Fuente: WIPO "tobacco agriculture" The invention provides a method for rapidly obtaining a high-nicotine tobacco mutant by screening tobacco root systems. Yunyan 87 mutation second-generation seeds and Yunyan 87 control seeds are subjected to spot seeding respectively, after the Yunyan 87 control seeds grow out two true leaves, Yunyan 87 mutation second-generation materials and Yunyan 87 control material seedlings are pulled out and cleaned to compare the root systems, and a mutant material KH65 with the more developed root systems is screened out and cultured and transplanted; after tobacco plants are mature, upper, middle andlower tobacco leaves are sampled to measure the nicotine content of a single plant KH65; after the tobacco plant KH65 blooms, selfing is conducted to collect seeds, and the seeds are sown again in the second year; the root system conditions of the mutant material are identified again, and after the tobacco plant is mature, sampling is conducted again to measure the nicotine content of the maturemutant material of the single plant; after the mature mutant tobacco plant grow to bloom, selfing is conducted to collect seeds, and the high-nicotine tobacco mutant is obtained. According to the method, the tobacco mutant material high in nicotine content can be rapidly identified and obtained by screening the root expression of the tobacco EMS mutant material.