Isozyme analysis of genetic variability and population structure of Lactuca L. germplasm

2017 ◽  
Vol 70 ◽  
pp. 73-79 ◽  
Author(s):  
Mohamed A. El-Esawi ◽  
Abd El-Zaher Mustafa ◽  
Salwa Badr ◽  
Reda Sammour
Keyword(s):  
Population Structure ◽  
Genetic Variability ◽  
Isozyme Analysis

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 Differentiation and genetic variability in natural populations of Anopheles (N.) triannulatus (Neiva& Pinto, 1922) of Brazilian Amazonia

2004 ◽  
Vol 64 (2) ◽  
pp. 327-336 ◽  
Author(s):  
J. M. M. Santos ◽  
J. F. Maia ◽  
W. P. Tadei
Keyword(s):  
Genetic Variability ◽  
Natural Populations ◽  
Isozyme Analysis ◽  
Brazilian Amazonia ◽  
F Statistics

Populations of Anopheles triannulatus from Macapá (AP), Aripuanã (MT), Ji-Paraná (RO), and Manaus-Janauari Lake (AM) were studied using 16 enzymatic loci. The results of the isozyme analysis showed that the population of Macapá presented higher polymorphism (56.3%). The lowest variability was observed in the population of Manaus (p = 25.0; Ho = 0.077 ± 0.046). The results of Wright's F statistics showed unbalance due to excess of homozygotes (Fis > Fst), denoting a certain intrapopulational differentiation. Although the populations are genetically very close (D = 0.003 - 0.052), the dendrogram separates the populations in two groups: Macapá separated from that of Manaus, Ji-Paraná, and Aripuanã. This result may suggest a reduction in the genic flow, which possibly had some influence in the substructuration of the populations.

Genetic variability and population structure in a collection of inbred lines derived from a core germplasm of castor

2016 ◽  
Vol 26 (1) ◽  
pp. 27-34 ◽  
Author(s):  
S. Senthilvel ◽  
Mobeen Shaik ◽  
K. Anjani ◽  
Ranjan K. Shaw ◽  
Poornima Kumari ◽  
...  
Keyword(s):  
Population Structure ◽  
Genetic Variability ◽  
Inbred Lines ◽  
Core Germplasm

scholarly journals Population structure of Czech cold-blooded breeds of horses

2011 ◽  
Vol 54 (1) ◽  
pp. 1-9
Author(s):  
L. Vostrý ◽  
Z. Čapková ◽  
J. Přibyl ◽  
B. Hofmanová ◽  
H. Vostrá Vydrová ◽  
...  
Keyword(s):  
Population Structure ◽  
Genetic Variability ◽  
Population Size ◽  
Effective Population Size ◽  
Inbreeding Coefficient ◽  
Effective Population ◽  
The Czech Republic ◽  
Generation Interval ◽  
Average Value ◽  
Inbreeding Coefficients

Abstract. In order to estimate effective population size, generation interval and the development of inbreeding coefficients (Fx) in three original breeds of cold-blooded horses kept in the Czech Republic: Silesian Noriker (SN), Noriker (N) and Czech-Moravian Belgian horse (CMB) all animals of the particular breeds born from 1990 to 2007 were analysed. The average values of generation interval between parents and their offspring were: 8.53 in SN, 8.88 in N and 8.56 in CMB. Average values of effective population size were estimated to be: 86.3 in SN, 162.3 in N and 104.4 in CMB. The average values of inbreeding coefficient were 3.13 % in SN stallions and 3.39 % in SN mares, in the N breed 1.76 % and 1.26 % and in the CMB breed 3.84 % and 3.26 % respectively. Overall averages of Fx were: 3.23 %, 1.51 % and 3.55 % for the breeds SN, N and CMB. The average value of inbreeding coefficient Fx increased by 1.22 % in SN, by 0.35 % in N and by 1.01 % in CMB, respectively. This may lead to a reduction in genetic variability. Reduction in genetic variability could be either controlled in cooperation with corresponding populations of cold-blooded breeds in other European countries or controlled by number of sires used in population

scholarly journals Genome-wide genetic diversity, population structure and admixture analysis in Eritrean Indigenous Cattle

2020 ◽  
Vol 49 (6) ◽  
pp. 1083-1092
Author(s):  
S Goitom ◽  
M.G. Gicheha ◽  
F.K. Njonge ◽  
N Kiplangat
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
Genetic Variability ◽  
Population Differentiation ◽  
Principal Component ◽  
Vital Role ◽  
Group Method ◽  
Indigenous Cattle ◽  
Ecological Zones ◽  
Genome Wide

