藜麦EST-SSR的开发及通用性分析

藜麦因营养均衡受到越来越多的关注，但尚未深入开展其基础研究。开发微卫星序列重复SSR分子标记将为藜麦的遗传分析提供重要资源。本研究利用NCBI数据库中藜麦RNA测序RNA-Seq及表达序列标签EST数据挖掘、验证及评价藜麦EST-SSR，共发现1862个藜麦非单核苷酸EST-SSR。其中，二核苷酸重复最多(38.3%)，六核苷酸重复最少(11.7%)。不同重复类型SSR的数量随着核苷酸数目的增加呈下降趋势。在随机选取验证的119个EST-SSR标记中，66 (55.9%)个能够扩增出清晰条带，39个在4份藜麦资源中具有多态性，且其多态性与重复序列长度不具有显著相关性。t测验显示，多态性EST-SSR在藜麦与其他藜科种质间不存在显著差异，说明其具有良好的通用性，可用于藜科物种的遗传关系分析。

Exploration and Transferability Evaluation of EST-SSRs in Quinoa

Quinoa draws more and more attentions from people, since quinoa seed as grain has comprehensive nutrients.But the fundamental research on quinoa just starts and remains in a moderated level. Simple sequence repeat (SSR) development in quinoa will enhance the resource for its genetic analysis. Here,the available RNA based sequencing (RNA-Seq) and expressed sequence tag (EST) data of quinoa deposited in the National Center for Biotechnology Information (NCBI) were engaged in EST-SSR development.Totally,1862 non-mononucleotide EST-SSRswere identified. Among the EST-SSRs, the dinucleotide type was the most abundant (38.3%), and the hexanucleotidewas the minimal(11.7%). The amount of the EST-SSR showed the declined trend along with the increase in its motif nucleotide length. Among 119 EST-SSR primersrandomly chosen for validation,66(55.9%) primers could give clearamplification bandsand 39 showed polymorphismsinfour quinoa accessions.Further analysis showed that the polymorphisms of EST-SSRs had no significant correlation with their motif nucleotide length. In addition, t-test demonstrated that the significant difference of EST-SSRpolymorphismswas not occurredbetween quinoa accessions and otherChenopodiaceae germplasm. These results indicating EST-SSRs developed in quinoa could be transferable in Chenopodiaceous genus and applied in genetic relationship analysis.