高温胁迫对不同油茶品种细胞膜稳定性的影响

为探讨高温条件下油茶叶片细胞膜的稳定性及变化规律,以来自江西省林业科学院油茶种质资源圃中耐热性不同的(包括感热型、中间型和耐热型3类)25个优良油茶品种为材料,对成年大树的水培枝条进行8h常温(对照)、40℃、45℃3种温度处理,测定了其叶片相对电导率、丙二醛(MDA)含量和超氧化物歧化酶(SOD)活性。结果表明:与常温相比,40℃、45℃高温胁迫后,25个油茶品种的叶片相对电导率平均值分别增加53.68%、113.00%,MDA含量平均值分别增加81.76%、198.46%,SOD活性平均值分别增加88.33%、131.5%;油茶品种间上述各指标在同一胁迫温度下差异极显著,由此可见,高温胁迫使油茶品种叶片的相对电导率、MDA含量和SOD活性均显著升高,且同一温度胁迫下感热型品种的变化幅度明显高于耐热性品种。综合分析表明,叶片相对电导率、MDA含量和SOD活性可以作为评价油茶耐热性的重要指标。

Effects of High Temperature Stress on Cell Membrane Stability in Different Camellia oleifera Varieties

In order to explore the change of cell membrane stability of Camellia oleifera under high temperature stress,the hydroponic branches of 25 varieties of Camellia oleifera growing in Camellia oleifera germplasm nursery in Jiangxi Academy of Forestry,which were classified into three heat tolerance types(heat-resistant type,medium-resistant type and heat-sensitive type),were respectively dealt with the temperatures of 40,45 ℃ and the normal temperature for 8 hours under hydroponic culture to assay the relative conductivity,MDA content,SOD activity of Camellia oleifera leaves.The results showed that compared with the situations under the normal temperature,the relative conductivity of leaves respectively increased by 53.68% and 113.00% under high temperature stress of 40 ℃ and 45 ℃,the MDA content in leaves respectively increased by 81.76% and 198.46%,and the SOD activity respectively increased by 88.33% and 131.5%.And the differences of the index of the Camellia oleifera varieties were significant under the same high temperature stress.These results demonstrated that high temperature stress made relative conductivity,MDA content,SOD activity of Camellia oleifera leaves increase remarkably,and the variation scope of heat-sensitive type was much higher than that of heat-resistant type at the same high temperature.The result of comprehensive analysis showed that the changes of physiological indexes of different Camellia oleifera varieties had significant correlation with heat resistance,suggesting that the relative conductivity,MDA content,and SOD activity could be considered as the most important indexes evaluating heat tolerance of Camellia oleifera.