高温胁迫下五种杜鹃花属植物的生理变化及其耐热性比较  

Physiological changes and heat tolerance comparison of five Rhododendron species under high-temperature stress

作　　者：张乐华[1] 孙宝腾[2] 周广[1,2] 王书胜[1] 李晓花[1] 单文[1] 

机构地区：[1]江西省、中国科学院庐山植物园,江西庐山332900 [2]南昌大学生命科学与食品工程学院,南昌330031

出　　处：《广西植物》2011年第5期651-658,共8页Guihaia

基　　金：科技部国际科技合作项目(2007DFA31410) ;江西省国际科技合作项目(2007BN18700) ;江西省星火计划项目(2008CX06500)~~

摘　　要：高温是制约分布于较高海拔地区杜鹃花迁地保育与园林应用的重要因子。为探讨杜鹃花属植物的高温致伤机理,该实验以隶属不同亚属的白花杜鹃、羊踯躅、毛棉杜鹃、红滩杜鹃及红棕杜鹃4年生实生苗为材料,通过人工气候箱的盆栽实验,研究了30℃、38℃高温胁迫下其叶片生理生化指标的变化,并利用隶属函数法及系统聚类分析法对其种间耐热性进行了综合评价。结果表明:高温胁迫下,5种杜鹃叶片的过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)活性及脯氨酸(Pro)、过氧化氢(H_2O_2)、丙二醛(MDA)含量均随着胁迫温度的升高而增大;超氧化物歧化酶(SOD)活性在30℃轻度胁迫时均小幅度上升,而38℃重度胁迫时下降。2个高温条件下,SOD、CAT的变化幅度与杜鹃种间耐热性总体呈正相关,而H_2O_2、MDA增幅与种间耐热性呈负相关;Pro增幅在30℃轻度胁迫时与种间耐热性呈负相关,而38℃重度胁迫时与耐热性呈正相关;APX增幅与种间耐热性的相关性较弱。隶属函数与聚类分析综合评判得出5种杜鹃耐热性强弱顺序为:白花杜鹃>羊踯躅、毛棉杜鹃>红滩杜鹃>红棕杜鹃,与其田间耐热性表现一致。High temperature is the important constraining factor of Rhododendron in ex situ conservation and landscape application In order to reveal the injury of mechanism of five Rhododendron species under high-temperature stress,R. mucronatum,R, molle,R, moulrnainense,R, chihsinianum and R. rubiginosum which belong to different subg. Rhododendron were used in the experiment. Four years-old seedlings of these five species were planted in artificial climate chambers and their changes of physiological and biochemical index were determined under hightemperature of 30 ℃ and 38 ℃ stress, and the heat tolerance was comprehensively evaluated with fuzzy subordinate function and system cluster analysis. The results showed that the activities of catalase（CAT）,ascorbate peroxidase（APX） in leaves of five species were increased with temperature becoming higher, so do the contents of proline（Pro）,hydrogen peroxide （H2 O2） and malondialdeyde（MDA）. The activity of superoxide dismutase（SOD）increased slightly under 30 （2 and decreased uncler ：Sb ℃. The variational extent of SOD and CAT had positive correlation with the heat tolerance and the increase extent of H2 02 and MDA had the negative correlation under high temperature. The increase extent of Pro had negative correlation with the heat tolerance under 30 ℃ and positive correlation under 38 ℃. There was weak correlation between the increase extent of APX and the heat tolerance. The comprehensive evaluation of subordinate function and cluster analysis indicate that the heat tolerance sequence of five Rhododendron species was R. mucronatum〉R, molle and R. 〉rmulmainense〉R. chihsinianum〉R, rubiginosum,in accordance with their behavior in the field.

关 键 词：杜鹃花属 高温胁迫 生理生化指标 耐热性 隶属函数 聚类分析 

分 类 号：Q945.78[生物学—植物学]