牛耳朵幼苗对低温胁迫的生理响应

【目的】探明牛耳朵对低温胁迫的生理响应,为其人工栽培提供理论参考。【方法】牛耳朵幼苗在5℃下处理12、24、36h,然后在25℃下恢复生长24、48h,分别测定各处理叶绿素荧光参数、叶片相对含水量、电解质外渗率、SOD活性、MDA含量等生理指标。【结果】叶绿素荧光参数（Fv/Fm）值随低温处理时间延长而下降,处理结束后可逐渐恢复正常;叶片含水率呈下降趋势但不明显;电解质外渗率随低温处理时间的延长而增加,恢复生长后开始降低;SOD活性、MDA含量均随着低温处理时间呈先增加后降低趋势,但处理结束后均可逐渐恢复。【结论】5℃连续处理36h以内对牛耳朵植株造成一定的生理胁迫,但在胁迫停止后可逐渐恢复正常,不会造成致命伤害。

Physiological response of Chirita eburnea Hance seedling to chilling stress

Objective Physiological response of Chirita eburnea Hance seedling to chilling stress was clarified to provide references for artificial cultivation. Method Young plants were treated under 5 ℃ for 12h, 24 h and 36 h respectively, and then recovered at 25℃ for 24 h and 48 h. The physiological indexes such as photochemical efficiency （Fv/Fm）, leaf relative water content, electrolyte leakage, SOD activity and MDA content were measured. ResultThe results showed that Fv/Fm decreased along with the increasing of chilling time and could be recovered to normal level after chilling. Water content of leaves had a slight descending trend. The electrolyte leakage increased with the increasing of low temperature treating time and dropped again during the recovery. SOD activity and MDA content increased along with the treating time but could recover gradually. Conclusion The continuous low temperature treatment for 36 h at 5℃ caused a certain physiological stress but not critical damage, so the young plants of Chirita eburnean could gradually recover to normal growth.