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Santangelo JS, Battlay P, Hendrickson BT, Kuo WH, Olsen KM, Kooyers NJ, Johnson MTJ, Hodgins KA, Ness RW. Haplotype-Resolved, Chromosome-Level Assembly of White Clover (Trifolium repens L., Fabaceae). Genome Biol Evol 2023; 15:evad146. [PMID: 37542471 PMCID: PMC10433932 DOI: 10.1093/gbe/evad146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 07/24/2023] [Accepted: 07/29/2023] [Indexed: 08/07/2023] Open
Abstract
White clover (Trifolium repens L.; Fabaceae) is an important forage and cover crop in agricultural pastures around the world and is increasingly used in evolutionary ecology and genetics to understand the genetic basis of adaptation. Historically, improvements in white clover breeding practices and assessments of genetic variation in nature have been hampered by a lack of high-quality genomic resources for this species, owing in part to its high heterozygosity and allotetraploid hybrid origin. Here, we use PacBio HiFi and chromosome conformation capture (Omni-C) technologies to generate a chromosome-level, haplotype-resolved genome assembly for white clover totaling 998 Mbp (scaffold N50 = 59.3 Mbp) and 1 Gbp (scaffold N50 = 58.6 Mbp) for haplotypes 1 and 2, respectively, with each haplotype arranged into 16 chromosomes (8 per subgenome). We additionally provide a functionally annotated haploid mapping assembly (968 Mbp, scaffold N50 = 59.9 Mbp), which drastically improves on the existing reference assembly in both contiguity and assembly accuracy. We annotated 78,174 protein-coding genes, resulting in protein BUSCO completeness scores of 99.6% and 99.3% against the embryophyta_odb10 and fabales_odb10 lineage datasets, respectively.
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Affiliation(s)
- James S Santangelo
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Paul Battlay
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | | | - Wen-Hsi Kuo
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Kenneth M Olsen
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Nicholas J Kooyers
- Department of Biology, University of Louisiana, Lafayette, Louisiana, USA
| | - Marc T J Johnson
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| | - Kathryn A Hodgins
- School of Biological Sciences, Monash University, Melbourne, Victoria, Australia
| | - Rob W Ness
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
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Yik MHY, Lo YT, Lin X, Sun W, Chan TF, Shaw PC. Authentication of Hedyotis products by adaptor ligation-mediated PCR and metabarcoding. J Pharm Biomed Anal 2021; 196:113920. [PMID: 33549873 DOI: 10.1016/j.jpba.2021.113920] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 01/13/2021] [Accepted: 01/19/2021] [Indexed: 01/25/2023]
Abstract
DNA barcoding is a widely used tool for species identification and authentication. However, it may not be applicable to highly processed herbal products due to severe DNA fragmentation. The emergence of DNA metabarcoding provides an alternative way to solve the problem. In this study, we are the first to combine the use of adaptor ligation-mediated PCR method and metabarcoding to reveal species identities in herbal products. As an illustration, we applied the method on three Hedyotis herbal products collected from China and Thailand. Results showed that H. diffusa and H. corymbosa were present in the products which were consistent with their label claims. Our study indicated that the adaptor ligation-mediated PCR with metabarcoding approach is useful for authentication of highly processed herbal products.
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Affiliation(s)
- Mavis Hong-Yu Yik
- Li Dak Sum Yip Yio Chin R & D Center for Chinese Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
| | - Yat-Tung Lo
- Li Dak Sum Yip Yio Chin R & D Center for Chinese Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; State Key Laboratory of Research on Bioactivities and Clinical Application of Medicinal Plants, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
| | - Xiao Lin
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; Centre for Soybean Research of the State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
| | - Wei Sun
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China.
