SO2胁迫对园林植物幼苗光合生理特征的影响

通过盆栽人工模拟熏气实验,设置不同浓度(2.86和5.72 mg/m3)SO2胁迫处理,以相对清洁区(CK)红花羊蹄甲、尖叶杜英、芒果、糖胶树、秋枫和樟树光合参数因子为对照,研究不同浓度SO2胁迫处理对6种园林植物光合生理特性的影响。结果表明:1)6种园林植物幼苗最大净光合速率随着SO2浓度的增加呈下降趋势,与CK相比,LSO2和HSO2处理下红花羊蹄甲、尖叶杜英、芒果、糖胶树、秋枫和樟树最大净光合速率分别下降了20.96%和38.35%、45.32%和52.17%、69.21%和71.19%、58.30%和61.88%、43.90%和56.10%、25.26%和40.34%;2)相对清洁区(CK),红花羊蹄甲、芒果、糖胶树、秋枫和樟树光饱和点介于748～1 016μmol/(m2.s)之间,光补偿点介于4.0～9.3μmol/(m2.s)之间,表现出较强的喜光和耐阴特性,在不同SO2浓度处理下,6种园林植物光饱和点与CK相比有不同程度的降低,下降幅度最大为芒果、糖胶树和秋枫,降幅最小的为樟树;3)不同SO2浓度对6种园林植物光补偿点的影响不明显,经过SO2污染胁迫后6种植物光适应范围变窄,适应性变差;4)红花羊蹄甲和樟树保持了较高的净光合速率和水分利用效率,对SO2胁迫适应能力较强。研究结果可为火电厂、陶瓷厂、钢铁厂、石化厂等重度酸污染地区植物选择提供参考。

Effects of SO2 stress on photosynthetic physiology of garden plant seedlings

Taking Bauhinia blakeana, Elaeocarpus apiculatus, Mangifera indica, Alstonia scholaris, Bischofia javanica, Cinnamomum camphora, in Guangzhou City as test objects, a pot experiment was conducted to study the photosynthetic characteristics of these seedlings under effects of artificial simulation of the fumigation experiments with a gradient of 2.86 mg/m^3 of SO2concentration （ LSO2 ） , 5.72 mg/m^3 of SO2concentration （HSO2 ） and relatively clean area （CK）. Results showed that： 1 ） Compared with CK, the maximum net photosynthetic rate of six garden plants seedlings showed a downward trend with the increase of the concentration of SO2. Under two concentrations of SO2 stress, LSO2 and HSO2 , the maximum net photosynthetic rate of Bauhinia blakeana, Elaeocarpus apiculatus, Mangifera indica, Alstonia scholaris, Bischofia javanica, Cinnamomum camphora decreased by 20.96% and 38.35% , 45.32% and 52. 17%, 69.21% and 71.19%, 58.30% and 61.88%, 43.90% and 56. 10%,25.26% and 40.34%. 2） Light saturation point of Bauhinia blakeana, Mangifera indica, Alstonia scholaris, Bischofia javanica, Cinnamomum camphora ranged from 748 -1 016 μmol/（m^2. s）, while their light compensation point ranged from 4.0 to 9.3 μmol/（ m^2. s） , and showed strong photophilic and shade-tolerant characteristics in a relatively clean area. Compared with CK, light saturation point of six kinds of garden plants occurred reduction to some extent. The largest decline of light saturation point was occurred in Mangifera indica, Alstonia scholaris, Bischofia javanica, while the smallest decline was in Cinnamomum camphora. 3） The effect of concentration of SO2 stress on light compensation point of six kinds of garden plants was not obvious. Under the stress of SO2 pollution, light adaptation range of six kinds of plants would be narrowing and poor. 4 ） Bauhinia blakeana and Cinnamomum camphora maintained the higher net photosynthetic rate and water use efficiency, and had higher adaptation ability to SO2 stress. The results would provide a reference for plants selection of severe acid contaminated areas such as thermal power plants, ceramic plants, steel mills and petrochemical plants.