高温对3种攀缘植物叶绿素荧光特性及耐脱水特性的影响

Chlorophyll Fluorescence Characteristics and Dehydration Tolerance of 3 Climbing Plants under High Temperature

利用植物叶绿素荧光技术,分析了高温对五叶地锦、胶东卫矛和南蛇藤的叶绿素荧光特性及高温脱水过程中叶片相对含水量(RWC)的变化,以明确攀缘植物的抗热特性。结果显示:(1)温度大于42℃时,南蛇藤F0升高的幅度和Fm下降程度均低于五叶地锦和胶东卫矛;54℃时,五叶地锦和胶东卫矛的F0与Fm近似相等,表明PSⅡ的反应中心完全关闭。(2)42℃时,南蛇藤、胶东卫矛和五叶地锦的PSⅡ最大光化学效率(Fv/Fm)显著降低,可逆变化的温度范围是24℃～42℃。(3)脱水末期(20.5h),五叶地锦RWC仍可高达(57.7±5.0)%,高于胶东卫矛的(19.6±4.1)%和南蛇藤的(11.6±2.5)%,但Fv/Fm显著降低时所对应的RWC分别为(75.6±3.3)%、(30.4±3.6)%和(19.1±3.3)%。研究表明,五叶地锦热稳定性和水稳定性均低于南蛇藤和胶东卫矛,但五叶地锦的耐脱水能力较高;高温(42℃)脱水过程中Fv/Fm值的改变可能主要是由于Fm下降造成的,而不是由于F0变化所致;建议在水分可以得到保证的高温地区,选用胶东卫矛和南蛇藤,而在水分条件不好,但温度相对低的地区,选择五叶地锦进行垂直绿化。

The responses of Parthenocissus quinquefolia Planch.,Euonymus kiuntschovicus and Celastrus obiculatus Thunb.to high temperature for chlorophyll fluorescence and dehydration were studied by chlorophyll fluorescence technique.The results showed that（1）The increase of F0 and the drop of Fm for P.quinquefolia were lower than that for P.quinquefolia and E.kiuntschovicus when the temperature is higher than 42℃.The F0 and Fm was closed to each other for P.quinquefolia and E.kiuntschovicus at 54℃.（2）The temperature when the maximum quantum yield of PSⅡ photochemistry（Fv/Fm）decreased significantly were 42℃ for 3 measured species,and the reversible temperature ranges were 24℃～30℃.（3）The final relative water contents（RWC）after dehydrated 20.5 h were（57.7±5.0）%,（19.6±4.1）% and（11.6±2.5）% for P.quinquefolia,E.kiuntschovicus and C.obiculatus respectively.The RWC when Fv/Fm began to decrease were（75.6±3.3）%,（30.4±3.6）% and（19.1±3.3）% for P.quinquefolia,E.kiuntschovicus and C.obiculatus respectively.It indicated that the dehydration tolerance of P.quinquefolia was higher than that of others,but both thermal stability and hydrostability of P.quinquefolia was lower than that of E.kiuntschovicus and C.obiculatus.Moreover,it was Fm,not F0 contributed to the decreasing of Fv/Fm during dehydration.Thus P.quinquefolia was better to grow in a region where was hot and wet,but for lower temperature and drought region E.kiuntschovicus and C.obiculatus were better.