Effects of drought stress on the photosynthetic physiological parameters of Populus 3 euramericana ‘‘Neva''

作     者：Guoting Liang Jianwen Bu Shuyong Zhang Guo Jing Guangcan Zhang Xia Liu 

作者机构：Shandong Provincial Key Laboratory of Soil Erosion and Ecological Restoration Forestry College of Shandong Agricultural University Taishan Forest Eco-station of State Forestry Administration Department of Food Science and Engineering Shandong Agriculture and Engineering University Forestry College of Nanjing Forestry University 

出 版 物：《Journal of Forestry Research》 (林业研究（英文版）)

年 卷 期：2019年第30卷第2期

页      面：409-416页

核心收录：

学科分类：0907[农学-林学] 08[工学] 0829[工学-林业工程] 09[农学] 

基　　金：financially supported by the National Public Welfare Industry Research Project of China(201504406) the National Natural Science Foundation of China(31770706) 

主　　题：Poplar seedlings Drought stress Gas exchange Chlorophyll fluorescence Antioxidantenzymes 

摘      要：Populus 9 euramericana ‘‘Neva is the main poplar species in China, where drought stress is becoming extremely urgent. We carried out this research to study the effects of drought stress on the photosynthesis of Populus 9 euramericana ‘‘Neva . Drought stress was induced by 58–62%(light), 48–52%(moderate), and 38–42%(severe) relative soil moisture content(RSMC). The effects of drought stress on photosynthetic rate, chlorophyll fluorescence parameters, and other related physiological parameters were investigated during treatment. Net photosynthetic rate(PN), and stomatal conductance decreased significantly and intercellular CO_2 concentration initially increased and then declined, whereas the stomatal limitation factors showed opposite trends in the light under moderate drought stress. Photosystem II(PSII) maximum photochemical efficiency, actual photochemical efficiency,and photochemical quenching decreased gradually under drought stress, whereas nonphotochemical quenching initially increased and then declined. Superoxide dismutase,peroxidase, and catalase activities initially increased and then decreased as RSMC was reduced, whereas malondialdehyde(MDA) content and relative electric conductivity(REC) increased gradually. These results suggest that stomatal factors accounted for the decline in PNunder light and moderate drought stress, whereas leaf PNdecreased mainly due to non-stomatal factors under severe drought stress. PSII was damaged; thus, photosynthetic electron transfer was restricted, indicating that heat dissipation is important for the light protection mechanism of *** enzymes increased at the beginning of treatment, and the increased MDA and REC led to cell membrane damage. These results suggest that poplar seedlings stabilized their photosynthetic apparatus by reducing the light trapping ability under light and moderate drought stress conditions. This helped dissipate heat and enhance antioxidant enzyme activity. Stomatal factors accoun