Hybrid performance as related to genomic diversity and population structure in public sorghum inbred lines

Abstract Background: Genetic improvement of pearl millet is lagging behind most of the major crops. Development of genomic resources is expected to expedite breeding for improved agronomic traits, stress tolerance, yield, and nutritional quality. Genotyping a breeding population with high throughput markers enables exploration of genetic diversity, population structure, and linkage disequilibrium (LD) which are important preludes for marker-trait association studies and application of genomic-assisted breeding. Results: Genotyping-by-sequencing (GBS) libraries of 309 inbred lines derived from landraces and improved varieties from Africa and India generated 54,770 high quality single nucleotide polymorphism (SNP) markers. On average one SNP per 29 Kb was mapped in the reference genome, with the telomeric regions more densely mapped than the pericentromeric regions of the chromosomes. Population structure analysis using 30,208 SNPs evenly distributed in the genome divided 309 accessions into five subpopulations with different levels of admixture. Pairwise genetic distance (GD) between accessions varied from 0.09 to 0.33 with the average distance of 0.28. Rapid LD decay implied low tendency of markers inherited together. Genetic differentiation estimates were the highest between subgroups 4 and 5, and the lowest between subgroups 1 and 2. Conclusions: Population genomic analysis of pearl millet inbred lines derived from diverse geographic and agroecological features identified five subgroups mostly following pedigree differences with different levels of admixture. It also revealed the prevalence of high genetic diversity in pearl millet, which is very useful in defining heterotic groups for hybrid breeding, trait mapping, and holds promise for improving pearl millet for yield and nutritional quality. The short LD decay observed suggests an absence of persistent haplotype blocks in pearl millet. The diverse genetic background of these lines and their low LD make this set of germplasm useful for traits mapping.

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Genomic diversity in pearl millet inbred lines derived from landraces and improved varieties

10.21203/rs.2.23078/v1 ◽

2020 ◽

Author(s):

Desalegn D. Serba ◽

Ghislain Kanfany ◽

Davina Rhodes ◽

Paul St. Amand ◽

Amy Bernardo ◽

...

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

Pearl Millet ◽

Nutritional Quality ◽

Inbred Lines ◽

Genomic Diversity ◽

Hybrid Breeding ◽

Heterotic Groups ◽

Improved Varieties ◽

Different Levels

Abstract Background: Genetic improvement of pearl millet is lagging behind most of the major crops. Development of genomic resources is expected to expedite breeding for improved agronomic traits, stress tolerance, yield, and nutritional quality. Genotyping a breeding population with high throughput markers enables exploration of genetic diversity, population structure, and linkage disequilibrium (LD) which are important preludes for marker-trait association studies and application of genomic-assisted breeding. Results: Sequencing the genotyping-by-sequencing (GBS) libraries of 309 inbred lines derived from landraces and improved varieties from Africa and India generated 54,770 high quality single nucleotide polymorphism (SNP) markers. On average one SNP per 29 Kb was mapped in the reference genome, with the telomeric regions more densely mapped than the pericentromeric regions of the chromosomes. Population structure analysis using 30,208 SNPs evenly distributed in the genome divided 309 accessions into five subpopulations with different levels of admixture. Pairwise genetic distance (GD) between accessions varied from 0.09 to 0.33 with the average distance of 0.28. Rapid LD decay implied low tendency of markers inherited together. Genetic differentiation estimates were the highest between subgroups 4 and 5, and the lowest between subgroups 1 and 2. Conclusions: Population genomic analysis of pearl millet inbred lines derived from diverse geographic and agroecological features identified five subgroups mostly following pedigree differences with different levels of admixture. It also revealed the prevalence of high genetic diversity in pearl millet, which is very useful in defining heterotic groups for hybrid breeding, trait mapping, and holds promise for improving pearl millet for yield and nutritional quality. The short LD decay observed suggests an absence of persistent haplotype blocks in pearl millet. The diverse genetic background of these lines and their low LD make this set of germplasm useful for traits mapping.

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Genomic diversity in pearl millet inbred lines derived from landraces and improved varieties

10.21203/rs.2.23078/v3 ◽

2020 ◽

Author(s):

Ghislain Kanfany ◽

Desalegn D. Serba ◽

Davina Rhodes ◽

Paul St. Amand ◽

Amy Bernardo ◽

...

