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1.
Genome Res ; 29(11): 1805-1815, 2019 11.
Article in English | MEDLINE | ID: mdl-31649058

ABSTRACT

Hybridization drives rapid speciation by shaping novel genotypic and phenotypic profiles. Genomic incompatibility and transcriptome shock have been observed in hybrids, although this is rarer in animals than in plants. Using the newly sequenced genomes of the blunt snout bream (Megalobrama amblycephala [BSB]) and the topmouth culter (Culter alburnus [TC]), we focused on the sequence variation and gene expression changes in the reciprocal intergeneric hybrid lineages (F1-F3) of BSB × TC. A genome-wide transcriptional analysis identified 145-974 expressed recombinant genes in the successive generations of hybrid fish, suggesting the rapid emergence of allelic variation following hybridization. Some gradual changes of gene expression with additive and dominance effects and various cis and trans regulations were observed from F1 to F3 in the two hybrid lineages. These asymmetric patterns of gene expression represent the alternative strategies for counteracting deleterious effects of the subgenomes and improving adaptability of novel hybrids. Furthermore, we identified positive selection and additive expression patterns in transforming growth factor, beta 1b (tgfb1b), which may account for the morphological variations of the pharyngeal jaw in the two hybrid lineages. Our current findings provide insights into the evolution of vertebrate genomes immediately following hybridization.


Subject(s)
Alleles , Cyprinidae/genetics , Hybridization, Genetic , Animals , Female , Male , Polymorphism, Genetic , Sequence Analysis/methods , Species Specificity
2.
Genomics ; 113(3): 1262-1271, 2021 05.
Article in English | MEDLINE | ID: mdl-33689785

ABSTRACT

Sclerotinia stem rot (SSR) is a disease of soybean [Glycine max (L.) Merr] that causes severe yield losses. We studied 185 representative soybean accessions to evaluate partial SSR resistance and sequenced these by the specific-locus amplified fragment sequencing method. In total, 22,048 single-nucleotide polymorphisms (SNPs), with minor allele frequencies (MAF) ≥5% and missing data <3%, were developed and applied to genome-wide association study of SSR responsiveness and assess linkage disequilibrium (LD) level for candidate gene selection. We identified 18 association signals related to SSR partial resistance. Among them, six overlapped the regions of previous quantitative trait loci, and twelve were novel. We identified 243 candidate genes located in the 200 kb genomic region of these peak SNPs. Based on quantitative real-time polymerase chain reaction and haplotype analysis, Glyma.03G196000 and Glyma.20G095100, encoding pentatricopeptide repeat proteins, might be important factors in the resistance response of soybean to SSR.


Subject(s)
Ascomycota , Genome-Wide Association Study , Ascomycota/genetics , Chromosome Mapping/methods , Disease Resistance/genetics , Genome-Wide Association Study/methods , Linkage Disequilibrium , Polymorphism, Single Nucleotide , Glycine max/genetics
3.
Plant J ; 104(4): 950-963, 2020 11.
Article in English | MEDLINE | ID: mdl-32862479

ABSTRACT

Isoflavone, a secondary metabolite produced by Glycine max (L.) Merr. (soybean), is valuable for human and plant health. The genetic architecture of soybean isoflavone content remains unclear, however, despite several mapping studies. We generated genomic data for 200 soybean cultivars and 150 recombinant inbred lines (RILs) to localize putative loci associated with soybean seed isoflavone content. Using a genome-wide association study (GWAS), we identified 87 single-nucleotide polymorphisms (SNPs) that were significantly associated with isoflavone concentration. Using linkage mapping, we identified 37 quantitative trait loci (QTLs) underlying the content of four isoflavones found in the RILs. A major locus on chromosome 8 (qISO8-1) was co-located by both the GWAS and linkage mapping. qISO8-1 was fine mapped to a 99.5-kb region, flanked by SSR_08_1651 and SSR_08_1656, in a BC2 F5 population. GmMPK1, encoding a mitogen-activated protein kinase, was identified as the causal gene in qISO8-1, and two natural GmMPK1 polymorphisms were significantly associated with isoflavone content. Overexpression of GmMPK1 in soybean hairy roots resulted in increased isoflavone concentrations. Overexpressing GmMPK1 in transgenic soybeans had greater resistance to Phytophthora root rot, suggesting that GmMPK1 might increase soybean resistance to biotic stress by influencing isoflavone content. Our results not only increase our understanding of the genetic architecture of soybean seed isoflavone content, but also provide a framework for the future marker-assisted breeding of high isoflavone content in soybean cultivars.


