Genetic characterisation of commercial Chinese cabbage varieties using SSR markers

摘要

Brassica rapa is an important species grown as a vegetable, oilseed or fodder crop primarily in Asia and Europe. Among several subspecies of B. rapa, Chinese cabbage (Brassica rapa ssp. pekinensis) is a major leafy vegetable used for kimchi in Korea. In this study, a total of 176 simple sequence repeat (SSR) primers were used to develop a core set of markers for genetic characterisation of F1 commercial varieties of Chinese cabbage. A set of 21 SSR markers that were distributed across 8 of 10 linkage groups was the most informative for differentiation of 162 Chinese cabbage genotypes. These markers detected a total of 119 alleles, for an average of 5.67 alleles per marker. The polymorphic information content (PIC) values of the markers ranged from 0.477 to 0.813, with an average of 0.681. Genetic diversity analysis based on the 21 markers revealed that the 162 varieties were separated into four distinct clusters corresponding to varietal types. In addition, the 21 SSR markers differentiated all of the 162 commercial varieties, suggesting these markers to be useful for cultivar identification. Our results will facilitate protection of breeders' rights and genetic purity test of F1 hybrid seeds in Chinese cabbage.