生菜EST-SSR的分布特征分析

摘要

从NCBI数据库下载了81518条生菜EST序列，处理后得到无冗余序列61757条，共搜索到2040个SSR位点，出现频率为3.3%。三碱基重复是主要的类型，占38.53%，其次是二碱基和六碱基重复，出现次数最低的是四碱基重复。在181种重复基元类型中，(AGA)n和(ATG)n是主导的重复基元类型，分别占12.01%和3.53%。设计合成的30对引物在50份生菜资源进行鉴定，共筛选出4个材料特异性标记。该研究为后续开发生菜多态性 EST-SSR标记，进行种质资源鉴定、分子标记辅助育种、遗传图谱构建奠定了基础。%From the NCBl database, 81,518 Lactuca sativa EST sequences were downloaded, from which 61,757 non-redundant sequences were obtained. ln total, 2040 SSR loci were identified, with the frequency of 3.3%. Trinucleotide repeat was dominant, fol owed by dinucleotide and hexanucleotide repeats. Among 181 types of repeat motifs, (AGA)n and (ATG)n were the dominant repeat motif types, taking up 12.01% and 3.53%, respectively. Total y, four material-special EST-SSR markers were characterized. This study enriches molecular markers of L. sativa, and also lays a theoretical foundation for fol owing germplasm identification, molecular marker assisted breeding and genetic map construction.