| Abstract: The effects of different substrate proportions on the growth of tomato seedlings and the changes of chlorophyll fluorescence parameters of leaves were studied by randomized block arrangement design and taking tomato cultivar 'Fumei No.10' as material. The results showed that the seedling emergence rate, plant height, stem diameter, number of leaves and root-shoot ratio were the best under the A3 treatment [V(peat)∶V(corn straw)∶V(cow dung)∶V(edible fungus residue)∶V(vermiculite)＝1∶2∶0.5∶0.5∶1], which were 98.25%, 44.60 cm, 0.50 cm, 9.12 pieces and 7.95, respectively. The values of PSII primary light energy conversion efficiency (Fv/Fm) and PSII potential activity (Fv/Fo) were the highest in the early, middle and late stages of seedling growth, and F v/Fm were 0.82, 0.74 and 0.79, respectively, and the values of Fv/Fo were 3.92, 2.97 and 3.23, respectively. The malondialdehyde (MDA) content in leaves was the lowest (6.02 μmol/g), but the root activity, superoxide dismutase (SOD), peroxidase (POD) and soluble protein content were the highest, they were 158.26 μg/(g?h), 386.23 U/g, 6.26 U/(g?min) and 0.203 mg/g, respectively, significantly higher than other treatments. The above all indicated that the substrate proportion of treatment A3 was more suitable for tomato seedling growth. |