Effects of Different Acid Rain Treatments on Biomass Allocation and Physiological Characteristics in Elaeocarpus glabripetalus Seedlings
Yu Fei;Song Qi;Liu Meihua;Dong Lianchun;Yi Lita;School of Forestry and Biotechnology,Zhejiang Agriculture and Forestry University;School of Biotechnology,Hangzhou Wanxiang Polytechnic;
【Objective 】Comparisons of direct,indirect and composition effects of acid rain treatments on biomass allocation and physiological characteristics in Elaeocarpus glabripetalus seedlings were carried out in order to provide a scientific basis to study the mechanism of E. glabripetalus seedlings responding to simulated acid rain. 【Method】Potted plants were used to establish the experiment,treatments included 2 different p H values of acid rain( pH2. 5 and p H5. 6)and 4 different models of exposure to acid rain,including 1) aboveground exposure: only the aboveground of seedlings were exposed to acid rain; 2) soil exposure: only the soil around seedlings was exposed to acid rain; 3) whole exposure:the seedlings and soil were both exposed to acid rain; 4) Control: exposed to distilled water with pH7. 0. Biomass accumulation and allocation,chlorophyll content and chlorophyll fluorescence characteristics,malondialdehyde( MDA)content and membrane permeability,the activity of antioxidant enzymes were measured. 【Result 】1) The growth ofseedlings were inhabited to different extents when exposed to acid rain at pH2. 5 level,and significant differences were found among the 3 models of exposure to acid rain. Compared with the control,total biomass,height increment,diameter increment of seedlings for the model of aboveground exposure decreased by 16. 7%,28. 1% and 25. 7% respectively;those of soil exposure decreased by 10. 9%,4. 7% and 17. 5% respectively; those of whole exposure decreased by 18. 5%,5. 2% and 27. 5% respectively. For the underground exposure,the ratio of leaf biomass to total biomass increased,and those of stem and root biomass decreased. The chlorophyll a( Chla) content,total chlorophyll( total Chl)content,chlorophyll a / b( Chla / b) were significantly lower than those of the control. For the aboveground exposure,primary photochemical efficiency of PS Ⅱ( F_v/ F_m) and potential activity of PSⅡ( F_v/ F_o) were significantly lower than those for the control; for the whole exposure the F_v/ F_oand actual photochemical efficiency of PS Ⅱ( Φ_(PSⅡ)) were significantly lower than those for the control; No significant differences were found between the soil exposure and the control in F_v/ F_m,F_v/ F_o and Φ_(PSⅡ). For all the 3 exposure models,membrane permeability,MDA content and antioxidant enzymes activity were significantly higher than those for the control,and those for the soil exposure were the highest. 2) At the p H5.6 level,there were no significant difference in biomass of seedlings between the 3 exposure models and the control,but Chl a content,total Chlcontent and Chla/b decreased significantly,and membrane permeability,MDA content,peroxidase( POD), catalase( CAT) activity increased significantly compared with the control. For the aboveground exposure and the whole exposure,Fv/ Foand Φ_(PSⅡ)were significantly lower than those for the control.【Conclusion】The soil exposure had both negative and positive effect on the seedlings,while the aboveground and whole exposures inhabited the seedlings,and the effect of whole exposure was greater than that of aboveground exposure,but the whole exposure did not change the biomass allocation of seedlings. The effect of acid rain at p H5.6 on seedlings was significantly lower than that of acid rain at pH2. 5.
【Fund】： 国家自然科学基金项目(31100325);; 浙江省教育厅项目(Y201326501);; 浙江省高等学校中青年学科带头人学术攀登项目(pd2013237)
【CateGory Index】： S792.99
【CateGory Index】： S792.99