scholarly journals Genetic architecture and marker-assisted breeding for salt tolerance in soybean

2018 ◽  
Author(s):  
◽  
Tuyen Duc Do

Salinity is one of the major abiotic stresses that inhibits plant growth and causes seed yield loss in soybean. Although a major gene for salt tolerance on chromosome (Chr.) 3 was mapped, cloned and characterized, it does not fully explain genetic variability for tolerance in soybean. Two mapping approaches, quantitative trait loci (QTL) mapping and genome-wide association study (GWAS), can complement each other to identify genomic regions and molecular markers associated with traits of interest. QTL mapping is more suitable to map traits governed by rare alleles in a designed population while GWAS is better in mapping traits underlined by few genes of large effect in the natural population. This study was performed to identify additional loci and new sources for salt tolerance by using both approaches. For bi-parental QTL mapping, salt tolerance of 132 F2 families was evaluated by accessing leaf scorch score (LSS), chlorophyll content ratio (CCR), leaf sodium content (LSC), and leaf chloride content (LCC). Their genotypes were obtained using the Illumina Infinium SoySNP6K BeadChip assay to map salt tolerant gene(s). A major locus significantly associated with LSS, CCR, LSC, and LCC was mapped to Chr. 3 with LOD scores of 19.1, 11.0, 7.7, and 25.6, respectively. In addition, a second locus associated with salt tolerance for LSC was also detected and mapped on Chr. 13 with a LOD score of 4.6 and an R2 of 0.115. The evaluation of salt tolerance of an F5 population derived from the same cross showed that combining salt tolerant alleles of major and minor loci significantly increased salt tolerance. On the other hand, GWAS for salt tolerance was conducted using SNPs of two datasets, SoySNP50K iSelect BeadChip and 3.7M SNP dataset (from whole-genome sequencing data), across 305 soybean accessions of a diverse panel. The known gene on Chr. 3 was confirmed by three gene-based markers (GBMs) that integrated into both datasets. Other genomic regions significantly associated with salt tolerance were identified on Chrs. 1, 2, 5, 6, 8, 14, 18, and 19 by analyzing 3.7M SNP dataset, in which the position on Chr. 8 strongly predicted a new minor locus for salt tolerance. The genotype-phenotype correlation using three GBMs discovered six new salt tolerant sources that may carry novel gene(s) for salt tolerance. By complementation tests and segregation analysis of salt tolerance among F2 plants developed from a cross of Fiskeby III and a salt tolerance accession, PI 468908, it was speculated that salt tolerance from PI 468908 was possibly controlled by a new gene instead of the known gene on Chr. 3. These significant loci in new salt tolerant sources coupled with significant SNP markers could be useful for marker-assisted selection in molecular breeding programs to improve salt tolerance in soybean.

Genes ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 803 ◽  
Author(s):  
Wang ◽  
Yan ◽  
Li ◽  
Li ◽  
Zhao ◽  
...  

Peanut (Arachis hypogaea L.) is one of the most important oil crops worldwide, and its yet increasing market demand may be met by genetic improvement of yield related traits, which may be facilitated by a good understanding of the underlying genetic base of these traits. Here, we have carried out a genome-wide association study (GWAS) with the aim to identify genomic regions and the candidate genes within these regions that may be involved in determining the phenotypic variation at seven yield-related traits in peanut. For the GWAS analyses, 195 peanut accessions were phenotyped and/or genotyped; the latter was done using a genotyping-by-sequencing approach, which produced a total of 13,435 high-quality single nucleotide polymorphisms (SNPs). Analyses of these SNPs show that the analyzed peanut accessions can be approximately grouped into two big groups that, to some extent, agree with the botanical classification of peanut at the subspecies level. By taking this genetic structure as well as the relationships between the analyzed accessions into consideration, our GWAS analyses have identified 93 non-overlapping peak SNPs that are significantly associated with four of the studied traits. Gene annotation of the genome regions surrounding these peak SNPs have found a total of 311 unique candidate genes. Among the 93 yield-related-trait-associated SNP peaks, 12 are found to be co-localized with the quantitative trait loci (QTLs) that were identified by earlier related QTL mapping studies, and these 12 SNP peaks are only related to three traits and are almost all located on chromosomes Arahy.05 and Arahy.16. Gene annotation of these 12 co-localized SNP peaks have found 36 candidates genes, and a close examination of these candidate genes found one very interesting gene (arahy.RI9HIF), the rice homolog of which produces a protein that has been shown to improve rice yield when over-expressed. Further tests of the arahy.RI9HIF gene, as well as other candidate genes especially those within the more confident co-localized genomic regions, may hold the potential for significantly improving peanut yield.


