烟草SSR分布特征与开发利用

Distribution Characteristics and Utilization of SSRs in Nicotiana tabacum

EST-SSR标记与gSSR标记是2种重要的分子标记,烟草EST序列数量与基因组序列数量的迅速增加为开发新的烟草分子标记提供了宝贵的数据资源。对GenBank上公布的158 098条EST序列及10 647条GSS序列进行大规模微卫星位点搜索,在EST中发现了8 088个微卫星位点(检出率为5.1%),在GSS中发现了2 020个微卫星位点(检出率为18.9%)。在EST中搜索到的重复单元共有176种,其中二核苷酸占主导地位,占到总SSR的近66%,出现次数在1～100之间的基序超过所有基序的90%;在GSS中搜索到重复单元81种,出现次数大部分在1～50之间,占88%。研究还挑选了烟草的150条EST序列,并对其进行了引物的设计。

EST-SSR and gSSR are two kinds of important SSR markers.As the amount of EST sequences and GSS sequences in Nicotiana tabacum has been increasing rapidly in recent years,data from them has become important resources for the development of new SSR markers.In this study large scale searches for microsatellites were performed based on 158 098 sequences of ESTs and 10 647 sequences of GSS in Nicotiana tabacum downloaded from GenBank.8 088 microsatellites were detected in EST and the detection rate was up to 5.1%,and a total of 176 sorts of repeat motifs were found in all these microsatellites.In GSS sequences 2 020 microsatellites were detected and the detection rate was 18.9%.Dinucleotide repeat motifs were dominant,accounting for 66% together in all SSRs.The motifs whose repeat counting between 1～100 account for more than 90% in all SSRs.Most of the motifs detected in GSS count between 1～50 counting for 88%.In addition,150 sequences of ESTs in Nicotiana tabacum were selected and 150 primer pairs for EST-SSR were markers designed.