Genetic diversity and linkage disequilibrium in the Argentine public maize inbred line collection

2016 ◽  
Vol 15 (6) ◽  
pp. 515-526 ◽  
Author(s):  
Sofía E. Olmos ◽  
Verónica V. Lia ◽  
Guillermo H. Eyhérabide

AbstractKnowledge of linkage disequilibrium (LD) patterns is considered a prerequisite for effective association mapping studies. However, no LD analysis in the Argentine public temperate maize collection has been reported to date. In this study, a panel of 111 temperate maize inbreds genotyped at 74 single sequence repeats (SSRs) loci was used to assess LD, genetic diversity and population structure to evaluate the suitability of the panel for association mapping. Mini-core sets were also designed for in-depth phenotyping and allele mining purposes. The panel consisted of: (1) locally developed orange flint germplasm; (2) temperate inbred lines with Iowa Stiff Stalk Synthetic background; and (3) eight historic flint lines, some of them from the Cuarentín race. As a result, four subpopulations were defined. Joint analysis of population structure and combining ability allowed identifying two main heterotic patterns. High molecular diversity, a low extent of LD and a high ratio of linked to unlinked SSR loci pairs in significant LD were detected indicating the suitability of the entire collection for association mapping. The fact that the LD extent in the mini-core sets was similar to that observed in the entire collection and that only a small percentage of allelic richness was reduced suggests that these mini-core sets are suitable to capture diversity, exploit phenotypic variance and discover useful variants representative of the entire collection.

Agronomy ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 118
Author(s):  
Ljiljana Brbaklić ◽  
Dragana Trkulja ◽  
Sanja Mikić ◽  
Milan Mirosavljević ◽  
Vojislava Momčilović ◽  
...  

Determination of genetic diversity and population structure of breeding material is an important prerequisite for discovering novel and valuable alleles aimed at crop improvement. This study’s main objective was to characterize genetic diversity and population structure of a collection representing a 40-year long historical period of barley (Hordeum vulgare L.) breeding, using microsatellites, pedigree, and phenotypic data. The set of 90 barley genotypes was phenotyped during three growing seasons and genotyped with 338 polymorphic alleles. The indicators of genetic diversity showed differentiation changes throughout the breeding periods. The population structure discriminated the breeding material into three distinctive groups. The principal coordinate analysis grouped the genotypes according to their growth habit and row type. An analysis of phenotypic variance (ANOVA) showed that almost all investigated traits varied significantly between row types, seasons, and breeding periods. A positive effect on yield progress during the 40-year long breeding period could be partly attributed to breeding for shorter plants, which reduced lodging and thus provided higher yield stability. The breeding material revealed a considerable diversity level based on microsatellite and phenotypic data without a tendency of genetic erosion throughout the breeding history and implied dynamic changes in genetic backgrounds, providing a great gene pool suitable for further barley improvement.


BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Paul I. Otyama ◽  
Andrew Wilkey ◽  
Roshan Kulkarni ◽  
Teshale Assefa ◽  
Ye Chu ◽  
...  

2017 ◽  
Vol 13 (6) ◽  
Author(s):  
Stijn Vanderzande ◽  
Diego Micheletti ◽  
Michela Troggio ◽  
Mark W. Davey ◽  
Johan Keulemans

2012 ◽  
Vol 4 (3) ◽  
pp. 757-767 ◽  
Author(s):  
M. M. Hassan ◽  
A. K. M. Shamsuddin ◽  
M. M. Islam ◽  
K. Khatun ◽  
J. Halder

