Tagging quantitative trait loci for dormancy, tuber shape, regularity of tuber shape, eye depth and flesh colour in diploid potato originated from six Solanum species

Potato breeding aims at breeding diversified cultivars not only suitable for different purposes, but also resistant to diseases, such as late blight caused by Phytophthora infestans, which is a major constraint in potato production. Resistance to P. infestans has been previously introduced into the diploid hybrid population 98-21 from Solanum verrucosum and Solanum microdontum. In the present study, we assessed the segregation of tuber dormancy, tuber shape, regularity of tuber shape, eye depth and flesh colour in this population. Quantitative Trait Loci (QTLs) affecting these important quality traits were tagged using the genetic map developed for this population to locate QTLs for late blight resistance. The most prominent QTL for dormancy was detected on chromosome II and explained 7.1% of the variance. The most important QTLs for tuber eye depth flesh colour, shape and shape regularity were identified on chromosomes X (R-2 = 14.7%), IV (R-2 = 5.8%), II (R-2 = 8.0%) and III (R-2 = 10.4%) respectively. All traits were also affected by minor QTLs. The obtained results improve our understanding of the inheritance of traits relevant for variety development in potato.