CO2浓度升高对灯盏花幼苗光合特性、抗氧化系统及有效成分积累的影响OA

To investigate the effects of CO2 concen-tration on the growth and development of Erigeron brevisca-pus,this study used E.breviscapus as the experimental ma-terial and regulated CO2 concentration in an artificial cli-mate chamber.Two treatments were set up,namely 400 μmol/mol(CK)and 800 μmol/mol(T).After 60 days of treatment,a systematic determination was conducted on various indices of the seedlings,including gas exchange parame-ters,photosynthetic pigment content,osmotic adjustment substance content,active ingredient content,and enzyme activity.The results showed that compared with CK,the stomatal density,stomatal length,transpiration rate and stomatal conduc-tance of E.breviscapus under T treatment decreased significantly by 19.43%,13.51%,69.09%and 70.41%,respectively(P＜0.05),while the intercellular CO2 concentration and water use efficiency increased significantly by 85.60%and 231.60%,respectively(P＜0.05).These findings indicated that under elevated CO2 conditions,E.breviscapus reduced water loss and improved water use efficiency by narrowing or closing stomata.Compared with CK,the malondialdehyde(MDA)content and ascorbate peroxidase(APX)activity under T treatment increased significantly by 145.74%and 121.68%,respectively(P＜0.05),the activities of superoxide dismutase(SOD)and peroxidase(POD)increased signifi-cantly by 40.66%and 12.78%,respectively(P＜0.05).Whereas the activities of glutathione reductase(GR)and nitrate reductase(NR)decreased significantly by 62.53%and 36.69%,respectively(P＜0.05).This suggested that elevated CO2 concentration induces oxidative stress in E.breviscapus by reducing photosynthetic pigment content and inhibiting the activi-ty of key enzymes involved in nitrogen assimilation,and the plants alleviate membrane lipid peroxidation damage by enhan-cing the activity of antioxidant enzymes.In addition,compared with CK,the contents of scutellarin,chlorophyll a and ca-rotenoids under T treatment decreased significantly by 25.26%,22.64%and 27.87%,respectively(P＜0.05),indicating that the content of active ingredients in E.breviscapus decreased significantly under elevated CO2 conditions.Overall,the results of this study provide a theoretical basis for the adaptive cultivation of Erigeron breviscapus.