SSR Core Primer Pairs Screened Of Establishing DNA Fingerprinting Database Of Chinese Cabbage Cultivars

In this study, we used SSR marker technology screening29markers as a set core primers. It was referenced for "Research on Establishing DNA Fingerprinting Database of Chinese cabbage cultivars" and the purity and reality identification of Chinese cabbage cultivars. The results were summarized as follows:Based on international references and Brassica Database, we found2129SSR markers and then screened544mapped SSR markers that distributed on the ten linkage groups of Chinese cabbage. We used12Chinese cabbage inbred line materials from263Chinese cabbage inbred lines to screen51markers that can amplify stably in PCR reaction and be easily scored and relatively evenly.263Chinese cabbages inbred lines were selected to study the genetic diversity using SSR techniques by twenty-nine core primer pairs.227alleles were detected among the Chinese cabbage inbred lines. The number of alleles per locus ranged from2to10and the mean was4. The values of polymorphism information content (PIC) for each SSR locus varied from0.2080-0.8154with an average of0.5159, in which primer NI4B03was the highest while the primer CX272719was the lowest.We used tassel4.0software to analysis PCA. It indicated that27PCs can represent85.5%cumulative proportion of51markers and screen24primer pairs. Consequently, we initially defined a set core primers of29SSR markers based on combined amplification, stability, repeatability, allele number, PIC value and PCA.We analyzed51Chinese cabbage inbred lines using29core primers and51polymorphic primers, respectively, which obtained the same results that were classed accroding to the maturity time and gathering way. Therefore, the29core primers may be considered as core primers for further study.We analyzed263Chinese cabbage inbred lines using29core primers and51polymorphic primers, respectively, which indicated that two kinds of dendrograms are roughly classified into two categories. The first category is spring and summer cabbage; second category is dominated autumn cabbage. It was also divided into three sub-categories:the first sub-category is stacked hold type, the second sub-category is screwed hold type, the third sub-category is encircle type. They had a high similarity clustering results. Therefore, based on the two clustering analysis, we concluded that the29core primers had high representation.