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

Pearl Millet ◽

Nutritional Quality ◽

Inbred Lines ◽

Genomic Diversity ◽

Hybrid Breeding ◽

Heterotic Groups ◽

Improved Varieties ◽

Different Levels

Abstract Background: Genetic improvement of pearl millet is lagging behind most of the major crops. Development of genomic resources is expected to expedite breeding for improved agronomic traits, stress tolerance, yield, and nutritional quality. Genotyping a breeding population with high throughput markers enables exploration of genetic diversity, population structure, and linkage disequilibrium (LD) which are important preludes for marker-trait association studies and application of genomic-assisted breeding. Results: Genotyping-by-sequencing (GBS) libraries of 309 inbred lines derived from landraces and improved varieties from Africa and India generated 54,770 high quality single nucleotide polymorphism (SNP) markers. On average one SNP per 29 Kb was mapped in the reference genome, with the telomeric regions more densely mapped than the pericentromeric regions of the chromosomes. Population structure analysis using 30,208 SNPs evenly distributed in the genome divided 309 accessions into five subpopulations with different levels of admixture. Pairwise genetic distance (GD) between accessions varied from 0.09 to 0.33 with the average distance of 0.28. Rapid LD decay implied low tendency of markers inherited together. Genetic differentiation estimates were the highest between subgroups 4 and 5, and the lowest between subgroups 1 and 2. Conclusions: Population genomic analysis of pearl millet inbred lines derived from diverse geographic and agroecological features identified five subgroups mostly following pedigree differences with different levels of admixture. It also revealed the prevalence of high genetic diversity in pearl millet, which is very useful in defining heterotic groups for hybrid breeding, trait mapping, and holds promise for improving pearl millet for yield and nutritional quality. The short LD decay observed suggests an absence of persistent haplotype blocks in pearl millet. The diverse genetic background of these lines and their low LD make this set of germplasm useful for traits mapping.

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Assessing genomic diversity and signatures of selection in Jiaxian Red cattle using whole-genome sequencing data

BMC Genomics ◽

10.1186/s12864-020-07340-0 ◽

2021 ◽

Vol 22 (1) ◽

Author(s):

Xiaoting Xia ◽

Shunjin Zhang ◽

Huaju Zhang ◽

Zijing Zhang ◽

Ningbo Chen ◽

...

Keyword(s):

Population Structure ◽

Whole Genome Sequencing ◽

Genome Sequencing ◽

Genomic Variation ◽

Genomic Diversity ◽

System Response ◽

Whole Genome ◽

Population Structure Analysis ◽

Native Cattle ◽

Genomic Regions

Abstract Background Native cattle breeds are an important source of genetic variation because they might carry alleles that enable them to adapt to local environment and tough feeding conditions. Jiaxian Red, a Chinese native cattle breed, is reported to have originated from crossbreeding between taurine and indicine cattle; their history as a draft and meat animal dates back at least 30 years. Using whole-genome sequencing (WGS) data of 30 animals from the core breeding farm, we investigated the genetic diversity, population structure and genomic regions under selection of Jiaxian Red cattle. Furthermore, we used 131 published genomes of world-wide cattle to characterize the genomic variation of Jiaxian Red cattle. Results The population structure analysis revealed that Jiaxian Red cattle harboured the ancestry with East Asian taurine (0.493), Chinese indicine (0.379), European taurine (0.095) and Indian indicine (0.033). Three methods (nucleotide diversity, linkage disequilibrium decay and runs of homozygosity) implied the relatively high genomic diversity in Jiaxian Red cattle. We used θπ, CLR, FST and XP-EHH methods to look for the candidate signatures of positive selection in Jiaxian Red cattle. A total number of 171 (θπ and CLR) and 17 (FST and XP-EHH) shared genes were identified using different detection strategies. Functional annotation analysis revealed that these genes are potentially responsible for growth and feed efficiency (CCSER1), meat quality traits (ROCK2, PPP1R12A, CYB5R4, EYA3, PHACTR1), fertility (RFX4, SRD5A2) and immune system response (SLAMF1, CD84 and SLAMF6). Conclusion We provide a comprehensive overview of sequence variations in Jiaxian Red cattle genomes. Selection signatures were detected in genomic regions that are possibly related to economically important traits in Jiaxian Red cattle. We observed a high level of genomic diversity and low inbreeding in Jiaxian Red cattle. These results provide a basis for further resource protection and breeding improvement of this breed.

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

Journal of Plant Biochemistry and Biotechnology ◽

10.1007/s13562-016-0356-8 ◽

2016 ◽

Vol 26 (1) ◽

pp. 27-34 ◽

Cited By ~ 6

Author(s):

S. Senthilvel ◽

Mobeen Shaik ◽

K. Anjani ◽

Ranjan K. Shaw ◽

Poornima Kumari ◽

...

Keyword(s):

Population Structure ◽

Genetic Variability ◽

Inbred Lines ◽

Core Germplasm

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Gastrointestinal carriage of Klebsiella pneumoniae in a general adult population in Norway: a cross-sectional study of risk factors and bacterial genomic diversity

10.1101/2021.02.06.21251253 ◽

2021 ◽

Author(s):

Niclas Raffelsberger ◽

Marit Andrea Klokkhammer Hetland ◽

Kristian Svendsen ◽

Lars Småbrekke ◽

Iren H. Löhr ◽

...

