摘要
为探求低温胁迫对广玉兰的影响机制,测定广玉兰体内相对电导率、丙二醛含量(MDA)、可溶性糖含量、脯氨酸含量及过氧化物酶(POD)、超氧化物歧化酶(SOD)活性等生理指标。结果表明:广玉兰抗寒能力较强,半致死温度为-10.39℃,致死温度为-21.76℃。随着处理温度的降低,广玉兰成活率逐渐降低,叶片中MDA、膜相对透性、脯氨酸和可溶性糖含量增加,SOD、POD活性呈先升后降的变化趋势。在低温胁迫中,丙二醛积累与相对电导率上升为影响广玉兰存活的负面因素;可溶性糖、脯氨酸调节渗透压成为广玉兰缓解低温胁迫的主要保护性因素,而POD、SOD酶活性受低温(≤-10℃)影响,去除活性氧自由基成为次要保护性因素。
To understand the physiological mechanism of low temperature stress affecting the growth of the Magnolia grandiflora,such physiological indexes as relative conductivity,the content of malonaldehyde,peroxidase and superoxide dismutase,soluble sugar and praline were measured by means of visible spectrophotometry.The results showed that the M.grandiflora had a stronger low temperature tolerance and its lethal and half lethal temperatures were-10.39℃ and-21.76℃,respectively.With the decrease of temperature,survival rate of M.grandiflora decreased gradually and MDA,relative permeability of membrane,proline and soluble sugar in the leaves increased,whereas the activity of SOD and POD increased and then decreased.Both accumulation of MDA and increase of relative conductance were factors adversely affecting survival of M.grandiflora under the low temperature stress.Soluble sugar and praline through adjusting osmotic pressure acted as the main protecting factors of M.grandiflora to alleviate stree.Activity of POD and SOD,however,were significantly affected by lower temperature(≤-10℃),thus deleting active oxygen free radical becomes the subordinate protective factors.
出处
《西北林学院学报》
CSCD
北大核心
2008年第6期38-42,共5页
Journal of Northwest Forestry University
基金
河南科技学院重点科研基金资助(040112)
湖南省林业科技重点项目(01-18)
关键词
低温胁迫
广玉兰
生理特性
可见分光光度法
low temperature stress
Magnolia grandiflora
physiological characteristic
visible spectrophotometry
