Genetic Diversity and Genome-Wide Association Study of Total Phenolics, Flavonoids, and Antioxidant Properties in Potatoes (Solanum tuberosum L.)

Genetic diversity of nutritional quality traits is crucial for potato breeding efforts to develop better varieties for the diverse market demands. In this study, the genetic diversity of 104 potato genotypes was estimated based on nutritional quality traits such as color parameters, total phenolic content, total flavonoid content, 2,2-Diphenyl-1-picrylhydrazyl (DPPH), and 2,2-azino-bis-(3-ethylbezothiazoline-6-sulphonic acid) radical scavenging potential across two environments. The results indicated that environment II, Hangzhou 2020, exhibited higher bioactive compounds and antioxidant properties than environment I, Hangzhou 2019. The colored potato accessions exhibited higher levels of total phenolic content, total flavonoid content, DPPH, and ABTS activities than the white potato accessions, indicating the superiority of the colored to white potato accessions. The genome sequencing identified 1,101,368 high-quality single-nucleotide polymorphisms (SNPs), and 141,656 insertion/deletions (Indels). A population structure analysis revealed that genotypes can be divided into two subpopulations. Genome-wide association studies (GWAS) identified 128 significant SNPs associated with potato's color, total phenolic content, total flavonoid content, and antioxidant properties. Thus, the study provides new opportunities for strategic breeding and marker-assisted selection of ideal varieties and favorable alleles to enhance bioactive compounds and health-beneficial properties.