Construction Of Diploid Potato Molecular Genetic Map And QTL Analysis Of Some Tuber Traits

Potato is the third important crop after rice and wheat in the world (2007, FAO). With the development of processing industry, breeding objectives of potato were more and more focused on tuber qualities. Potato breeding technology will be improved by constructing a high density molecular linkage map and analyzing QTLs of tuber traits.In this study, the P1 population including 167 progenies derived from two diploid potato parents was used for a molecular genetic map construction based on SSR markers, and QTLs analysis of tuber agronomic traits. The main results are summarized as follows:1. 22 diploid genotypes material were selected with lightest chipping color after storage under 6℃for 60 days, which could be used as cold-sweetening breeding material.2. The software Joinmap3.0 was used for linkage analysis with polymorphic markers of 129 SSR markers, among which 53 SSR markers were newly designed. A molecular genetic map consisted of 13 linkage groups which located on 11 chromosomes including 86 SSR markers, among which 34 SSR markers were newly designed. The map covered a total distance of 645cM with an average interval of 7.5cM between markers. in the groups varied from 3 to13. The genetic length of the groups varied from 2 cM to 91cM and the numbers of SSR marker linkage to each groups ranged from 3 to 13 with the average interval distances from 0.3 cM to 13.3 cM between markers, respectively.3. MapQTL 4.0 software and interval mapping were employed in study of the quantitative trait loci (QTL) controlled tuber agronomic traits. 2 QTLs for tuber set were located on chromosome V and IX respectively, and explained the genetic variance of 37.8% and 52.1%; 4 QTLs for tuber yield were located on chromosomes V, VII and XI, and explained the genetic variance of 41.0%, 12.3%, 9.0% and 5.8% respectively; 2 QTLs for tuber size were located on chromosomes V and XI, and explained the genetic variance of 33.0% and 16.1% respectively; 1 QTLs for specific gravity was located on chromosome V and explained the genetic variance of 11.2%; 1 QTLs for chipping color was located on chromosome XI and explained the genetic variance of 57.3%.4. In this thesis, 6 QTLs were mapped differently from the previous study. It could be concluded that the 6 QTLs including qTSET-1 for tuber set, qTY-1, qTY-3 and qTY-4 for potato yield, qSIZE-1 for tuber size, and qCC-1 for chipping color were newly determined.