西瓜EST资源的SSR信息分析

Analysis of SSR Information in EST Resource of Watermelon (Citrullus lanatus)

对5034条西瓜无冗余EST序列进行了搜索,共检索出347个SSR,检出率为6.89%,平均分布距离为7.49kb。包括91种重复基元,其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39.48%和46.68%。AT是二核苷酸中的优势基元,占二核苷酸重复类型的23.35%。三核苷酸重复基元分布比较分散,优势基元GAA仅占三核苷酸重复类型的8.64%。理论上表明这些EST-SSR具有较高的可用性。

5 034 non-redundant ESTs of watermelon 〔Citrullus lanatus （ Thunb. ） Matsum. et Na- kai〕were screened and 347 SSRs were mined out. The frequency of these EST - SSRs was 6. 89 % and the mean distance was 7. 49 kb in non-redundant ESTs. All these SSRs included 91 kinds of repeat motifs. Among them the dinucleotide and trinucleotide repeats were dominant types,accounting for 39. 48 % and 46. 68 % ,respectively. AT is most frequent motif in dinucleotide accounting for 23. 35 % . The distribu-tion of trinucleotide repeats was dispersive and the dominant motif was GAA, only accounting for 8.64 % in all the trinucleotide repeats. The EST- SSRs are highly feasible in theory.