随着气温回升 ,冬小麦将进入返青期。这时若遇上低温（俗称“倒春寒”） ,冬小麦最易遭受冻害而死亡。冬小麦返青期遇到低温 ,一般在细胞间隙出现结冰状态。由于细胞间隙的水溶液浓度比细胞液浓度低 ,因此 ,在细胞间隙首先发生结冰现象。如果温度继续下降 ,冰晶逐渐增大 ,就会 As the temperature picks up, winter wheat will enter the greenback period. At this time if the encounter low temperature (commonly known as “late spring”), winter wheat is most vulnerable to frost damage and death. Winter wheat turning green encountered low temperature, usually in the intercellular space appeared frozen state. As the concentration of aqueous solution in the cell gap is lower than that in the cell solution, icing occurs first in the intercellular space. If the temperature continues to drop, ice crystals will gradually increase, it will be