| | - Ting-Fung Chan
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; Centre for Soybean Research of the State Key Laboratory of Agrobiotechnology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
| | - Pang-Chui Shaw
- Li Dak Sum Yip Yio Chin R & D Center for Chinese Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; State Key Laboratory of Research on Bioactivities and Clinical Application of Medicinal Plants, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; School of Life Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
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Cost-effective detection of genome-wide signatures for 2,4-D herbicide resistance adaptation in red clover. Sci Rep 2019; 9:20037. [PMID: 31882573 PMCID: PMC6934753 DOI: 10.1038/s41598-019-55676-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 11/26/2019] [Indexed: 12/04/2022] Open
Abstract
Herbicide resistance is a recurrent evolutionary event that has been reported across many species and for all major herbicide modes of action. The synthetic auxinic herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) has been widely used since the 1940s, however the genetic variation underlying naturally evolving resistance remains largely unknown. In this study, we used populations of the forage legume crop red clover (Trifolium pratense L.) that were recurrently selected for 2,4-D resistance to detect genome-wide signatures of adaptation. Four susceptible and six derived resistant populations were sequenced using a less costly approach by combining targeted sequencing (Capture-Seq) with pooled individuals (Pool-Seq). Genomic signatures of selection were identified using: (i) pairwise allele frequency differences; (ii) genome scan for overly differentiated loci; and (iii) genome‐wide association. Fifty significant SNPs were consistently detected, most located in a single chromosome, which can be useful for marker assisted selection. Additionally, we searched for candidate genes at these genomic regions to gain insights into potential molecular mechanisms underlying 2,4-D resistance. Among the predicted functions of candidate genes, we found some related to the auxin metabolism, response to oxidative stress, and detoxification, which are also promising for further functional validation studies.
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Vendramin V, Ormanbekova D, Scalabrin S, Scaglione D, Maccaferri M, Martelli P, Salvi S, Jurman I, Casadio R, Cattonaro F, Tuberosa R, Massi A, Morgante M. Genomic tools for durum wheat breeding: de novo assembly of Svevo transcriptome and SNP discovery in elite germplasm. BMC Genomics 2019; 20:278. [PMID: 30971220 PMCID: PMC6456968 DOI: 10.1186/s12864-019-5645-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 03/25/2019] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND The tetraploid durum wheat (Triticum turgidum L. ssp. durum Desf. Husnot) is an important crop which provides the raw material for pasta production and a valuable source of genetic diversity for breeding hexaploid wheat (Triticum aestivum L.). Future breeding efforts to enhance yield potential and climate resilience will increasingly rely on genomics-based approaches to identify and select beneficial alleles. A deeper characterisation of the molecular and functional diversity of the durum wheat transcriptome will be instrumental to more effectively harness its genetic diversity. RESULTS We report on the de novo transcriptome assembly of durum wheat cultivar 'Svevo'. The transcriptome of four tissues/organs (shoots and roots at the seedling stage, reproductive organs and developing grains) was assembled de novo, yielding 180,108 contigs, with a N50 length of 1121 bp and mean contig length of 883 bp. Alignment against the transcriptome of nine plant species identified 43% of transcripts with homology to at least one reference transcriptome. The functional annotation was completed by means of a combination of complementary software. The presence of differential expression between the A- and B-homoeolog copies of the durum wheat tetraploid genome was ascertained by phase reconstruction of polymorphic sites based on the T. urartu transcripts and inferring homoeolog-specific sequences. We observed greater expression divergence between A and B homoeologs in grains rather than in leaves and roots. The transcriptomes of 13 durum wheat cultivars spanning the breeding period from 1969 to 2005 were analysed for SNP diversity, leading to 95,358 non-rare, hemi-SNPs shared among two or more cultivars and 33,747 locus-specific (diploid inheritance) SNPs. CONCLUSIONS Our study updates and expands the de novo transcriptome reference assembly available for durum wheat. Out of 180,108 assembled transcripts, 13,636 were specific to the Svevo cultivar as compared to the only other reference transcriptome available for durum, thus contributing to the identification of the tetraploid wheat pan-transcriptome. Additionally, the analysis of 13 historically relevant hallmark varieties produced a SNP dataset that could successfully validate the genotyping in tetraploid wheat and provide a valuable resource for genomics-assisted breeding of both tetraploid and hexaploid wheats.