Keyword(s):

Risk Factors ◽

Population Structure ◽

General Population ◽

Klebsiella Pneumoniae ◽

Representative Sample ◽

Adult Population ◽

Antibiotic Use ◽

Genomic Diversity ◽

Prescription Database ◽

Hospitalised Patients

SummaryBackgroundKlebsiella pneumoniae is a leading public health threat due to its increasing prevalence of antibiotic resistance. Gastrointestinal carriage of K. pneumoniae is a risk factor for subsequent infections in hospitalised patients. We determined risk factors for gastrointestinal carriage and the genomic population structure of K. pneumoniae colonising humans in a representative sample of a general population.Methods2,975 individuals (54% women) ≥40y participating in the population-based Tromsø Study 7 (2015-2016) were included. Faecal samples were screened for K. pneumoniae which were characterised using whole-genome sequencing. Risk factors for carriage were analysed using data from the Norwegian Prescription Database and questionnaires, using multivariable logistic regression.FindingsPrevalence of K. pneumoniae gastrointestinal carriage was 16·3% (95% CI 15·0-17·7%) with no gender difference. Risk factors associated with carriage included age ≥60y, travel to Greece or Asia past 12 months (adjusted odds ratio 1·49, 95% CI 1·11-2·00), Crohn’s disease/ulcerative colitis (2·26, 1·20-4·27), use of protein pump inhibitors (1·62, 1·18-2·22) and non-steroidal anti-inflammatory drugs past six months (1·38, 1·04-1·84), and antibiotic use last month (1·73, 1·05-2·86). Prevalence was higher among those having used combinations of drug classes and decreased over time with respect to preceding antibiotic use. The K. pneumoniae population was diverse with 300 sequence types among 484 isolates distributed across four phylogroups. Among the isolates, 5·2% and 11·6% harboured acquired resistance and virulence factors, respectively.InterpretationIdentification of risk factors for gastrointestinal carriage in a representative sample of a general population allows for identification of individuals that may have a higher risk of extraintestinal infection during hospitalisation. The diverse population structure of K. pneumoniae carriage isolates reflects the ecologically adaptive capacity of the bacterium, and the low antibacterial consumption probably contributes to the low prevalence of resistance in clinical isolates in Norway.

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Phenotypic and molecular characterization of a set of tropical maize inbred lines from a public breeding program in Brazil

BMC Genomics ◽

10.1186/s12864-021-08127-7 ◽

2022 ◽

Vol 23 (1) ◽

Author(s):

Sirlene Viana de Faria ◽

Leandro Tonello Zuffo ◽

Wemerson Mendonça Rezende ◽

Diego Gonçalves Caixeta ◽

Hélcio Duarte Pereira ◽

...

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

Inbred Lines ◽

Breeding Program ◽

Tropical Maize ◽

Maize Breeding ◽

Breeding Programs ◽

The Public ◽

Maize Inbred Lines

Abstract Background The characterization of genetic diversity and population differentiation for maize inbred lines from breeding programs is of great value in assisting breeders in maintaining and potentially increasing the rate of genetic gain. In our study, we characterized a set of 187 tropical maize inbred lines from the public breeding program of the Universidade Federal de Viçosa (UFV) in Brazil based on 18 agronomic traits and 3,083 single nucleotide polymorphisms (SNP) markers to evaluate whether this set of inbred lines represents a panel of tropical maize inbred lines for association mapping analysis and investigate the population structure and patterns of relationships among the inbred lines from UFV for better exploitation in our maize breeding program. Results Our results showed that there was large phenotypic and genotypic variation in the set of tropical maize inbred lines from the UFV maize breeding program. We also found high genetic diversity (GD = 0.34) and low pairwise kinship coefficients among the maize inbred lines (only approximately 4.00 % of the pairwise relative kinship was above 0.50) in the set of inbred lines. The LD decay distance over all ten chromosomes in the entire set of maize lines with r2 = 0.1 was 276,237 kb. Concerning the population structure, our results from the model-based STRUCTURE and principal component analysis methods distinguished the inbred lines into three subpopulations, with high consistency maintained between both results. Additionally, the clustering analysis based on phenotypic and molecular data grouped the inbred lines into 14 and 22 genetic divergence clusters, respectively. Conclusions Our results indicate that the set of tropical maize inbred lines from UFV maize breeding programs can comprise a panel of tropical maize inbred lines suitable for a genome-wide association study to dissect the variation of complex quantitative traits in maize, mainly in tropical environments. In addition, our results will be very useful for assisting us in the assignment of heterotic groups and the selection of the best parental combinations for new breeding crosses, mapping populations, mapping synthetic populations, guiding crosses that target highly heterotic and yielding hybrids, and predicting untested hybrids in the public breeding program UFV.