Subject(s)
Glycine max/genetics , Isoflavones/metabolism , Mitogen-Activated Protein Kinases/metabolism , Phytophthora/physiology , Plant Diseases/immunology , Quantitative Trait Loci/genetics , Chromosome Mapping , Disease Resistance , Gene Expression , Genome-Wide Association Study , Isoflavones/analysis , Mitogen-Activated Protein Kinases/genetics , Plant Diseases/parasitology , Plant Proteins/genetics , Plant Proteins/metabolism , Plant Roots/chemistry , Plant Roots/genetics , Plant Roots/immunology , Plant Roots/parasitology , Plants, Genetically Modified , Polymorphism, Single Nucleotide/genetics , Seeds/chemistry , Seeds/genetics , Seeds/immunology , Seeds/parasitology , Glycine max/chemistry , Glycine max/immunology , Glycine max/parasitology , Stress, Physiological
4.
Plant Cell Environ ; 44(8): 2777-2792, 2021 08.
Article in English | MEDLINE | ID: mdl-33866595

ABSTRACT

Soybean mosaic virus (SMV) is one of the most widespread and devastating viral diseases worldwide. The genetic architecture of qualitative resistance to SMV in soybean remains unclear. Here, the Rsvg2 locus was identified as underlying soybean resistance to SMV by genome-wide association and linkage analyses. Fine mapping results showed that soybean resistance to SMV strains G2 and G3 was controlled by a single dominant gene, GmST1, on chromosome 13, encoding a sulfotransferase (SOT). A key variation at position 506 in the coding region of GmST1 associated with the structure of the encoded SOT and changed SOT activity levels between RSVG2-S and RSVG2-R alleles. In RSVG2-S allele carrier "Hefeng25", the overexpression of GmST1 carrying the RSVG2-R allele from the SMV-resistant line "Dongnong93-046" conferred resistance to SMV strains G2 and G3. Compared to Hefeng25, the accumulation of SMV was decreased in transgenic plants carrying the RSVG2-R allele. SMV infection differentiated both the accumulation of jasmonates and expression patterns of genes involved in jasmonic acid (JA) signalling, biosynthesis and catabolism in RSVG2-R and RSVG2-S allele carriers. This characterization of GmST1 suggests a new scenario explaining soybean resistance to SMV.


Subject(s)
Glycine max/genetics , Glycine max/virology , Plant Diseases/virology , Potyvirus/pathogenicity , Soybean Proteins/genetics , Alleles , Chromosomes, Plant , Disease Resistance/genetics , Gene Expression Regulation, Plant , Genetic Linkage , Genome-Wide Association Study , Plant Diseases/genetics , Plants, Genetically Modified , Polymorphism, Genetic , Soybean Proteins/metabolism , Sulfotransferases/genetics , Sulfotransferases/metabolism
5.
Opt Lett ; 46(11): 2714-2717, 2021 Jun 01.
Article in English | MEDLINE | ID: mdl-34061095

ABSTRACT

A special open-cavity Mach-Zehnder salinity sensor is presented and verified in this Letter, which has obvious advantages in salinity sensitivity and loss. The open-cavity structure is composed of a short section of etched double-side hole fiber spliced between a pair of multimode fibers and connected in series between a pair of single-mode fibers, which is the SMF-MMF-etched DSHF-MMF-SMF structure proposed in the paper. According to the experiment results, when the cavity length is about 100 µm, the salinity sensitivity of the sensing probe can reach 2 nm/‰, and its refractive index (RI) sensitivity can be more than 10,000 nm/RIU, while having a low loss of ${-}{15}\;{\rm dB}$ and a detection limit of 0.23‰. Based on its characteristics, the sensor is a prospective online monitor of ocean salinity. At the same time, it also provides a low-cost way to construct an open cavity instead of femtosecond inscribing.

