辣椒EST-SSR标记的开发与应用

Development and Application of EST-SSR Markers in Pepper

通过对数据库中32 295条非冗余的辣椒EST序列进行搜索,发现3 396个SSR分布于3 277条EST序列中,EST-SSR频率为10.52%,平均分布距离为4.46 kb.在辣椒EST-SSR中,二核苷酸和三核苷酸重复基元占主导地位,分别占总SSR的43.02%和37.84%.优势重复基元为GA/TC、AG/CT和AT,分别占15.99%、11.98%和11.37%.用Primer Premier 5.0软件设计了420对引物,对辣椒抗疫病自交系‘B072’和感疫病自交系‘B088’进行PCR扩增,403对引物有扩增产物,引物有效扩增率为95.96%,其中76对引物有多态性,多态性引物占可扩增引物的18.86%.试验证明,利用辣椒EST序列开发SSR标记是可行的.

A total of 32 295 non-redundant expressed sequence tags（ESTs） in pepper were screened by using bioinformatics software to search for SSR motifs,3 396 SSRs were sought out,distributing in 3 277 ESTs,corresponding to one SSR in every 4.46 kb of the ESTs.Dinucleotide and trinucleotide repeats were major types among the obtained unigenes,accounting for 43.02% and 37.84%,respectively.GA/TC（15.99%）,AG/CT（11.98%） and AT（11.37%） were the most abundant motifs.Based on the flanking sequences of these 3 396 SSRs,420 primer pairs were designed by using Primer Premier 5.0 software.403 SSRs（95.96%） were successfully amplified and 76 of them（18.86%） showed polymorphism between ＇B072＇（the resistance inbred line） and ＇B088＇（the susceptible inbred line）.These results proved that it is an effective and feasible approach to developing SSR markers based on ESTs in Capsicum annuum L.