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Affiliation(s)
- Vera Vendramin
- IGA Technology Services, via J. Linussio 51, 33100, Udine, Italy.
| | - Danara Ormanbekova
- Department of Agricultural and Food Sciences DISTAL, University of Bologna, Viale G. Fanin 44, 40127, Bologna, Italy
| | - Simone Scalabrin
- IGA Technology Services, via J. Linussio 51, 33100, Udine, Italy
| | - Davide Scaglione
- IGA Technology Services, via J. Linussio 51, 33100, Udine, Italy
| | - Marco Maccaferri
- Department of Agricultural and Food Sciences DISTAL, University of Bologna, Viale G. Fanin 44, 40127, Bologna, Italy
| | - Pierluigi Martelli
- Biocomputing Group, University of Bologna, via San Giacomo 9/2, 40126, Bologna, Italy
| | - Silvio Salvi
- Department of Agricultural and Food Sciences DISTAL, University of Bologna, Viale G. Fanin 44, 40127, Bologna, Italy
| | - Irena Jurman
- Istituto di Genomica Applicata, via J. Linussio 51, 33100, Udine, Italy
| | - Rita Casadio
- Biocomputing Group, University of Bologna, via San Giacomo 9/2, 40126, Bologna, Italy
| | | | - Roberto Tuberosa
- Department of Agricultural and Food Sciences DISTAL, University of Bologna, Viale G. Fanin 44, 40127, Bologna, Italy
| | - Andrea Massi
- Società produttori Sementi Bologna, Via Macero 1, 40050, Argelato, BO, Italy
| | - Michele Morgante
- Istituto di Genomica Applicata, via J. Linussio 51, 33100, Udine, Italy.,Department od Agricultural, Food, Environmental and Animal Research - DI4A, University of Udine, via delle Scienze 206, 33100, Udine, Italy
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Inostroza L, Bhakta M, Acuña H, Vásquez C, Ibáñez J, Tapia G, Mei W, Kirst M, Resende M, Munoz P. Understanding the Complexity of Cold Tolerance in White Clover using Temperature Gradient Locations and a GWAS Approach. THE PLANT GENOME 2018; 11. [PMID: 30512038 DOI: 10.3835/plantgenome2017.11.0096] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
White clover ( L.) is the most important grazing perennial forage legume in temperate climates. However, its limited capacity to survive and restore growth after low temperatures during winter constrains the productivity and wide adoption of the crop. Despite the importance of cold tolerance for white clover cultivar development, the genetic basis of this trait remains largely unknown. Hence, in this study, we performed the first genome-wide association study (GWAS) analyses in white clover to identify quantitative trait loci (QTL) for cold-tolerance-related traits. Seeds from 192 divergent genotypes from six populations in the Patagonia region of South America were collected and seed-derived plants were further clonally propagated. Clonal trials were established in three locations representing temperature gradient associated with elevation. Given the allotetraploid nature of the white clover genome, distinct genetic models (diploid and tetraploid) were tested. Only the tetraploid parameterization was able to detect the 53 loci associated with cold-tolerance traits. Out of the 53 single nucleotide polymorphism (SNP) trait associations, 17 controlled more than one trait or were stable across multiple sites. This work represents the first report of QTL for cold-tolerance-related traits, providing insights into its genetic basis and candidate genomic regions for further functional validation studies.
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Paudel D, Kannan B, Yang X, Harris-Shultz K, Thudi M, Varshney RK, Altpeter F, Wang J. Surveying the genome and constructing a high-density genetic map of napiergrass (Cenchrus purpureus Schumach). Sci Rep 2018; 8:14419. [PMID: 30258215 PMCID: PMC6158254 DOI: 10.1038/s41598-018-32674-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2018] [Accepted: 09/13/2018] [Indexed: 01/17/2023] Open
Abstract
Napiergrass (Cenchrus purpureus Schumach) is a tropical forage grass and a promising lignocellulosic biofuel feedstock due to its high biomass yield, persistence, and nutritive value. However, its utilization for breeding has lagged behind other crops due to limited genetic and genomic resources. In this study, next-generation sequencing was first used to survey the genome of napiergrass. Napiergrass sequences displayed high synteny to the pearl millet genome and showed expansions in the pearl millet genome along with genomic rearrangements between the two genomes. An average repeat content of 27.5% was observed in napiergrass including 5,339 simple sequence repeats (SSRs). Furthermore, to construct a high-density genetic map of napiergrass, genotyping-by-sequencing (GBS) was employed in a bi-parental population of 185 F1 hybrids. A total of 512 million high quality reads were generated and 287,093 SNPs were called by using multiple de-novo and reference-based SNP callers. Single dose SNPs were used to construct the first high-density linkage map that resulted in 1,913 SNPs mapped to 14 linkage groups, spanning a length of 1,410 cM and a density of 1 marker per 0.73 cM. This map can be used for many further genetic and genomic studies in napiergrass and related species.
