纳米二氧化钛对浮萍生长和生理特征的影响

Effects of TiO_(2)-NPs on Growth and Physiological Characteristics of Lemna minor

为了揭示纳米二氧化钛(TiO_(2)-NPs)对水生植物生长和生理特征的影响,选取浮萍为受试物种,输入锐钛矿型、金红石型和P25混合型(m(锐钛矿)∶m(金红石)=4∶1)3种晶型的TiO_(2)-NPs,测定不同浓度(CK:0 mg·L^(-1),T25:25 mg·L^(-1),T50:50 mg·L^(-1),T75:75 mg·L^(-1),T100:100 mg·L^(-1))对浮萍叶片数、叶面积、叶绿素含量、超氧化物歧化酶(SOD)活性、过氧化物酶(POD)活性和过氧化氢酶(CAT)活性的影响。结果表明:(1)锐钛矿处理中,不同浓度处理均抑制浮萍生长,T25和T50处理对叶绿素a含量产生抑制作用,T75和T100处理对叶绿素a含量产生促进作用;不同浓度处理对叶绿素b和总叶绿素含量产生抑制作用,对SOD和POD活性产生促进作用;T25和T75处理对CAT活性产生促进作用,T50和T100处理对CAT活性产生抑制作用。(2)金红石处理中,不同浓度处理促进浮萍生长;对叶绿素a含量产生促进作用;对叶绿素b和总叶绿素含量产生抑制作用,T25、T50和T100处理对SOD活性产生促进作用,T75处理对SOD活性产生抑制作用;不同浓度处理对POD活性产生促进作用;T25、T75和T100处理对CAT活性产生抑制作用,T50处理对CAT活性产生促进作用。(3)P25处理中,不同浓度处理促进浮萍生长,对叶绿素a含量产生促进作用,对叶绿素b含量产生抑制作用,随着浓度的增加,抑制作用增强;T25、T50和T100处理对总叶绿素含量产生促进作用,T75处理对总叶绿素含量产生抑制作用;对SOD和POD活性均产生促进作用,T25、T50和T100处理对CAT活性产生抑制作用,T75处理对CAT活性产生促进作用。锐钛矿型TiO_(2)-NPs会抑制浮萍生长,金红石型和P25混合型TiO_(2)-NPs会促进浮萍生长。

To reveal the influence of TiO_(2)-NPs on the growth and physiological characteristics of aquatic plants,Lemna minor was selected as the subject species and the three crystal types of TiO_(2)-NPs(CK:0 mg·L^(-1),T25:25 mg·L^(-1),T50:50 mg·L^(-1),T75:75 mg·L^(-1),T100:100 mg·L^(-1))were input,which are anatase type,rutile type and P25 mixture type(anatase∶rutile=4∶1),and the effect of TiO_(2)-NPs on the indexes of leaf number,leaf area,chlorophyll content,the activities of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)of Lemna minor were measured.The results indicate that:(1)In the anatase type treated group,the growth of Lemna minor was inhibited by different concentration treatment,T25 and T50 treatment inhibited chlorophyll a content,T75 and T100 treatment promoted chlorophyll a content;different concentration treatment inhibited chlorophyll b and total chlorophyll content,and promoted SOD and POD activity;T25 and T75 treatment promoted CAT activity,T50 and T100 treatment inhibited CAT activity.(2)In the rutile type,treatment with different concentrations promoted the growth of Lemna minor,promoted chlorophyll a content and inhibited chlorophyll b and total chlorophyll content;T25,T50 and T100 treatment promoted SOD activity,T75 treatment inhibited SOD activity;different concentration treatment promoted POD activity;T25,T75 and T100 treatment inhibited CAT activity,T50 treatment promoted CAT activity.(3)In the P25 mixture type,treatment with different concentrations promoted the growth of Lemna minor,promoted chlorophyll a content,inhibited chlorophyll b content and with the increase of concentration,the inhibitory effect increased;T25,T50 and T100 treatment promoted total chlorophyll content,T75 treatment inhibited total chlorophyll content;SOD and POD activity were promoted by different concentration treatment;T25,T50 and T100 treatment inhibited CAT activity,T75 treatment promoted CAT activity.