烟草叶绿体基因组和线粒体基因组SSR位点分析

摘要

In order to develop the simple sequence repeat (SSR) primers from the chloroplast genome and mitochondria genome in tobacco (Nicotiana) ,SSRs of chloroplast genome and mitochondria genome in tobacco downloaded from the public data were analyzed by the bioinformatics method. 186 and 578 SSR loci were mined out in chloroplast genome and mitochondria genome,and the average distance between SSR loci was approximately 838 bp and 745 bp, respectively. Almost all the SSR loci were distributed in UTR domain, especially the 5'UTR. Dinucleotide and trinucleotide repeats, totally accounting for more than 90%, were the main motif types and the trinucleotide was the most abundance in all SSRs. All the 657 SSR primer pairs were subjected to PCR using 10 tobacco accessions as materials and the results showed that all the primer pairs could produce clear,stable and target bands. 26 SSR primers from tobacco chloroplast genome and 178 SSR primers from tobacco mitochondria genome were polymorphic in 5 wild tobacco accessions, while none were polymorphic among 5 cultivated tobacco (N. Tabacum) varieties. The results indicated that SSR markers from chloroplast genome and mitochondria genome were suitable for the evolution,classification and diversity analysis among different tobacco species.%利用生物信息学方法对烟草叶绿体和线粒体基因组数据中的SSR信息进行了分析.结果表明,在叶绿体和线粒体基因组中分别获得186和578个SSR位点,SSR间的平均距离分别为838 bp和745 bp.在SSR的分布区域上,绝大多数SSR位点分布在UTR(尤其是5’UTR)区域；在SSR重复碱基类型上,主要集中在二、三碱基重复,二者占总SSR位点的90％以上,其中三碱基重复类型丰度最高.利用全部657对SSR引物在供试的10份烟草材料中进行扩增,发现所有引物均能获得目的片段,但在普通烟草内品种间并未检测到多态性,而在烟草种间有26对叶绿体基因组SSR引物和178对线粒体基因组SSR引物扩增出多态性条带,表明来源于烟草叶绿体基因组和线粒体基因组的SSR标记适合用于烟草种间进化、分类、遗传多样性等方面研究.