Xin Yue, Gao Feng, Feng Zhao-Zhong
State Key Laboratory of Urban and Regional Ecology, Research Centre for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 101408, China.
Huan Jing Ke Xue. 2016 Jun 8;37(6):2359-2367. doi: 10.13227/j.hjkx.2016.06.046.
The open top chambers were used to explore the photosynthetic characteristics of three genotypes of poplar ('546', '90' and '84K') in response to different ozone exposures. The results showed that net photosynthetic rate (), transpiration rate (), water use efficiency (WUE), apparent electron transport rate (ETR), excitation energy capture efficiency of PSⅡ reaction center ('/'), coefficient of photochemical quenching (qP), actual photochemical efficiency of PSⅡ in the light (PhiPS2), chlorophyll a (Chla), chlorophyll b (Chlb), total chlorophyll (Chla+b) and carotenoid (Car)contents were significantly decreased with the increasing ozone concentrations. However, intercellular CO concentration () was significantly increased and stomatal conductance () remained unchanged. There was significant difference in photosynthetic characteristics among three genotypes of poplar. The genotype'546' showed a significant linear correlation (<0.01) between photosynthetic parameters (except ) and the ozone dose index AOT40(accumulated hourly O concentration over a threshold of 40 nmol·mol during daylight hours). Among the three genotypes of poplar, photosynthesis pigments contents in '546' significantly declined with the increase of ozone concentration but not in '90' and '84K'. According to the linear relationship of most photosynthetic parameters and AOT40, especially the total chlorophyll, '546' showed the maximum slope, follows by '90' and then '84K'. So the order of the ozone sensitivity of three poplar genotypes was '546'> '90'> '84K'. The results of this study can provide an important basis for breeding ozone resistant genotype of poplar as well as protecting poplar from ozone damage.
采用开顶式气室研究了3种杨树基因型（‘546’、‘90’和‘84K’）在不同臭氧暴露条件下的光合特性。结果表明，随着臭氧浓度升高，净光合速率（）、蒸腾速率（）、水分利用效率（WUE）、表观电子传递速率（ETR）、PSⅡ反应中心激发能捕获效率（‘/’）、光化学猝灭系数（qP）、PSⅡ在光照下的实际光化学效率（PhiPS2）、叶绿素a（Chla）、叶绿素b（Chlb）、总叶绿素（Chla+b）和类胡萝卜素（Car）含量均显著降低。然而，胞间CO浓度（）显著升高，气孔导度（）保持不变。3种杨树基因型的光合特性存在显著差异。基因型‘546’的光合参数（除外）与臭氧剂量指数AOT40（白天每小时积累的O浓度超过40 nmol·mol阈值）之间呈显著线性相关（<0.01）。在3种杨树基因型中，‘546’的光合色素含量随臭氧浓度升高显著下降，而‘90’和‘84K’则没有。根据大多数光合参数与AOT40的线性关系，尤其是总叶绿素，‘546’的斜率最大，其次是‘90’，然后是‘84K’。因此，3种杨树基因型对臭氧的敏感顺序为‘546’>‘90’>‘84K’。本研究结果可为杨树抗臭氧基因型育种以及保护杨树免受臭氧伤害提供重要依据。
