蒙古栎幼苗光合作用以及叶绿素荧光对温度和降水交互作用的响应

Response in photosynthesis and chlorophyll fluorescence of Quercus mongolica seedlings to the interaction of temperature and precipitation

为了阐明未来温度升高和降水格局变化对蒙古栎幼苗光合作用和叶绿素荧光特性的影响,通过人工模拟温度升高(2、4、6℃)和降水变化(+30%、-30%)的实验方法对蒙古栎幼苗光响应曲线及其特征参数、叶绿素荧光参数和光合色素含量进行了分析。结果表明:温度处理除了对表观量子效率(AYQ)和7月所测非光化学淬灭系数(qN)没有显著影响之外,对其他参数均有极显著影响;降水处理仅对9月所测实际光化学效率(Yield)、光化学淬灭系数(qP)以及叶绿素a、叶绿素b和总叶绿素含量有显著影响;温度和降水的交互作用对最大净光合速率(Pmax)、7月的Yield、qN和qP、9月的最大光化学效率(Fv/Fm)、Yield、qN和qP以及叶绿素a、叶绿素b和总叶绿素含量有显著影响。温度增加4℃时多数表征蒙古栎幼苗生长状况的参数表现出了一些优势,而当温度增加6℃时,所有降水处理的Pn、Pmax、AYQ以及7月所测Fv/Fm、Yield和qP均低于温度对照组。在降水处理+30%或-30%的范围内,适度的增温有利于蒙古栎幼苗的生长,其中以温度升高4℃对幼苗生长的促进作用最大。

In order to clarify the impact of temperature and precipitation pattern changes on the photosynthesis and chlorophyll fluorescence characteristics of Quercus mongolica seedlings, we analyzed light response curve and its characteristic parameters and chlorophyll fluorescence parameters and photosynthetic pigment content of Q. mongolica seedlings by artificial simulation method of temperature increase （2, 4, 6 ℃） and precipitation changes （＋30%,-30%）. The results showed that： Temperature treatment had no significant effects in addition to non-photochemical quenching （qN） in July and apparent quantum efficiency （AYQ）, showing a significant impact on the other parameters; precipitation treatment had a significant effect on actual photochemical efficiency （Yield） in September, photochemical quenching coefficient （qP）, chlorophyll a, chlorophyll b and total chlorophyll content; interaction of temperature and precipitation had a significant effect on the maximum net photosynthetic rate （Pmax）, Yield, qN and qp in July, maximum photochemical efficiency （Fv/Fm）, Yield, qN and qp in September and chlorophyll a, chlorophyll b and total chlorophyll content. These results showed that the majority of characterization parameters of Q. mongolica seedlings showed some advantages in the temperature increase of 4 ℃, but when the temperature increased by 6 ℃, Pn, Pmax, AYQ and Fv/Fm, Yield and qp measured in July of all precipitation processing were lower than temperature control group. Within the range of ＋30% and -30% of precipitation processing, moderate warming is good for seedling growth of Q. mongolica, especially when the temperature increases by 4 ℃.