The genetic control of dormancy is poorly understood in most plant species, but dormancy is a prominent feature for the potato industry. We used the microtuber system, in which tubers were produced in vitro and stored at 20°C, to perform quantitative trait locus (QTL) analysis for dormancy and gibberellic acid (GA3) content in an F1 population consisting of 178 genotypes derived from an interspecific cross between Solanum chacoense acc. PI 320285 (long dormancy) and Solanum phureja acc. DM1-3 516 R44 (short dormancy). In this analysis, 163 markers were used to construct a genetic map with a total length of 591.8 cM. Through QTL analysis, we identified 22 markers closely linked to the timing of dormancy release and GA3 content. The male parent alleles were closely related with long dormancy, with the most significant effect on chromosome I, which accounted for 9.4% of phenotypic variation. The dormancy and GA3 QTLs localized to the same position in the genome, confirming that same genomic region controls GA3 content at different developmental stages or in dormant and sprouting tubers. The identified QTLs may be useful for future breeding strategies and studies of dormancy in potato.

Abscisic acid (ABA) is known to impact many areas of plant growth and development and is also assumed to facilitate plant stress regulation. ABA is also involved in the rapid suberization of wounds and is the essential dormancy release regulator. The direct application of DNA markers to plant populations enables the use of mapping to help determine the regulation of a quantitatively inherited trait isolated in a population. QTLs represent a chromosomal region that is linked to a marker gene and that significantly affects the quantitative trait under review. In the present study, we investigated the ABA content after harvest and after sprouting in a diploid population. The most noticeable QTLs related to ABA were found on chromosomes I and IV, and these QTLs fully explained 6.5% and 7% of the entire phenotypic variance, respectively. The acquired information advances our understanding of the inheritance of traits applicable for variety development.