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GENOTYPIC DIVERSITY IN 291 MAIZE LINES FROM CIMMYT AND PHENOTYPIC CHARACTERIZATION IN SOUTHERN CORDOBA, ARGENTINA

Journal of Basic and Applied Genetics ◽

10.35407/bag.2019.xxx.01.04 ◽

2019 ◽

Vol 30 (1) ◽

pp. 25-33

Author(s):

E.A. Rossi ◽

M. Ruiz ◽

M. Di Renzo ◽

N.C. Bonamico

Keyword(s):

Population Structure ◽

Morphological Traits ◽

Phenotypic Diversity ◽

Genotypic Diversity ◽

Inbred Lines ◽

Environmental Adaptation ◽

Procrustes Analysis ◽

Phenotypic Characterization ◽

Breeding Programs ◽

Maize Inbred Lines

CIMMYT maize inbred lines (CMLs) are freely distributed to breeding programs around the world. Better information on phenotypic and genotypic diversity may provide guidance to breeders on how to use more efficiently the CMLs in their breeding programs. In this study a group of 291 CIMMYT maize inbred lines, was phenotyped by nine agro-morphological traits in south Córdoba, Argentina and genotyped using 18,082 SNPs. Based on the geographic information and the environmental adaptation, 291 CMLs were classified into eight subgroups. Anthesis-silking interval (IAE) was the trait with higher phenotypic diversity. A 40% of maize inbred lines, with IAE less than five days, show a good adaptation to growing conditions in south Córdoba, Argentina. The low phenotypic variation explained by environmental adaptation subgroups indicates that population structure is only a minor factor contributing to phenotypic diversity in this panel. Principal component analysis (ACP) allowed us to obtain phenotypic and genotypic orderings. Generalized procrustes analysis (APG) indicated a 60% consensus between both data type from the total panel of maize lines. In each environmental adaptation subgroup, the APG consensus was higher. This result, which might indicate linkage disequilibrium between SNPs markers and the genes controlling these agro-morphological traits, is promising and could be used as an initial tool in the identification of Quantitative Trait Loci (QTL). Information on genetic diversity, population structure and phenotypic diversity in local environments will help maize breeders to better understand how to use the current CIMMYT maize inbred lines group. Key words: broad-sense heritability, multivariate analysis, SNPs, agro-morphological traits.

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Whole-genome SNP analysis elucidates the genetic population structure and diversity of Acrocomia species

10.1101/2020.10.08.331140 ◽

2020 ◽

Author(s):

Brenda G. Díaz ◽

Maria I. Zucchi ◽

Alessandro. Alves-Pereira ◽

Caléo P. de Almeida ◽

Aline C. L. Moraes ◽

...

Keyword(s):

Genetic Diversity ◽

Population Structure ◽

Genetic Structure ◽

Genetic Relationships ◽

Geographical Area ◽

Taxonomic Classification ◽

Genomic Diversity ◽

Productive Capacity ◽

Snp Analysis ◽

Genetic Population

AbstractAcrocomia (Arecaceae) is a genus widely distributed in tropical and subtropical America that has been achieving economic interest due to the great potential of oil production of some of its species. In particular A. aculeata, due to its vocation to supply oil with the same productive capacity as the oil palm even in areas with water deficit. Although eight species are recognized in the genus, the taxonomic classification based on morphology and geographic distribution is still controversial. Knowledge about the genetic diversity and population structure of the species is limited, which has limited the understanding of the genetic relationships and the orientation of management, conservation, and genetic improvement activities of species of the genus. In the present study, we analyzed the genomic diversity and population structure of seven species of Acrocomia including 117 samples of A. aculeata covering a wide geographical area of occurrence, using single nucleotide Polymorphism (SNP) markers originated from Genotyping By Sequencing (GBS). The genetic structure of the Acrocomia species were partially congruent with the current taxonomic classification based on morphological characters, recovering the separation of the species A. aculeata, A. totai, A. crispa and A. intumescens as distinct taxonomic groups. However, the species A. media was attributed to the cluster of A. aculeata while A. hassleri and A. glauscescens were grouped together with A. totai. The species that showed the highest and lowest genetic diversity were A. totai and A. media, respectively. When analyzed separately, the species A. aculeata showed a strong genetic structure, forming two genetic groups, the first represented mainly by genotypes from Brazil and the second by accessions from Central and North American countries. Greater genetic diversity was found in Brazil when compared to the other countries. Our results on the genetic diversity of the genus are unprecedented, as is also establishes new insights on the genomic relationships between Acrocomia species. It is also the first study to provide a more global view of the genomic diversity of A. aculeata. We also highlight the applicability of genomic data as a reference for future studies on genetic diversity, taxonomy, evolution and phylogeny of the Acrocomia genus, as well as to support strategies for the conservation, exploration and breeding of Acrocomia species and in particular A. aculeata.

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