6.
Opt Lett ; 46(13): 3069, 2021 Jul 01.
Article in English | MEDLINE | ID: mdl-34197381

ABSTRACT

This publisher's note contains corrections to Opt. Lett.46, 2714 (2021).OPLEDP0146-959210.1364/OL.428001.

7.
Opt Lett ; 45(24): 6631-6634, 2020 Dec 15.
Article in English | MEDLINE | ID: mdl-33325856

ABSTRACT

A multifunctional optical fiber sensor fabricated by asymmetric offset splicing is proposed in this Letter. The light is divided into several parts at the offset interface, among which the transmitted light forms the Mach-Zehnder interference (MZI) spectrum while the reflected light forms the Fabry-Perot interference (FPI) spectrum. The online monitoring system is built to create a better light distribution at the offset interface. Theoretical analysis and experimental verification are carried out. The results of the experiment show that the proposed sensor has good characteristics of salinity and temperature, and the salinity sensitivity is as high as -2.4473nm/‰ in the range of 20-40‰; the temperature sensitivity is better than 2.17 nm/°C in the range of 28-48 °C. The two interferometers involved have different responses to temperature and salinity, contributing to the effective elimination of cross-sensitivity. The proposed optical fiber sensor has the benefits of compact size, high sensitivity, and multispectral measurement function.

8.
BMC Genomics ; 20(1): 68, 2019 Jan 21.
Article in English | MEDLINE | ID: mdl-30665360

ABSTRACT

BACKGROUND: The nutritional value of soybean oil is largely influenced by the proportions of unsaturated fatty acids (FAs), including oleic acid (OA, 18:1), linoleic acid (LLA, 18:2), and linolenic acid (LNA, 18:3). Genome-wide association (GWAS) studies along with gene expression studies in soybean [Glycine max (L.) Merr.] were leveraged to dissect the genetics of unsaturated FAs. RESULTS: A association panel of 194 diverse soybean accessions were phenotyped in 2013, 2014 and 2015 to identify Single Nucleotide Polymorphisms (SNPs) associated with OA, LLA, and LNA content, and determine putative candidate genes responsible for regulating unsaturated FAs composition. 149 SNPs that represented 73 genomic regions were found to be associated with the unsaturated FA contents in soybean seeds according to the results of GWAS. Twelve novel genes were predicted to be involved in unsaturated FA synthesis in soybean. The relationship between expression pattern of the candidate genes and the accumulation of unsaturated FAs revealed that multiple genes might be involved in unsaturated FAs regulation simultaneously but work in very different ways: Glyma.07G046200 and Glyma.20G245500 promote the OA accumulation in soybean seed in all the tested accessions; Glyma.13G68600 and Glyma.16G200200 promote the OA accumulation only in high OA germplasms; Glyma.07G151300 promotes OA accumulation in higher OA germplasms and suppresses that in lower OA germplasms; Glyma.16G003500 has the effect of increasing LLA accumulation in higher LA germplasms; Glyma.07G254500 suppresses the accumulation of LNA in lower OA germplasms; Glyma.14G194300 might be involved in the accumulation of LNA content in lower LNA germplasms. CONCLUSIONS: The beneficial alleles and candidate genes identified might be valuable for improving marker-assisted breeding efficiency and exploring the molecular mechanisms underlying unsaturated fatty acid of soybean.


Subject(s)
Fatty Acids, Unsaturated/biosynthesis , Glycine max/genetics , Genes, Plant , Genome-Wide Association Study , Linkage Disequilibrium , Polymorphism, Single Nucleotide , Seeds/metabolism , Glycine max/metabolism , Transcription, Genetic
9.
BMC Genomics ; 20(1): 458, 2019 Jun 06.
Article in English | MEDLINE | ID: mdl-31170907

