scholarly journals Parental selection based on molecular information under a population genetics approach

2021 ◽  
Vol 7 ◽  
pp. 1-9
Author(s):  
Renato Domiciano Silva Rosado ◽  
Ana Maria Cruz Oliveira ◽  
Iara Gonçalves Santos ◽  
Pedro Crescêncio Souza Carneiro ◽  
Cosme Damião Cruz ◽  
...  

The correct choice of parents that will compose optimal segregating populations is the key to success for breeding programs. It was postulated the hypothesis that this choice of these parents could be made based on information of molecular markers analyzed in the context of population structure. Ten parental populations were simulated and 45 hybrid combinations were obtained from the dialel crosses. Each population consisted of 200 individuals with 50 independent loci. The populations were evaluated for the Hardy-Weinberg Equilibrium (HWE), Coefficient of Inbreeding (F), Heterozygosity (H), and the Polymorphic Information Content (PIC). Genetic diversity between pairs of parental populations was evaluated using five dissimilarity measures. Values of Mantel correlation were obtained for the pairs of the dissimilarity matrices, and the PIC, H, and F values ​​were obtained in the hybrid combinations. All parental populations were under HWE, and the combination that emerged from this condition was the hybrid 3x5, with only 26% of the loci manifesting HWE. This same hybrid was among those with lower F estimates and higher values ​​of H, which indicated the existence of greater divergence between their parentals. There was agreement on the indication of the more and less divergent hybrid combinations for the dissimilarity measures. This fact is important because the variability, associated with the good average potential, are important criteria for the formation of an initial population in breeding programs of any kind, involving sexual processes.

2017 ◽  
Vol 1 (01) ◽  
pp. 46-51
Author(s):  
OUMER SHERIFF ◽  
KEFYALEW ALEMAYEHU

Sheriff O, Alemayehu K. 2017. Review: Genetic diversity studies using microsatellite markers and their contribution in supporting sustainable sheep breeding programs. Asian J Agric 1: 46-51. Microsatellites have been widely accepted and employed as useful molecular markers for measuring genetic diversity and divergence within and among populations. The various parameters developed so far to measure genetic diversity within and among populations are observed and expected heterozygosities (Ho and He), the mean number of alleles per locus (MNA),polymorphic information content (PIC), genetic distance and phylogenetic or tree building approach.The objective of thisreview was therefore to quantifythe genetic diversity studies of domestic sheep populations using microsatellite markersand their contribution in supporting sustainable sheep breeding programs. From the review, it is possible to see that there was high within population genetic variations in all the studied sheep populations, poor level of population differentiations and high levels of inbreeding. On the other hand, low estimates of hetrozygosities and mean number of alleles and employing only few and weak markers were observed in some of the studies. The gaps observed in the previous genetic diversity studies of the sheep populations may demand further works to reveal more information on the population structures andto start appropriate and sustainable breeding programs.


2021 ◽  
Vol 34 (2) ◽  
Author(s):  
MUHAMMAD FORHAD ALI ◽  
◽  
MD. RAFIQUL ISLAM SARDER ◽  
MOHAMMAD MATIUR RAHMAN ◽  
MD. FAZLUL AWAL MOLLAH ◽  
...  

Genetic information is essential for conservation and future aquaculture development of the endangered catfish Rita rita (Hamilton, 1822). Two hundred catfish, R. rita, 50 from four rivers, the Old Brahmaputra, Jamuna, Meghna and Kangsa were collected and analysed to evaluate the genetic diversity and population structure using five microsatellite primers (Cba06-KUL, Cba08-KUL, Cba09-KUL, Phy03-KUL and Phy07-KUL). Four of the five amplified loci were found polymorphic (P95) in all the populations and 46 alleles were recorded with 9 to 14 alleles per locus. Differences were observed in the total number of alleles ranging from 41 to 44, effective number of alleles from 29.96 to 37.46, observed heterozygosity from 0.57 to 0.76, Shannon’s information index from 2.09 to 2.30 and polymorphic information content from 0.84 to 0.88 among the four populations. Results exposed the highest levels of genetic diversity in the Meghna population while the lowest in the Kangsa population of R. rita. All the populations were significantly deviated (P < 0.001) from the Hardy-Weinberg equilibrium for all the loci. Nei’s genetic distance between populations ranged 0.007 to 0.017 with low overall genetic difference FST = 0.011 and high gene flow Nm = 24.333, indicating that R. rita populations were not subdivided. This study revealed a high level of gene diversity with deficiency in genetic heterogeneity in all the populations of R. rita, emphasising natural management, conservation and rehabilitation measures of this species.


