Genome-wide association study and genomic prediction of white rust resistance in USDA GRIN Spinach Germplasm

White rust, caused by Albugo
occidentalis, is one of the major yield-limiting
diseases of spinach (Spinacia oleracea) in some major commercial
production areas. The use of host resistance is the most economical and environment-friendly
approach to manage white rust in spinach production. The objectives of this
research were to conduct a genome-wide associating study (GWAS), to identify
single nucleotide polymorphism (SNP) markers associated with white rust
resistance in spinach, and to perform genomic prediction (GP) to estimate the prediction
efficiency (PA). A GWAS panel of 346 USDA germplasm accessions was phenotyped for
white rust resistance under field conditions and genotyped with 13,235 SNPs postulated
from whole-genome resequencing (WGR). The SNP markers and the high PA can provide valuable information for
breeders to improve spinach by marker-assisted selection (MAS) and genomic
selection (GS).