Identification by GWAS of marker haplotypes relevant to breed potato for Globodera pallida resistance.

Key message: Identified and validated QTL GpaVa_MRQ and GpaIX_MRQ provide robust tools for improving potato resistance to Globodera pallida via marker-assisted selection. Potato (Solanum tuberosum L.), a vital food crop globally, faces significant yield losses due to potato cyst nematodes (PCN). This study aimed to identify and validate genomic regions conferring resistance to Globodera pallida, to facilitate the development of resistant potato varieties through marker-assisted selection (MAS). We conducted Genome-Wide Association Studies (GWAS) on a pre-breeding panel genotyped using Genotyping by Sequencing (GBS) and the SolCAP DNA array. Significant resistance-associated SNP markers were identified on chromosomes III, IV, V, IX and XI. Quantitative trait loci (QTL), including the major-effect QTL GpaVa_MRQ on chromosome V and the QTL GpaIX_MRQ on chromosome IX, were validated and shown to account for substantial phenotypic variance in a validation potato panel. Haplotype-based marker sets were defined at four QTL regions, enabling the practical application of MAS. The successful conversion of SNPs to PACE markers at the two main QTL GpaVa_MRQ and GpaIX_MRQ further supports their use in breeding programs. This study provides valuable insights and robust tools for enhancing potato resistance to G. pallida, contributing to sustainable agricultural practices and global food security.