Additive and epistatic QTLs underlying the dormancy in a diploid potato population across seven environments

Tuber dormancy is important for potato tuber quality and is a typical quantitative trait. Understanding the genetic basis of potato tuber dormancy is essential for controlling the potato tuber dormancy length. In order to analyze the quantitative trait, a diploid potato population EB with a genetic background derived from S. tuberosum, S. berthaultii, S. phureja, S. vernei, etc, was used for QTL analyses. With tubers of population EB harvested from seven environments, six QTLs with additive effects and four other QTLs involved in epistatic interactions were uncovered. These QTLs might partially demonstrate the gene regulatory network of tuber dormancy in potato. The fine mapping and map-based cloning of these QTLs, especially DorE4.6 and DorB5.3 with major additive effects across seven environments, will further the understanding of the genetic mechanism of potato tuber dormancy. The molecular markers linked to the stable QTLs, DorE4.6 and DorB5.3, provided good assistant marker candidates for pyramid breeding aiming at the potato cultivar with a desirable dormancy length.