Fecha de publicación: 28/02/2020 Fuente: WIPO "tobacco agriculture" The invention discloses a nicotine quantitative conversion rate and gene expression based cherry-red tobacco seed screening method. The method includes: selecting seeds from a cherry-red tobacco seedbank, and performing seedling cultivation; after seedling emergence, when seedlings grow to 30-40cm in 30-40d, sampling from bottom 2th-4th tobacco leaves in good conditions; soaking samples in ethephon and abscisic acid mixed solution, perforating, and drying remaining tobacco leaves after perforation until no moisture is left on surfaces; drying the moisture-free tobacco leaves to a constant weight; chemically analyzing nicotine and nornicotine contents of the tobacco leaves, and calculating the nicotine conversion rate; detecting perforated tobacco leaf CYP82E4 gene expression; according tothe nicotine conversion rate and CYP82E4 gene expression, screening out tobacco plants according with a nicotine quantitative conversion rate to cultivate, and removing tobacco plants not accordant with the conversion rate; bagging the screened tobacco plants until maturity is achieved, and reserving seeds to obtain cherry-red tobacco seeds in the nicotine quantitative conversion rate. The methodhas advantages of stability, reliability, high screening speed, high accuracy, controllable seed nicotine conversion rate and the like.