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. 2017 Nov 14:8:1954.
doi: 10.3389/fpls.2017.01954. eCollection 2017.

A Novel QTL for Powdery Mildew Resistance in Nordic Spring Barley (Hordeum vulgare L. ssp. vulgare) Revealed by Genome-Wide Association Study

Therése Bengtsson  1 , Inger Åhman  1 , Outi Manninen  2 , Lars Reitan  3 , Therese Christerson  4 , Jens Due Jensen  5 , Lene Krusell  6 , Ahmed Jahoor  1   5 , Jihad Orabi  5
Affiliations

A Novel QTL for Powdery Mildew Resistance in Nordic Spring Barley (Hordeum vulgare L. ssp. vulgare) Revealed by Genome-Wide Association Study

Therése Bengtsson et al. Front Plant Sci. .

Abstract

The powdery mildew fungus, Blumeria graminis f. sp. hordei is a worldwide threat to barley (Hordeum vulgare L. ssp. vulgare) production. One way to control the disease is by the development and deployment of resistant cultivars. A genome-wide association study was performed in a Nordic spring barley panel consisting of 169 genotypes, to identify marker-trait associations significant for powdery mildew. Powdery mildew was scored during three years (2012-2014) in four different locations within the Nordic region. There were strong correlations between data from all locations and years. In total four QTLs were identified, one located on chromosome 4H in the same region as the previously identified mlo locus and three on chromosome 6H. Out of these three QTLs identified on chromosome 6H, two are in the same region as previously reported QTLs for powdery mildew resistance, whereas one QTL appears to be novel. The top NCBI BLASTn hit of the SNP markers within the novel QTL predicted the responsible gene to be the 26S proteasome regulatory subunit, RPN1, which is required for innate immunity and powdery mildew-induced cell death in Arabidopsis. The results from this study have revealed SNP marker candidates that can be exploited for use in marker-assisted selection and stacking of genes for powdery mildew resistance in barley.

Keywords: Blumeria graminis f. sp. hordei; GWAS; Hordeum vulgare L.; linkage disequilibrium; mlo; plant breeding; resistance.

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Figures

FIGURE 1
FIGURE 1
Frequency distribution of the barley lines based on their powdery mildew mean scores in the Nordic field trials 2012, 2013, and 2014. Each mean value is based on replicates of a certain line, observation time, location, and year (N = 169). Infection was scored on a 1–9 scale, where 1 = not infected and 9 = heavily infected.
FIGURE 2
FIGURE 2
Sub-groups in the Nordic spring barley panel according to STRUCTURE software analysis. The table shows number of lines in each sub-group from each breeding entity, split on two-rowed and six-rowed genotypes.
FIGURE 3
FIGURE 3
Model comparisons for the genome-wide association study. Quantile–quantile plot of the expected versus the observed distribution of p-values were computed from 5,556 SNP markers for the different association models.
FIGURE 4
FIGURE 4
Manhattan plot showing the genome-wide association study (GWAS) results for powdery mildew in the Nordic spring barley panel. The Bonferroni adjusted cut-off for accepting associations were set to –log10 (p)-value ≥ 5.0 corresponding to an experiment wise error rate of 0.05. U = genetic chromosomal location currently unknown.
See this image and copyright information in PMC

References

    1. Aghnoum R., Marcel T. C., Johrde A., Pecchioni N., Schweizer P., Niks R. E. (2010). Basal host resistance of barley to powdery mildew: connecting quantitative trait loci and candidate genes. Mol. Plant Microbe Interact. 23 91–102. 10.1094/MPMI-23-1-0091 - DOI - PubMed
    1. Ames N., Dreiseitl A., Steffenson B. J., Muehlbauer G. J. (2015). Mining wild barley for powdery mildew resistance. Plant Pathol. 64 1396–1406. 10.1111/ppa.12384 - DOI
    1. Bengtsson T., Manninen O., Jahoor A., Orabi J. (2017). Genetic diversity, population structure and linkage disequilibrium in Nordic spring barley (Hordeum vulgare L. subsp. vulgare). Genet. Resour. Crop Evol. 64 2021–2033. 10.1007/s10722-017-0493-5 - DOI
    1. Bonferroni C. E. (1935). Il Calcolo Delle Assicurazioni su Gruppi di Teste. Rome: Tipografia del Senato.
    1. Bonferroni C. E. (1936). Teoria Statistica Delle Classi e Calcolo Delle Probabilita. Florence: Libreria internazionale Seeber.