Screening of Salinity Tolerance and Response of Seedling to Salt Stress in Sugar Beet (Beta vulgaris L.)

To study the salt-tolerance mechanism and differences of salt-tolerant mechanism in every salt injury-tolerance,forty sugar beet varieties were used in this study. Hoagland solution culture method was applied to investigate the fresh weight,the activity of superoxide dismutase (SOD),the content of MDA and leaf plasma-membrane permeability. The results showed that 'KWS0143' had the best salt-tolerance; six varieties had high salt-tolerance,including 'ACERO'; fourteen kinds of materials including 'HI0183' had the moderate salt-tolerance; while five kinds of materials including 'OVITO' had lower salt-tolerance in the shoot and seedling among forty sugar beet varieties. In the same stress periods,the seedling fresh weight of various materials was decreasing with the salt concentration increasing,however 'KWS0143' and 'ACERO' materials decreased more slowly than other salt-sensitive materials. SOD activity of varieties with different salt-tolerant grades increased primary stage and then decreased with the concentration and duration of NaCl stress increasing,and the highest salt-tolerant grade varieties had the largest SOD activity. MDA content and leaf plasma-membrane permeability in varieties with different salt-tolerant grade elevated with the increase of concentration and duration of NaCl stress. The lower salt-tolerant grade varieties,such as 'OVATIO' significantly had more obvious change than the other ones.