scholarly journals Genome wide association study reveals novel candidate genes associated with productivity and disease resistance to Moniliophthora spp. in cacao (Theobroma cacao L.)

2019 ◽  
Author(s):  
Jaime A. Osorio-Guarín ◽  
Jhon A. Berdugo-Cely ◽  
Roberto A. Coronado-Silva ◽  
Eliana Baez ◽  
Yeirme Jaimes ◽  
...  

ABSTRACTCacao (Theobroma cacao L.), the source of chocolate, is one the most important commodity products for farmers to improve their economic benefits. However, diseases such as frosty pod rot (FPRD) caused by Moniliophthora roreri and witches’ broom (WBD) caused by Moniliophthora perniciosa, limits the increase in yields. Molecular tools can help to develop more rapidly cacao varieties with disease resistance. In the present study, we sequenced by genotyping-by-sequencing (GBS), 229 cacao accessions to examine their genetic diversity and population structure. From those accessions, 102 have been evaluated for disease resistance and productivity to conduct a genome-wide association study (GWAS) based on 9,003 and 8,131 SNPs recovered by mapping against to the annotated cacao genomes (Criollo and Matina). Three promissory accessions for productivity and 10 accessions showing good tolerance to the evaluated diseases were found in the phenotypic evaluation. The work presented herein provides the first association mapping study in cacao using SNP markers based on GBS data. The GWAS identified two genes associated to productivity and seven to disease resistance. The results enriched the knowledge of the genetic regions associated to important traits in cacao that can have significant implications for conservation and breeding strategies such as marker-assisted selection (MAS).


2020 ◽  
Vol 10 (5) ◽  
pp. 1713-1725 ◽  
Author(s):  
Jaime A. Osorio-Guarín ◽  
Jhon A. Berdugo-Cely ◽  
Roberto A. Coronado-Silva ◽  
Eliana Baez ◽  
Yeirme Jaimes ◽  
...  

Cacao (Theobroma cacao L.), the source of chocolate, is one of the most important commodity products worldwide that helps improve the economic livelihood of farmers. Diseases like frosty pod rot caused by Moniliophthora roreri and witches’ broom caused by Moniliophthora perniciosa limit the cacao productivity, this can be solved by using resistant varieties. In the current study, we sequenced 229 cacao accessions using genotyping-by-sequencing to examine the genetic diversity and population structure employing 9,003 and 8,131 single nucleotide polymorphisms recovered by mapping against two cacao genomes (Criollo B97-61/B2 v2 and Matina 1-6 v1.1). In the phenotypic evaluation, three promising accessions for productivity and 10 with good tolerance to the frosty pod rot and witches’ broom diseases were found. A genome-wide association study was performed on 102 accessions, discovering two genes associated with productivity and seven to disease resistance. The results enriched the knowledge of the genetic regions associated with important cacao traits that can have significant implications for conservation and breeding strategies like marker-assisted selection.



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



Animals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 260 ◽  
Author(s):  
Bo Zhu ◽  
Qinghe Li ◽  
Ranran Liu ◽  
Maiqing Zheng ◽  
Jie Wen ◽  
...  

Presently, the heterophil-to-lymphocyte (H/L) ratio is being studied extensively as a disease resistance trait. Through intricate mechanisms to identify and destroy pathogenic microorganisms, heterophils play a pivotal role in the immune defense systems of avian species. To reveal the genetic basis and molecular mechanisms affecting the H/L ratio, phenotypic and H/L data from 1650 white feather chicken broilers were used in performing a genome-wide association study. A self-developed, chicken-specific 55K chip was used for heterophils, lymphocytes, and H/L classification, according to individual genomic DNA profiles. We identified five significant single nucleotide polymorphisms (SNPs) when the genome-wide significance threshold was set to 5% (p < 2.42 × 10−6). A total of 15 SNPs obtained seemingly significant levels (p < 4.84 × 10−5). Gene annotation indicated that CARD11 (Caspase recruitment domain family member 11), BRIX1 (Biogenesis of ribosomes BRX1), and BANP (BTG3 associated nuclear protein) play a role in H/L-associated cell regulation and potentially constitute candidate gene regions for cellular functions dependent on H/L ratios. These results lay the foundation for revealing the genetic basis of disease resistance and future marker-assisted selection for disease resistance.



