Juho Hautsalo, Fluturë Novakazi, Marja Jalli, Magnus Göransson, Outi Manninen, Mika Isolahti, Lars Reitan, Stein Bergersen, Lene Krusell, Charlotte Damsgård Robertsen, Jihad Orabi, Jens Due Jensen, Ahmed Jahoor, Therése Bengtsson & the PPP Barley Consortium

Theoretical and Applied Genetics December 2021; vol. 134, pages 3829–3843

Genome-Wide Association Studies (GWAS) of four Multi-parent Advanced Generation Inter-Cross (MAGIC) populations identified nine regions on chromosomes 1H, 3H, 4H, 5H, 6H and 7H associated with resistance against barley scald disease. Three of these regions are putatively novel resistance Quantitative Trait Loci (QTL). Barley scald is caused by Rhynchosporium commune, one of the most important barley leaf diseases that are prevalent in most barley-growing regions. Up to 40% yield losses can occur in susceptible barley cultivars. Four MAGIC populations were generated in a Nordic Public–Private Pre-breeding of spring barley project (PPP Barley) to introduce resistance to several important diseases. Here, these MAGIC populations consisting of six to eight founders each were tested for scald resistance in field trials in Finland and Iceland. Eight different model covariate combinations were compared for GWAS studies, and the models that deviated the least from the expected p-values were selected. For all QTL, candidate genes were identified that are predicted to be involved in pathogen defence. The MAGIC progenies contained new haplotypes of significant SNP-markers with high resistance levels. The lines with successfully pyramided resistance against scald and mildew and the significant markers are now distributed among Nordic plant breeders and will benefit development of disease-resistant cultivars.

See: https://link.springer.com/article/10.1007/s00122-021-03930-y

Figure 1:

a–d Distribution of best linear unbiased estimators for scald scores (BLUEs) in separate MAGIC populations [MAGIC 1 + 2 in (a), MAGIC 3 in (b), MAGIC 4 in (c) and MAGIC 1 to 4 in (d)] studied and among the founders in each population