烟草SRAP和ISSR分子遗传连锁图谱构建

Construction of A Molecular Genetic Linkage Map of Tobacco Based on SRAP and ISSR Markers

采用烤烟品种台烟7号与白肋烟品种白肋21杂交,构建了187个单株的F2遗传作图群体,利用所筛选的68个能扩增出多态性条带的SRAP和ISSR引物,对F2作图群体进行PCR扩增和遗传连锁分析,初步构建了一张包含26个连锁群、112个(92个SRAP和20个ISSR)标记位点的烟草遗传连锁图谱。该图谱覆盖长度为1560.2cM,平均图距18.1cM。有16个标记未进入连锁群。26个连锁群包含2～20标记不等,连锁群遗传距离0～291.0cM。连锁群上有24.1%的标记出现偏分离,主要集中在LG1和LG4连锁群上,其余分散在不同连锁群。该图谱为烟草重要农艺性状的基因定位、以及分子标记辅助选择等研究奠定基础。

High-density genetic linkage maps are useful tools for studying genome, phylogeny and evolution, and for mapping and Cloning genes of interest. In this study, a molecular genetic map was constructed with F2 population consisting of 187 individuals from a cross of flue-cured tobacco cultivar Taiyan 7 and burley tobacco cultivar Bailei 21 by using a total of 513 SRAP primers and 42 ISSR primers. Approximately 58 out of 513 and 10 out of 42 primers, respectively, showed polymorphisms. Each of this polymorphic primers produced at least one scorable polymorphic DNA band which was visible enough for detection and scoring. The map consisted of 26 linkage groups which included 112 （92 SRAP and 10 ISSR） markers, and covered 1 560.2 cM with an average distance of 18.1 cM. Sixteen markers were still unlinked. All 26 linkage groups consisted of 2-20 markers ranging in length from 0-291.0 cM. A total of 24.1% distorted markers distributed in the map, mainly concentrated in the LG1 and LG4 linkage groups, and the others were mapped on diverse linkage groups respectively. This map will provide the basis for gene mapping and marker-assisted selection of important agronomic traits in tobacco.