Whole-genome resequencing of Osmanthus fragrans provides insights into flower color evolution

AbstractOsmanthus fragrans is a well-known ornamental plant that has been domesticated in China for 2500 years. More than 160 cultivars have been found during this long period of domestication, and they have subsequently been divided into four cultivar groups, including the Yingui, Jingui, Dangui, and Sijigui groups. These groups provide a set of materials to study genetic evolution and variability. Here, we constructed a reference genome of O. fragrans ‘Liuyejingui’ in the Jingui group and investigated its floral color traits and domestication history by resequencing a total of 122 samples, including 119 O. fragrans accessions and three other Osmanthus species, at an average sequencing depth of 15×. The population structure analysis showed that these 119 accessions formed an apparent regional cluster. The results of linkage disequilibrium (LD) decay analysis suggested that varieties with orange/red flower color in the Dangui group had undergone more artificial directional selection; these varieties had the highest LD values among the four groups, followed by the Sijigui, Jingui, and Yingui groups. Through a genome-wide association study, we further identified significant quantitative trait loci and genomic regions containing several genes, such as ethylene-responsive transcription factor 2 and Arabidopsis pseudoresponse regulator 2, that are positively associated with petal color. Moreover, we found a frameshift mutation with a 34-bp deletion in the first coding region of the carotenoid cleavage dioxygenase 4 gene. This frameshift mutation existed in at least one site on both alleles in all varieties of the Dangui group. The results from this study shed light on the genetic basis of domestication in woody plants, such as O. fragrans.

Download Full-text

An FGA Frameshift Variant Associated with Afibrinogenemia in Dachshunds

Genes ◽

10.3390/genes12071065 ◽

2021 ◽

Vol 12 (7) ◽

pp. 1065

Author(s):

Reinhard Mischke ◽

Julia Metzger ◽

Ottmar Distl

Keyword(s):

Protein Sequence ◽

Sanger Sequencing ◽

Selective Breeding ◽

Genome Wide Association Study ◽

Frameshift Mutation ◽

Homozygosity Mapping ◽

Genomic Region ◽

Severe Bleeding ◽

Genome Wide ◽

A Genome

Congenital fibrinogen disorders are very rare in dogs. Cases of afibrinogenemia have been reported in Bernese Mountain, Bichon Frise, Cocker Spaniel, Collie, Lhasa Apso, Viszla, and St. Bernard dogs. In the present study, we examined four miniature wire-haired Dachshunds with afibrinogenemia and ascertained their pedigree. Homozygosity mapping and a genome-wide association study identified a candidate genomic region at 50,188,932–64,187,680 bp on CFA15 harboring FGB (fibrinogen beta chain), FGA (fibrinogen alpha chain), and FGG (fibrinogen gamma-B chain). Sanger sequencing of all three fibrinogen genes in two cases and validation of the FGA-associated mutation (FGA:g.6296delT, NC_006597.3:g.52240694delA, rs1152388481) in pedigree members showed a perfect co-segregation with afibrinogenemia-affected phenotypes, obligate carriers, and healthy animals. In addition, the rs1152388481 variant was validated in 393 Dachshunds and samples from 33 other dog breeds. The rs1152388481 variant is predicted to modify the protein sequence of both FGA transcripts (FGA201:p.Ile486Met and FGA-202:p.Ile555Met) leading to proteins truncated by 306 amino acids. The present data provide evidence for a novel FGA truncating frameshift mutation that is very likely to explain the cases of severe bleeding due to afibrinogenemia in a Dachshund family. This mutation has already been spread in Dachshunds through carriers before cases were ascertained. Genetic testing allows selective breeding to prevent afibrinogenemia-affected puppies in the future.

Download Full-text

Simultaneous Dissection of Grain Carotenoid Levels and Kernel Color in Biparental Maize Populations with Yellow-to-Orange Grain

10.1101/2021.09.01.458275 ◽

2021 ◽

Author(s):

Mary-Francis LaPorte ◽

Mishi Vachev ◽

Matthew Fenn ◽

Christine Diepenbrock

Keyword(s):

