ASHS 2025 Conference

Spinach (Spinacia oleracea L.) is a globally valued vegetable, renowned for its rich nutritional content and health-enhancing benefits. Leaf texture, ranging from smooth to savoy, is an important trait influencing consumer preference, taste, and nutritional compositions. This study aimed to conduct a comprehensive genome-wide association study (GWAS) to identify single nucleotide polymorphism (SNP) markers associated with leaf texture in spinach, along with genomic prediction (GP) to facilitate trait screening in breeding programs. GWAS was performed on a panel of 103 USDA spinach germplasm accessions using 12,744 high-quality filtered SNPs obtained from whole-genome resequencing. Several statistical models, including MLMM, MLM, FarmCPU, and BLINK, were applied using the GAPIT 3 tool. Two significant quantitative trait locus (QTL) regions were identified on chromosome 1, spanning from 13,798,232 bp to 51,588,552 bp. Within this region, three SNP markers—SOVchr1_13798232 (LOD 5.84), SOVchr1_51500008 (LOD 9.73), and SOVchr1_51588552 (LOD 5.77) and—showed strong associations with leaf texture. Additionally, another SNP marker, SOVchr2_8225269, on chromosome 2, also exhibited a strong association with this trait. Furthermore, the gene SOV1g002810, located between 13,795,625 bp and 13,803,405 bp on chromosome 1, encodes a ULP_PROTEASE domain-containing protein and is proposed as a potential candidate associated with the trait. GP revealed strong predictive accuracy (PA), with an r value of 0.43. The identified SNP markers and PA metrics provide valuable tools for breeders to spinach breeding programs through marker-assisted selection (MAS) and genomic selection (GS), thereby accelerating the development of spinach lines with desired leaf textures.