An Integrated High-Density Genetic Linkage Map of Tobacco (Nicotiana tabacum L.)

Tobacco is an important non-food crop with many applications, which is widely cultivated worldwide. Genetic linkage maps play an important role in QTL mapping, gene cloning, marker assistant selection, and genome assembly However, due to the narrow genetic background and large genome of tobacco, the research on the tobacco genetic map lags behind. At present, although several linkage maps have been constructed based on SSR (simple sequence repeat) markers, different SSR markers limit their widespread applications. In order to construct an integrated linkage map, we identified the redundancy of tobacco SSR markers, and constructed a high-quality genetic map by using the integration method based on four tobacco genetic maps. Finally, 20 redundant markers were found from 3.354 SSR markers, and the integrated high-density genetic linkage map (IHD) had a total of 3.377 loci with a length of 2.489.82 cM and a density of 1.36 locus/cM. The high-density integrated genetic map will have great application in the field of QTL mapping and marker-assisted breeding in tobacco.