Which QTL Associations in Potato Confer Efficient and Durable Resistance to the Cyst Nematode Globodera pallida?

Potato cyst nematode Globodera pallida is a major threat to potato crops, yet few resistant varieties exist, all based on Solanum vernei. Two other wild species, S. sparsipilum and S. spegazzinii, share a major resistance QTL named GpaV. S. sparsipilum also carries a minor QTL, GpaXIspl, which when combined with GpaV triggers early necrotic reactions that block larval development. INRA and French breeders created and tested genotypes combining GpaV from different sources with GpaXIspl. Across all combinations, the dual-QTL genotypes showed early nematode arrest and effective control of both experimentally selected and naturally virulent nematode populations, offering a path to broader-spectrum and longer-lasting resistance.