Fuente: WIPO "tobacco agriculture" The invention discloses co-dominant SSR (simple sequence repeat) markers closely interlinked with a major regulation and control gene nic1 of nicotine synthesis of nicotiana tabacum and application ofthe co-dominant SSR markers. The serial numbers of the co-dominant SSR markers closely interlinked with the major regulation and control gene nic1 of nicotine synthesis of nicotiana tabacum are TM22038, TM23004 and TM22041, and nucleotide sequences of PCR (polymerase chain reaction) amplification products of the markers are respectively shown in SEQ ID No.1, SEQ ID No.2 and SEQ ID No.3 and SEQ IDNo.4, SEQ ID No.5 and SEQ ID No.6. The application refers to application of the co-dominant SSR markers closely interlinked with the major regulation and control gene nic1 of nicotine synthesis of nicotiana tabacum in detecting whether nicotiana tabacum genome DNA (deoxyribonucleic acid) has a homozygous genotype nic1 or not and a nicotiana tabacum variety of a low nicotine content is available or not. The co-dominant SSR markers disclosed by the invention have the characteristics of being stable, reliable, simple and convenient, rapid and low in cost, so that the molecular markers can be applied to assistant selection of molecular markers of the low nicotine content gene nic1 in high-quality nicotiana tabacum breeding.