2016 ◽  
Author(s):  
Lyndal Henden ◽  
Stuart Lee ◽  
Ivo Mueller ◽  
Alyssa Barry ◽  
Melanie Bahlo

AbstractIdentification of genomic regions that are identical by descent (IBD) has proven useful for human genetic studies where analyses have led to the discovery of familial relatedness and fine-mapping of disease critical regions. Unfortunately however, IBD analyses have been underutilized inanalysis of other organisms, including human pathogens. This is in part due to the lack of statistical methodologies for non-diploid genomes in addition to the added complexity of multiclonal infections. As such, we have developed an IBD methodology, called isoRelate, for analysis of haploid recombining microorganisms in the presence of multiclonal infections. Using the inferred IBD status at genomic locations, we have also developed a novel statistic for identifying loci under positive selection and propose relatedness networks as a means of exploring shared haplotypes within populations. We evaluate the performance of our methodologies for detecting IBD and selection, including comparisons with existing tools, then perform an exploratory analysis of whole genome sequencing data from a global Plasmodium falciparum dataset of more than 2500 genomes. This analysis identifies Southeast Asia as havingmany highly related isolates, possibly as a result of both reduced transmission from intensified control efforts and population bottlenecks following the emergence of antimalarial drug resistance. Many signals of selection are also identified, most of which overlap genes that are known to be associated with drug resistance, in addition to two novel signals observed in multiple countries that have yet to be explored in detail. Additionally, we investigate relatedness networks over the selected loci and determine that one of these sweeps has spread between continents while the other has arisen independently in different countries. IBD analysis of microorganisms using isoRelate can be used for exploring population structure, positive selection and haplotype distributions, and will be a valuable tool for monitoring disease control and elimination efforts of many diseases.


2020 ◽  
Author(s):  
Pengfei Hu ◽  
Yongyan Deng ◽  
Hengxing Ba ◽  
chunyi li

Abstract Sika deer (Cervus nippon) constitutes one of the most valuable animal genetic resources in east Asia. The aim of this study was to identify and validate single nucleotide polymorphisms (SNPs) from antler growth-related genes of sika deer. The whole genome sequencing data of sika deer were used to identify SNP markers. Among them, 31 SNPs from antler growth-related genes exhibited significant polymorphism using genotyping by mass spectrometry. The observed and expected heterozygosities were ranged from 0.147 to 0.997 and 0.201 to 0.500, respectively. Significant deviation from the Hardy-Weinberg equilibrium was observed in 6 loci. These findings provide effective molecular detection markers for the study of variation in antler growth rate of sika deer.


2021 ◽  
Vol 32 (Issue 1) ◽  
pp. 25-33
Author(s):  
M. Ruiz ◽  
E.A. Rossi ◽  
N.C. Bonamico ◽  
M.G. Balzarini

Maize (Zea Mays L.) production has been greatly benefited from the improvement of inbred lines in regard to the resistance to diseases. However, the absence of resistant genotypes to bacteriosis is remarkable. The aim of the study was to identify genomic regions for resistance to Mal de Río Cuarto (MRC) and to bacterial disease (BD) in a diverse maize germplasm evaluated in the Argentinian region where MRC virus is endemic. A maize diverse population was assessed for both diseases during the 2019-2020 crop season. Incidence and severity of MRC and BD were estimated for each line and a genome wide association study (GWAS) was conducted with 78,376 SNP markers. A multi-trait mixed linear model was used for simultaneous evaluation of resistance to MRC and BD in the scored lines. The germplasm showed high genetic variability for both MRC and BD resistance. No significant genetic correlation was observed between the response to both diseases. Promising genomic regions for resistance to MRC and BD were identified and will be confirmed in further trials. Key words: maize disease; genome wide association study; SNP; multi-trait model


2021 ◽  
Vol 32 (Issue 1) ◽  
pp. 25-33
Author(s):  
M. Ruiz ◽  
E.A. Ross ◽  
N.C. Bonamico ◽  
M.G. Balzarini

Maize (Zea Mays L.) production has been greatly benefited from the improvement of inbred lines in regard to the resistance to diseases. However, the absence of resistant genotypes to bacteriosis is remarkable. The aim of the study was to identify genomic regions for resistance to Mal de Río Cuarto (MRC) and to bacterial disease (BD) in a diverse maize germplasm evaluated in the Argentinian region where MRC virus is endemic. A maize diverse population was assessed for both diseases during the 2019-2020 crop season. Incidence and severity of MRC and BD were estimated for each line and a genome wide association study (GWAS) was conducted with 78,376 SNP markers. A multi-trait mixed linear model was used for simultaneous evaluation of resistance to MRC and BD in the scored lines. The germplasm showed high genetic variability for both MRC and BD resistance. No significant genetic correlation was observed between the response to both diseases. Promising genomic regions for resistance to MRC and BD were identified and will be confirmed in further trials. Key words: maize disease; genome wide association study; SNP; multi-trait model


2021 ◽  
Author(s):  
Ankita Narang ◽  
Paul Lacaze ◽  
Kathlyn Ronaldson ◽  
John McNeil ◽  
Mahesh Jayaram ◽  
...  

