EGTA与有机酸联合施用对黄麻修复Cd污染土壤的影响

Effect of combined application of EGTA and organic acid on remediation of Cd-contaminated soil by Corchorus capsularis L.

采用盆栽试验研究了柠檬酸(CA)和酒石酸(TA)分别与螯合剂乙二醇双(2-氨基乙基醚)四乙酸(EGTA)的配施对改进黄麻部分生理特性和Cd提取效率的影响。结果表明,EGTA与有机酸配施能促进黄麻光合色素的合成,增加抗氧化酶活性。各处理均提高了黄麻的株高、根长和各器官的干质量,T2E2处理的总干质量最大,为对照的2.69倍。EGTA与CA和TA的配施不同程度提高了黄麻各器官中的Cd含量和积累量,在E1C1处理中,黄麻具有最大的地上部Cd积累量643.02μg·plant-1。各处理地上部和地下部富集系数均有所提高,地上部增幅达1.30～2.14倍,地下部增幅达0.11～0.80倍。各处理的迁移系数分别较CK增加了0.64～1.66倍,其中,T1E2处理的迁移系数最高,达3.15。土壤净化率明显提高,在T2E2和C1E1处理中达最大值0.346%。综上所述,EGTA与TA或CA配施能显著改善黄麻对Cd的提取效率。

In this study,we focused on the effects of combined application of chelating agents and organic acid on Cd absorption and accumulation by Corchorus capsularis L.Pot experiments were conducted to investigate the effects of citric acid(CA)and tartaric acid(TA)combined with EGTA on physiological characteristics and Cd accumulation in C.capsularis.The results showed that the application of EGTA and organic acids promoted the synthesis of photosynthetic pigments and increased the activity of antioxidant enzymes in C.capsularis.All treatments increased plant height,root length and biomass of C.capsularis,and the maximum biomass of plant when the EGTA and TAwere both at 2 mol·L^-1 T2 E2 treatment(EGTA and TA were both at 2 mol·L^-1)was 2.69 higher than that of the control.The combination ofEGTA with CA and TA increased the concentration and accumulation of Cd in different organs of C.capsularis,and the highest shoot Cd accumulation reached 643.02μg·plant-1 with the C1 E1 treatment(EGTA and CA were both at 1 mol·L^-1).The bioconcentration factor of theroot and shoot improved after the treatments,with an increase of 1.30~2.14 times and 0.11~0.80 times,respectively.With the application ofEGTA and organic acid,the transportation factor increased by 0.64~1.66 times,and reached a maximum of 3.15.The Cd purification ratewas significantly increased,reaching a maximum of 0.346%in the T2 E2 and C1 E1 treatments,which 7.69 times higher than that of the control.The overall results demonstrate that the application of EGTA and organic acids together improve the phytoextraction in C.capsularis.