蝴蝶兰EST 资源SSR 标记分析与开发

 利用SSRIT软件对NCBI上蝴蝶兰的8 188条EST序列按照碱基重复单元数8以上的标准进行SSR位点查找，发掘出246条EST序列，共含有261个SSR位点，检出率为3.19%。二核苷酸重复是最主要的重复类型，占SSR总数的94.25%。SSR的不同重复单元中，最常见的重复单元是：(TA)_n和(GA)_n，其余出现频率较高的依次为(TC)_n、(AT)_n和(AG)_n。设计了32对EST-SSR引物，以蝴蝶兰品种‘V31’的DNA为模板进行PCR扩增，发现16对引物能扩增出预期产物。进一步用这16对引物对16个蝴蝶兰品种（系）进行PCR扩增，9对引物有多态性，多态性条带数在2 ~ 12个之间。结果表明，设计开发的蝴蝶兰的EST-SSR标记是有效的。

Analysis of SSRs Information and Development of SSR Markers from Phalaenopsis ESTs

Using SSRIT software,8 188 ESTs of Phalaenopsis from NCBI were screened,according to the standard of repeat motif number above eight.The results showed that 261 SSRs were mined from 246 ESTs with a frequency of 3.19%.Dinucleotide repeats EST-SSRs were dominant,accounting for 94.25% in all SSRs.(TA)nand(GA)nwere the most frequent motifs,accounting for 26.42% and 25.61% in dinucleotide repeats,followed by(TC)n,(AT)nand(AG)n.Thirty-two primer pairs were designed and 16 primer pairs had expected products using the template of cultiva‘r V31’.The sixteen workable primer pairs were chosen to PCR amplification in 16 Phalaenopsis cultivars and 9 primer pairs had polymorphism bands between 2 to 12.The results indicated that it was an effective approach to develop EST-SSR markers based on EST database of Phalaenopsis.