| 摘要: |
| 【目的】筛选适宜无养护轻型屋顶绿化的耐热植物。【方法】以胭脂红景天(Sedum spurium‘Coccineum’)、佛甲草(S.lineare)、金叶佛甲草(S.lineare ‘JinYe’)、八宝景天(S.spectabile ‘Borea’)、松塔景天(S.nicaeense)等9种景天属植物为试验材料，通过光照培养箱模拟屋顶绿化环境进行高温试验，设置40，45 和50 ℃ 3个高温梯度处理，以25 ℃为对照，研究高温胁迫下9种植物耐热相关生理指标超氧化物歧化酶(SOD)活性及丙二醛(MDA)、可溶性蛋白质、脯氨酸和叶绿素含量的变化情况，同时观察景天属植物的外部形态变化，计算各指标的耐热性系数，并进行相关性及主成分分析，采取隶属函数法对不同品种的耐热性进行综合评价。【结果】在3种高温处理中，景天属植物的SOD活性、MDA与脯氨酸含量与对照相比基本呈现上升趋势，可溶性蛋白质与叶绿素含量大多呈现下降趋势，其中金叶佛甲草多数指标变化幅度较大，八宝景天大多指标变化幅度较小。9种植物的MDA含量与脯氨酸含量呈极显著正相关关系（P<0.01）。通过主成分分析可将5个原始指标转换为3个综合指标，其中SOD活性、MDA与脯氨酸含量起主要作用。隶属函数法综合分析发现，不同高温处理下各品种耐热性排序不同：在40 ℃处理下，耐热性较强的为佛甲草、金叶佛甲草与松塔景天；在45 ℃处理下，耐热性较强的为德景天、八宝景天与佛甲草；在50 ℃处理下，耐热性较强的为德景天、胭脂红景天与佛甲草。【结论】高温胁迫下景天属植物主要通过提高SOD活性与脯氨酸含量来减轻伤害，同一品种对不同高温胁迫强度的耐受程度与生理响应具有一定的差异，综合评价后筛选佛甲草、德景天、八宝景天、垂盆草用作无人养护屋顶的绿化植物。 |
| 关键词: 高温胁迫 景天 耐热性 屋顶绿化 生理特征 |
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| 基金项目:武汉市晨光计划项目 (200950431211) |
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| Heat tolerance of 9 Sedums plants for light roof greening |
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ZHOU Yuan,GUO Cai-xia,DONG Yan-fang,et al
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| Abstract: |
| 【Objective】This study aimed to select heat-tolerant plants for un-serviced light roof greening. 【Method】9 Sedum cultivars including Sedum spurium ‘Coccineum’,S.lineare,S.lineare ‘JinYe’,S.spectabile ‘Borea’ and S.nicaeense were investigated.SOD (superoxide dismutase) activity,MDA (malondialdehyde) content,soluble protein content,proline content,chlorophyll content and plant appearance were observed under high temperature treatments (40 ℃,45 ℃ and 50 ℃,25 ℃ as control) in light incubators.The heat-tolerance coefficients,correlation and principal components of measured indexes were calculated and analyzed before the heat tolerance of tested Sedums plants were comprehensively evaluated using subordinate function method.【Result】Under 3 high temperature treatments,SOD activity,MDA content and proline content of Sedums plants increased while the protein content and chlorophyll content decreased compared to the control.The changes of S.lineare ‘JinYe’ were the largest while that of S.spectabile ‘Borea’ was the least.The contents of MDA and proline had extremely significant positive correlation (P<0.01).5 original indexes were converted into 3 synthetic indexes by principle component analysis.SOD,MDA and proline played the dominating role.9 tested Sedums plants exhibited different orders of heat-tolerance under different temperature treatments based on subordinate function method:at 40 ℃,S.lineare,S.lineare ‘JinYe’ and S.nicaeense had strong heat-tolerance,at 45 ℃,S.hybridum,S.spectabile ‘Borea’ and S.lineare had strong heat-tolerance and at 50 ℃,S.hybridum,Sedum spurium ‘Coccineum’ and S.lineare had strong heat-tolerance.【Conclusion】The Sedums plants reduced heat injury mainly by increasing SOD activity and proline content.Same cultivars had different tolerances and physiological responses to different high temperature stresses.S.lineare,S.hybridum,S.spectabile ‘Borea’ and S.sarmentosum were selected for un-serviced light roof greening by comprehensive evaluation. |
| Key words: heat stress Sedums heat tolerance roof greening physiological characters |
