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Journal ArticleDOI

A haplotype map of genomic variations and genome-wide association studies of agronomic traits in foxtail millet (Setaria italica)

TL;DR: This study sequenced 916 diverse foxtail millet varieties, identified 2.58 million SNPs and used 0.8 million common SNPs to construct a haplotype map of the foxtailed millet genome, and identified 512 loci associated with 47 agronomic traits by genome-wide association studies.
Abstract: Foxtail millet (Setaria italica) is an important grain crop that is grown in arid regions. Here we sequenced 916 diverse foxtail millet varieties, identified 2.58 million SNPs and used 0.8 million common SNPs to construct a haplotype map of the foxtail millet genome. We classified the foxtail millet varieties into two divergent groups that are strongly correlated with early and late flowering times. We phenotyped the 916 varieties under five different environments and identified 512 loci associated with 47 agronomic traits by genome-wide association studies. We performed a de novo assembly of deeply sequenced genomes of a Setaria viridis accession (the wild progenitor of S. italica) and an S. italica variety and identified complex interspecies and intraspecies variants. We also identified 36 selective sweeps that seem to have occurred during modern breeding. This study provides fundamental resources for genetics research and genetic improvement in foxtail millet.
Citations
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Journal ArticleDOI
TL;DR: The developed array and cluster identification algorithms provide an opportunity to infer detailed haplotype structure in polyploid wheat and will serve as an invaluable resource for diversity studies and investigating the genetic basis of trait variation in wheat.
Abstract: High-density single nucleotide polymorphism (SNP) genotyping arrays are a powerful tool for studying genomic patterns of diversity, inferring ancestral relationships between individuals in populations and studying marker-trait associations in mapping experiments. We developed a genotyping array including about 90,000 gene-associated SNPs and used it to characterize genetic variation in allohexaploid and allotetraploid wheat populations. The array includes a significant fraction of common genome-wide distributed SNPs that are represented in populations of diverse geographical origin. We used density-based spatial clustering algorithms to enable high-throughput genotype calling in complex data sets obtained for polyploid wheat. We show that these model-free clustering algorithms provide accurate genotype calling in the presence of multiple clusters including clusters with low signal intensity resulting from significant sequence divergence at the target SNP site or gene deletions. Assays that detect low-intensity clusters can provide insight into the distribution of presence-absence variation (PAV) in wheat populations. A total of 46 977 SNPs from the wheat 90K array were genetically mapped using a combination of eight mapping populations. The developed array and cluster identification algorithms provide an opportunity to infer detailed haplotype structure in polyploid wheat and will serve as an invaluable resource for diversity studies and investigating the genetic basis of trait variation in wheat.

1,451 citations


Cites background from "A haplotype map of genomic variatio..."

  • ...…to analyse variation in this wild species and to map introgressions of genetic material from this wild relative which has been extensively used as a source of alleles contributing to abiotic and biotic stress tolerance in wheat (Jones et al., 2013; Periyannan et al., 2013; Sohail et al., 2011)....

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Journal ArticleDOI
TL;DR: Together, these studies reveal the functions of genes that are involved in the evolution of crops that are under domestication, the types of mutations that occur during this process and the parallelism of mutations That occur in the same pathways and proteins, as well as the selective forces that are acting on these mutations.
Abstract: Domestication is a good model for the study of evolutionary processes because of the recent evolution of crop species (<12,000 years ago), the key role of selection in their origins, and good archaeological and historical data on their spread and diversification. Recent studies, such as quantitative trait locus mapping, genome-wide association studies and whole-genome resequencing studies, have identified genes that are associated with the initial domestication and subsequent diversification of crops. Together, these studies reveal the functions of genes that are involved in the evolution of crops that are under domestication, the types of mutations that occur during this process and the parallelism of mutations that occur in the same pathways and proteins, as well as the selective forces that are acting on these mutations and that are associated with geographical adaptation of crop species.

804 citations

Journal ArticleDOI
TL;DR: The development of sequencing-based genotyping and genome-wide association studies in crops are described and the advent of high-throughput sequencing technology enables rapid and accurate resequencing of a large number of crop genomes to detect the genetic basis of phenotypic variations in crops.
Abstract: Natural variants of crops are generated from wild progenitor plants under both natural and human selection. Diverse crops that are able to adapt to various environmental conditions are valuable resources for crop improvements to meet the food demands of the increasing human population. With the completion of reference genome sequences, the advent of high-throughput sequencing technology now enables rapid and accurate resequencing of a large number of crop genomes to detect the genetic basis of phenotypic variations in crops. Comprehensive maps of genome variations facilitate genome-wide association studies of complex traits and functional investigations of evolutionary changes in crops. These advances will greatly accelerate studies on crop designs via genomics-assisted breeding. Here, we first discuss crop genome studies and describe the development of sequencing-based genotyping and genome-wide association studies in crops. We then review sequencing-based crop domestication studies and offer a perspecti...

503 citations


Cites background or methods from "A haplotype map of genomic variatio..."

  • ...Genetic mapping and comparative genome analysis found that the Shattering 1 gene for seed shattering was under parallel selection during sorghum, foxtail millet, rice, and maize domestication (50, 64)....

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  • ...A total of 916 diverse foxtail millet varieties, including both traditional landraces and modern cultivars, were genotyped through whole-genome low-coverage sequencing (50)....

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  • ...For this, a k nearest neighbor–based algorithm that explores local haplotype similarity to infer the missing calls was developed, and applications in both rice and foxtail millet showed high accuracy (41, 50)....

