Research PaperConstruction of a genetic linkage map in tree peony (Paeonia Sect. Moutan) using simple sequence repeat (SSR) markers

- A genetic map for tree peony based on SSR markers was constructed in tree peony.
- The constructed map contained 35 SSR markers with total length of 338.2 cM.
- Eleven QTLs were detected that were related to nineteen phenotypic traits of the F1 progenies.

In this study, an F1 population derived from a cross of P. ostti 'Feng Dan' × P. suffruticosa 'Xin Riyuejin' was used to construct a genetic map for tree peony based on simple sequence repeat (SSR) markers. A total of 705 pair primers were used and finally 124 pair polymorphic primers were screened for the construction of the genetic map. The constructed map contained 35 SSR markers with total length of 338.2 cM, covering 5 linkage groups, of which ranging from 29.8 cM to 120.9 cM in length and including 3-14 markers, .the average distance between each marker was 9.7 cM. Finding the shortest and longest distance between two adjacent markers were 1.4 cM and 37.5 cM, respectively. Furthermore, by the interval mapping (IM) method, 11 QTLs were detected that were related to the phenotypic traits which were investigated among nineteen phenotypic traits of the F1 progenies in 2014 and 2015, and the range of explained the phenotypic variance was from 9.60% to 46.2%. Among 11 QTLs, the number of characters that were associated with the shoot number, leaf length, flower number, pod height, pod diameter and flower diameter was range from 1 to 4 loci. In conclusion, this genetic map constructed with simple sequence repeat (SSR) markers would be a base for the further molecular breeding study in tree peony.