龙眼叶片对低温胁迫的生理响应研究

摘要

The physiological and biochemical changes in longan ( Dimocarpus longan Lour cv.Fuyan ) leaves under low temperature treatments ( 4℃,0℃,and -10 ℃) were studied by means of artificial temper-ature-controlled phytotron .The results showed that the relative conductivity of longan leaves increased slowly , chlorophyll content declined gradually , and the carotenoid content first increased and then decreased subse-quently with the longer stress of low temperature .The activities of superoxide dismutase (SOD),and peroxide dismutase ( POD) in longan leaves declined and malonaldehyde ( MDA) contents increased at the beginning of low temperature treatments .With the increasing of stress the POD activity increased significantly and the MDA content declined .The contents of proline ,soluble sugar ,and soluble protein increased significantly in the treat-ments with lower temperature and longer stress .These physiological and biochemical changes may help to alle-viate the low-temperature injury to longan plants .%以福眼成年树的离体叶片为试验材料，人工模拟低温逆境，研究4℃、0℃和-10℃低温胁迫对龙眼叶片生理特性的影响。结果表明，随着胁迫时间的增加，龙眼叶片的相对电导率呈现缓慢上升的变化趋势，叶绿素含量缓慢下降，类胡萝卜素含量则先下降后升高。低温胁迫初期龙眼叶片中SOD和POD活性均呈下降趋势， MDA含量增加；随胁迫程度加重，POD活性表现出显著上升，SOD活性变化缓慢，MDA含量下降。低温胁迫使叶片中游离脯氨酸、可溶性蛋白和可溶性糖含量明显高于对照，且随温度的降低和处理时间的延长呈上升趋势，表现出对低温逆境的适应性。