不同光照和温度对暗受冷菜豆幼苗的影响

EFFECTS OF DIFFERENT LIGHT INTENSITIES AND TEMPERATURES ON BEAN SEEDLINGS AFTER LOW TEMPERATURE TREATMENT IN DARKNESS

将暗中（4±1℃）低温胁迫12h的菜豆幼苗分别置于中温弱光（15℃±1℃，72μmol·m-2·s-1）、高温强光（20℃±3℃，224-340μmol·m-2·s-1）、低温弱光（4℃±1℃，72μmol·m-2·s-1）3种条件下进行处理，结果发现2d中低温弱光和高温强光下菜豆幼苗的MDA含量不断上升，其SOD、POD、CAT酶活力也维持在较低水平．质膜外渗电导率在处理第1天时上升到最大，之后缓慢下降。而中温弱光条件下的菜豆幼苗MDA含量上升较少，SOD、POD、CAT酶活力恢复较快，质膜外渗电导率在2d后即接近正常值，菜豆幼苗冷害恢复较迅速。施用低温保护剂Mefluidide可减轻菜豆幼苗冷伤害并加快其恢复。

Beau seedlings stressed by low temperature (4℃±1℃ ) in darkness for 12 h were treated with middle temperature and low light intensity (15℃±1℃, 72 μmol· m-2·s-1 ), high temperature and high light intensity (20℃±3℃, 224 - 340 μmol· m-2·s-1 ), and low temperature and low light intensity (4℃±1℃, 72 μmol· m-2· s-2), respectively. In the chilled seedlings treated with low temperature and low light intensity,and high temperature and high light intensity,the contents of MDA increased continuously during two days,the lower activities of SOD,POD and CAT were keeped,the electrolyte leakage of plasmalemma reached their maxima at the first day and then decreased slowly. But in ones treated with middle temperature and low light intensity,the content of MDA increased less, the activities of SOD, POD and CAT recovered more rapidly, the electrolyte leakage of plasmalemma approached normal value after two days, the chilled seedlings restored more quickly. Use of the chilling protective agent mefluidide could reduce chilling injury of beau seedlings and accelerated them restoration.