The effects of using DNA markers for elimination of genetic background in backcross breeding were examined through the introduction of PVY-T resistance to an industrial variety. The recipient parent was Coker 319, the most cultivated variety in Japan, and the donor parent for PVY-T resistance was Kerti No.1, a Hungarian domestic air-cured variety. The deficiency of the PVY-T susceptible gene ( Va ) causes the resistance ( nul/nul) of some varieties, such as Perevi and Virgin A Mutant. The resistance of Kerti No.1 is caused by the allele ( va-k ) with Va and is recessive. DNA polymorphisms between Coker 319 and Kerti No.1 were detected by the amplified fragment length polymorphism method (AFLP) and the randomly amplified DNA method (RAPD). Eighty-six Kerti No.1 specific genomic markers, of which 76 were detected by AFLP and 10 by RAPD, were identified and used as background markers for this breeding program. For the selection of Va/va-k plants from 200 plants from each backcross generation, the testcross with Kerti No.1 and inoculation test with PVY-T were used. The number of background makers of the selected plants ( Va/va-k ) was investigated and a plant with the fewest number of background markers was selected in each backcross generation. At the BC₃ generation, a plant with two background markers and a plant with three background markers were selected. The number of background makers of PVY-T resistant plants of the BC₃S₁generation, the selfed progenies of these plants, was investigated, and three plants with no background makers were selected. At present, the actual field characteristics and the yield and quality of cured leaves of three lines of the BC₃S₂ generation are being investigated.