One of the concerns limiting the use of clozapine in schizophrenia treatment is the risk of rare but potentially fatal myocarditis. Our previous genome-wide association study and human leucocyte antigen analyses identified putative loci associated with clozapine-induced myocarditis. However, the contribution of DNA variation in cytochrome P450 genes, copy number variants and rare deleterious variants have not been investigated. We explored these unexplored classes of DNA variation using whole-genome sequencing data from 25 cases with clozapine-induced myocarditis and 25 demographically-matched clozapine-tolerant control subjects. We identified 15 genes based on rare variant gene-burden analysis (MLLT6, CADPS, TACC2, L3MBTL4, NPY, SLC25A21, PARVB, GPR179, ACAD9, NOL8, C5orf33, FAM127A, AFDN, SLC6A11, PXDN) nominally associated (p<0.05) with clozapine-induced myocarditis. Of these genes, 13 were expressed in human myocardial tissue. Although independent replication of these findings is required, our study provides preliminary insights into the potential role of rare genetic variants in susceptibility to clozapine-induced myocarditis.


Author(s):  
Sofonias K Tessema ◽  
Nicholas J Hathaway ◽  
Noam B Teyssier ◽  
Maxwell Murphy ◽  
Anna Chen ◽  
...  

Abstract Background Targeted next-generation sequencing offers the potential for consistent, deep coverage of information-rich genomic regions to characterize polyclonal Plasmodium falciparum infections. However, methods to identify and sequence these genomic regions are currently limited. Methods A bioinformatic pipeline and multiplex methods were developed to identify and simultaneously sequence 100 targets and applied to dried blood spot (DBS) controls and field isolates from Mozambique. For comparison, whole-genome sequencing data were generated for the same controls. Results Using publicly available genomes, 4465 high-diversity genomic regions suited for targeted sequencing were identified, representing the P. falciparum heterozygome. For this study, 93 microhaplotypes with high diversity (median expected heterozygosity = 0.7) were selected along with 7 drug resistance loci. The sequencing method achieved very high coverage (median 99%), specificity (99.8%), and sensitivity (90% for haplotypes with 5% within sample frequency in dried blood spots with 100 parasites/µL). In silico analyses revealed that microhaplotypes provided much higher resolution to discriminate related from unrelated polyclonal infections than biallelic single-nucleotide polymorphism barcodes. Conclusions The bioinformatic and laboratory methods outlined here provide a flexible tool for efficient, low-cost, high-throughput interrogation of the P. falciparum genome, and can be tailored to simultaneously address multiple questions of interest in various epidemiological settings.


2020 ◽  
Vol 61 (7) ◽  
pp. 1285-1296
Author(s):  
Lorraine Mhoswa ◽  
Marja M O’Neill ◽  
Makobatjatji M Mphahlele ◽  
Caryn N Oates ◽  
Kitt G Payn ◽  
...  

Abstract The galling insect, Leptocybe invasa, causes significant losses in plantations of various Eucalyptus species and hybrids, threatening its economic viability. We applied a genome-wide association study (GWAS) to identify single-nucleotide polymorphism (SNP) markers associated with resistance to L. invasa. A total of 563 insect-challenged Eucalyptus grandis trees, from 61 half-sib families, were genotyped using the EUChip60K SNP chip, and we identified 15,445 informative SNP markers in the test population. Multi-locus mixed-model (MLMM) analysis identified 35 SNP markers putatively associated with resistance to L. invasa based on four discreet classes of insect damage scores: (0) not infested, (1) infested showing evidence of oviposition but no gall development, (2) infested with galls on leaves, midribs or petioles and (3) stunting and lethal gall formation. MLMM analysis identified three associated genomic regions on chromosomes 3, 7 and 8 jointly explaining 17.6% of the total phenotypic variation. SNP analysis of a validation population of 494 E. grandis trees confirmed seven SNP markers that were also detected in the initial association analysis. Based on transcriptome profiles of resistant and susceptible genotypes from an independent experiment, we identified several putative candidate genes in associated genomic loci including Nucleotide-binding ARC- domain (NB-ARC) and toll-interleukin-1-receptor-Nucleotide binding signal- Leucine rich repeat (TIR-NBS-LRR) genes. Our results suggest that Leptocybe resistance in E. grandis may be influenced by a few large-effect loci in combination with minor effect loci segregating in our test and validation populations.


