中文摘要：

以4个5年生杜鹃品种为试验材料,采用盆栽控水法研究杜鹃植株在不同干旱程度下的形态与生理响应。旱害指数结果表明：‘国旗红’抗旱性最强,‘玉蝴蝶’次之,胭脂蜜抗旱性最弱。随着干旱胁迫程度加深,杜鹃的相对含水量显著下降（P〈0.05）;丙二醛（MDA）含量、相对电导率随干旱胁迫程度加深呈上升趋势;而过氧化氢酶（CAT）活性、可溶性糖含量则因品种的不同而表现出不同的结果,‘国旗红’、‘大青莲’、‘胭脂蜜’的CAT活性在重度胁迫后下降,这时可能已经达到植株耐受干旱的极限,清除氧自由基的能力降低。通过相关性和主成分分析发现CAT活性、可溶性糖、MDA含量、相对电导率、相对含水量与杜鹃抗旱性密切相关。采用隶属函数法对4个杜鹃品种的抗旱性进行综合评价,结果表明,4个品种抗旱性强弱依次为‘国旗红’〉‘玉蝴蝶’〉‘大青莲’〉‘胭脂蜜’,与旱害指数结果一致。

英文摘要：

The experiment was conducted to study the morphological and physiological of 4 cultivars of 5-year-old Rhododendron under different drought stress. The results of drought damage index showed that the order of drought resistance from strong to weak was‘Guoqihong＇‘Yuhudie＇‘Daqinglian＇‘Yanzhimi＇. With the drought stress increase,the relative water content of Rhododendron decrease significantly（ P 0. 05） while Malondialdehyde（ MDA） content and relative conductivity had a upward trend; Catalase（ CAT） activity and soluble sugar showed different results due to various cultivars. The CAT activity of‘Guoqihong＇,‘Daqinglian＇and ‘Yanzhimi＇decreased under the severe drought stress which was related to the plants have reached the limit drought stress and the ability of scavenging oxygen free radicals become decrease. Correlation analysis and principal component analysis showed that CAT,soluble sugar,MDA,relative conductivity and relative water content were closely related with drought resistance of Rhododendron.Drought resistance of 4 Rhododendron cultivars from strong to weak,evaluated by the method of membership function,were‘Guoqihong＇〉‘Yuhudie＇〉‘Daqinglian＇〉‘Yanzhimi＇which was consistent with drought damage index.