2019 ◽  
Vol 27 (3) ◽  
pp. 135
Author(s):  
O.A.M. Badr ◽  
I.I.S. El-Shawaf ◽  
M.H.A. Khalil ◽  
M.H. Refaat ◽  
S.I.A. Ramadan

<p>The limited rabbit resources in Egypt are threatened by the danger of extinction, whereas genetic diversity studies of native breeds could play a vital role in conservation and improvement of these breeds. In this study, 3 native rabbit breeds: Gabali (G), Baladi Red (BR) and Baladi Black (BB), in addition to New Zealand White (NZW), were genotyped using 12 microsatellite markers. All the typed microsatellites were polymorphic by average number of alleles 5.25 per locus. Observed and expected heterozygosity per locus averaged 0.62 and 0.68, respectively. The average polymorphic information content was 0.71 and the highest polymorphic information content was recorded in locus SOL33 by 0.85. All the studied loci except SAT7 and SAT2 showed deviation from Hardy-Weinberg equilibrium with significant level. The inbreeding coefficient of the individuals relative to the total population was 0.07. The within-population heterozygote deficit averaged 0.07 and ranged from 0.141 in BR to 0.015 in BB breeds. The highest pairwise differentiation among the populations was recorded between BB and NZW (0.071), while the lowest value was recorded between BR and both of G (0.038) and BB (0.039). The lowest pairwise Nei’s genetic distance was recorded between BR and BB (0.190), while the highest was recorded between NZW and BB breeds (0.409). BR and G populations were clustered together forming an admixed mosaic cluster. BR recorded the highest contribution in the aggregate genetic diversity based on the three prioritisation methods used.</p>


Author(s):  
Maizura Abu Sin ◽  
Ghizan Saleh ◽  
Nur Ashikin Psyquay Abdullah ◽  
Pedram Kashiani

Genetic diversity and phenotypic superiority are important attributes of parental inbred lines for use in hybrid breeding programs. In this study, genetic diversity among 30 maize (Zea mays L.) inbred lines comprising of 28 introductions from the International Maize and Wheat Improvement Center (CIMMYT), one from Indonesia and a locally developed, were evaluated using 100 simple sequence repeat (SSR) markers, as early screening for potential parents of hybrid varieties. All markers were polymorphic, with a total of 550 unique alleles detected on the 100 loci from the 30 inbred lines. Allelic richness ranged from 2 to 13 per locus, with an average of 5.50 alleles (na). Number of effective alleles (ne) was 3.75 per locus, indicating their high effectiveness in revealing diversity among inbred lines. Average polymorphic information content (PIC) was 0.624, with values ranging from 0.178 to 0.874, indicating high informativeness of the markers. High gene diversity was observed on Chromosomes 8 and 4, with high number of effective alleles, indicating their potential usefulness for QTL analysis. The UPGMA dendrogram constructed identified four heterotic groups within a similarity index of 0.350, indicating that these markers were able to group the inbred lines. The three-dimensional PCoA plot also supports the dendrogram grouping, indicating that these two methods complement each other. Inbred lines in different heterotic groups have originated from different backgrounds and population sources. Information on genetic diversity among the maize inbred lines are useful in developing strategies exploiting heterosis in breeding programs


Genes ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1233
Author(s):  
Alemayehu Teressa Negawo ◽  
Meki S. Muktar ◽  
Yilikal Assefa ◽  
Jean Hanson ◽  
Alieu M. Sartie ◽  
...  

