低温胁迫对不同种源蒙古莸叶绿素荧光特性的影响

Effect of Low Temperature Stress on Chlorophyll Fluorescence Characteristics of Different Provenances of Caryopteris mongolica

以4个种源(BLG、XS、LJD、JB)的蒙古莸种子培育出的实生苗为试材,对其进行不同温度的处理(3、7、11、15℃),探究不同低温胁迫条件下各种源蒙古莸在不同光强度下叶绿素荧光参数变化规律,旨在阐明其对光照环境条件变化的适应。结果表明:低温胁迫导致其PSⅡ反应中心功能下降,更易失活,对光合器官造成伤害;蒙古莸主要通过降低电子传递速率(ETR)并降低实际光化学效率(Yield)的方式降低光能捕捉效率,减少过剩光能的积累,并以此减弱光抑制带来的伤害;低温胁迫后对光破坏防御能力最差的是LJD种源。

In this study,the seedlings cultivated from four provenances(BLG,XS,LJD,JB)were used as test materials.By treating these seedlings at different temperatures(3℃,7℃,11℃,15℃),the changes of chlorophyll fluorescence parameters under different light intensities of various sources were analyzed for understanding their capacity of adaptation to the changes of light environmental conditions.The results showed that the low temperature stress led to the decrease of the PSⅡreaction center function,easier deactivation,harm the photosynthetic organs.The harm of photo-inhibition was mitigated by reducing the efficiency of light capture,the actual photo-chemical efficiency(Yield)and the accumulation of excess light energy reduced by lowering the electron transfer rate(ETR).LJD has the worst ability to defend against light damage.