高温胁迫下大苞景天的形态特征及生理响应

摘要

To study the thermal stability of Sedum amplibracteatum K. T. Fu and physiological characteristics under different high temperature stress, the Licor 6400 portable photosynthetic apparatus produced by U.S.A. was used to determine fluorescence parameters of S. amplibracteatum. The results show that since the degrees of high temperature stress were slowly increased, S. amplibracteatum leaves appeared symptoms of curly, dry, yellow wilting, dried-up and drop, part of the plant stem base were soft and rot, the symptoms reflected that S. amplibracteatum had not temperature withstanding characteristics. In the process of the high temperature stress, the relative water content of leaves and fluorescence parameters of S.amplibracteatum had a descending trend; and the conductivity showed a upward trend. From the physiological change and morphological characteristics, S. amplibracteatum cannot resist high temperature.%为了研究大苞景天 Sedum amplibracteatum K. T. Fu 的耐热性及在不同高温胁迫下的生理特点，采用美国生产的 Licor6400便携式光合仪对大苞景天的荧光参数进行了测定。结果表明：随着高温胁迫程度的慢慢增加，大苞景天叶片出现卷曲、萎蔫、变黄、干枯脱落等症状，部分植物茎基部变软腐烂，反映了其不耐高温的特点。在高温胁迫过程中，大苞景天叶片相对含水量和荧光参数呈下降趋势，电导率呈上升趋势。大苞景天的生理变化和形态特征，表明其不耐高温。