Abstract:

To improve the yield and quality of cucumber, the study dealt with the effects of zinc on growth and activities of protective enzymes of cucumber seedling roots, which cultivated in hydroponic nutrient solution (zinc deficiency 1/2 Hoagland nutrient solution), with different concentrations of ZnSO4?7H2O solution (0, 0.1, 0.2, 0.4 mg/L). The results showed that: (1) With increasing concentrations of zinc, the total length of roots of cucumber seedlings, average diameter, total area, total volume, the number of root tips increased gradually, reached the peak in Zn3 (0.4 mg/L). (2)In the Zn0 (0 mg/L) to Zn2 (0.2 mg/L) range, with the zinc concentration increased, POD, CAT activity increased. When zinc concentrations greater than Zn2, POD, CAT activity decreased; SOD activity increased significantly with increase in zinc concentration; malondialdehyde (MDA) content significantly reduced with increase of zinc. (3)Considering the physiological indicators of root growth of cucumber seedlings, the optimum concentration of ZnSO4?7H2O was: 0.2mg/L of 1/2Hoagland nutrient solution.