ABSTRACT

BACKGROUND: Chinese bayberry (Myrica rubra Sieb. & Zucc.) is an economically important fruit tree characterized by its juicy fruits rich in antioxidant compounds. Elucidating the genetic basis of the biosynthesis of active antioxidant compounds in bayberry is fundamental for genetic improvement of bayberry and industrial applications of the fruit's antioxidant components. Here, we report the genome sequence of a multiple disease-resistant bayberry variety, 'Zaojia', in China, and the transcriptome dynamics in the course of fruit development. RESULTS: A 289.92 Mb draft genome was assembled, and 26,325 protein-encoding genes were predicted. Most of the M. rubra genes in the antioxidant signaling pathways had multiple copies, likely originating from tandem duplication events. Further, many of the genes found here present structural variations or amino acid changes in the conserved functional residues across species. The expression levels of antioxidant genes were generally higher in the early stages of fruit development, and were correlated with the higher levels of total flavonoids and antioxidant capacity, in comparison with the mature fruit stages. Based on both gene expression and biochemical analyses, five genes, namely, caffeoyl-CoA O-methyltransferase, anthocyanidin 3-O-glucosyltransferase, (+)-neomenthol dehydrogenase, gibberellin 2-oxidase, and squalene monooxygenase, were suggested to regulate the flavonoid, anthocyanin, monoterpenoid, diterpenoid, and sesquiterpenoid/triterpenoid levels, respectively, during fruit development. CONCLUSIONS: This study describes both the complete genome and transcriptome of M. rubra. The results provide an important basis for future research on the genetic improvement of M. rubra and contribute to the understanding of its genetic evolution. The genome sequences corresponding to representative antioxidant signaling pathways can help revealing useful traits and functional genes.


Subject(s)
Genome, Plant , Myrica/genetics , Antioxidants/metabolism , Fruit/genetics , Fruit/growth & development , Fruit/metabolism , Genomics , Myrica/growth & development , Myrica/metabolism , Transcriptome
10.
BMC Genomics ; 20(1): 954, 2019 Dec 09.
Article in English | MEDLINE | ID: mdl-31818245

ABSTRACT

BACKGROUND: Predatory mites (Acari: Phytoseiidae) are the most important beneficial arthropods used in augmentative biological pest control of protected crops around the world. However, the genomes of mites are far less well understood than those of insects and the evolutionary relationships among mite and other chelicerate orders are contested, with the enigmatic origin of mites at one of the centres in discussion of the evolution of Arachnida. RESULTS: We here report the 173 Mb nuclear genome (from 51.75 Gb pairs of Illumina reads) of the predatory mite, Neoseiulus cucumeris, a biocontrol agent against pests such as mites and thrips worldwide. We identified nearly 20.6 Mb (~ 11.93% of this genome) of repetitive sequences and annotated 18,735 protein-coding genes (a typical gene 2888 bp in size); the total length of protein-coding genes was about 50.55 Mb (29.2% of this assembly). About 37% (6981) of the genes are unique to N. cucumeris based on comparison with other arachnid genomes. Our phylogenomic analysis supported the monophyly of Acari, therefore rejecting the biphyletic origin of mites advocated by other studies based on limited gene fragments or few taxa in recent years. Our transcriptomic analyses of different life stages of N. cucumeris provide new insights into genes involved in its development. Putative genes involved in vitellogenesis, regulation of oviposition, sex determination, development of legs, signal perception, detoxification and stress-resistance, and innate immune systems are identified. CONCLUSIONS: Our genomics and developmental transcriptomics analyses of N. cucumeris provide invaluable resources for further research on the development, reproduction, and fitness of this economically important mite in particular and Arachnida in general.


Subject(s)
Genome/genetics , Mites/classification , Mites/genetics , Acari/classification , Acari/genetics , Adaptation, Physiological/genetics , Animals , Biological Control Agents , Evolution, Molecular , Genomics , Immunity, Innate/genetics , Life Cycle Stages/genetics , Mites/growth & development , Mites/physiology , Phylogeny , Repetitive Sequences, Nucleic Acid , Reproduction/genetics , Sequence Analysis, DNA , Species Specificity , Transcriptome
11.
Mol Genet Genomics ; 294(3): 607-620, 2019 Jun.
Article in English | MEDLINE | ID: mdl-30739204

