聚乙二醇模拟干旱胁迫下紫斑牡丹的抗旱性研究

Drought resistance of Paeonia rockii under polyethylene glycol simulated drought stress

【目的】探讨紫斑牡丹(Paeonia rockii)抗旱性研究的最佳模拟条件,对不同品种紫斑牡丹的抗旱性进行比较,并筛选出鉴定紫斑牡丹抗旱性的指标。【方法】以4年生的‘紫斑粉’、‘书生捧墨’、‘蓝海银波’、‘艳冠群芳’、‘紫楼闪金’和‘鹤翎白’6个紫斑牡丹品种及在中原地区广泛栽培的牡丹(Paeonia suffruticosa)为材料,用0,0.1,0.2,0.3kg/L的聚乙二醇(PEG-6000)浇灌供试植物盆栽幼苗,测定其叶片含水量、相对含水量、相对电导率、丙二醛、可溶性糖、游离脯氨酸、叶绿素等。用隶属函数法评价不同品种紫斑牡丹的抗旱性,用关联度分析法筛选评价紫斑牡丹抗旱性的指标。【结果】研究紫斑牡丹抗旱性的最佳模拟条件为,以0.2kg/L的PEG-6000胁迫8d。根据隶属函数平均值进行抗旱性评价,6个紫斑牡丹品种和牡丹的抗旱性排序为:‘紫斑粉’>‘蓝海银波’>‘书生捧墨’>‘艳冠群芳’>‘紫楼闪金’>‘鹤翎白’>牡丹。11个测试指标与隶属函数平均值的关联系数大小依次为:相对电导率>叶绿素a>游离脯氨酸>叶绿素总含量>可溶性糖>类胡萝卜素>叶绿素b>丙二醛>相对含水量>叶绿素a/b>叶片含水量。【结论】模拟干旱条件下,相对电导率、叶绿素a和游离脯氨酸对紫斑牡丹抗旱性影响较大,可作为评价紫斑牡丹抗旱性的候选指标,‘紫斑粉’抗旱性最强。

【Objective】The article studied the optimum simulated conditions to investigate drought stress of Paeonia rockii,compare the drought resistances of different cultivars and screen the indexes for identification of drought resistance.【Method】Using six 4-year old P.rockii cultivars ‘Zibanfen’,‘Shushengpengmo’,‘Lanhaiyinbo’,‘Yanguanqunfang’,‘Ziloushanjin’ and ‘Helingbai’,and P.suffruticosa which is widely planted in Central China as materials,changes in leaf water content,relative water content （RWC）,relative electric conductivity （REC）,malondialdehyde （MDA）, contents of soluble sugar,proline and chlorophy Ⅱ under drought stress simulated by 0,0.1,0.2 and 0.3 kg/L polyethylene glycol （PEG-6000） were compared.Subordinate function was used to comprehensively evaluate the drought resistance and correlative degree analysis was used to screen drought resistance indexes.【Result】The optimum simulated drought stress was using 0.2 kg/L PEG for 8 d.The drought resistant capabilities of 6 P.rockii cultivars and P.suffruticosa were in a decreasing order of ‘Zibanfen’〉‘Lanhaiyinbo’〉‘Shushengpengmo’〉‘Yanguanqunfang’〉‘Ziloushanjin’〉‘Helingbai’〉P.suffruticosa.The correlative degrees of drought resistance and 11 measured indexes were in a decreasing order of REC〉chlorophy a〉proline〉total content of chlorophyⅡ〉soluble sugar〉carotenoid〉chlorophy b〉MDA〉RWC〉chlorophyⅡ a /b〉leaf water content.【Conclusion】REC,chlorophy a and proline had significant influences on the drought resistance of P.rockii against simulated drought stress,so they can be used as candidate indexes to evaluate the drought resistance of P.rockii.‘Zibanfen’ had the highest drought resistance.