高温胁迫对岷江百合幼苗耐热指数和理化特性的影响

Effects of High Temperature on Survival Rate and Physiological Characteristics in Seedlings of Lilium regale

为了探明岷江百合幼苗在高温胁迫下的生理反应,以离体扩繁的岷江百合幼苗为研究材料,对其进行了不同高温(37℃/30℃、42℃/37℃)和不同时间(0、4、8、16、32、48 h)处理,研究了高温胁迫对其耐热指数和有关生理生化指标(叶绿素、丙二醛、游离脯氨酸、可溶性蛋白含量和SOD活性)的影响.结果表明:随着温度的升高和处理时间的延长,植株的耐热指数不断下降,叶绿素含量减少,丙二醛(MDA)含量增加;42℃胁迫32 h后,游离脯氨酸、可溶性蛋白含量、SOD活性均达到最大值,分别比对照增加了0.66倍、1.77倍和9.78倍.但胁迫48 h后,指标显著下降,这说明,42℃间断胁迫48 h对植株产生了不可逆的的热伤害作用.

To ascertain physiological response of Lilium regale to high temperature stress, seedlings of Lilium regale were subjected to different temperature （37 ℃/30 ℃ ,42℃/37℃）for different times （0, 4, 8, 16, 32, 48 h）. Heat-resistance index and some physiological characteristics（ heat-resistance index, chlorophyll content, malondialdehyde content, free proline content, soluble protein content and SOD activity） were determined. The results showed that heat-resistance index and chlorophyll content in leaf were decreased significantly under high temperature stress, while malondialdehyde content increased. SOD activity, free proline content and soluble protein content in leaf of seedlings treated for 32 h under 42℃ reached the peak, increasing 0. 66, 1.77 and 9.78 times respectively compared the control, but 48 h later, they declined. The results indicated that discontinuous stress under 42℃ for 48 h had irreversible heat injury effects on seedlings.