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  • ...GWAS have now been carried out successfully in many crops, including maize, rice, sorghum, and foxtail millet (41, 42, 50, 58, 61, 76, 109, 136)....

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Journal ArticleDOI
TL;DR: In this paper, the authors identified agronomically important genes in rice using GWAS based on whole-genome sequencing, followed by the screening of candidate genes based on the estimated effect of nucleotide polymorphisms.
Abstract: A genome-wide association study (GWAS) can be a powerful tool for the identification of genes associated with agronomic traits in crop species, but it is often hindered by population structure and the large extent of linkage disequilibrium. In this study, we identified agronomically important genes in rice using GWAS based on whole-genome sequencing, followed by the screening of candidate genes based on the estimated effect of nucleotide polymorphisms. Using this approach, we identified four new genes associated with agronomic traits. Some genes were undetectable by standard SNP analysis, but we detected them using gene-based association analysis. This study provides fundamental insights relevant to the rapid identification of genes associated with agronomic traits using GWAS and will accelerate future efforts aimed at crop improvement.

437 citations

Journal ArticleDOI
TL;DR: This study provides insights into the genetic correlation among complex traits and will facilitate future soybean functional studies and breeding through molecular design.
Abstract: Soybean (Glycine max [L.] Merr.) is one of the most important oil and protein crops. Ever-increasing soybean consumption necessitates the improvement of varieties for more efficient production. However, both correlations among different traits and genetic interactions among genes that affect a single trait pose a challenge to soybean breeding. To understand the genetic networks underlying phenotypic correlations, we collected 809 soybean accessions worldwide and phenotyped them for two years at three locations for 84 agronomic traits. Genome-wide association studies identified 245 significant genetic loci, among which 95 genetically interacted with other loci. We determined that 14 oil synthesis-related genes are responsible for fatty acid accumulation in soybean and function in line with an additive model. Network analyses demonstrated that 51 traits could be linked through the linkage disequilibrium of 115 associated loci and these links reflect phenotypic correlations. We revealed that 23 loci, including the known Dt1, E2, E1, Ln, Dt2, Fan, and Fap loci, as well as 16 undefined associated loci, have pleiotropic effects on different traits. This study provides insights into the genetic correlation among complex traits and will facilitate future soybean functional studies and breeding through molecular design.

372 citations


Additional excerpts

  • ...maize [12, 13], and foxtail millet [14]....

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References
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Journal Article

16,851 citations

Journal ArticleDOI
TL;DR: Haploview is a software package that provides computation of linkage disequilibrium statistics and population haplotype patterns from primary genotype data in a visually appealing and interactive interface.
Abstract: Summary: Research over the last few years has revealed significant haplotype structure in the human genome. The characterization of these patterns, particularly in the context of medical genetic association studies, is becoming a routine research activity. Haploview is a software package that provides computation of linkage disequilibrium statistics and population haplotype patterns from primary genotype data in a visually appealing and interactive interface. Availability: http://www.broad.mit.edu/mpg/haploview/ Contact: jcbarret@broad.mit.edu

13,862 citations

Journal ArticleDOI
TL;DR: The European Molecular Biology Open Software Suite is a mature package of software tools developed for the molecular biology community that includes a comprehensive set of applications for molecular sequence analysis and other tasks and integrates popular third-party software packages under a consistent interface.

9,493 citations

Journal ArticleDOI
01 Apr 2001-Genetics
TL;DR: It was concluded that selection on genetic values predicted from markers could substantially increase the rate of genetic gain in animals and plants, especially if combined with reproductive techniques to shorten the generation interval.
Abstract: Recent advances in molecular genetic techniques will make dense marker maps available and genotyping many individuals for these markers feasible. Here we attempted to estimate the effects of ∼50,000 marker haplotypes simultaneously from a limited number of phenotypic records. A genome of 1000 cM was simulated with a marker spacing of 1 cM. The markers surrounding every 1-cM region were combined into marker haplotypes. Due to finite population size (Ne = 100), the marker haplotypes were in linkage disequilibrium with the QTL located between the markers. Using least squares, all haplotype effects could not be estimated simultaneously. When only the biggest effects were included, they were overestimated and the accuracy of predicting genetic values of the offspring of the recorded animals was only 0.32. Best linear unbiased prediction of haplotype effects assumed equal variances associated to each 1-cM chromosomal segment, which yielded an accuracy of 0.73, although this assumption was far from true. Bayesian methods that assumed a prior distribution of the variance associated with each chromosome segment increased this accuracy to 0.85, even when the prior was not correct. It was concluded that selection on genetic values predicted from markers could substantially increase the rate of genetic gain in animals and plants, especially if combined with reproductive techniques to shorten the generation interval.

6,036 citations

Journal ArticleDOI
01 Nov 1994-Genetics
TL;DR: An empirical method is described, based on the concept of a permutation test, for estimating threshold values that are tailored to the experimental data at hand, and is demonstrated using two real data sets derived from F(2) and recombinant inbred plant populations.
Abstract: The detection of genes that control quantitative characters is a problem of great interest to the genetic mapping community. Methods for locating these quantitative trait loci (QTL) relative to maps of genetic markers are now widely used. This paper addresses an issue common to all QTL mapping methods, that of determining an appropriate threshold value for declaring significant QTL effects. An empirical method is described, based on the concept of a permutation test, for estimating threshold values that are tailored to the experimental data at hand. The method is demonstrated using two real data sets derived from F(2) and recombinant inbred plant populations. An example using simulated data from a backcross design illustrates the effect of marker density on threshold values.

4,964 citations

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