辣椒EST-SSR信息分析及标记开发

Information and Exploitation of EST-SSRs Loci in Pepper(Capsicum annuum)

利用SSRIT软件从NCBI数据库中19 173条辣椒EST序列中筛选到612个SSR,检出率为3.19%。共观察到51种重复基元,其中三核苷酸基序是主导类型,占总SSR的60.46%;AG/GA/CT/TC,AAG/AGA/GAA/CTT/TTC/TCT,TAAT,ATATA和CTGCTC分别是二、三、四、五和六核苷酸基序的优势重复基序,在所有SSR中的出现频率各自为13.40%、16.18%、1.80%、3.27%及2.12%。辣椒EST-SSR以5~10次重复为主,基序长度集中在15~20 bp范围内。利用含SSR的576条EST序列共设计357对引物,在合适的PCR条件下337（94.40%）对引物显示出清晰条带,75对（21.01%）引物表现多态性,表明EST-SSR标记在辣椒遗传分析与应用中是有价值且可行的。

In this report,19173 ESTs of Capsicum annuum were downloaded from NCBI,of which 612 SSRs were screened,by using software SSRIT,and the frequency was 3.19%.51 types of repeat motifs were detected and the dominant type was trinucleotide,accounted for 60.46% out of total SSRs.Predominant motifs of di-,tri-,tetra-,penta-and hexa-nucleotide repeats were AG/GA/CT/TC,AAG/AGA/GAA/CTT/TTC/TCT,TAAT,ATATA and CTGCTC,with the frequencies of 13.40%,16.18%,1.80%,3.27%,and 2.12%,respectively.The repeat number of pepper EST-SSR was mainly 5-10 and the motif length ranged from 15 bp to 20 bp.337 out of 357（94.40%） candidate primer pairs designed for 576 EST-SSRs showed clear amplification under optimal PCR conditions,and 75 of them（21.01%） demonstrated polymorphism.The presenting results suggested the feasibility and potential of EST-SSR markers for genetic analysis and applications in pepper.