橡胶树 EST-SSR标记开发及特性研究

摘要

为进一步开发橡胶树 EST-SSR标记，该研究下载并组装了来自 NCBI和马来西亚橡胶树 EST数据库 EST序列。在3733个组装的橡胶树单一基因中共鉴定到566个潜在的 SSR位点，平均3.96 kb会出现一个 SSR位点。二核苷酸重复为最丰富的 SSR重复类型，接下来是三核苷酸、四核苷酸、五核苷酸和六核苷酸重复。SSR位点重复单元数目最多的是5，接下来是12、6和7。在该研究中鉴定的51种类型 SSR模体中，二核苷酸、三核苷酸、四核苷酸、五核苷酸和六核苷酸重复分别有6、26、5、3和11种。 GA/CT二核苷酸数目最多，接下来是 TC/AG、AT/TA、CTT/GAA、TTC/AAG和 TCT/AGA。在158个新开发的橡胶树EST-SSR 标记中，99个可在橡胶树品种RRIM600中产生清晰扩增条带。该研究开发的 EST-SSR标记丰富了橡胶树分子标记数量，必将在橡胶树 DNA指纹图谱、遗传多样性、标记辅助选择、遗传图谱等方面得到广泛应用。%To further develop EST-SSR marker in rubber tree, we assembled the sequences downloaded from NCBI and Malaysia EST databases of rubber tree. By analyzing the assembled 3 733 unigenes, we identified 566 potential SSR sites in this study. That is to say, there was one EST-SSR in every 3.96 kb. The di-nu-cleotide repeat was the most abundant type, fol owed by tri-, hexa-, tetra- and pen-ta-nucleotide repeat. The most common number of repeat units was 5, fol owed by more than 12, 6 and 7. Of 51 SSR motifs identified in this study, di-, tri-, tetra-, penta- and hexa-nucleotide repeats were 6, 26, 5, 3 and 11 types, respectively. The GA/CT di-nucleotide repeat was the most abundant motif, fol owed by TC/AG, AT/TA, CTT/GAA, TTC/AAG and TCT/AGA. In total, 158 new EST-SSRs were developed and amplified with the DNA of RRIM600 as a template. The results showed that the PCR products of 99 EST-SSRs generated clear amplifying bands. The EST-SSR markers developed in this study further enrich the number of molecular marker in rubber tree, and they wil be widely applied in DNA fingerprinting, genetic diver-sity, marker-assisted selection and genetic mapping, etc.