ABSTRACT

As an important and complex trait, inflorescence length (IL) of soybean [Glycine max (L.) Merr.] significantly affected seed yields. Therefore, elucidating molecular basis of inflorescence architecture, especially for IL, was important for improving soybean yield potentials. Longer IL meaned to have more pod and seed in soybean. Hence, increasing IL and improving yield are targets for soybean breeding. In this study, a association panel, comprising 283 diverse samples, was used to dissect the genetic basis of IL based on genome-wide association analysis (GWAS) and haplotype analysis. GWAS and haplotype analysis were conducted through high-throughout single-nucleotide polymorphisms (SNP) developed by SLAF-seq methodology. A total of 39, 057 SNPs (minor allele frequency ≥ 0.2 and missing data ≤ 10%) were utilized to evaluate linkage disequilibrium (LD) level in the tested association panel. A total of 30 association signals were identified to be associated with IL via GWAS. Among them, 13 SNPs were novel, and another 17 SNPs were overlapped or located near the linked regions of known quantitative trait nucleotide (QTN) with soybean seed yield or yield component. The functional genes, located in the 200-kb genomic region of each peak SNP, were considered as candidate genes, such as the cell division/ elongation, specific enzymes, and signaling or transport of specific proteins. These genes have been reported to participant in the regulation of IL. Ten typical long-IL lines and ten typical short-IL lines were re-sequencing, and then, six SNPs from five genes were obtained based on candidate gene-based association. In addition, 42 haplotypes were defined based on haplotype analysis. Of them, 11 haplotypes were found to regulate long IL (> 14 mm) in soybean. The identified 30 QTN with beneficial alleles and their candidate genes might be valuable for dissecting the molecular mechanisms of IL and further improving the yield potential of soybean.


Subject(s)
Genome-Wide Association Study/methods , Glycine max/genetics , Inflorescence/genetics , Polymorphism, Single Nucleotide , Chromosome Mapping , Chromosomes, Plant/genetics , Gene Frequency , Genes, Plant/genetics , Genome, Plant/genetics , Genotype , Haplotypes , Inflorescence/anatomy & histology , Linkage Disequilibrium , Plant Breeding , Quantitative Trait Loci/genetics , Glycine max/anatomy & histology
12.
Theor Appl Genet ; 132(2): 431-441, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30456717

ABSTRACT

KEY MESSAGE: Association analysis techniques were used to identify and verify twelve single nucleotide polymorphisms (SNPs) associated with Fusarium graminearum resistance. Two novel candidate genes were obtained. Fusarium graminearum causes seed and root rot and seedling damping-off of soybean, leading to severe yield loss. Presently, the genetic basis of resistance to F. graminearum is elucidated in only four soybean accessions, which is not sufficient for resistance improvement. The objective of the present study was to identify the genome-wide genetic architecture of resistance to F. graminearum in landraces and cultivated soybeans based on a growth room evaluation. The resistance levels of 314 diverse accessions were tested, and 22,888 single nucleotide polymorphisms (SNPs) with a minor allele frequency of > 0.05 were developed using the specific-locus amplified fragment sequencing (SLAF-seq) approach. Twelve SNPs were identified as associated with F. graminearum resistance, and these SNPs were located at 12 genomic regions on eight chromosomes (Chr.) and could explain 5.53-14.71% of the observed phenotypic variation. One SNP, rs9479021, located on Chr.6, overlapped with qRfg_Gm06, the known QTL for resistance to F. graminearum. The other SNPs were novel and associated with resistance to F. graminearum. Nine novel candidate genes were predicted to contribute to resistance to F. graminearum according to the haplotype and transcript abundance analysis of the candidate genes. The identified markers and resistant cultivars are valuable for the improvement of resistance to F. graminearum.


Subject(s)
Disease Resistance/genetics , Genes, Plant , Glycine max/genetics , Plant Diseases/genetics , Quantitative Trait Loci , Fusarium/pathogenicity , Gene Frequency , Haplotypes , Linkage Disequilibrium , Phenotype , Plant Diseases/microbiology , Polymorphism, Single Nucleotide , Glycine max/microbiology
14.
Cell Physiol Biochem ; 45(2): 677-691, 2018.
Article in English | MEDLINE | ID: mdl-29428937

