EVALUATION OF LOW-TEMPERATURE ADAPTABILITY OF DIFFERENT LILY VARIETIES

. Individuals of 13 lily varieties were treated in artificial climate chambers at a day/night temperature of 25/15 °C as control, and low-temperature at 15/5 °C for 1 day (D 1 ), 3 days (D 2 ), 5 days (D 3 ) respectively, and rewarmed under the control temperature for 2 days (D 4 ) after D 3 treatment. The physiological indexes including electrical conductivity (Rec), osmotic adjustment substance contents of proline (Pro), soluble sugar (SS) and soluble protein (SP), and activity of superoxide dismutase (SOD) were measured. The results showed that the Rec of most varieties increased significantly under 1 day low-temperature stress and then showed a decreasing trend with the extension of stress time. The Pro of all varieties increased significantly under low-temperature stress, but the SP of most varieties decreased significantly. The SS content of more than half of the varieties increased significantly with the extension of low-temperature stress. The SOD activities of all varieties increased and most of them increased significantly under stress. After rewarming, the Rec of 54% of the varieties increased, and 31% increased significantly compared with D 3 . SS contents of about 62% of the varieties and SP contents of about 46% of the varieties increased significantly. Pro contents of 77% of the varieties decreased. The SOD activity of 77% of the varieties increased and 31% of the varieties increased significantly. After comprehensive analysis by the membership function method the cold adaptability of lily varieties showed a descending order as Concad’Or > Tiber > Asopus > Golden Matrlx > Red twin > Willmottiae > Orange Matrlx > Maximowiczii > Viviana Zantriana > Dauricum > Maldano > Robina > Eyeliner. The results of this study provided a theoretical basis for screening suitable lily varieties for gardens in the northeast of China.