辣椒EST-SSR标记的开发与验证

从NCBI数据库下载118 900条辣椒相关EST,对其进行SSR位点搜索,共搜索出3 343条SSR,分布密度为1/17.20kb,共有287种重复基元。在辣椒EST-SSR中,二核苷酸(1 476个SSR)和六核苷酸(1 128个SSR)占主导地位,所占比例分别为44.15%和33.74%;出现最多的重复基元是GA/TC,占总数的14.30%,其次为CT/AG(94个,占8.11%)。针对3 343条含有SSR的EST设计合成了200对引物。用17份辣椒种质对200对引物进行筛选,196对引物有扩增产物,71对引物表现出多态性,共有220个多态性位点。利用71对多态性引物,对特定亲本P181-2-6和P230-2-5及其杂种一代F1的亲缘关系进行检测,结果说明从辣椒相关EST数据库中开发的SSR引物有较好的可用性。

Development and Utility of EST-SSR Marker in Capsicum annuum L

A total of 1 18, 900 ESTs in Capsicum annuum L were downloaded from NCBI for identifying and developing an SSR marker.As a result,3,343 SSRs in the ESTs with an average of one SSR per 1 7.20 kb were found,including 283 SSR motifs.Analysis on the SSR motifs revealed that they were mostly di-nucleotides (1,476 SSR)and hexa-nucleotides (1,128 SSR),accounting for 44.1 5% and 33.74% of the total,respectively.GA/TC was the most frequently found motifs (14.30% of all),which was followed by CT/AG (94 SSR,and 8.1 1% of all).From the 3,343 SSR-containing ESTs,200 primer pairs were designed and validated for amplification using 1 7 pepper inbred lines.The results showed that 71 primer pairs yielded 220 amplification bands.Using those 71 pairs of polymorphic primers,the genetic relationship between the parents,P181-2-6 and P230-2-5,and their F1 hybrid was determined.It appeared that the SSR markers identified from the ESTs of C.annuum were potentially of practical applicatios.