Construction of SSR fingerprint database of Chinese cabbage varieties (Brassica campestris L. ssp. Pekinensis) | 白菜品种的SSR指纹图谱数据库的构建

Chinese. 本研究利用SSR标记技术筛选出合适的核心引物，对70个白菜品种进行DNA指纹分析，构建白菜SSR指纹图谱数据库。首先从500对引物中筛选出80对具有多态性的引物，再从其中选取20对多态性高，稳定性好且均匀分布在白菜10条染色体上的核心引物进行PCR扩增，引物多态信息含量（polymorphism information content，PIC）平均为0.716，变化范围0.473～0.932，平均杂合率0.5044。经PCR电泳检测统计得到的指纹图谱进行综合分析，形成各个白菜品种的SSR指纹代码，并且采用ClusterProject对构建的指纹图谱数据进行分析整理，得到各品种的指纹模式图谱，进而分析得到20个核心引物组合可以将70个白菜品种完全分开，并最终建立了白菜品种的SSR指纹图谱数据库。本研究构建的白菜品种SSR指纹图谱数据库，为建立白菜品种特异性、一致性及纯度的鉴定技术体系提供了基础依据。

English. In order to construct SSR fingerprint database of Chinese cabbage varieties, the SSR marker technique was employed to screen suitable core SSR primers to detect SSR fingerprints of 70 Chinese cabbage varieties used in this research. First of all, eighty pairs of SSR with polymorphism among tested varieties were selected from of the used 500 pairs of SSR primers, and then twenty of the selected 80 core primers that exhibit high polymorphism, good stability and evenly distributed in the ten chromosomes of genome were further selected to perform PCR amplification PCR analysis showed that Polymorphism Information Content (PIC) of the 20 core primers is 0.716 in average with ranges from 0.473 to 0.932 and that the Heterozygous ratio of the 20 core primers is 0.504 4 in average as well. A comprehensive statistic analysis was conducted based on the fingerprints obtained by PCR electrophoresis, which formed SSR fingerprint code of each tested Chinese cabbage varieties. Furthermore the fingerprint data were sorted out by Cluster Project to generate the fingerprint profile of each variety. The results showed that using the twenty core primers can easily distinguish the tested 70 Chinese cabbage varieties, and eventually the database based on SSR fingerprint for Chinese cabbage varieties was established in this research. The constructed SSR fingerprint database of the Chinese cabbage variety would provide a basis on establishment of identification technology for Chinese cabbage variety specificity, consistency and purity.