Assignment of DNA markers to Nicotiana sylvestris chromosomes using monosomic alien addition lines

A sesquidiploid hybrid (PPS, 2n = 32) between Nicotiana plumbaginifolia (PP, 2n = 20) and N. sylvestris (SS, 2n = 24) was backcrossed to N. plumbaginifolia to produce monosomic alien addition lines. A total of 89 2n = 21 plants, each containing two sets of N. plumbaginifolia chromosomes and a single N. sylvestris chromosome, were obtained in the BC1 and BC2 generations. These plants were classified into 12 groups based on morphological characteristics. The N. sylvestris chromosomes in these plants were identified by RFLP and karyotype analyses. Among the 84 probes tested, 20 could not detect N. sylvestris-specific DNA bands, and the remaining 64 were assigned to 9 normal and 6 aberrant synteny groups. The 9 normal synteny groups corresponded to chromosomes 2, 4, 5, 6, 7, 8, 9, 10 and 12, respectively. Four aberrant synteny groups were the result of chromosome translocations, and 2 were deletions.