus sylvestris (L.) Mill.) and the occurrence of hybrids in its populations. We analyzed a total of 107 putative European crab apple trees in Slovenia: 92 from nine natural populations, five from a seed stand and 10 from a stand of unnatural origin. We also included 18 domesticated apple trees (Malus × domestica Borkh.) and two Japanese flowering crab apple trees (Malusfloribunda van Houtte) as outliers. The trees were classified into groups of European crab apples, hybrids and domesticated apples according to their morphological and genetic characteristics. Classification based on morphological traits produced different results (58.75% European crab apple, 37.11% hybrids and 4.14% domesticated apple) compared to those based on genetic analysis (70.10% European crab apple, 21.64% hybrids and 8.26% domesticated apple). When genetic and morphological characteristics were combined, only 40.20% of the trees were classified as European crab apple, and an additional group of feral cultivars of domesticated apples (6.18%) was identified. The analysis revealed that hybridization with domesticated apple is taking place in all studied natural European crab apple populations; however, hybrids and feral cultivars only occur to a limited extent. When introducing European crab apple into forests in the future, only genetically verified forest reproductive material obtained exclusively from suitable seed stands should be used.

scholarly journals Analysis of variance of partial diallel tables

2000 ◽  
Vol 23 (1) ◽  
pp. 229-234 ◽  
Author(s):  
José Marcelo Soriano Viana ◽  
Cosme Damião Cruz ◽  
Antonio Américo Cardoso ◽  
Adair José Regazzi
Keyword(s):  
Genetic Variability ◽  
Common Bean ◽  
Statistical Tests ◽  
Diallel Analysis ◽  
The Other ◽  
F1 Hybrids ◽  
Dominance Testing ◽  
The Common ◽  
The Mean ◽  
Partial Diallel

The theory of variance analysis of partial diallel tables, following Hayman's proposal of 1954, is presented. As several statistical tests yield similar inferences, the present analysis mainly proposes to assess genetic variability in two groups of parents and to study specific, varietal and mean heteroses. Testing the nullity of specific heteroses equals testing absence of dominance. Testing equality of varietal heteroses of the parents of a group is equivalent to testing the hypothesis that in the other group allelic genes have the same frequency. Rejection of the hypothesis that the mean heterosis is null indicates dominance. The information obtained complements that provided by diallel analysis involving parents and their F1 hybrids or F2 generations. An example with the common bean is included.

scholarly journals UAV AND GIS BASED TOOL FOR COLLECTION AND PROPAGATION OF SEEDS MATERIAL – FIRST RESULTS

2016 ◽  
Vol XLI-B8 ◽  
pp. 663-667 ◽  
Author(s):  
K. Stereńczak ◽  
P. Mroczek ◽  
S. Jastrzębowski ◽  
G. Krok ◽  
M. Lisańczuk ◽  
...  
Keyword(s):  
Seed Quality ◽  
The State ◽  
Annual Reports ◽  
Estimation Methods ◽  
Selection Strategy ◽  
Seed Crop ◽  
Forest Reproductive Material ◽  
First Results ◽  
Reproductive Material ◽  
Seed Management

Seed management carried out by The State Forests National Forest Holding is an integral part of rational forest management. Seed collection takes place mainly from stands belonging to first category of forest reproductive material, which is the largest seed base in Poland. In smaller amount, seeds are collected in selective objects of highest forest reproductive material category (selected seed stands, seed orchards). The previous estimation methods of seed crop were based on visual assessment of cones in the stands for their harvest. Following the rules of FRM transfer is additional difficulty of rational seed management which limits the possibility of the use of planting material in Poland. &lt;br&gt;&lt;br&gt; Statements concerning forecast of seed crop and monitoring of seed quality is based on annual reports from the State Forest Service. Forest Research Institute is responsible for preparing and publishing above-mentioned statements. A small extent of its automatization and optimization is a large disadvantage of this procedure. In order to make this process more effective web-based GIS application was designed. Its main performance will give a possibility to upload present-day information on seed efficiency, their spatial pattern and availability. Currently this system is under preparation. &lt;br&gt;&lt;br&gt; As a result, the project team will get a possibility to increase participation of seed material collected from selected seed base and to share good practices on this issue in more efficient way. In the future this will make it possible to obtain greater genetic gain of selection strategy. &lt;br&gt;&lt;br&gt; Additionally, first results presented in literature showed possible use of unmanned aerial system/vehicle (UAS/V) for supporting of seed crop forecast procedure.

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