Extreme-Phenotype Genome-Wide Association Study (XP-GWAS) and Marker Development for Powdery Mildew Race 2W Tolerance in the USDA Citrullus Germplasm Collection

Historical data from the USDA Germplasm Resource Information Network was used for an extreme phenotype genome wide association study of resistance to Podosphaera xanthii race 2W in watermelon. Genomic DNA from three bulks (resistant, susceptible and random) was submitted for whole genome resequencing producing 150-bp paired-end reads with a minimum of 30X genomic coverage.