Fuente: WIPO "tobacco agriculture" The invention provides a codominant SSR (simple sequence repeat) marker closely linked with a tobacco pectin gene qPec and an application method of the codominant SSR marker. The serial numbers of the codominant SSR marker closely linked with the tobacco pectin gene qPec are IDYK05838 and IDYK05784, and the nucleotide sequences of PCR (Polymerase Chain Reaction) amplification products of the codominant SSR marker closely linked with the tobacco pectin gene qPec are respectively shown as SEQ ID No. 1, SEQ ID No. 2, SEQ ID No. 3 and SEQ ID No. 4. The application is the application of the codominant SSR marker closely linked with the tobacco pectin gene qPec in detecting whether the tobacco pectin gene qPec exists in tobacco genome DNA (Deoxyribose Nucleic Acid) or not. Compared with a method in the prior art, the codominant SSR marker has the characteristics of accuracy, high efficiency, stability, convenience, low cost and no detection opportunity limitation, so that the molecular marker can be applied to auxiliary selection of the molecular marker of the pectin gene qPec in tobacco breeding.