ABSTRACT

BACKGROUND/AIMS: Circular RNAs (circRNAs) are a class of long noncoding RNAs with a closed loop structure that regulate gene expression as microRNA sponges. CircRNAs are more enriched in brain tissue, but knowledge of the role of circRNAs in temporal lobe epilepsy (TLE) has remained limited. This study is the first to identify the global expression profiles and characteristics of circRNAs in human temporal cortex tissue from TLE patients. METHODS: Temporal cortices were collected from 17 TLE patients and 17 non-TLE patients. Total RNA was isolated, and high-throughput sequencing was used to profile the transcriptome of dysregulated circRNAs. Quantitative PCR was performed for the validation of changed circRNAs. RESULTS: In total, 78983 circRNAs, including 15.29% known and 84.71% novel circRNAs, were detected in this study. Intriguingly, 442 circRNAs were differentially expressed between the TLE and non-TLE groups (fold change≥2.0 and FDR≤0.05). Of these circRNAs, 188 were up-regulated, and 254 were down-regulated in the TLE patient group. Eight circRNAs were validated by real-time PCR. Remarkably, circ-EFCAB2 was intensely up-regulated, while circ-DROSHA expression was significantly lower in the TLE group than in the non-TLE group (P<0.05). Bioinformatic analysis revealed that circ-EFCAB2 binds to miR-485-5p to increase the expression level of the ion channel CLCN6, while circ-DROSHA interacts with miR-1252-5p to decrease the expression level of ATP1A2. CONCLUSIONS: The dysregulations of circRNAs may reflect the pathogenesis of TLE and circ-EFCAB2 and circ-DROSHA might be potential therapeutic targets and biomarkers in TLE patients.


Subject(s)
Epilepsy, Temporal Lobe/pathology , RNA/metabolism , Temporal Lobe/metabolism , Adolescent , Adult , Biomarkers/metabolism , Child , Child, Preschool , Chloride Channels/genetics , Chloride Channels/metabolism , Computational Biology , Down-Regulation , Electroencephalography , Epilepsy, Temporal Lobe/diagnosis , Epilepsy, Temporal Lobe/genetics , Female , Gene Expression Regulation , High-Throughput Nucleotide Sequencing , Humans , Male , MicroRNAs/metabolism , Middle Aged , RNA, Circular , Sequence Analysis, RNA , Sodium-Potassium-Exchanging ATPase/genetics , Sodium-Potassium-Exchanging ATPase/metabolism , Up-Regulation , Young Adult
15.
Plant Biotechnol J ; 16(7): 1363-1374, 2018 07.
Article in English | MEDLINE | ID: mdl-29271050

ABSTRACT

Pomegranate (Punica granatum L.) has an ancient cultivation history and has become an emerging profitable fruit crop due to its attractive features such as the bright red appearance and the high abundance of medicinally valuable ellagitannin-based compounds in its peel and aril. However, the limited genomic resources have restricted further elucidation of genetics and evolution of these interesting traits. Here, we report a 274-Mb high-quality draft pomegranate genome sequence, which covers approximately 81.5% of the estimated 336-Mb genome, consists of 2177 scaffolds with an N50 size of 1.7 Mb and contains 30 903 genes. Phylogenomic analysis supported that pomegranate belongs to the Lythraceae family rather than the monogeneric Punicaceae family, and comparative analyses showed that pomegranate and Eucalyptus grandis share the paleotetraploidy event. Integrated genomic and transcriptomic analyses provided insights into the molecular mechanisms underlying the biosynthesis of ellagitannin-based compounds, the colour formation in both peels and arils during pomegranate fruit development, and the unique ovule development processes that are characteristic of pomegranate. This genome sequence provides an important resource to expand our understanding of some unique biological processes and to facilitate both comparative biology studies and crop breeding.


