Only 11 Simple Sequence Repeats Needed to Identify Chinese Cabbage (Brassica rapa L.) Cultivars

Chinese cabbage is a popular leaf vegetable, and many cultivars have been developed for different regions and growing seasons. For the identification of the cultivars, many marker systems have been applied, but they usually require a large number of markers and expensive equipment. Therefore, it is necessary to develop an efficient and economical method for identifying Chinese cabbage cultivars. In this study, we aimed to develop a marker system with the minimum number of markers using simple PCR and gel electrophoresis. A total of 48 simple sequence repeats (SSRs) in a previous study were screened based on their chromosomal location and applied to 105 Chinese cabbage cultivars. The minimum number of markers was selected based on their genomic location, polymorphic information content, and allele frequency. To validate the cultivar identification capability of selected SSRs, they were applied to genetically similar cultivar pairs from a previous study. Eleven SSRs were finally selected, and they successfully identified cultivars with high genetic similarity, as well as all 105 Chinese cabbage cultivars tested. The proposed SSRs require only 11 primer sets, simple PCR, and gel electrophoresis, which need less time and resources compared to previous ones. These SSRs can be used not only in small seed companies and laboratories but also in large-scale seed companies.