Abstract:Kales (Brassica oleracea var. acephala), which are widely cultivated as ornamental plants in wintertime or cold areas, play important roles for urban landscaping. Domestic breeding of ornamental kale starts later, and there was a lack of system researches about genetic backgrounds of germplasm resources. SSR markers were utilized in this research for genotypic and genetic relationship analysis of different ornamental kale types. 46 pairs of polymorphic SSR primers from 99 SSR primers which were uniformly distributed on B. oleracea genome were selected for polymorphism and genotypic analysis of 27 ornamental kales. 210 polymorphic loci were obtained by 46 pairs of SSR primers and the average polymorphism information content (PIC) was 0.58. The genotypic result of 27 ornamental kales was used for further STRUCTRE, UPGMA and heatmap clustering analysis. 27 ornamental kales were classified into three groups: round leaf group, leather leaf group and crinkle leaf group by STRUCTRE, UPGMA and heatmap clustering analysis whose clustering results were consistent. Round leaf and leather leaf group have close genetic relationship, while crinkle leaf group has longer genetic distance with them. And STRUCTURE analysis can also distinct hybrids whose parents belongs to diverse groups. The genotypic results can be well demonstrated by heatmap clustering analysis. These results can lay the foundation for constructing molecular fingerprints of ornamental kale, illuminating genetic background of germplasm resources, developing molecular assistant selection in ornamental kale breeding, and breeding new varieties with independent intellectual property rights.