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Affiliation(s)
- Dev Paudel
- Agronomy Department, IFAS, University of Florida, Gainesville, FL, 32611, USA
| | - Baskaran Kannan
- Agronomy Department, IFAS, University of Florida, Gainesville, FL, 32611, USA
| | - Xiping Yang
- Agronomy Department, IFAS, University of Florida, Gainesville, FL, 32611, USA
| | - Karen Harris-Shultz
- Crop Genetics and Breeding Research Unit, USDA-Agricultural Research Service, 115 Coastal Way, Tifton, GA, 31793, USA
| | - Mahendar Thudi
- Center of Excellence in Genomics & Systems Biology, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, 502324, Telangana State, India
| | - Rajeev K Varshney
- Center of Excellence in Genomics & Systems Biology, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Hyderabad, 502324, Telangana State, India
| | - Fredy Altpeter
- Agronomy Department, IFAS, University of Florida, Gainesville, FL, 32611, USA.,Plant Molecular and Cellular Biology Program, Genetic Institute, University of Florida, Gainesville, FL, 32611, USA
| | - Jianping Wang
- Agronomy Department, IFAS, University of Florida, Gainesville, FL, 32611, USA. .,Plant Molecular and Cellular Biology Program, Genetic Institute, University of Florida, Gainesville, FL, 32611, USA. .,Center for Genomics and Biotechnology, Key Laboratory of Genetics, Breeding and Multiple Utilization of Corps, Ministry of Education, Fujian Provincial Key Laboratory of Haixia Applied Plant Systems Biology, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350002, China.
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Capstaff NM, Miller AJ. Improving the Yield and Nutritional Quality of Forage Crops. FRONTIERS IN PLANT SCIENCE 2018; 9:535. [PMID: 29740468 PMCID: PMC5928394 DOI: 10.3389/fpls.2018.00535] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 04/06/2018] [Indexed: 05/02/2023]
Abstract
Despite being some of the most important crops globally, there has been limited research on forages when compared with cereals, fruits, and vegetables. This review summarizes the literature highlighting the significance of forage crops, the current improvements and some of future directions for improving yield and nutritional quality. We make the point that the knowledge obtained from model plant and grain crops can be applied to forage crops. The timely development of genomics and bioinformatics together with genome editing techniques offer great scope to improve forage crops. Given the social, environmental and economic importance of forage across the globe and especially in poorer countries, this opportunity has enormous potential to improve food security and political stability.
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Bisaga M, Lowe M, Hegarty M, Abberton M, Ravagnani A. Deep Sequencing of Suppression Subtractive Hybridisation Drought and Recovery Libraries of the Non-model Crop Trifolium repens L. FRONTIERS IN PLANT SCIENCE 2017; 8:213. [PMID: 28280499 PMCID: PMC5322231 DOI: 10.3389/fpls.2017.00213] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 02/03/2017] [Indexed: 05/08/2023]
Abstract
White clover is a short-lived perennial whose persistence is greatly affected by abiotic stresses, particularly drought. The aim of this work was to characterize its molecular response to water deficit and recovery following re-hydration to identify targets for the breeding of tolerant varieties. We created a white clover reference transcriptome of 16,193 contigs by deep sequencing (mean base coverage 387x) four Suppression Subtractive Hybridization (SSH) libraries (a forward and a reverse library for each treatment) constructed from young leaf tissue of white clover at the onset of the response to drought and recovery. Reads from individual libraries were then mapped to the reference transcriptome and processed comparing expression level data. The pipeline generated four robust sets of transcripts induced and repressed in the leaves of plants subjected to water deficit stress (6,937 and 3,142, respectively) and following re-hydration (6,695 and 4,897, respectively). Semi-quantitative polymerase chain reaction was used to verify the expression pattern of 16 genes. The differentially expressed transcripts were functionally annotated and mapped to biological processes and pathways. In agreement with similar studies in other crops, the majority of transcripts up-regulated in response to drought belonged to metabolic processes, such as amino acid, carbohydrate, and lipid metabolism, while transcripts involved in photosynthesis, such as components of the photosystem and the biosynthesis of photosynthetic pigments, were up-regulated during recovery. The data also highlighted the role of raffinose family oligosaccharides (RFOs) and the possible delayed response of the flavonoid pathways in the initial response of white clover to water withdrawal. The work presented in this paper is to our knowledge the first large scale molecular analysis of the white clover response to drought stress and re-hydration. The data generated provide a valuable genomic resource for marker discovery and ultimately for the improvement of white clover.
