Effects of Exogenous Silicon on Growth and Physiological Characteristics of Tobacco under Drought Stress

PurposeTo explore the effects of exogenous silicon on the growth and physiological characteristics of tobacco under drought stress.

MethodsYunyan87 potted seedlings were treated with well water (90%-95% field water holding capacity) and drought stress (35%-40% field water holding capacity), and applied with different contents of exogenous silicon fertilizer (K₂SiO₃, 0, 1.0, 1.5, 2.0 g/kg). The growth morphology, biomass, photosynthetic pigment content, osmotic regulatory substance content and antioxidant enzyme activity of tobacco plants under different treatments were measured when the tobacco plants grew to the flourishing period (45 days).

ResultsUnder drought stress, plant height, leaf number, single leaf area, biomass, photosynthetic pigment content and antioxidant enzyme activity of tobacco plant were decreased, but specific leaf area and osmotic regulatory substance content were increased compared with that of well water treatment group. The application of exogenous silicon of 1.0 to 2.0 g/kg could promote the growth of tobacco under drought stress, and the main effects were increased in plant height, leaf number, leaf area, specific leaf area, total biomass and root-shoot ratio, the contents of photosynthetic pigments and osmotic regulatory substances, and the antioxidant enzyme activities; but the malondialdehyde content was significantly decreased (P<0.05). And 2.00 g/kg silicon treatment effect was the most obvious.

ConclusionApplication of exogenous silicon can alleviate the damage of drought stress on tobacco and improve the drought resistance.