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.