模拟SO_2湿沉降对桑树叶片光合日变化和生长的影响  

Diurnal changes of leaf photosynthesis and growth of mulberry in response to simulated SO_2 wet deposition

作　　者：吉仁慈 朱义勇[1] 柴源[1] 侯薪鑫 高帅[1] 张秀丽[1] 孙广玉[1] 

机构地区：[1]东北林业大学生命科学学院,黑龙江哈尔滨150040

出　　处：《江苏农业学报》2016年第6期1396-1403,共8页Jiangsu Journal of Agricultural Sciences

基　　金：黑龙江省大学生创新训练计划项目(201510225109);黑龙江省教育厅科学技术研究项目(12543013);黑龙江省青年科学基金项目(QC2016018)

摘　　要：为研究桑树生长及叶片光合气体交换参数日变化对SO2湿沉降的响应情况,以一年生桑树(Morus alba L.)作为试验材料,利用亚硫酸钠和亚硫酸氢钠混合液模拟不同浓度的SO2湿沉降。结果表明:与未进行SO2湿沉降处理(CK)相比,浓度为50 mmol/L和100 mmol/L SO2处理,净光合速率全天均明显低于CK,尤其是"光合午休"期间,气孔导度值下降,气孔限制值升高,胞间CO2浓度升高,说明导致高浓度SO2对桑树"光合午休"期间光合抑制的原因在于气孔和非气孔因素共同限制。而20 mmol/L SO2处理,相应参数日变化趋势与CK相同,其中气孔导度值高于CK,胞间CO2浓度较CK低,说明20 mmol/L SO2可促进"光合午休"期间桑树叶片的气孔开度和CO2同化,有效缓解"光合午休"的光抑制。相关性分析结果表明,桑树叶片CO2同化受到抑制的主要原因在于水分的匮乏,而20 mmol/L SO2湿沉降处理,蒸腾速率和水分利用效率均高于CK,叶面饱和水汽压亏缺显著低于CK,说明20 mmol/L SO2湿沉降可促进桑树光合作用中水分的供应,有利于桑树的生长,最终体现在桑树株高显著高于CK。To study the effects of SO2 on diurnal variation of mulberry leaf photosynthetic gas exchange parametersand growth, the mixed solution of NagSOg and NaHSO3 （molar concentration 3 颐 1） simulated as SO2 wet deposition was ap-plied to one-year-old mulberry seedlings. Results showed that net photosynthesis rate （ Pn） all through the day decreased, especially during noon-break in the treatments of 50 mmol/L and 100 mmol/L SO2 ,in which stomatal conductance （ Gs ） decreased, stomatal limitation value （ Ls） and intercellular CO2 concentration （ C; ） increased, suggesting that the photoin- bition in high-concentration SO2 treatments came from stomatal and non-stomatal limitations. Mid-day depression of photosynthesis of mulberry was alleviated in 20 mmol/L SO2 treatment, in which Gs was increased, Ls and C.＇ decreased, leading to the wider stomatal opening and CO2 assimilation. The correlation analysis indicated that CO2 assimilation inhibition most resulted from water shortage. In the treatment of 20 mmol/L SO2 , higher transpiration rate （ Tr） and water use effi-ciency （ WUE） and lower leaf saturation water vapor pressure deficit （ Vpd]） improved leaf photosynthesis, resulting in better mulberry growth reflected by higher plant height than CK.

关 键 词：桑树 SO2湿沉降 光合午休 光呼吸 

分 类 号：Q945.1[生物学—植物学]