Rhodes grass (Chloris gayana Kunth) is one of the most important forage grasses used throughout the tropical and subtropical regions of the world. Enhancing the conservation and use of genetic resources requires the development of knowledge and understanding about the existing global diversity of the species. In this study, 104 Rhodes grass accessions, held in trust in the ILRI forage genebank, were characterized using DArTSeq markers to evaluate the genetic diversity and population structure, and to develop representative subsets, of the collection. The genotyping produced 193,988 SNP and 142,522 SilicoDArT markers with an average polymorphic information content of 0.18 and 0.26, respectively. Hierarchical clustering using selected informative markers showed the presence of two and three main clusters using SNP and SilicoDArT markers, respectively, with a cophenetic correction coefficient of 82%. Bayesian population structure analysis also showed the presence of two main subpopulations using both marker types indicating the existence of significant genetic variation in the collection. A representative subset, containing 21 accessions from diverse origins, was developed using the SNP markers. In general, the results revealed substantial genetic diversity in the Rhodes grass collection, and the generated molecular information, together with the developed subset, should help enhance the management, use and improvement of Rhodes grass germplasm in the future.


2014 ◽  
Vol 34 (1) ◽  
pp. 98-102 ◽  
Author(s):  
Graziela Vieira Fonteque ◽  
Jaqueline Battilana ◽  
Ediane Paludo ◽  
Carlos André da Veiga Lima-Rosa

The purpose of this study was to investigate the genetic polymorphism of fifteen microsatellites loci in Brazilian (blue-egg Caipira) chickens. Samples were collected from 100 blue eggs of Caipira chickens from rural properties in the city of Dois Lajeados, RS. After DNA extraction, the fragments related to molecular markers LEI0248, LEI0221, LEI0214, LEI0192, LEI0217, LEI0254, LEI0194, LEI0212, MCW0371, ADL0278, LEI0234, MCW0183, MCW0216, MCW0330 and MCW0081 were obtained by polymerase chain reaction (PCR). The statistical analysis were carried out with the softwares ARLEQUIN 3.5 version and CERVUS 3.0.3 version. The allelic and genotypic frequencies, deviations from Hardy-Weinberg equilibrium, estimates of observed (HO) and expected (HE) heterozygosity and polymorphic information content (PIC) were obtained for each marker locus. A total of 186 alleles from 15 loci were obtained, with sizes ranging of 83 to 490 base pairs. The medium number of alleles was 12.4, the HE was 0.76±0.14 and HO was 0.49±0.21 and PIC was 0.706. The first conclusion is that the microsatellites used are polymorphic and can be used to genetic studies in chickens. The second is that the "Caipira" chicken (blue eggs) population investigated has a great genic variability, which makes than an important source of genetic resources for future animal breeding programs.


2018 ◽  
Vol 42 (4) ◽  
Author(s):  
Slamet Diah Volkandari ◽  
Aina Nadila ◽  
Nani Radiastuti ◽  
Endang Tri Margawati

The aim of this study was to determine genetic diversity of Calpastatin gene (CAST) in Pasundan cattle. Forty-four fresh blood samples were collected from UPTD BPPT Beef Cattle Ciamis West Java. Genomic DNA samples were extracted using High Salt method. A 523 bp fragment of Calpastatin gene was successfully amplified using PCR method. Genotyping of CAST gene was conducted by PCR-RFLP method using RsaI restriction enzyme (GT^AC). Genotypes and alleles were analyzed using software Cervus 3.0.7. Parameters were observed i.e genotypes and alleles frequencies, heterozygosity observed (Ho) and expected (He), Hardy Weinberg Equilibrium (HWE), and Polymorphic Information Content (PIC). Result showed that three variant genotypes of GG, GC and CC were found and two variant alleles of G and C. Allele G was found higher (0.77) than allele C (0.23). Population of Pasundan cattle was found polymorphism and in the Hardy Weinberg Equilibrium. Polymorphic Information Content (PIC) value showed in a moderate (0.290) condition. Values of Heterozygosity observed and expected were 0.409 and 0.355 respectively. This research concludes that there is polymorphism of CAST gene in Pasundan cattle population and has genetic diversity. This result could be used as early genetic information in exploration of Pasundan cattle.