Indigenous cattle play a vital role in subsistence and livelihood of pastoral producers in Eritrea. In order to optimally utilize and conserve these valuable indigenous cattle genetic resources, the need to carry out an inventory of their genetic diversity was recognized. This study assessed the genetic variability, population structure and admixture of the indigenous cattle populations (ICPs) of Eritrea using a genotype by sequencing (GBS) approach. The authors genotyped 188 animals, which were sampled from 27 cattle populations in three diverse agro-ecological zones (western lowlands, highlands and eastern lowlands). The genome-wide analysis results from this study revealed genetic diversity, population structure and admixture among the ICPs. Averages of the minor allele frequency (AF), observed heterozygosity (HO), expected heterozygosity (HE), and inbreeding coefficient (FIS) were 0.157, 0.255, 0.218, and -0.089, respectively. Nei’s genetic distance (Ds) between populations ranged from 0.24 to 0.27. Mean population differentiation (FST) ranged from 0.01 to 0.30. Analysis of molecular variance revealed high genetic variation between the populations. Principal component analysis and the distance-based unweighted pair group method and arithmetic mean analyses revealed weak substructure among the populations, separating them into three genetic clusters. However, multi-locus clustering had the lowest cross-validation error when two genetically distinct groups were modelled. This information about genetic diversity and population structure of Eritrean ICPs provided a basis for establishing their conservation and genetic improvement programmes. Keywords: genetic variability, molecular characterization, population differentiation

Isozyme Variation in Broom Snakeweed (Gutierrezia sarothrae)

Weed Science ◽  
1995 ◽  
Vol 43 (1) ◽  
pp. 156-162 ◽  
Author(s):  
Yanglin Hou ◽  
Tracy M. Sterling
Keyword(s):  
Cluster Analysis ◽  
New Mexico ◽  
Genetic Variability ◽  
Gel Electrophoresis ◽  
Isozyme Analysis ◽  
Starch Gel Electrophoresis ◽  
Enzyme Systems ◽  
Starch Gel ◽  
Morphological Differences ◽  
Gutierrezia Sarothrae

Broom snakeweed, a perennial rangeland shrub, is highly variable morphologically and can grow under a broad range of environmental conditions. In this study, isozyme analysis using starch gel electrophoresis was used to quantify genetic variability within and among New Mexico populations of broom snakeweed. Eight separate populations of broom snakeweed and one population of threadleaf snakeweed as a comparison were investigated. of the 10 enzyme systems examined, 16 loci were identified in eight populations and two species. Eleven loci were monomorphic in eight populations and two species and five loci were polymorphic in at least one population or species. Genetic variability was large in broom and threadleaf snakeweed populations as determined by isozyme analysis. Genetic variability among broom snakeweed populations was greater than that within populations for the five polymorphic loci. Cluster analysis of genetic distance and identity for the eight populations and two species characterized two major groups. Within broom snakeweed, cluster analysis characterized five groups. The two species shared most common alleles. The genetic variation identified in this research may account for the morphological differences and broad geographical distribution of broom snakeweed.

scholarly journals Genetic improvement and population structure of the Nelore breed in Northern Brazil

2010 ◽  
Vol 45 (10) ◽  
pp. 1109-1116 ◽  
Author(s):  
Carlos Henrique Mendes Malhado ◽  
Paulo Luiz Souza Carneiro ◽  
Ana Claudia Mendes Malhado ◽  
Raimundo Martins Filho ◽  
Riccardo Bozzi ◽  
...  
Keyword(s):  
Population Structure ◽  
Genetic Variability ◽  
Genetic Improvement ◽  
Selective Breeding ◽  
Growth Traits ◽  
Management Strategies ◽  
Pedigree Information ◽  
Effective Number ◽  
Northern Brazil ◽  
Nelore Cattle

The objective of this work was to evaluate the population structure and the genetic and phenotypic progress of Nelore cattle in Northern Brazil. Pedigree information concerning animals born between 1942 and 2006 were analyzed. Population structure was performed using the Endog program. Out of the 140,628 animals studied, 67.7, 14.52 and 3.18% had complete pedigree record of the first, second and third parental generation, respectively. Inbreeding and average relatedness coefficients were low: 0.2 and 0.13%, respectively. However, these parameters may have been underestimated, since information on pedigree was incomplete. The effective number of founders was 370 and the genetic contribution of 10, 50 and 448 most influent ancestors explained 13.2, 28 and 50% of the genetic variability in the population, respectively. The genetic variability for growth traits and population structure demonstrates high probability of increasing productivity through selective breeding. Moreover, management strategies to reduce the currently observed age at first calving and generation intervals are important for Nelore cattle genetic improvement.

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