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Affiliation(s)
| | | | | | | | - Adriana Ravagnani
- Institute of Biological, Environmental and Rural Sciences, Aberystwyth UniversityAberystwyth, UK
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Abstract
High-throughput next-generation sequence-based genotyping and single nucleotide polymorphism (SNP) detection opens the door for emerging genomics-based breeding strategies such as genome-wide association analysis and genomic selection. In polyploids, SNP detection is confounded by a highly similar homeologous sequence where a polymorphism between subgenomes must be differentiated from a SNP. We have developed and implemented a novel tool called SWEEP: Sliding Window Extraction of Explicit Polymorphisms. SWEEP uses subgenome polymorphism haplotypes as contrast to identify true SNPs between genotypes. The tool is a single command script that calls a series of modules based on user-defined options and takes sorted/indexed bam files or vcf files as input. Filtering options are highly flexible and include filtering based on sequence depth, alternate allele ratio, and SNP quality on top of the SWEEP filtering procedure. Using real and simulated data we show that SWEEP outperforms current SNP filtering methods for polyploids. SWEEP can be used for high-quality SNP discovery in polyploid crops.
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Clevenger J, Chavarro C, Pearl SA, Ozias-Akins P, Jackson SA. Single Nucleotide Polymorphism Identification in Polyploids: A Review, Example, and Recommendations. MOLECULAR PLANT 2015; 8:831-46. [PMID: 25676455 DOI: 10.1016/j.molp.2015.02.002] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Revised: 01/21/2015] [Accepted: 02/01/2015] [Indexed: 05/23/2023]
Abstract
Understanding the relationship between genotype and phenotype is a major biological question and being able to predict phenotypes based on molecular genotypes is integral to molecular breeding. Whole-genome duplications have shaped the history of all flowering plants and present challenges to elucidating the relationship between genotype and phenotype, especially in neopolyploid species. Although single nucleotide polymorphisms (SNPs) have become popular tools for genetic mapping, discovery and application of SNPs in polyploids has been difficult. Here, we summarize common experimental approaches to SNP calling, highlighting recent polyploid successes. To examine the impact of software choice on these analyses, we called SNPs among five peanut genotypes using different alignment programs (BWA-mem and Bowtie 2) and variant callers (SAMtools, GATK, and Freebayes). Alignments produced by Bowtie 2 and BWA-mem and analyzed in SAMtools shared 24.5% concordant SNPs, and SAMtools, GATK, and Freebayes shared 1.4% concordant SNPs. A subsequent analysis of simulated Brassica napus chromosome 1A and 1C genotypes demonstrated that, of the three software programs, SAMtools performed with the highest sensitivity and specificity on Bowtie 2 alignments. These results, however, are likely to vary among species, and we therefore propose a series of best practices for SNP calling in polyploids.
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Affiliation(s)
- Josh Clevenger
- Institute of Plant Breeding, Genetics & Genomics, University of Georgia, Tifton, GA 31793, USA
| | - Carolina Chavarro
- Center for Applied Genetic Technologies, University of Georgia, Athens, GA 30602, USA
| | - Stephanie A Pearl
- Center for Applied Genetic Technologies, University of Georgia, Athens, GA 30602, USA
| | - Peggy Ozias-Akins
- Institute of Plant Breeding, Genetics & Genomics, University of Georgia, Tifton, GA 31793, USA.
| | - Scott A Jackson
- Center for Applied Genetic Technologies, University of Georgia, Athens, GA 30602, USA.
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