Establishment and application of molecular ID in the main inbred lines of Chinese cabbage.

Chinese cabbage is an important cruciferous vegetable in China. The differences in the morphology and other characteristics of the different varieties of Chinese cabbage are generally caused by their different genes. Using the simple sequence repeat (SSR) DNA molecular markers is an effective way to identify different genotypes. The identification of a genetic relationship is a key point in the breeding process, and it plays an important role in guiding parent selection and breeding of high-yield varieties. Moreover, the establishment of genomic fingerprints is significant for plant variety protection. Three to five SSR sites were selected from each of the 10 Chinese cabbage chromosomes on the basis of the abundance of SSR loci on them. According to the differences in the SSR polymorphic bands, a genomic fingerprint comprising 36 different loci was established in the 20 main inbred lines of Chinese cabbage, and this fingerprint was converted digitally into a molecular ID with 36 numbers based on the 36 SSR sites. The utility of this core set SSRs was demonstrated in 20 main inbred lines of Chinese cabbage, which could be placed into six clusters that were largely consistent with previous classification based on morphology data. Moreover, the molecular ID of an F1 hybrid can be deduced from its parents molecular IDs, and its purity can be determined by selecting one or two SSR loci from the 36 different loci.