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.



2012 ◽  
Vol 15 (6) ◽  
pp. 767-774 ◽  
Author(s):  
Michael B. Miller ◽  
Saonli Basu ◽  
Julie Cunningham ◽  
Eleazar Eskin ◽  
Steven M. Malone ◽  
...  

As part of the Genes, Environment and Development Initiative, the Minnesota Center for Twin and Family Research (MCTFR) undertook a genome-wide association study, which we describe here. A total of 8,405 research participants, clustered in four-member families, have been successfully genotyped on 527,829 single nucleotide polymorphism (SNP) markers using Illumina's Human660W-Quad array. Quality control screening of samples and markers as well as SNP imputation procedures are described. We also describe methods for ancestry control and how the familial clustering of the MCTFR sample can be accounted for in the analysis using a Rapid Feasible Generalized Least Squares algorithm. The rich longitudinal MCTFR assessments provide numerous opportunities for collaboration.



2018 ◽  
Vol 75 (9) ◽  
pp. 1427-1435 ◽  
Author(s):  
Eef Cauwelier ◽  
John Gilbey ◽  
James Sampayo ◽  
Lee Stradmeyer ◽  
Stuart J. Middlemas

Examination of the genetic basis of the timing of the return migration of Atlantic salmon (Salmo salar) to fresh water from the sea, a trait of economic and conservation interest, was carried out using a genome-wide association study. We examined genotype data of 52 731 single nucleotide polymorphic (SNP) markers from 73 early and 49 late running two-sea-winter salmon from five rivers in eastern Scotland. A single region of the Atlantic salmon chromosome Ssa09 was identified, containing nine SNP markers significantly associated with run timing, a region previously linked to variation in sea age at maturity. Validation of the markers in a group of 233 one- and two-sea-winter fish, including adults from a novel river, again showed significant associations between the trait and the Ssa09 region, explaining ∼24% of the trait variance. The SNP loci identified provide the ability to examine trait variation in populations of Atlantic salmon and so help facilitate conservation management of the differing run timing phenotypes.





HortScience ◽  
2019 ◽  
Vol 54 (4) ◽  
pp. 629-632 ◽  
Author(s):  
Katie O’Connor ◽  
Ben Hayes ◽  
Craig Hardner ◽  
Mobashwer Alam ◽  
Bruce Topp

Current macadamia breeding programs involve a lengthy and laborious two-stage selection process: evaluation of a large number of unreplicated seedling progeny, followed by replicated trials of clonally propagated elite seedlings. Yield component traits, such as nut-in-shell weight (NW), kernel weight (KW), and kernel recovery (KR) are commercially important, are more easily measured than yield, and have a higher heritability. A genome-wide association study (GWAS) combined with marker-assisted selection offers an opportunity to reduce the time of candidate evaluation. In this study, a total of 281 progeny from 32 families, and 18 of their 29 parents have been genotyped for 7126 single nucleotide polymorphism (SNP) markers. A GWAS was performed using ASReml with 4352 SNPs. We found five SNPs significantly associated with NW, nine with KW, and one with KR. Further, three of the top 10 markers for NW and KW were shared between the two traits. Future macadamia breeding could involve prescreening of individuals for desired traits using these significantly associated markers, with only predicted elite individuals continuing to the second stage of selection, thus potentially reducing the selection process by 7 years.



PLoS ONE ◽  
2017 ◽  
Vol 12 (2) ◽  
pp. e0171105 ◽  
Author(s):  
Rodrigo Iván Contreras-Soto ◽  
Freddy Mora ◽  
Marco Antônio Rott de Oliveira ◽  
Wilson Higashi ◽  
Carlos Alberto Scapim ◽  
...  


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