Linkage Analysis and QTL Mapping in Tetraploid Potato

With the availability of a genome-wide set of single nucleotide polymorphism (SNP) markers and the development of statistical tools for the utilization of allele dosage information, it is now possible to generate high-resolution maps for autotetraploid potato. The aim of this study was to construct a SNP-based genetic map at the tetraploid level to locate quantitative trait loci contributing to economically important traits. A 162 F₁ progeny and parents of a cross (PRRG) between "Premier Russet" and "Rio Grande Russet" were genotyped with the Infinium 8303 Potato Array. Furthermore, the PRRG population and parents were evaluated for 24 phenotypic traits in two locations, Idaho and North Carolina, over two years. We have developed the linkage maps for both parents by analyzing allele dosage from a set of ~ 2500 segregating SNPs.  A preliminary data analysis using these maps revealed quantitative trait loci and candidate SNPs for key agronomic and tuber quality traits including reducing sugars, specific gravity, growth habit, and plant maturity. These candidate SNPs are of interest and are the focus of further marker development.