麻风树EST-SSR的筛选和分析

目的]开发麻风树EST-SSR标记,为遗传多样性分析、种质资源鉴定等研究提供理论依据。方法]以麻风树EST序列为材料,运用CAP3软件对EST序列进行组装后,再运用SSRIT软件进行EST-SSR标记的预测。结果]麻风树13193条EST序列经组装后获得6281个UniGene,其中1367个Contig,4914个Singleton。利用SSRIT在线软件对UniGene分析得到206条EST-SSR。拼接后的Unigene含有SSR位点的频率为3.28%,麻风树EST-SSR的发生频率为1/29kb。这些EST重复基元中,三核苷酸重复和二核苷酸重复最多,分别占24.76%和21.84%;五、六核苷酸重复次之,分别占16.50%、20.39%;单、四核苷酸的重复基序最少,分别占9.71%和6.80%。在所有的核苷酸重复基序中,二核苷酸重复序列AG所占比例最高,约占12.62%;三核苷酸重复序列中,所占比例最高的是AAT和AAG,各占6.80%、6.31%。结论]上述结果对于开展麻风树分子辅助育种研究具有一定的指导意义。

Screening and analysis of EST-SSR in Jatropha curcas

Objection] The aim was to develop EST-SSR of Jatropha curcas and provid theoretic basis for genetic diversity analysis and germplasm resource identification of J. curcas. Method]EST sequences of J. curcas were assembled with software CAP3 and predicted for EST-SSR with software SSRIT. Result] 13 193 ESTs were asembled into a total of 6 281 non-redundant Unigenes including 1 367 Contigs and 4 914 Singletons.These non-redundant Unigenes were usded for searching SSR through the software SSRIT and a total of 206 SSR loci were found,with the frequency of 3.28% in Unigene and l/29 kb of EST-SSR occurrence trequenoy were identified. Trinueleotides and dinueleotides were observed at the highest frequencies, which accounted for 24.76% and 21.84%, respectively. And then penta nueleotides, hexa nueleotides followed,which accounted for 16.50% and 20.39%, respectively.while mono nueleotide and tetra nueleotieds were the lowest, which aceocunted for 9.71% and 6.80%, respectively. AG (12.62%)was the most frequent repeat in all Trinucleotide repeat motifs,AAT and AAG (6.80% and 6.31%, respectively) was the most frequenee motifs in trinucleotides. Conclusion]These obtained results and conclusions might provide important information for the molecular assisted selection in J. curcas.