Effects Of ⁶⁰Co-γ Radiation On Salt Tolerance Of Glycyrrhiza Uralensis Fish

Soil salinization is one of the important factors to influence the agricultural production, because it limits crops growth and reduces its production. 60Co-γ radiation as an important means, plays a certain role to improve the resistance of salt stress.The study took Glycyrrhiza uralensis as the research object, used 60Co-γ radiation of different doses(0-300 Gy) to deal with G.uralensis seeds, and explored effects of 60Co-γ radiation on the characteristics of seeds germination, seedling growth and development, salt secretion rate of the leaves and physiological and biochemical response of G.uralensis under different salt stress, reveal the physiological response mechanism of G.uralensis to radiation and salt stress, for the purpose of providing a theoretical basis for G.uralensis breeding and cultivation under salt-alkali enviroment. The main results are as follows:1.Effects of 60Co-γ radiation on seeds germination of G.uralensis under different salt stress.Under different salt-alkali stress, the seeds germination percentage showed a negative correlation to salt-alkali concentrationi. With the increase of salt-alkali concentrations, the seeds germination percentage of G.uralensis decreased, G.uralensis initial germination time and the time required for the maximum germination percentage prolonged. However, in different salt environment, germination percentage of seed of G.uralensis Fisch exposed to 60Co-γ radiation was higher than controls, indicating that 60Co-γ radiation could effectively improve seeds germination percentage of G.uralensis under different salt-alkali treatments. G.uralensis seeds exposed to 100 Gy and 300 Gy radiation treatmen showd a well tolerance to the pressure of Na Cl and Na HCO3. 100 Gy radiation treatment can effectively improve the seeds germination percentage of G.uralensis under different stress of Na2SO4 Under different stress of salt, the seeds accumulated germination rate of G.uralensis showed a gradual increase, and finally tends to the stable changing pattern: the higher the concentrations is, the longer the time of tending to be stable is.2.Effects of 60Co-γ radiation on the growth of G.uralensis seedlings under different salt stress.The results showed that a certain salt concentration can improve the development of G.uralensis, However, in high salt concentration, the growth of G.uralensis was restrained. Under the same concentration of salt stress, the seeds of G.uralensis exposed to 100 Gy radiation treatment can effectively promote the dry weight of roots and the seeds of G.uralensis exposed to 200 Gy radiation treatment can effectively promote the seedling height and dry weight of the above ground part. Thus, 60Co-γ radiation treatment can promote the growth of G.uralensis seedlingsand improve its salt tolerance to Na2SO4 stress.The roots morphological characteristics( the total length of roots, the total area of roots and total volume of roots) of G.uralensis are all increased under relatively lower salt concentration and then it significantly inhibited under higher concentrations. Comparing to the control samples, after 100 Gy radiated, the total length of seedlings roots with different diameters were increased in various degrees under Na2SO4 stress, which can effectively improved roots water and nutrient absortion area, promoted roots funcions of transport and storage.3. Effects of 60Co-γ radiation on physiological and ciochemical charateristics of G.uralensis under different salt stress.Under different Na2SO4 stress, G.uralensis can reduce the toxicity of the ion by secreting Na+、K+、Ca2+ and synthesis of proline, improve the ability of osmotic regulation alility, and start the antioxidant system in order to improve its salt tolerance. The seedlings radiated by 60Co-γ radiations has comparatively higher osmotic regulation and antioxidant enzymes activity.