Effects Of Exogenous Vitamins On Cucumber Seed Germination And Physiological Characteristics Of Seedling Under Salt Stress

Effects of four kinds of exogenous vitamins including VC,VB1,VB6 and VPP on cucumber seed germination and physiological characteristics of seedling under salt stress were studied. This study made sure that these four kinds of vitamins can promote cucumber seed germinating, and the best working concentration was selected for further study. By spaying vitamin solutions on cucumber leaves, the effects of different vitamins on plant growth, lipid peroxidation, osmotic adjustment ability and the activities of antioxidant enzymes were studied in different period of salt stress. Furthermore, the physiological mechanism of these four vitamins in inducing salt resistance of cucumber in different stages was discussed. The experimental results are as follows:1. VC,VB1,VB6 and VPP can enhance cucumber seed germination and seedling growth. The content of Pro increased and the content of MDA decreased, Under salt stress condition, which all indicates that vitamins can relieve the harm caused by salt stress. The results also showed that four vitamins were all worked best at the concentration of 80mg-L-1.2. Spraying leaves with four vitamin solutions can promote the cucumber seedling growth. The plant height, root length and stem diameter all increased, and leaf number and leaf area increased too. At the same time, dry and fresh weight and plant water content, increased. The root activity was strengthened and the content of chlorophyll was raised too. VB1 at 80mg·L-1 showed the best promoting effect.3. Spraying leaves with four vitamin solutions can relieve the lipid peroxidation of cucumber seedling. The MDA content and relative conductivity all decreased compared with the ones of the treat under salt stress alone. As salt stress carrying on, these two indexes were all decreased first and then increased. The value reached minimum in the 7th day under salt stress. 4. The content of proline, soluble sugar and soluble protein all increased after spraying leaves with four vitamin solutions. The proline content decreased gradually as the salt stress carrying on, while the content of soluble sugar and soluble protein all decreased first and then increased. The results also showed that VB1 at the concentration of 80mg·L-1 performed best.5. Spraying leaves with vitamin solutions raise the activity of SOD, POD and CAT to some extent. While this effect is not obvious at initial stage of salt stress, but become clear as the salt stress getting more and more serious.