Development of DArT markers for a linkage map of flue-cured tobacco

Tobacco (Nicotiana tabacum) is one of the most economically important nonfood crops, and flue-cured tobacco accounts for approximately 80% of world tobacco production. An extremely narrow genetic diversity in the tobacco pool has led to a low efficiency of PCR-based molecular markers (such as AFLP and SSR). Diversity Arrays Technology (DArT) is a high-throughput hybridisation-based marker system that has been developed in many plants including wheat, which, like tobacco, has a complex genome. In this study, we developed a tobacco DArT chip that included 7680 representative sequence tags based on typical tobacco accessions. The 1076 DArT markers of flue-cured tobacco were identified and most (82.1%) of their polymorphism information contents (PICs) were greater than 0.4. An integrated linkage map that included 851 markers (238 DArT and 613 SSR), which is the highest density map of flue-cured tobacco to date, was constructed. This chip-based DArT system provides an alternative in high-throughput marker genotyping for tobacco.