Genome wide association study and genomic prediction for stripe rust resistance at the seedling stage in advanced spring bread wheat genotypes of ICARDA Morocco

Abstract

One of the most devastating diseases impacting wheat (Triticum aestivum L.) worldwide is stripe rust, which is propagated by Puccinia striiformis f. Sp. Tritici (Pst). The development and utilization of resistant cultivars offer an effective and eco-friendly approach to manage this disease. However, the emergence of new virulent strains of Pst, driven by continuous mutations within the pathogen, rapidly undermines the effectiveness of existing resistance genes. This necessitates the ongoing identification and incorporation of new resistance genes to breed wheat varieties that can maintain resistance against evolving strains of the pathogen. A genome-wide association study (GWAS) and genomic prediction (GP) were conducted using yellow rust data from the seedling stage under controlled conditions, involving 200 elite bread wheat genotypes and 13,151 SNP markers. GWAS analysis identified fourteen SNP markers significantly associated with yellow rust resistance, using a general linear model (GLM). The markers (wsnp Ex c1085 2078944, wsnp Ku c3682 6,786,230) on chromosome 1D and (wsnp Ex c8240 13,914,674) on chromosome 3A were notably correlated with seedling-level resistance to yellow rust. Additionally, the marker 'AX-94703603′ on chromosome 3A, which recorded the highest -Log10(p) value, was linked to the gene 'TraesCS3A02G335300' encoding the protein kinase domain. These markers, after validation, could be utilized for gene pyramiding in wheat breeding programs to enhance rust resistance through marker-assisted selection.