亚麻EST-SSR信息分析与标记开发

与基因组SSR相比,以EST为基础的EST-SSR分子标记具有自身的优点。本研究从11240条亚麻（Linum sitatissmum L.）EST序列中检索出877条含有SSR的序列,其出现频率为7.8%。其中以三核苷酸重复出现的频率最高,占总SSR序列的60.1%;其次是二核苷酸重复,占21.9%;四、五和六核苷酸重复占18%。根据这些含SSR的EST序列共设计了73对SSR引物,在8份亚麻材料间通过PCR扩增检测,有63对引物扩增出清晰条带,引物可用率86.3%;有17对引物在8份亚麻材料间显现出多态性,占可扩增引物的26.3%。

Flax (Linum sitatissimum L.) EST-SSR Information Analysis and Marker Development

Compared with SSR markers derived from genomic DNA,the EST-derived SSR markers have remarkable advantages,such as simpler development,greater information and high transferability.In this study,11240 flax ESTs were screened and 877 SSRs were mined out,accounting for 7.8% of the ESTs.Trinucleotide motifs were most abundant（60.1%）,followed by dinucleotides（21.9%）.The AGA/TCT,GA/CT,AAG/TTC,TC/AG,and TA/AT motifs were themain repeat types,accounting for 6.2%,6.2%,5.9%,5.8% and 5.8% of the 877 SSRs respectively.Tetra-,penta-and hexa-nucleotide motifs represented 18% of the SSRs identified.Seventy-three primer pairs were designed from the SSR containing ESTs,and PCR amplifications were performed among eight flax cultivars.Sixty-three primer pairs yielded amplification products,accounting for 86.3% of the total primers.Polymorphisms among the eight cultivars were found in 17 primer pairs,accounting for 26.3% of the primers with amplification products.