Abstract:

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.

Key words: Tobacco, SRAP, ISSR, Genetic linkage map