Subject(s)
Flowers/growth & development , Fruit/genetics , Genome, Plant/genetics , Lythraceae/genetics , Anthocyanins/biosynthesis , Fruit/anatomy & histology , Hydrolyzable Tannins/metabolism , Lythraceae/anatomy & histology , Lythraceae/growth & development , Metabolic Networks and Pathways/genetics , Phylogeny , Quantitative Trait, Heritable , Retroelements/genetics
16.
BMC Genomics ; 18(1): 462, 2017 06 14.
Article in English | MEDLINE | ID: mdl-28615053

ABSTRACT

BACKGROUND: Soybean (Glycine max L. Merr.) cyst nematode (SCN, Heterodera glycines I,) is a major pest of soybean worldwide. The most effective strategy to control this pest involves the use of resistant cultivars. The aim of the present study was to investigate the genome-wide genetic architecture of resistance to SCN HG Type 2.5.7 (race 1) in landrace and elite cultivated soybeans. RESULTS: A total of 200 diverse soybean accessions were screened for resistance to SCN HG Type 2.5.7 and genotyped through sequencing using the Specific Locus Amplified Fragment Sequencing (SLAF-seq) approach with a 6.14-fold average sequencing depth. A total of 33,194 SNPs were identified with minor allele frequencies (MAF) over 4%, covering 97% of all the genotypes. Genome-wide association mapping (GWAS) revealed thirteen SNPs associated with resistance to SCN HG Type 2.5.7. These SNPs were distributed on five chromosomes (Chr), including Chr7, 8, 14, 15 and 18. Four SNPs were novel resistance loci and nine SNPs were located near known QTL. A total of 30 genes were identified as candidate genes underlying SCN resistance. CONCLUSIONS: A total of sixteen novel soybean accessions were identified with significant resistance to HG Type 2.5.7. The beneficial alleles and candidate genes identified by GWAS might be valuable for improving marker-assisted breeding efficiency and exploring the molecular mechanisms underlying SCN resistance.


Subject(s)
Disease Resistance/genetics , Genes, Plant/genetics , Genetic Loci/genetics , Glycine max/genetics , Glycine max/parasitology , Nematoda/physiology , Plant Diseases/parasitology , Animals , Genome-Wide Association Study , Genomics , Linkage Disequilibrium , Quantitative Trait Loci/genetics , Glycine max/immunology
17.
BMC Genomics ; 18(1): 149, 2017 02 10.
Article in English | MEDLINE | ID: mdl-28187716

ABSTRACT

BACKGROUND: The formation of an allopolyploid is a two step process, comprising an initial wide hybridization event, which is later followed by a whole genome doubling. Both processes can affect the transcription of homoeologues. Here, RNA-Seq was used to obtain the genome-wide leaf transcriptome of two independent Triticum turgidum × Aegilops tauschii allotriploids (F1), along with their spontaneous allohexaploids (S1) and their parental lines. The resulting sequence data were then used to characterize variation in homoeologue transcript abundance. RESULTS: The hybridization event strongly down-regulated D-subgenome homoeologues, but this effect was in many cases reversed by whole genome doubling. The suppression of D-subgenome homoeologue transcription resulted in a marked frequency of parental transcription level dominance, especially with respect to genes encoding proteins involved in photosynthesis. Singletons (genes where no homoeologues were present) were frequently transcribed at both the allotriploid and allohexaploid plants. CONCLUSIONS: The implication is that whole genome doubling helps to overcome the phenotypic weakness of the allotriploid, restoring a more favourable gene dosage in genes experiencing transcription level dominance in hexaploid wheat.


Subject(s)
Genome, Plant/genetics , Hybridization, Genetic , Polyploidy , Sequence Homology, Nucleic Acid , Triticum/genetics , Down-Regulation/genetics , Phenotype , RNA, Messenger/genetics
18.
Plant J ; 82(2): 245-55, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25736370