Genome Wide Association Study ◽

Vitamin A Deficiency ◽

Provitamin A ◽

Human Populations ◽

Carotenoid Cleavage Dioxygenase ◽

Total Carotenoids ◽

Nested Association Mapping ◽

Kernel Color ◽

A Genome ◽

Variation Explained

ABSTRACTMaize enriched in provitamin A carotenoids could be key in combatting vitamin A deficiency in human populations relying on maize as a food staple. Consumer studies indicate that orange maize may be regarded as novel and preferred. This study identifies genes of relevance for grain carotenoid concentrations and kernel color, through simultaneous dissection of these traits in 10 families of the U.S. maize nested association mapping population that have yellow to orange grain. Quantitative trait loci (QTL) were identified via joint-linkage analysis, with phenotypic variation explained for individual kernel color QTL ranging from 2.4 to 17.5%. These QTL were cross-analyzed with significant marker-trait associations in a genome-wide association study that utilized ∼27 million variants. Nine genes were identified: four encoding activities upstream of the core carotenoid pathway, one at the pathway branchpoint, three within the α- or β-pathway branches, and one encoding a carotenoid cleavage dioxygenase. Of these, three exhibited significant pleiotropy between kernel color and one or more carotenoid traits. Kernel color exhibited moderate positive correlations with β-branch and total carotenoids and negligible correlations with α-branch carotenoids. These findings can be leveraged to simultaneously achieve desirable kernel color phenotypes and increase concentrations of provitamin A and other priority carotenoids.

Download Full-text

Genome-Wide Association Mapping of Late Blight Tolerance Trait in Potato (Solanum tuberosum L.)

Frontiers in Genetics ◽

10.3389/fgene.2021.714575 ◽

2021 ◽

Vol 12 ◽

Author(s):

Fang Wang ◽

Meiling Zou ◽

Long Zhao ◽

Zhiqiang Xia ◽

Jian Wang

Keyword(s):

Solanum Tuberosum ◽

Late Blight ◽

Potato Breeding ◽

Genome Wide Association Study ◽

Solanum Tuberosum L ◽

Potato Cultivars ◽

Genome Wide Association ◽

Genome Wide ◽

Population Structure Analysis ◽

A Genome

Uncovering the genetic basis and optimizing the late blight tolerance trait in potatoes (Solanum tuberosum L.) are crucial for potato breeding. Late blight disease is one of the most significant diseases hindering potato production. The traits of late blight tolerance were evaluated for 284 potato cultivars to identify loci significantly associated with the late blight tolerance trait. Of all, 37 and 15 were the most tolerant to disease, and 107 and 30 were the most susceptible. A total of 22,489 high-quality single-nucleotide polymorphisms and indels were identified in 284 potato cultivars. All the potato cultivars were clustered into eight subgroups using population structure analysis and principal component analysis, which were consistent with the results of the phylogenetic tree analysis. The average genetic diversity for all 284 potato cultivars was 0.216, and the differentiation index of each subgroup was 0.025–0.149. Genome-wide linkage disequilibrium (LD) analysis demonstrated that the average LD was about 0.9 kb. A genome-wide association study using a mixed linear model identified 964 loci significantly associated with the late blight tolerance trait. Fourteen candidate genes for late blight tolerance traits were identified, including genes encoding late blight tolerance protein, chitinase 1, cytosolic nucleotide-binding site–leucine-rich repeat tolerance protein, protein kinase, ethylene-responsive transcription factor, and other potential plant tolerance-related proteins. This study provides novel insights into the genetic architecture of late blight tolerance traits and will be helpful for late blight tolerance in potato breeding.

Download Full-text

GWAS Analysis of Wheat Pre-breeding Germplasm for Terminal Drought Stress Using Next Generation Sequencing Technology

10.20944/preprints202002.0272.v1 ◽

2020 ◽

Cited By ~ 1

Author(s):

Sajid Shokat ◽

Deepmala Sehgal ◽

Fulai Liu ◽

Sukhwinder Singh

Keyword(s):