Author(s):  
Syeda Asma Koinain ◽  
V S Hegde ◽  
C . Bharadwaj

Genetic diversity among 30 chickpea genotypes was evaluated using simple sequence repeat (SSR) molecular markers. The studies using Sequence Tagged Microsatellite Site (STMS) markers markers revealed that among the primers used across the genotypes produced a total of 35 alleles representing 21 SSR loci with frequencies ranging from one to two (mean 1.66) alleles per locus. Polymorphic Information Content (PIC) ranged from 0.098 to 0.500 (CAM0443, CAM0446). These primers might be an effective and useful tool to determine the genetic differences among chickpea genotypes and to study the phylogenetic relationships. Polymorphic percentage was 96.42. Hierarchical neighbour-joining UPGMA cluster analysis based on simple matching similarity matrix resolved the 30 genotypes into seven clusters. Based on STMS markers highest similarity index 0.850 was observed between BGD 72 and Annigeri-1whereas BGD 9920 and ICC 92944 showed the lowest similarity index 0.214 between them. The STMS clustering pattern indicated the presence of wide genetic diversity between the genotypes. Overall, the study ascertained that SSRs provide powerful marker tools in revealing genetic diversity and relationships in chickpeas, thereby proving useful for selection of parents in breeding programs and also for DNA fingerprinting for identification of cultivars.


2020 ◽  
Vol 36 (2) ◽  
pp. 33-44
Author(s):  
I.O. Iseghohi ◽  
A.I. Adesoye ◽  
D.A. Oludare ◽  
F.V. Agunbiade ◽  
N. Unachukwu

Understanding the genetic diversity of cowpea (Vigna unguiculata L. Walp.) landraces is useful for effective characterization and ex-situ conservation of germplasm. The analysis of genetic diversity of eighteen cowpea landraces collected from five agro-ecological zones in Nigeria was reported in this study. Five individuals per landrace were genotyped with six polymorphic microsatellite markers. Three to 5 alleles with a mean of 3.833 were detected. Mean Polymorphic information content (PIC) and observed heterozygosity of the markers were 0.5721 and 0.2433, respectively. Analysis of Molecular Variance (AMOVA) showed that variation due to agroecological zone constituted 24%, while variations among and within landraces as well as within individuals constituted 25%, 17% and 33%, respectively. Landraces collected from the humid rainforest zone showed high within landrace diversity and were not significantly different (P ≥ 0.001) from other landraces collected from the same zone. Landraces from the savannah zones showed low within landrace diversity and homozygous across all loci. Consequently, among landrace diversity was higher in the savannah zone with landraces collected from guinea savannah been the most diverse, followed by landraces from the derived savannah and Sudan savannah. Mantel test showed positive and significant correlation (r= 0.377, p= 0.01) between genetic and geographical distance of landrace collections. The findings are important for up-to-date characterizations of cowpea germplasm in Nigeria for improved breeding programs. Keywords: Genetic diversity, cowpea, Alleles, Polymorphic information content, AMOVA,


PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260651
Author(s):  
Sintayehu Admas ◽  
Kassahun Tesfaye ◽  
Teklehaimanot Haileselassie ◽  
Eleni Shiferaw ◽  
K. Colton Flynn

Evaluation of the genetic diversity and an understanding of the genetic structure and relationships of chickpea genotypes are valuable to design efficient germplasm conservation strategies and crop breeding programs. Information is limited, in these regards, for Ethiopian chickpea germplasms. Therefore, the present study was carried out to estimate the genetic diversity, population structure, and relationships of 152 chickpea genotypes using simple sequence repeats (SSR) markers. Twenty three SSR markers exhibited polymorphism producing a total of 133 alleles, with a mean of 5.8 alleles per locus. Analyses utilizing various genetic-based statistics included pairwise population Nei’s genetic distance, heterozygosity, Shannon’s information index, polymorphic information content, and percent polymorphism. These analyses exemplified the existence of high genetic variation within and among chickpea genotypes. The 152 genotypes were divided into two major clusters based on Nei’s genetic distances. The exotic genotypes were grouped in one cluster exclusively showing that these genotypes are distinct to Ethiopian genotypes, while the patterns of clustering of Ethiopian chickpea genotypes based on their geographic region were not consistent because of the seed exchange across regions. Model-based population structure clustering identified two discrete populations. These finding provides useful insight for chickpea collections and ex-situ conservation and national breeding programs for widening the genetic base of chickpea.


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