Study On Protective And Repairing Function Of The Vicia Faba L Seedlings To Damaged By Enhanced UV-B Radiations

My study, by using Vicia faba L as an experimental material, under the condition of greenhouse with the aids of laser radiation(6mW·mm-2, radiated for 2 min) is to illustrate that laser beam really has the protective and repairing properties for the seedlings during the time of growth, and laser beam really has the physiological and Biochemical effects on enhanced ultraviolet(5.76kJ·m-2·d-1) radiations. The results are as followings:1. The He-Ne laser beam can greatly promote the growth of Vicia faba seedlings.after the seeds were treated by it, and the He-Ne laser beam can also raise up the masses of protein, the chlorophyll, the water use efficiency, as well as the net photosynthetic rate and total biomass.2. Ultraviolet-B radiation can cause beans seedlings damaged during their growth. And UV-B radiation can also cause the masses of protein, the chlorophyll, the water use efficiency greatly reduced, as well as the net photosynthetic rate and total biomass. My experiments show facts for that.3. The content of MDA, the UV absorption substances from seedlings were increased after UV-B radiation treatment, but the content of GSH, AsA and anti-oxidant enzymes activities of SOD, POD, CAT were decreased because excessive free radicals were produced and also because the seedling lipid per-oxidation was produced.4. My experiments show that after the enhancement of UV-b radiation treatment, the bean-plant's growth was slowed down, the leaves were curled, the color was burned. But when giving laser treatment, great degrees of ease works took place. My experiments also show that laser radiation can increase plant sprouting and amylase activity in the early days, protein and RNA synthesis, therefore promoting the germination of Vicia faba and growth.5.The He-Ne laser beam has sufficiently protective effect upon bean seeds when the bean seeds are pre-treated with the laser beam just because of its anti-radiation ability. In the contrast, after the measurement of bean's physiological index, UV-B radiation has significantly decreased such concentrations as those from SOD, CAT, POD, GSH, AsA and ultraviolet absorptions, but laser irradiation has increased the concentration of MDA, the content of AsA, GSH, the ultraviolet absorption substances, the activity of antioxidant enzymes such as SOD, CAT, POD, as well as the antioxidant properties, physiological level and their repairing abilities.6. The results also indicate that He-Ne laser has a good repairing ability to prevent the seedlings from enhanced UV-B damage. The result also shows that the He-Ne laser beam, after the beans radiated first by the UV-B and then treated by the He-Ne beams again, really has the promotional effects on the water use efficiency, net photosynthetic rate, the content of chlorophyll, MDA, GSH, AsA, the total biomass and the anti-oxidant enzymes activities of SOD, POD, CAT at a certain extent. It means that the He-Ne laser radiation in Biological effect could motivate and reinforce the UV-B resistance capacity to the seedlings in some extent...