Drought Stress ◽

Candidate Genes ◽

Vegetation Index ◽

Genome Wide Association Study ◽

Potential Candidate ◽

Terminal Drought ◽

Genome Wide ◽

Population Structure Analysis ◽

A Genome ◽

Terminal Drought Stress

Bread wheat (Triticum aestivum L.) is one of the most important cereal crops for food security. Of all the stresses that curtail wheat productivity, drought has the most detrimental effects. Especially terminal drought stress i.e. at the time of flowering imposes a big challenge to sustain grain production. In the current study, 339 pre-breeding lines derived from three-way crosses of exotics x elite lines were evaluated in the irrigated and drought stress environments at Obregon, Mexico for the year 2016 and 2018. Drought significantly reduced yield (Y), spike length (SL), number of grains per spikes (NGS) and thousand kernel weight (TKW) by 46.4, 19.2, 23.5 and 25.9%, respectively in comparison to irrigated conditions. Kernel abortion (KA), highly correlated with Y, increased significantly (11.6%) under drought stress environment. Population structure analysis in this panel revealed three sub-populations and a genome wide linkage disequilibrium (LD) decay was at 2.5 cM. Single marker and haplotypes-based genome wide association study (GWAS) revealed significant associations on three chromosomes; 4A (HB10.7), 2D (HB6.10) and 3B (HB8.12) with Y, SL and TKW, respectively. Likewise, associations on chromosomes 6B (HB17.1) and 3A (HB7.11) were identified for NGS and on 3A (HB7.12) for KA. Five traits i.e. normalized difference vegetation index (NDVI), canopy temperature depression (CTD) days to heading (DTH), NGS, KA were associated at chromosome 3A both under irrigated and drought conditions however, different haplotypes were estimated. Twenty-six SNPs were part of 10 haplotype blocks associated with Y, SL, TKW, NGS and KA. In silico analysis of the associated SNPs/haplotypes showed hits with candidate genes known to confer abiotic stress resistance in model species and crops. Potential candidate genes include those coding for sulfite exporter TauE/SafE family in Arabidopsis thaliana, TBC domain containing protein in Oryza sativa subsp. Japonica and heat shock proteins in Aegilops tauschii subsp. tauschii were revealed. The SNPs linked to the promising genes identified in the study can be used for marker-assisted selection.

Download Full-text

Simultaneous Dissection of Grain Carotenoid Levels and Kernel Color in Biparental Maize Populations with Yellow-to-Orange Grain

G3 Genes|Genome|Genetics ◽

10.1093/g3journal/jkac006 ◽

2022 ◽

Author(s):

Mary-Francis LaPorte ◽

Mishi Vachev ◽

Matthew Fenn ◽

Christine Diepenbrock

Keyword(s):

Genome Wide Association Study ◽

Vitamin A Deficiency ◽

Provitamin A ◽

Human Populations ◽

Carotenoid Cleavage Dioxygenase ◽

Total Carotenoids ◽

Nested Association Mapping ◽

Kernel Color ◽

Mapping Panel ◽

A Genome

ABSTRACT Maize enriched in provitamin A carotenoids could be key in combatting vitamin A deficiency in human populations relying on maize as a food staple. Consumer studies indicate that orange maize may be regarded as novel and preferred. This study identifies genes of relevance for grain carotenoid concentrations and kernel color, through simultaneous dissection of these traits in 10 families of the U.S. maize nested association mapping panel that have yellow to orange grain. Quantitative trait loci (QTL) were identified via joint-linkage analysis, with phenotypic variation explained for individual kernel color QTL ranging from 2.4 to 17.5%. These QTL were cross-analyzed with significant marker-trait associations in a genome-wide association study that utilized ∼27 million variants. Nine genes were identified: four encoding activities upstream of the core carotenoid pathway, one at the pathway branchpoint, three within the α- or β-pathway branches, and one encoding a carotenoid cleavage dioxygenase. Of these, three exhibited significant pleiotropy between kernel color and one or more carotenoid traits. Kernel color exhibited moderate positive correlations with β-branch and total carotenoids and negligible correlations with α-branch carotenoids. These findings can be leveraged to simultaneously achieve desirable kernel color phenotypes and increase concentrations of provitamin A and other priority carotenoids.

Download Full-text

Genome-Wide Association Study in Wheat Identifies Resistance to the Cereal Cyst Nematode Heterodera filipjevi

Phytopathology ◽

10.1094/phyto-02-16-0054-fi ◽

2016 ◽

Vol 106 (10) ◽

pp. 1128-1138 ◽

Cited By ~ 21

Author(s):

Shree R. Pariyar ◽

Abdelfattah A. Dababat ◽

Wiebke Sannemann ◽

Gul Erginbas-Orakci ◽

Abdelnaser Elashry ◽

...

Keyword(s):