Information on the patterns of genetic variation and population structure is essential for rational use and efficient management of germplasms. It helps in monitoring germplasm and can also be used to predict potential genetic gains. Therefore, in the present study genetic diversity of 59 rice genotypes were assessed using 8 simple sequence repeat (SSR) primers. By the DNA profiling, a total of 114 alleles were detected. Allele number per/locus ranged from 9 to 27, with an average of 14.25. Average polymorphism information content (PIC) value was 0.857 with lowest 0.767 to highest 0.857. Mean gene diversity over all SSR loci was 0.870 with a range from 0.792 to 0.948. Fst values for each locus varied from 0.071 to 0.262. Genetic distance between the variety pair ranged from 0.33 to 1.0. The lowest genetic distance was found between Rajashili and Kumragori (2). Cluster and principal coordinate analysis (PCoA) analysis revealed similar pattern of variation. Marker RM11300 was found most polymorphic and robust among the accessions and can be widely used for rice germplasm characterization. The exclusive variability and unique feature of germplasm found in this study can be a gateway for both domestic and global rice improvement.© 2012 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved.doi: http://dx.doi.org/10.3329/jsr.v4i3.10416 J. Sci. Res. 4 (3), 757-767 (2012)


2020 ◽  
Vol 73 (4) ◽  
Author(s):  
Salem Marzougui ◽  
Mohamed Kharrat ◽  
Mongi Ben Younes

In barley breeding programs, information about genetic dissimilarity and population structure is very important for genetic diversity conservation and new cultivar development. This study aimed to evaluate the genetic variation in Tunisian barley accessions (<em>Hordeum</em><em> </em><em>vulgare </em>L.) based on simple sequence repeat (SSR). A total of 89 alleles were detected at 26 SSR loci. The allele number per locus ranged from two to five, with an average of 3.4 alleles per locus detected from 32 barley accessions, and the average value of polymorphic information content was 0.45. A cluster analysis based on genetic similarity was performed, and the 32 barley resources were classified into five groups. Principal coordinates (PCoA) explained 12.5% and 9.3% of the total variation, and the PCoA was largely consistent with the results of cluster separation of STRUCTURE software analysis. The analysis of genetic diversity in barley collection will facilitate cultivar development and effective use of genetic resources.


Genes ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 676 ◽  
Author(s):  
Farahani ◽  
Maleki ◽  
Mehrabi ◽  
Kanouni ◽  
Scheben ◽  
...  

Characterization of genetic diversity, population structure, and linkage disequilibrium is a prerequisite for proper management of breeding programs and conservation of genetic resources. In this study, 186 chickpea genotypes, including advanced “Kabuli” breeding lines and Iranian landrace “Desi” chickpea genotypes, were genotyped using DArTseq-Based single nucleotide polymorphism (SNP) markers. Out of 3339 SNPs, 1152 markers with known chromosomal position were selected for genome diversity analysis. The number of mapped SNP markers varied from 52 (LG8) to 378 (LG4), with an average of 144 SNPs per linkage group. The chromosome size that was covered by SNPs varied from 16,236.36 kbp (LG8) to 67,923.99 kbp (LG5), while LG4 showed a higher number of SNPs, with an average of 6.56 SNPs per Mbp. Polymorphism information content (PIC) value of SNP markers ranged from 0.05 to 0.50, with an average of 0.32, while the markers on LG4, LG6, and LG8 showed higher mean PIC value than average. Unweighted neighbor joining cluster analysis and Bayesian-based model population structure grouped chickpea genotypes into four distinct clusters. Principal component analysis (PCoA) and discriminant analysis of principal component (DAPC) results were consistent with that of the cluster and population structure analysis. Linkage disequilibrium (LD) was extensive and LD decay in chickpea germplasm was relatively low. A few markers showed r2 ≥ 0.8, while 2961 pairs of markers showed complete LD (r2 = 1), and a huge LD block was observed on LG4. High genetic diversity and low kinship value between pairs of genotypes suggest the presence of a high genetic diversity among the studied chickpea genotypes. This study also demonstrates the efficiency of DArTseq-based SNP genotyping for large-scale genome analysis in chickpea. The genotypic markers provided in this study are useful for various association mapping studies when combined with phenotypic data of different traits, such as seed yield, abiotic, and biotic stresses, and therefore can be efficiently used in breeding programs to improve chickpea.


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