增温对毛白杨幼苗叶绿素及叶绿素荧光参数的影响

以毛白杨鲁毛50为研究材料,采用人工气候室内模拟温度增加(+2℃和+4℃)的环境条件(对照为常温条件),研究了温度升高对毛白杨幼苗叶绿素含量和叶绿素荧光参数的影响。结果表明:同常温下生长的毛白杨相比,增温2℃和增温4℃处理都显著降低了毛白杨幼苗的叶绿素a(Chla)和总叶绿素(Chla+b)含量,降幅分别为12.97%和13.66%,11.91%和12.61%。但2种增温处理对叶绿素b(Chlb)和Chla/b的影响不显著,降幅分别为6.84%和7.53%,6.96%和6.60%。增温2℃和增温4℃处理对PSⅡ最大光化学效率(Fv/Fm)几乎没有影响,但对电子传递效率(Yield)和光化学淬灭系数(qP)的影响效果不同:增温2℃几乎没有引起Yield值和qP值的变化,但增温4℃却显著降低了Yield值和qP值,降幅分别为7.11%和12.74%。同时,增温2℃和增温4℃都显著降低了毛白杨幼苗的非光化学淬灭系数(qN),降幅分别为6.47%和7.09%。从2种增温处理对毛白杨幼苗叶绿素和叶绿素荧光参数的影响来看,增温对毛白杨幼苗Chla及总叶绿素含量具有抑制效应,同时对毛白杨幼苗光合电子传递过程及效率也具有一定的抑制效应。

Effects of Enhanced Temperature on Chlorophyll Content and Chlorophyll Fluorescence Parameters in Populus tomentosa Carr.

The effects of elevated temperature(+2℃ and +4℃) on chlorophyll content and chlorophyll fluorescence in Populus tomentosa Carr.were imitated in artificial climate room using the variety of Populus tomentosa Lumao50 as material.The results showed that,elevation of 2℃ and 4℃ significantly decreased chlorophyll a and chlorophyll a+b content,12.97%,13.66% and 11.91%,12.61%,respectively.However,it gave little effect on chlorophyll b and chlorophylla/b,6.84%,7.53% and 6.96%,6.60%,respectively.On the other hand,elevation of 2℃ and 4℃ showed little influence on Fv/Fm.In relation to the effects on Yield and qP,elevated 2℃ and 4℃ caused different results.Elevation of 2℃ little changed Yield and qP,while elevation of 4℃ signi-ficantly reduced the Yield and qP values(7.11% and 12.74%).Meanwhile,elevation of 2℃ and 4℃ significantly decreased qN value in the observed seedlings(6.47% and 7.09%).In conclusion,the elevated temperature showed significant inhibition on the chlorophyll a and total chlorophyll content,and also inhibited the procedure and efficiency of photosynthetic electron transport.