Study of K+ uptake kinetics of flue-cured tobacco in K+-enriched and conventional tobacco genotypes

Screening of potassium efficient genotypes will be one of the best ways to solve the low potassium content of flue-cured tobacco. The study was conducted to determine whether the potassium efficient genotypes could be screening with high K⁺ uptake efficiency. The K⁺ uptake characteristics of a high K⁺ content line (GK8) and the conventional cultivated variety (K326) of flue-cured tobacco were compared at the seedling stage. K_m, C_min, and I_max values were higher in young seedlings (4?～?5 versus 6?～?7 leaf stage) and cultures with high initial K⁺ concentration (0.35 versus 0.25?mmol?L^?1). Culture solutions with a high K⁺ concentration (2.0 versus 0.6?mmol?L^?1) showed a high K_m, and C_min, but the I_max was lower as compared with the young seedlings and the solution with high initial K⁺ concentration. In conclusion, the GK8?line had a stronger ability for limited K⁺ uptake than K.