不同浓度PAHs对4种绿化树种光合特性的影响

Effects on different concentrations of PAHs on photosynthesis characteristics of 4 greening tree species

利用盆栽试验对樟树、栾树、广玉兰、马褂木4种绿化树种进行不同浓度的PAHs污染处理,研究在不同污染浓度处理下,不同浓度PAHs处理对4种树种的光合特性(光合速率、气孔导度日变化,胞间CO2浓度)的影响。结果表明:PAHs污染处理下,4个树种的光合日进程均受到影响。污染处理组栾树、樟树、马褂木3个树种的净光合速率Pn和气孔导度VCond的日变化曲线呈现单峰曲线,而对照组为双峰曲线,污染处理改变了3个树种的午休机制。栾树和马褂木在低、中、高污染下的VCond值均要大于对照,马褂木的VCond值随浓度升高而增大;樟树和广玉兰的VCond在中浓度时最大且大于对照,高浓度污染下VCond最小且小于对照。栾树污染处理下的Ci高于无污染对照,而污染下樟树和广玉兰的Ci则小于对照,马褂木仅在高浓度污染下Ci大于对照组。研究结果对于研究利用植物修复PAHs污染具有积极的指导意义。

Pot experiments were carried out on Cinnamomum camphora,Koelreuteria paniculata,Magnolia grandiflora,Liriodendron chinese Sarg 4 tree species with different concentrations of PAHs pollution treatment.The effects of different concentrations of PAHs on photosynthetic characteristics of 4 tree species（photosynthetic rate,daily variation in stomatal conductance,intercellular CO2 concentration） were investigated.The results show that the 4 species’ diurnal photosynthetic processes were affected by PAHs pollution treatments;the net photosynthetic rate（Pn） and stomatal conductance（VCond） curves of pollution treatment group of K.paniculata,C.camphora and L.chinese Sarg 3 species appeared diurnal variation of unimodal curve,while the control group appeared a bimodal curve,the pollution treatments altered the lunch break mechanism of 3 tree species;the VCond values of K.paniculata and L.chinese with low,middle,high pollution were greater than the control’s,that of L.chinese raised with the increase of of VCond concentration value;the VCond of C.camphora and M.grandiflora with middle concentration were greater than that of the control’s,the VCond of C.camphora and M.grandiflora with high concentration were the minimal and less than the control’s;the Ci of K.paniculata with pollution treatment was higher than that of no pollution and pollution control’s,the Ci of C.camphora and M.grandiflora was less than that of the control,the Ci of L.chinese only with high concentration was higher than that of control group.The findings of the study on phytoremediation of contaminated by PAHs has a positive guiding significance.