土壤灭菌和杀真菌剂对大豆生长和重金属累积的影响

Effects of Soil Sterilization and Fungicide Application on Growth and Heavy Metal Accumulation in Soybean

【目的】研究土壤灭菌和杀真菌剂(苯菌灵)对大豆生长和重金属累积的影响。【方法】以污染农田土壤为基质开展室内盆栽试验,在土壤灭菌和施用苯菌灵的条件下,测定大豆的生长指标、叶绿素含量、抗氧化生理指标、重金属(铅、锌、镉和铜)含量与累积量以及土壤重金属有效态含量。【结果】与原状土壤相比,土壤灭菌处理导致大豆株高、茎叶和果实生物量分别降低21.00%、43.92%和44.47%,但可以使根系生物量增加56.57%。土壤灭菌和施用苯菌灵处理均可显著增加土壤有效态铅含量,增幅分别为160.62%和179.00%;均可显著降低土壤有效态锌含量,降幅分别为33.82%和17.37%。土壤灭菌还可显著增加大豆根系中的锌、镉含量以及铅、锌、镉、铜累积量,显著降低大豆茎叶和果实中的铅、铜累积量,增加铅、锌和镉的富集系数。施用苯菌灵可显著增加类胡萝卜素以及茎叶和根系中的铅含量,增幅分别为77.00%、36.87%和12.43%;显著增加大豆茎叶中的铅累积量;显著增加铅的富集系数和转运系数;但对大豆生长、抗氧化生理及其他重金属累积无显著影响。【结论】完全消除土壤微生物抑制了大豆的生长,并显著降低了大豆对重金属的耐性与累积能力,说明土壤微生物在大豆生长和重金属耐性方面有重要作用。

[Purpose]To study the effects of soil sterilization and the fungicide benomyl on soybean growth and heavy metal accumulation.[Methods]Taking polluted farmland soil as the substrate,indoor pot experiments were carried out to determine the growth indexes,chlorophyll content,antioxidant physiological indicators,content and accumulation of heavy metals lead(Pb),zinc(Zn),cadmium(Cd),cuprum(Cu)of soybean,and the available content of heavy metals in soil under the conditions of soil sterilization and benomyl application.[Results]Compared with original soil,under soil sterilization treatment,the plant height,stem and leaf biomass,and fruit biomass of soybeans decreased by 21.00%,43.92%,and 44.47%,respectively;but the root biomass increased by 56.57%.Soil sterilization and benomyl treatments significantly increased the soil available Pb content,by 160.62%and 179.00%,respectively;and significantly reduced soil available Zn content by 33.82%and 17.37%,respectively.Soil sterilization also significantly increased the contents of Zn and Cd,and the accumulation of Pb,Zn,Cd,and Cu in soybean roots,and significantly decreased the accumulation of Pb and Cu in soybean stems,leaves and fruits,and also increased the enrichment coefficient of Pb,Zn,and Cd.The application of benomyl significantly increased carotenoid and Pb content in stems,leaves,and roots,by 77.00%,36.87%,and 12.43%,respectively;and significantly increased the accumulation of Pb in soybean stems and leaves;the enrichment coefficient and transport coefficient of Pb were increased significantly;but there was no significant effect on the soybean growth,antioxidant physiology,and other heavy metal accumulation.[Conclusion]The complete elimination of soil microbes inhibits soybean growth and significantly reduce the plant’s ability to tolerate and accumulate heavy metals,indicating that soil microorganisms play a crucial role in soybean growth and heavy metal tolerance.