Construction Of Molecular Genetic Map Of Brassica Rapa Ssp. Pekinens And B. Rapa Ssp. Rapifera Using SSR Anchor Markers

Originally cultivated in China, Brassica rapa is an economically important group among Brassica crops of the Cruciferae family, and the most widely cultivated vegetable crops in China. A detailed genetic linkage map offer the possibility of developing genetic studies on various agronomic traits through the localization of major genes and quantitative trait loci (QTLs), helping breeding programs with marker-assisted selection (MAS), as well as for comparative genomics and map-based cloning.In order to construct linkage maps of Brassica rapa corresponding to reference map of Brassica A genome crops. A set of SSR markers, provided anchors to previously published linkage maps for B. rapa, were used to designate linkage groups. Out of 326 SSR markers, 86 ones showed polymorphism between 2 parents and be further analyzed in DH population. Adding 400 previously mapped molecular markers,an integrated genetic linkage maps have been constructed. This map contains 347 loci and covered 1008.7cM with an average distance 2.91cM. All markers were designated as A1-A10 through alignment and orientation using 56 markers anchored to previously published B. rapa reference maps. Number of markers included in linkage groups varied from 25 to 58, the length of linkage groups from 60.6 cM to 177.0cM and mean marker interval distance from 1.33cM to 4.92 cM. This map is useful to gene localization of important agronomic traits and share genetic information with other maps in B. rapa.