ABSTRACT

Soybean white mold (SWM), caused by Sclerotinia sclerotiorum ((Lib.) W. Phillips), is currently considered to be the second most important cause of soybean yield loss due to disease. Research is needed to identify SWM-resistant germplasm and gain a better understanding of the genetic and molecular basis of SWM resistance in soybean. Stem pigmentation after treatment with oxaloacetic acid is an effective indicator of resistance to SWM. A total of 128 recombinant inbred lines (RILs) derived from a cross of 'Maple Arrow' (partial resistant to SWM) and 'Hefeng 25' (susceptible) and 330 diverse soybean cultivars were screened for the soluble pigment concentration of their stems, which were treated with oxalic acid. Four quantitative trait loci (QTLs) underlying soluble pigment concentration were detected by linkage mapping of the RILs. Three hundred and thirty soybean cultivars were sequenced using the whole-genome encompassing approach and 25 179 single-nucleotide polymorphisms (SNPs) were detected for the fine mapping of SWM resistance genes by genome-wide association studies. Three out of five SNP markers representing a linkage disequilibrium (LD) block and a single locus on chromosome 13 (Gm13) were significantly associated with the soluble pigment content of stems. Three more SNPs that represented three minor QTLs for the soluble pigment content of stems were identified on another three chromosomes by association mapping. A major locus with the largest effect on Gm13 was found both by linkage and association mapping. Four potential candidate genes involved in disease response or the anthocyanin biosynthesis pathway were identified at the locus near the significant SNPs (<60 kbp). The beneficial allele and candidate genes should be useful in soybean breeding for improving resistance to SWM.


Subject(s)
Ascomycota/physiology , Chromosome Mapping , Glycine max/genetics , Glycine max/microbiology , Chromosomes, Plant/genetics , Genome-Wide Association Study , Linkage Disequilibrium/genetics , Plant Diseases/genetics , Plant Diseases/microbiology , Polymorphism, Single Nucleotide/genetics , Quantitative Trait Loci/genetics
19.
New Phytol ; 209(2): 871-84, 2016 Jan.
Article in English | MEDLINE | ID: mdl-26479264

ABSTRACT

Present-day soybeans consist of elite cultivars and landraces (Glycine max, fully domesticated (FD)), annual wild type (Glycine soja, nondomesticated (ND)), and semi-wild type (semi-domesticated (SD)). FD soybean originated in China, although the details of its domestication history remain obscure. More than 500 diverse soybean accessions were sequenced using specific-locus amplified fragment sequencing (SLAF-seq) to address fundamental questions regarding soybean domestication. In total, 64,141 single nucleotide polymorphisms (SNPs) with minor allele frequencies (MAFs) > 0.05 were found among the 512 tested accessions. The results indicated that the SD group is not a hybrid between the FD and ND groups. The initial domestication region was pinpointed to central China (demarcated by the Great Wall to the north and the Qinling Mountains to the south). A total of 800 highly differentiated genetic regions and > 140 selective sweeps were identified, and these were three- and twofold more likely, respectively, to encompass a known quantitative trait locus (QTL) than the rest of the soybean genome. Forty-three potential quantitative trait nucleotides (QTNs; including 15 distinct traits) were identified by genome-wide association mapping. The results of the present study should be beneficial for soybean improvement and provide insight into the genetic architecture of traits of agronomic importance.


Subject(s)
Crops, Agricultural/genetics , Domestication , Glycine max/genetics , China , Gene Flow , Gene Frequency , Genome, Plant , Genome-Wide Association Study , Plant Breeding , Polymorphism, Single Nucleotide , Quantitative Trait Loci , Selection, Genetic
20.
Poult Sci ; 95(3): 500-6, 2016 Mar.
Article in English | MEDLINE | ID: mdl-26614681

ABSTRACT

Carcass traits are important to the commercial chicken industry, and understanding the genetics of these traits will be useful in the development of commercially viable varieties of chickens. We conducted a genome-wide association study based on 8 carcass trait phenotypes in a population of 400 43-week-old Jinghai Yellow chickens. Specific-locus amplified fragment sequencing technology was used to identify 90,961 single nucleotide polymorphisms (SNP) distributed among 29 chromosomes and the mitochondrial genome. SNP that were significantly associated with phenotypic traits were identified by a simple general linear model. Fifteen SNP attained genome-wide significance (P < 1.87E−6) and were associated with 5 of the 8 carcass traits; only one SNP was significantly associated with 2 traits (foot weight and wing weight). Twelve genes were associated with these 15 SNP. A region of chromosome 4 between 75.5 and 76.1 Mb was associated with carcass weight, foot weight, and wing weight. An 84-kb region on chromosome 3 (51.2 Mb) was associated with eviscerated weight and semi-eviscerated weight.


Subject(s)
Chickens/physiology , Genome-Wide Association Study , Polymorphism, Single Nucleotide , Animals , Body Weight , Chickens/genetics , Female , Organ Size
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