Association Study ◽

Genome Wide Association Study ◽

Phenotypic Diversity ◽

Cyst Nematode ◽

Genome Wide Association ◽

Cyst Nematodes ◽

Genome Wide ◽

Population Structure Analysis ◽

A Genome ◽

Heterodera Filipjevi

The cyst nematode Heterodera filipjevi is a plant parasite causing substantial yield loss in wheat. Resistant cultivars are the preferred method of controlling cyst nematodes. Association mapping is a powerful approach to detect associations between phenotypic variation and genetic polymorphisms; in this way favorable traits such as resistance to pathogens can be located. Therefore, a genome-wide association study of 161 winter wheat accessions was performed with a 90K iSelect single nucleotide polymorphism (SNP) chip. Population structure analysis grouped into two major subgroups and first principal component accounted 6.16% for phenotypic diversity. The genome-wide linkage disequilibrium across wheat was 3 cM. Eleven quantitative trait loci (QTLs) on chromosomes 1AL, 2AS, 2BL, 3AL, 3BL, 4AS, 4AL, 5BL, and 7BL were identified using a mixed linear model false discovery rate of P < 0.01 that explained 43% of total genetic variation. This is the first report of QTLs conferring resistance to H. filipjevi in wheat. Eight QTLs on chromosomes 1AL, 2AS, 2BL, 3AL, 4AL, and 5BL were linked to putative genes known to be involved in plant−pathogen interactions. Two other QTLs on 3BL and one QTL on 7BL linked to putative genes known to be involved in abiotic stress.

Download Full-text

SARS-CoV-2 genetic variations associated with COVID-19 severity

10.1101/2020.05.27.20114546 ◽

2020 ◽

Cited By ~ 4

Author(s):

Pakorn Aiewsakun ◽

Patompon Wongtrakoongate ◽

Yuttapong Thawornwattana ◽

Suradej Hongeng ◽

Arunee Thitithanyanont

Keyword(s):

Genome Wide Association Study ◽

Genetic Variations ◽

Genome Wide Association ◽

Clinical Samples ◽

Structural Protein ◽

Coding Region ◽

Patient Status ◽

Genome Wide ◽

A Genome ◽

Asymptomatic Infections

AbstractHerein, we performed a genome-wide association study on SARS-CoV-2 genomes to identify genetic variations that might be associated with the COVID-19 severity. 152 full-length genomes of SARS-CoV-2 that were generated from original clinical samples and whose patient status could be determined conclusively as either “asymptomatic” or “symptomatic” were retrieved from the GISAID database. We found that nucleotide variations at the genomic position 11,083, locating in the coding region of non-structural protein 6, were associated with the COVID-19 severity. While the 11083G variant (i.e. having G at the position 11,083) was more commonly found in symptomatic patients, the 11083T variant appeared to associate more often with asymptomatic infections. We also identified three microRNAs that differentially target the two variants, namely miR-485-3p, miR-539-3p, and miR-3149. This may in part contribute to the differential association of the two SARS-CoV-2 variants with the disease severity.

Download Full-text

Genome-Wide Association Study of Kernel Traits in Aegilops tauschii

Frontiers in Genetics ◽

10.3389/fgene.2021.651785 ◽

2021 ◽

Vol 12 ◽

Author(s):

Qing Wang ◽

Ning Yan ◽

Hao Chen ◽

Sirui Li ◽

Haiyan Hu ◽

...

Keyword(s):

Population Structure ◽

Genome Wide Association Study ◽

Aegilops Tauschii ◽

Genome Wide Association ◽

Kernel Width ◽

Genome Wide ◽

Population Structure Analysis ◽

Kernel Length ◽

A Genome ◽

Kernel Traits

Aegilops tauschii is the diploid progenitor of the D subgenome of hexaploid wheat (Triticum aestivum L.). Here, the phenotypic data of kernel length (KL), kernel width (KW), kernel volume (KV), kernel surface area (KSA), kernel width to length ratio (KWL), and hundred-kernel weight (HKW) for 223 A. tauschii accessions were gathered across three continuous years. Based on population structure analysis, 223 A. tauschii were divided into two subpopulations, namely T-group (mainly included A. tauschii ssp. tauschii accessions) and S-group (mainly included A. tauschii ssp. strangulata). Classifications based on cluster analysis were highly consistent with the population structure results. Meanwhile, the extent of linkage disequilibrium decay distance (r2 = 0.5) was about 110 kb and 290 kb for T-group and S-group, respectively. Furthermore, a genome-wide association analysis was performed on these kernel traits using 6,723 single nucleotide polymorphism (SNP) markers. Sixty-six significant markers, distributed on all seven chromosomes, were identified using a mixed linear model explaining 4.82–13.36% of the phenotypic variations. Among them, 15, 28, 22, 14, 21, and 13 SNPs were identified for KL, KW, KV, KSA, KWL, and HKW, respectively. Moreover, six candidate genes that may control kernel traits were identified (AET2Gv20774800, AET4Gv20799000, AET5Gv20005900, AET5Gv20084100, AET7Gv20644900, and AET5Gv21111700). The transfer of beneficial genes from A. tauschii to wheat using marker-assisted selection will broaden the wheat D subgenome improve the efficiency of breeding.

Download Full-text