丹参EST序列中SSR信息的分析及分子标记的建立

本文对从NCBI下载的鼠尾草属11747条EST序列（其中，丹参10228条）进行分析，搜索到含SSR的序列1911条，共含有SSR 2156个，出现频率为18.35%。在丹参EST-SSR中，核苷酸重复基元种类共77种。单核苷酸重复最多，出现频率为10.45%，二、三核苷酸的出现频率为3.72%、4.40%。三核苷酸重复中ACG/CTG为主要类型，占27.3%。共设计引物143对，合成13对（其中，丹参6对，Salvia fruticosa7对），在对引物、dNTP、MgCl2进行测试后，建立了合适的PCR反应体系。引物筛选发现7对引物（丹参6对，S.fruticosa 1对）对丹参基因组DNA均有良好的扩增，并对11个不同产地丹参样品进行扩增均呈现良好的多态性。本研究结果证明根据丹参EST资源建立丹参EST-SSR标记是可行的。

Analysis of SSR Information in EST Resource of Salvia miltiorrhiza and Associated EST-SSR Markers

Authors downloaded and analysed11,747 ESTs of Slvia genus containing 10228 ESTs of S. miltiorrhiza in the database of NCBI. Search resulted in 2156 SSRs distributed in 1911 ESTs , or 18.35% of the total. 77 repeat motifs were mined out. The mononucleotide repeat was the dominant type, accounting for 10.45% . The frequency of occurrence of dinucleotide and trinucleotide reached 3.72% and 4.40% respectively. The most common repeat motifs of trinucleotide was AGG/CTG , or 27.3%. 143 pairs of primer were designed. 13 pairs of them are made up of 6 pairs from S. miltiorrhiza, and 7 pairs from S.fruticosa as synthesized by TaKaRa Biotechnology (Dalian) Co., Ltd . After testing the concentration of primers, dNTP and MgCl2 , a suitable PCR system was established. Screening against genomic DNA of S. miltiorrhiza and 7 primer pairs showed the amplification. The primers showing amplification were subject to PCR for DNAs from 11 S. miltiorrhiza cultivars. All the 7 primer pairs showed polymorphism. Results prove that it is an effective and feasible approach to develop SSR markers based on ESTs in S. miltiorrhiza.