DA-6和EDDS施用对龙葵生长、 Cd吸收和土壤细菌群落结构的影响

Effects of DA-6 and EDDS on Growth and Cd Uptake by Solanum nigrum L.and on the Soil Bacterial Community Structure

通过盆栽试验,探讨植物生长调节剂DA-6和螯合剂EDDS施用对Cd污染土壤上龙葵生长、Cd吸收及土壤细菌群落结构的影响,以此评估不同修复处理的实际应用效果.结果表明,单独添加DA-6、将DA-6和EDDS联合施用均能促进龙葵的生长,使其地上部鲜重较对照分别显著增加了24.58%和19.57%,同时龙葵叶片的叶绿素含量和抗氧化酶活性也呈增加趋势,而丙二醛含量则有所降低.施用DA-6和EDDS还显著提高了土壤有效态Cd含量,促进了龙葵对Cd的吸收.与对照相比,龙葵地上部Cd提取量分别显著提高了39.42%(DA-6)、30.17%(EDDS)和51.04%(DA-6+EDDS).结果还发现,单独施用EDDS一方面使土壤细菌群落ACE指数显著降低,而Simpson指数显著增加;另一方面使土壤Lysobacter菌属丰度显著降低.将DA-6和EDDS联用后,土壤细菌群落的多样性以及分类学组成得到改善.

The effects of the plant growth regulator DA-6 and chelator EDDS on the growth,Cd absorption,and soil bacterial community structure of Solanum nigrum L.on Cd-polluted soil were examined through a pot experiment,so as to evaluate the practical application effects of different remediation treatments.The results showed that the addition of DA-6 alone and the combined application of DA-6 and EDDS could promote the growth of S.nigrum L.,and the shoot fresh weight increased by 24.58%and 19.57%,respectively,compared with that in the control.At the same time,the chlorophyll content and antioxidant enzyme activity of S.nigrum L.leaves also increased,whereas the content of malondialdehyde decreased.The application of DA-6 and EDDS also significantly increased the content of soil available Cd and promoted the absorption of Cd by S.nigrum L.Compared with that in the control,the extraction amount of Cd from S.nigrum L.shoots was significantly increased by 39.42%(DA-6),30.17%(EDDS),and 51.04%(DA-6+EDDS),respectively.It was also found that the application of EDDS alone significantly reduced the ACE index of the soil bacterial community and significantly increased the Simpson index,and the abundance of the Lysobacter genus in the soil was significantly reduced.After the combination of DA-6 and EDDS,the diversity and taxonomic composition of the soil bacterial community were improved.