[Objective] In order to study the tolerance of "Liuqiuhong" to low temperature.[Method] By pot experiment with Rhododendron hybridum "Liuqiuhong" as experimental material,studied the changes of 3 kinds of antioxidant enzymes in the leaves of Rhododendron hybridum " Liuqiuhong" (CAT,POD and SOD),relative conductivity,malondialdehyde (MDA) content,soluble protein content,under 0 ℃,-3 ℃ and-6 ℃(T1,T2 and T3) low temperature conditions for 1 d,2 d,3 d,4 d,5 d,6 d.[Result] Under low temperature stress,Rhododendron hybridum "Liuqiuhong" in the leaves of (MDA) content,soluble protein content,and Rhododendron hybridum "Liuqiuhong" leaf antioxidant enzymes CAT,POD and SOD activity increased at first,and MDA content,soluble protein content and enzyme activity was the highest after low temperature stress for 4 days.With the increase of low temperature stress time,MDA content,the soluble protein content and enzyme activity declined firstly,reached the lowest point after cold stress 6d,and slight wilting in Rhododendron hybridum and control more obvious changes.The results showed that the Rhododendron hybridum "Liuqiuhong" maintained normal physiological indexes in the-6 ℃ low temperature stress 3 d,and the changes of the external morphological characteristics,antioxidant enzyme activities were significantly changed after chilling stress in 3 d.Under low temperature stress Rhododendron hybridum "Liuqiuhong" by improving antioxidant enzyme activity,antioxidant content and soluble protein content,reduced the accumulation of reactive oxygen species (ROS) and lipid peroxidation products,enhanced the ability of resistance to low temperature stress,but with the increase of stress time,plant cells were irreversibly damaged,resulting in antioxidant enzyme activity concentration decreased.The experiment showed that the lower temperature of the "Liuqiuhong" Rhododendron hybridum can be tolerated was-3 ℃.[Conclusion]The research can give reference for using "Linqiuhong"as a green platt in Ningbo and surrounding cities.%[目的]研究“琉球红”对低温的耐受能力.[方法]试验采用盆栽方法,以“琉球红”杜鹃为试验材料,研究了“琉球红”杜鹃叶片中3种保护酶活性[过氧化氢酶(CAT)、过氧化物酶(POD)和超氧化物歧化酶(SOD)]、相对电导率、丙二醛(MDA)含量、可溶性蛋白含量等理化指标,在0、-3和-6℃(T1、T2和T3)低温条件下,处理1、2、3、4、5、6d时的变化情况.[结果]在低温胁迫下“琉球红”杜鹃叶片中MDA含量,可溶性蛋白含量,及“琉球红”杜鹃叶片保护酶CAT、POD和SOD活性先升高,且在低温胁迫4d时,MDA含量、可溶性蛋白含量和酶活性达到最高,随着低温胁迫时间的增加,MDA含量、可溶性蛋白含量和保护酶活性开始下降,在低温胁迫6d时达到最低,且杜鹃叶片出现轻微萎蔫情况与对照变化较为明显.试验证明“琉球红”杜鹃在-6℃低温胁迫3d内保持着正常的生理指标,在低温胁迫3d后,包括外部形态特征、保护酶活性均发生较明显变化.在低温胁迫下“琉球红”杜鹃通过提高保护酶活性及可溶性蛋白含量等,减少了活性氧(ROS)的积累和膜脂过氧化产物的产生,增强了“琉球红”杜鹃耐低温胁迫的能力,但是随着低温胁迫时间的增加,植物细胞受到不可逆的破坏,导致抗氧化酶活性下降,试验表明,“琉球红”杜鹃能耐受的较低温度为-3℃.[结论]该研究可为宁波及周边城市将“琉球红”作为绿化植物提供参考.
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