Effects of Low Temperature Stress on the Related Physiological Indexes in Grape Seedlings

[Objective] The research aimed to explore the effects of low temperature stress on the related physiological indexes in grape seedlings.[Method] Using the seedlings of Zaoheibao grape in vitro as materials,the grape seedlings with 5～6 euphylla and the same growth vigor were treated with 3 kinds of temperature including normal temperature(25 ℃ as CK),15 ℃and 5 ℃. All the physiological indexes were determined on 0 th,2 nd,4 th,6 th,8 th after the treatments.And then the treatment of normal temperature was resumed for 2 d(R2) and 4 d(R4) to determine the related physiological indexes.The effects of different degree of low temperature treatments on the morphological indexes and the physiological indexes(chlorophyll content,the content of soluble sugar,SOD activity,POD activity、MDA activity and relative permeability of plasma membrane(PMP)) of grape seedlings in vitro were studied.[Result] After low temperature stress,chlorophyll content of grape seedlings in vitro was decreased and the content of soluble sugar was increased,and the activities of SOD and POD were first increased and then decreased.Low temperature caused the peroxidation of membrane lipid in grape seedlings in vitro,the increase of MDA content and the enlargement of PMP.[Conclusion] The injury of low temperature treatment at 15 ℃ to grape seedlings in vitro was reversible and the treatment at 5 ℃ caused the irreversible injury.