Plants ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 97
Author(s):  
Juyun Zheng ◽  
Zeliang Zhang ◽  
Zhaolong Gong ◽  
Yajun Liang ◽  
Zhiwei Sang ◽  
...  

Soil salinization is the main abiotic stress factor affecting agricultural production worldwide, and salt stress has a significant impact on plant growth and development. Cotton is one of the most salt-tolerant crops. Therefore, the selection and utilization of salt-tolerant germplasm resources and the excavation of salt resistance genes play important roles in improving cotton production in saline–alkali soils. In this study, we analysed the population structure and genetic diversity of a total 149 cotton plant materials including 137 elite Gossypium hirsutum cultivar accessions collected from China and 12 elite Gossypium hirsutum cultivar accessions collected from around the world. Illumina Cotton SNP 70 K was used to obtain genome-wide single-nucleotide polymorphism (SNP) data for 149 elite Gossypium hirsutum cultivar accessions, and 18,430 highly consistent SNP loci were obtained by filtering. It was assessed by using PCA principal component analysis so that the 149 elite Gossypium hirsutum cultivar accessions could be divided into two subgroups, including subgroup 1 with 78 materials and subgroup 2 with 71 materials. Using the obtained SNP and other marker genotype test results, under salt stress, the salt tolerance traits 3d Germination potential, 3d Radicle length drop rate, 7d Germination rate, 7d Radicle length drop rate, 7d Germination weight, 3d Radicle length, 7d Radicle length, Relative Germination potential, Relative Germination rate, 7d Radicle weight drop rate, Salt tolerance index 3d Germination potential index, 3d Radicle length index, 7d Radicle length index, 7d Radicle weight index and 7d Germination rate index were evaluated by GWAS (genome-wide association analysis). A total of 27 SNP markers closely related to the salt tolerance traits and 15 SNP markers closely related to the salt tolerance index were detected. At the SNP locus associated with phenotyping, Gh_D01G0943, Gh_D01G0945, Gh_A01G0906, Gh_A01G0908, Gh_D08G1308 and Gh_D08G1309 related to plant salt tolerance were detected, and they were found to be involved in intracellular transport, sucrose synthesis, osmotic pressure balance, transmembrane transport, N-glycosylation, auxin response and cell amplification. This study provides a theoretical basis for the selection and breeding of salt-tolerant upland cotton varieties.


2021 ◽  
Author(s):  
Zeliang Zhang ◽  
Juyun Zheng ◽  
Zhaolong Gong ◽  
Yajun Liang ◽  
Zhiwei Sang ◽  
...  

Soil salinization is the main abiotic stress factor affecting agricultural production worldwide, and salt stress has a significant impact on plant growth and development. Cotton is one of the most salt-tolerant crops. Its salt tolerance varies greatly depending on the variety, growth stage, organs, and soil salt types. Therefore, the selection and utilization of excellent salt-tolerant germplasm resources and the excavation of excellent salt-tolerant salt and salt resistance genes play important roles in improving cotton production in saline-alkali soils. In this study, we analysed the population structure and genetic diversity of 144 elite Gossypium hirsutum cultivar accessions collected from around the world, and especially from China. Illumina Cotton SNP 70K was used to obtain genome-wide single-nucleotide polymorphism (SNP) data for 149 experimental materials, and 18,432 highly consistent SNP loci were obtained by filtering. PCA (principal component analysis)indicated that 149 upland cotton materials could be divided into 2 subgroups, including subgroup 1 with 78 materials and subgroup 2 with 71 materials. Using the obtained SNP and other marker genotype test results, under salt stress, the salt tolerance traits 3d_Germination_potential, 3d_Bud_length_drop_rate, 7d_Germination_rate, 7d_Bud_length_drop_rate, 7d_Germination_weight, 3d_Bud_length, 7d_Bud_length, relative_germination_potential, Relative_germination_rate, 7d_Bud_weight_drop_rate, Salt tolerance index 3d_Germination_potential_index, 3d_Bud_length_index, 7d_Bud_length_index, 7d_Bud_weight_index, and 7d_Germination_rate_index were evaluated by genome association analysis. A total of 27 SNP markers closely related to salt tolerance traits and 15 SNP markers closely related to salt tolerance index were detected. At the SNP locus associated with the traits of the bud length decline rate at 7 days, alleles Gh_A01G0034 and Gh_D01G0028 related to plant salt tolerance were detected, and they are related to intracellular transport, membrane microtubule formation and actin network. This study provides a theoretical basis for the selection and breeding of salt-tolerant upland cotton varieties.


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